Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Calcifediol supplementation to reduce pulse pressure in a limited sample of vitamin D deficient older adults with elevated parathyroid hormone levels
Grootswagers, Pol ; Vaes, Anouk M.M. ; Tieland, Michael ; Groot, Lisette C.P.G.M. de - \ 2019
Clinical Nutrition Experimental 24 (2019). - ISSN 2352-9393 - p. 77 - 82.
Older adults - Parathyroid hormone - Pulse pressure - Randomized clinical trial - Vitamin D

Vitamin D is proposed as an antihypertensive agent, but current evidence is inconclusive. Calcifediol is more potent in raising vitamin D status. It might, therefore, be more effective in lowering pulse pressure than cholecalciferol especially in patients with low vitamin D status and high levels of parathyroid hormone (PTH). This study investigated the efficacy of calcifediol on pulse pressure in older adults with vitamin D deficiency and elevated PTH levels. Supplementation with 15 μg calcifediol resulted in lower pulse pressure (Δ 35.4 mm Hg, 95%CI: 4.8, 66.1 mm Hg, P = 0.021) and PTH levels (Δ 1.83 pmol/l, 95%CI: −0.1, 3.7 pmol/l, P = 0.065) compared to 5 μg calcifediol. These effects were observed in a limited sample size of 16 older adults and therefore need confirmation in a larger trial. In conclusion, supplementation with 15 μg calcifediol might be an effective way to reduce pulse pressure in elderly with vitamin D deficiency and elevated PTH levels.

Effectiveness of nutritional interventions in older adults at risk of malnutrition across different health care settings: Pooled analyses of individual participant data from nine randomized controlled trials
Reinders, Ilse ; Volkert, Dorothee ; Groot, Lisette C.P.G.M. de; Beck, Anne Marie ; Feldblum, Ilana ; Jobse, Inken ; Neelemaat, Floor ; Schueren, Marian A.E. de van der; Shahar, Danit R. ; Smeets, Ellen T.H.C. ; Tieland, Michael ; Twisk, Jos W.R. ; Wijnhoven, Hanneke A.H. ; Visser, Marjolein - \ 2019
Clinical Nutrition 38 (2019)4. - ISSN 0261-5614 - p. 1797 - 1806.
Dietary counseling - Oral nutritional supplements - Protein-energy malnutrition - Undernutrition - Weight gain

Background & aims: Protein-energy malnutrition is a health concern among older adults. Improving nutritional status by increasing energy and protein intake likely benefits health. We therefore aimed to investigate effects of nutritional interventions in older adults (at risk of malnutrition) on change in energy intake and body weight, and explore if the intervention effect was modified by study or participants’ characteristics, analysing pooled individual participant data. Methods: We searched for RCTs investigating the effect of dietary counseling, oral nutritional supplements (ONS) or both on energy intake and weight. Principle investigators of eligible studies provided individual participant data. We investigated the effect of nutritional intervention on meaningful increase in energy intake (>250 kcal/day) and meaningful weight gain (>1.0 kg). Logistic generalized estimating equations were performed and ORs with 95% CIs presented. Results: We included data of nine studies with a total of 990 participants, aged 79.2 ± 8.2 years, 64.5% women and mean baseline BMI 23.9 ± 4.7 kg/m2. An non-significant intervention effect was observed for increase in energy intake (OR:1.59; 95% CI 0.95, 2.66) and a significant intervention effect for weight gain (OR:1.58; 95% CI 1.16, 2.17). Stratifying by type of intervention, an intervention effect on increase in energy intake was only observed for dietary counseling in combination with ONS (OR:2.28; 95% CI 1.90, 2.73). The intervention effect on increase in energy intake was greater for women, older participants, and those with lower BMI. Regarding weight gain, an intervention effect was observed for dietary counseling (OR:1.40; 95% CI 1.14, 1.73) and dietary counseling in combination with ONS (OR:2.48; 95% CI 1.92, 3.31). The intervention effect on weight gain was not influenced by participants’ characteristics. Conclusions: Based on pooled data of older adults (at risk of malnutrition), nutritional interventions have a positive effect on energy intake and body weight. Dietary counseling combined with ONS is the most effective intervention.

Expression of protocadherin gamma in skeletal muscle tissue is associated with age and muscle weakness
Hangelbroek, R.W.J. ; Fazelzadeh, P. ; Tieland, C.A.B. ; Boekschoten, M.V. ; Hooiveld, G.J.E.J. ; Duynhoven, J.P.M. van; Timmons, James ; Verdijk, L. ; Groot, C.P.G.M. de; Loon, L.J.C. van; Müller, M.R. - \ 2018
GSE117525 - Homo sapiens - PRJNA482398
The skeletal muscle system plays an important role in the independence of older adults. In this study we examine differences in the skeletal muscle transcriptome between healthy young and older subjects and (pre‐)frail older adults. Additionally, we examine the effect of resistance‐type exercise training on the muscle transcriptome in healthy older subjects and (pre‐)frail older adults. Baseline transcriptome profiles were measured in muscle biopsies collected from 53 young, 73 healthy older subjects, and 61 frail older subjects. Follow‐up samples from these frail older subjects (31 samples) and healthy older subjects (41 samples) were collected after 6 months of progressive resistance‐type exercise training. Frail older subjects trained twice per week and the healthy older subjects trained three times per week. At baseline genes related to mitochondrial function and energy metabolism were differentially expressed between older and young subjects, as well as between healthy and frail older subjects. Three hundred seven genes were differentially expressed after training in both groups. Training affected expression levels of genes related to extracellular matrix, glucose metabolism, and vascularization. Expression of genes that were modulated by exercise training was indicative of muscle strength at baseline. Genes that strongly correlated with strength belonged to the protocadherin gamma gene cluster (r = −0.73). Our data suggest significant remaining plasticity of ageing skeletal muscle to adapt to resistance‐type exercise training. Some age‐related changes in skeletal muscle gene expression appear to be partially reversed by prolonged resistance‐type exercise training. The protocadherin gamma gene cluster may be related to muscle denervation and re‐innervation in ageing muscle.
Cholecalciferol or 25-hydroxycholecalciferol supplementation does not affect muscle strength and physical performance in prefrail and frail older adults
Vaes, Anouk M.M. ; Tieland, Michael ; Toussaint, Nicole ; Nilwik, Rachel ; Verdijk, Lex B. ; Loon, Luc J.C. van; Groot, Lisette C.P.G.M. de - \ 2018
The Journal of Nutrition 148 (2018)5. - ISSN 0022-3166 - p. 712 - 720.
25-hydroxyvitamin D - Cholecalciferol - Lower extremity function - Muscle strength - Older adults

Background: Vitamin D supplementation is proposed as a potential treatment strategy to counteract functional decline in older adults. However, data from randomized trials are either limited or inconsistent. Objective: This study investigated the effect of daily supplementationwith 25-hydroxycholecalciferol [25(OH)D3] or cholecalciferol (vitamin D3) on muscle strength and physical performance in older adults. Methods: This was a randomized, double-blind, placebo-controlled trial of 6 mo including 78 prefrail or frail (according to the Fried criteria), community-dwelling older adults (n = 43 men) aged ≥65 y, with a baseline 25-hydroxyvitamin D [25(OH)D] concentration between 20 and 50 nmol/L. Participants were supplemented daily with 10 μg 25(OH)D3, 20 μg vitamin D3, or a placebo capsule. Serum 25(OH)D was measured by liquid chromatography-tandem mass spectrometry. The primary outcome wasmaximal isometric knee-extension strength (Biodex System 4); secondary outcomes included knee-flexion and hand grip strength, Short-Physical Performance Battery score, Timed Up and Go score, postural sway, muscle mass (dual-energy X-ray absorptiometry), and muscle fiber type and size. Results: The mean baseline serum 25(OH)D concentration was 37.7 nmol/L (95% CI: 35.4, 39.9 nmol/L). After 6 mo of supplementation, concentrations increased to 98.7 nmol/L (95% CI: 93.1, 104.4 nmol/L) in the 25(OH)D3 group and to 72.0 nmol/L (95% CI: 66.1, 77.8 nmol/L) in the vitamin D3 group, compared with 47.5 nmol/L (95% CI: 41.8, 53.3 nmol/L) in the placebo group (P-interaction < 0.01). Knee-extension strength did not significantly change in the 25(OH)D3 group (5.9 Nm; 95% CI: -6.2, 18.0 Nm), in the vitamin D3 group (5.5 Nm; 95% CI: -6.8, 17.8 Nm), or in the placebo group (1.8 Nm; 95% CI: -10.7, 14.4 Nm) (P-interaction = 0.74). Furthermore, mean changes in physical performance tests, muscle mass, and muscle fiber type and size did not differ between the groups. Conclusion: Increasing the serum 25(OH)D concentration over a period of 6 mo did not significantly change muscle strength and physical performance in prefrail and frail older adults.

The association between 25-hydroxyvitamin D concentration, physical performance and frailty status in older adults
Vaes, Anouk M.M. ; Brouwer-Brolsma, Elske M. ; Toussaint, Nicole ; Regt, Margot de; Tieland, Michael ; Loon, Luc J.C. van; Groot, Lisette C.P.G.M. de - \ 2018
European Journal of Nutrition 58 (2018). - ISSN 1436-6207 - p. 1173 - 1181.
25-Hydroxyvitamin D - Frailty - Muscle strength - Physical performance - Vitamin D
Purpose: Sufficient 25-hydroxyvitamin D (25(OH)D) concentrations might prevent a decline in physical performance, and are considered important for the prevention of frailty. This study investigates the association of serum 25(OH)D concentration with physical performance and frailty status in Dutch older adults. Methods: This cross-sectional study included 756 men and women, aged ≥ 65 years. Serum 25(OH)D concentration and frailty status (Fried criteria) were assessed in the total population. Screening for frailty status included functional tests of gait speed and hand grip strength. In a subgroup (n = 494), the Timed Up and Go test (TUG) and knee-extension strength were measured. Associations of serum 25(OH)D status with physical performance were examined by multiple linear regression. Prevalence ratios (PR) were used to quantify associations between serum 25(OH)D deficiency (< 50 nmol/L) and frailty. Results: In total, 45% of the participants were vitamin D deficient. Participants with vitamin D status < 50 and 50–75 nmol/L had significantly lower scores on the TUG and gait speed test, compared to participants with vitamin D status > 75 nmol/L. No significant associations with serum 25(OH)D concentrations were observed for handgrip strength or knee-extension strength. Participants with serum 25(OH)D status < 50 nmol/L were about two times more likely to be frail compared to participants with serum 25(OH)D status ≥ 50 nmol/L. No significant associations were observed between the pre-frail state and serum 25(OH)D status. Conclusion: In this study, serum 25(OH)D concentrations were significantly associated with frailty status and measures of physical performance, including gait speed and TUG, but not with strength-related outcomes.
Attenuated strength gains during prolonged resistance exercise training in older adults with high inflammatory status
Hangelbroek, R.W.J. ; Knuiman, P. ; Tieland, Michael ; Groot, C.P.G.M. de - \ 2018
Experimental Gerontology 106 (2018). - ISSN 0531-5565 - p. 154 - 158.
Objectives: Chronic systemic low grade inflammation is associated with the age-related loss of muscle mass. Resistance exercise has been suggested to reduce or lower chronic systemic low grade inflammation. However, systemic chronic low-grade inflammation may adversely affect the adaptive response to exercise training. We investigated the effect of resistance exercise training on systemic chronic low-grade inflammation in older adults. In addition, we studied the association between systemic chronic low-grade inflammation and the adaptive response to exercise training. Design/setting/participants: Frail and pre-frail older adults (61 subjects) performed 24 weeks of progressive resistance exercise training. Frailty was assessed using the Fried frailty criteria. Measurements: Lean body mass (DXA), strength (1RM), circulating levels of IL-1β, IL-6, IL-8 and TNF-α were measured prior to exercise training, after 12 weeks of training, and after 24 weeks of training. Results: Prolonged progressive resistance exercise training did not affect circulating levels of IL-6, IL-8 and TNF-α. However, exercise training led to a small but significant increase of 0.052 pg/mL in IL-1β. Higher circulating levels of TNF-α, IL-8 and IL-6 during the training period were negatively associated with strength gains for the leg press. A doubling of plasma TNF-α, IL-8 or IL-6 resulted in reduced strength gains for leg press with coefficients of −3.52, −3.42 and −1.54 respectively. High levels of circulating TNF-α were also associated with decreased strength gains for the leg extension (coefficient −1.50). Inflammatory cytokines did not appear to have an effect on gains in lean mass. Conclusion: Our findings suggest that increased levels of plasma cytokines (TNF-α, IL-6 and IL-8) are associated with lower strength gains during resistance exercise training.
An Even Distribution of Protein Intake Daily Promotes Protein Adequacy but Does Not Influence Nutritional Status in Institutionalized Elderly
Tieland, Michael ; Beelen, Janne ; Laan, Anna C.M. ; Poon, Shirley ; Groot, Lisette C.P.G.M. de; Seeman, Ego ; Wang, Xiaofang ; Iuliano, Sandra - \ 2018
Journal of the American Medical Directors Association 19 (2018)1. - ISSN 1525-8610 - p. 33 - 39.
Elderly - Energy intake - Malnutrition - Protein distribution
Objective: Although it has been established that sufficient protein is required to maintain good nutritional status and support healthy aging, it is not clear if the pattern of protein consumption may also influence nutritional status, especially in institutionalized elderly who are at risk of malnutrition. Therefore, we aim to determine the association between protein intake distribution and nutritional status in institutionalized elderly people. Design: Cross-sectional study among 481 institutionalized older adults. Methods: Dietary data from 481 ambulant elderly people (68.8% female, mean age 87.5 ± 6.3 years) residing in 52 aged-care facilities in Victoria, Australia, were assessed over 2 days using plate waste analysis. Nutritional status was determined using the Mini-Nutritional Assessment tool and serum (n = 208) analyzed for albumin, hemoglobin, and IGF-1. Protein intake distribution was classified as: spread (even distribution across 3 meals, n = 65), pulse (most protein consumed in one meal, n = 72) or intermediate (n = 344). Regression analysis was used to investigate associations. Results: Mean protein intakes were higher in the spread (60.5 ± 2.0 g/d) than intermediate group (56.0 ± 0.8 g/d, P = .037), and tended to be higher than those in the pulse group (55.9 ± 1.9 g/d, P = .097). Residents with an even distribution of protein intake achieved a higher level of the recommended daily intake for protein (96.2 ± 30.0%) than the intermediate (86.3 ± 26.2%, P = .008) and pulse (87.4 ± 30.5%, P = .06) groups, and also achieved a greater level of their estimated energy requirements (intermediate; P = .039, pulse; P = .001). Nutritional status (Mini-Nutritional Assessment score) did not differ between groups (pulse; 20.5 ± 4.5, intermediate; 21.0 ± 2.5, spread; 20.5 ± 3.5), nor did any other indices of nutritional status. Conclusions: Meeting protein requirements is required before protein distribution may influence nutritional status in institutionalized elderly. Achieving adequate protein and energy intakes is more likely when protein is distributed evenly throughout the day. Provision of high protein foods especially at breakfast, and in the evening, may support protein adequacy and healthy aging, especially for institutionalized elderly.
Dose-response effects of supplementation with calcifediol on serum 25-hydroxyvitamin D status and its metabolites : A randomized controlled trial in older adults
Vaes, Anouk M.M. ; Tieland, Michael ; Regt, Margot F. de; Wittwer, Jonas ; Loon, Luc J.C. van; Groot, Lisette C.P.G.M. de - \ 2018
Clinical Nutrition 37 (2018)3. - ISSN 0261-5614 - p. 808 - 814.
25-Hydroxyvitamin D - Calcifediol - Dose-response - PTH - Supplementation - Vitamin D

Background & aims: Oral supplementation with vitamin D is recommended for older adults to maintain a sufficient 25-hydroxyvitamin D (25(OH)D) status throughout the year. While supplementation with vitamin D2 or D3 is most common, alternative treatment regimens exist which require further investigation with respect to increasing 25(OH)D concentration. We investigated the dose-response effects of supplementation with calcifediol compared to vitamin D3 and assessed the dose which results in mean serum 25(OH)D3 concentrations between 75 and 100 nmol/L. Methods: This randomized, double-blind intervention study included men and women aged ≥65 years (n = 59). Participants received either 5, 10 or 15 μg calcifediol or 20 μg vitamin D3 per day, for a period of 24 weeks. Blood samples were collected every four weeks to assess response profiles of vitamin D related metabolites; serum vitamin D3, 25(OH)D3, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3). Further, serum calcium, plasma parathyroid hormone, and urinary calcium were evaluated. Results: Supplementation with 20 μg vitamin D3 increased 25(OH)D3 concentrations towards 70 nmol/L within 16 weeks. Supplementation with 10 or 15 μg calcifediol increased 25(OH)D3 levels >75 nmol/L in 8 and 4 weeks, respectively. Steady state was achieved from week 12 onwards with serum 25(OH)D3 levels stabilizing between 84 and 89 nmol/L in the 10 μg calcifediol group. A significant association was observed between the changes in 25(OH)D3 and 24,25(OH)2D3 (R2 = 0.83, P < 0.01), but not between 25(OH)D3 and 1,25(OH)2D3 (R2 = 0.04, P = 0.18). No cases of hypercalcemia occurred in any treatment during the study period. Conclusions: Calcifediol supplementation rapidly and safely elevates serum 25(OH)D3 concentrations to improve vitamin D status in older adults. A daily dose of 10 μg calcifediol allows serum 25(OH)D3 concentrations to be maintained between 75 and 100 nmol/L. Trial registration number: NCT01868945.

The effect of nutritional intervention in older adults on handrip strenght and mortality: results from 9 pooled RCTs
Zwienen-Pot, Judith ; Reinders, I. ; Groot, C.P.G.M. de; Beck, A. ; Beck, A. ; Feldblum, I. ; Jobse, I. ; Neelemaat, F. ; Schueren, M.A.E. ; Shahar, D.R. ; Smeets, Ellen ; Tieland, C.A.B. ; Wijnhoven, H.A.H. ; Volkert, D. ; Visser, M. - \ 2017
Clinical Nutrition 36 (2017)Supplement 1. - ISSN 0261-5614 - p. S166 - S167.
Vitamin D for older adults : Determinants of status, supplementation strategies and its role in muscle function
Vaes, Anouk M.M. - \ 2017
Wageningen University. Promotor(en): C.P.G.M. de Groot, co-promotor(en): M. Tieland. - Wageningen : Wageningen University - ISBN 9789463436144 - 164
vitamin d - deficiency - aging - vitamin supplements - dosage effects - musculoskeletal system - literature reviews - food enrichment - skeletal muscle - food supplements - randomized controlled trials - vitamine d - deficiëntie - verouderen - vitaminetoevoegingen - doseringseffecten - skeletspierstelsel - literatuuroverzichten - voedselverrijking - skeletspier - voedselsupplementen - gestuurd experiment met verloting

Vitamin D has been identified as an important factor in healthy aging and is receiving growing attention in clinical research. Vitamin D is a fat-soluble molecule, which is synthesized by hepatic and renal or extra-renal hydroxylation into the active hormone 1,25-dihydroxyvitamin D (1,25(OH)2D). The main function of this metabolite is to regulate calcium and phosphorus homeostasis and to support bone mineralization. In the circulation, the 25-hydroxyvitamin D metabolite (25(OH)D) is most stable and thus, considered the best marker of vitamin D status. A serum 25(OH)D concentration <30-50 nmol/L is considered deficient. Given the increased risk of deficiency and the potential beneficial effect of supplementation on musculoskeletal health, older adults present a specific target group for vitamin D interventions. However, the optimal serum 25(OH)D concentration is a matter of ongoing debate as randomized trials show conflicting results.

With the research presented in this thesis, we aimed to gain insight in the prevalence and main determinants of a low vitamin D status, to investigate strategies to prevent or reverse vitamin D deficiency, and to study the effect of vitamin D supplementation on muscle strength and physical performance in Dutch older adults.

In chapter 2, we examined the prevalence and the main determinants of a low vitamin D status in a large population of community-dwelling older adults (n=2857). Vitamin D deficiency was highly prevalent, with serum 25(OH)D concentrations <50 nmol/L in 45%, and <30 nmol/L in 14% of the population. When exploring the main determinants of serum 25(OH)D status, significant associations were observed with age, BMI, dietary intake, sun exposure behavior, and genetic polymorphisms encoding for enzymes in the vitamin D pathway. Combined, these factors explained 35% of the variation in serum 25(OH)D concentrations.

To explore potential strategies that prevent vitamin D deficiency, we investigated the contribution of dietary vitamin D intake and specific food groups to serum 25(OH)D concentration in chapter 3. Daily vitamin D intake from dietary sources showed a median (25-75th percentile) intake of 4.0 (3.0-5.4) µg/day (n=595) and only 12-20% of older adults reported to take vitamin D supplements. These findings are in sharp contrast with the current nutrient guidelines and show that the vast majority of older adults do not meet the reference intakes for vitamin D. Nevertheless, significant associations were observed between the highest tertile of dietary vitamin D intake and serum 25(OH)D concentration, suggesting that regular intake of foods rich in vitamin D can support the prevention of modest insufficiency.

For the majority of older adults, supplementation is required to ensure sufficient serum 25(OH)D concentrations throughout the year. Currently, supplementation with vitamin D3 is the most common strategy. However, alternative treatment regimens exist that require further investigation. In chapter 4, we report on a dose-response trial (n=59) that investigated the efficacy of calcifediol (5, 10 or 15 µg/d) as a supplementation strategy. Compared to vitamin D3, calcifediol is more hydrophilic, does not require hepatic hydroxylation, and binds with higher affinity to its binding proteins. In our study, we observed that calcifediol was safe and well tolerated in the supplemented doses over the entire study period of 6-months. We concluded that a dose of 10 µg/day resulted in sustained serum 25(OH)D concentrations between 75-100 nmol/L. Furthermore, calcifediol had a ~3 times higher potency when compared to vitamin D3, in increasing serum 25(OH)D concentrations. All in all, calcifediol may offer a valuable supplementation regimen to rapidly correct deficiency.

Vitamin D presents an important endocrine regulator in the musculoskeletal health of older adults. Besides its role in bone health, low serum 25(OH)D concentrations have been linked to impaired physical performance and increased risk of falling. The active metabolite 1,25-dihydroxyvitamin D is suggested to act upon a wide variety of cells throughout the body, including muscle cells. Although the exact mechanisms by which vitamin D acts on muscle are unclear, several indirect or direct regulatory pathways have been described, including effects of 1,25-dihyroxyvitamin D through intracellular calcium and phosphate homeostasis, or via activation of transcription factors when binding to the vitamin D receptor in muscle cells.

In chapter 5 we observed significant associations between low serum 25(OH)D concentrations, physical performance and frailty in community-dwelling older adults (n=494-756). However, randomized trials are needed to define the causality of the observed associations. A previous pilot study indicated plausible beneficial effects of calcifediol over vitamin D3 on performance and strength. As such, we aimed to further explore the potential role of calcifediol or vitamin D3 on muscle function in chapter 6. We performed a placebo-controlled trial in pre-frail and frail, vitamin D deficient older adults, supplementing either 10 µg/d calcifediol or 20 µg/d vitamin D3, compared to placebo over a 6-month period (n=78). Again, calcifediol induced a faster and higher increase in serum 25(OH)D status when compared to vitamin D3. However, we observed no effect of either supplementation regimen on lower extremity strength or physical performance. Current literature suggests positive effects on strength and balance when supplementing with vitamin D, however, results are inconsistent. Meta-analyses of randomized trials indicate that the beneficial effects of vitamin D supplementation might be more pronounced in vulnerable populations with more severe vitamin D deficiencies.

All in all, the high prevalence of vitamin D deficiency is alarming. Promoting adequate vitamin D status is important considering the beneficial effects on bone health. In the last decade, research has come a long way in exploring the role of vitamin D in muscle function. However, the evidence base remains uncertain and further research on the optimal vitamin D status for older adults is needed to guide clinical practice. Until then, focus should be placed on prevention and identification of deficiency.

The diuretic action of weak and strong alcoholic beverages in elderly men : A randomized diet-controlled crossover trial
Polhuis, Kristel C.M.M. ; Wijnen, Annemarthe H.C. ; Sierksma, Aafje ; Calame, Wim ; Tieland, Michael - \ 2017
Nutrients 9 (2017)7. - ISSN 2072-6643
Beer - Dehydration - Hydration - Moderate alcohol consumption - Spirits - Wine
With ageing, there is a greater risk of dehydration. This study investigated the diuretic effect of alcoholic beverages varying in alcohol concentration in elderly men. Three alcoholic beverages (beer (AB), wine (AW), and spirits (S)) and their non-alcoholic counterparts (non-alcoholic beer (NAB), non-alcoholic wine (NAW), and water (W)) were tested in a diet-controlled randomized crossover trial. For the alcoholic beverages, alcohol intake equaled a moderate amount of 30 g. An equal volume of beverage was given for the non-alcoholic counterpart. After consumption, the urine output was collected every hour for 4 h and the total 24 h urine output was measured. AW and S resulted in a higher cumulative urine output compared to NAW and W during the first 4 h (effect size: 0.25 mL p < 0.003, effect size: 0.18 mL, p < 0.001, respectively), but not after the 24h urine collection (p > 0.40, p > 0.10). AB and NAB did not differ at any time point (effect size: −0.02 mL p > 0.70). For urine osmolality, and the sodium and potassium concentration, the findings were in line. In conclusion, only moderate amounts of stronger alcoholic beverages, such as wine and spirits, resulted in a short and small diuretic effect in elderly men.
The impact of protein quantity during energy restriction on genome-wide gene expression in adipose tissue of obese humans
Bussel, I.P.G. van; Backx, E.M.P. ; Groot, C.P.G.M. de; Tieland, M. ; Muller, Michael ; Afman, L.A. - \ 2017
International Journal of Obesity 41 (2017). - ISSN 0307-0565 - p. 1114 - 1120.
Background:Overweight and obesity is a growing health problem worldwide. The most effective strategy to reduce weight is energy restriction (ER). ER has been shown to be beneficial in disease prevention and it reduces chronic inflammation. Recent studies suggest that reducing the protein quantity of a diet contributes to the beneficial effects by ER. The organ most extensively affected during ER is white adipose tissue (WAT).Objective:The first objective was to assess changes in gene expression between a high-protein diet and a normal protein diet during ER. Second, the total effect of ER on changes in gene expression in WAT was assessed.Methods:In a parallel double-blinded controlled study, overweight older participants adhered to a 25% ER diet, either combined with high-protein intake (HP-ER, 1.7 g kg-1 per day), or with normal protein intake (NP-ER, 0.9 g kg-1 per day) for 12 weeks. From 10 HP-ER participants and 12 NP-ER participants subcutaneous WAT biopsies were collected before and after the diet intervention. Adipose tissue was used to isolate total RNA and to evaluate whole-genome gene expression changes upon a HP-ER and NP-ER diet.Results:A different gene expression response between HP-ER and NP-ER was observed for 530 genes. After NP-ER, a downregulation in expression of genes linked to immune cell infiltration, adaptive immune response and inflammasome was found, whereas no such effect was found after HP-ER. HP-ER resulted in upregulation in expression of genes linked to cell cycle, GPCR signalling, olfactory signalling and nitrogen metabolism. Upon 25% ER, gene sets related to energy metabolism and immune response were decreased.Conclusions:Based on gene expression changes, we concluded that consumption of normal protein quantity compared with high-protein quantity during ER has a more beneficial effect on inflammation-related gene expression in WAT
Protein Supplementation Augments Muscle Fiber Hypertrophy but Does Not Modulate Satellite Cell Content During Prolonged Resistance-Type Exercise Training in Frail Elderly
Dirks, Marlou L. ; Tieland, Michael ; Verdijk, Lex B. ; Losen, Mario ; Nilwik, Rachel ; Mensink, Marco ; Groot, Lisette C.P.G.M. de; Loon, Luc J.C. van - \ 2017
Journal of the American Medical Directors Association 18 (2017)7. - ISSN 1525-8610 - p. 608 - 615.
Amino acids - Resistance exercise - Sarcopenia - Skeletal muscle

Objective: Protein supplementation increases gains in lean body mass following prolonged resistance-type exercise training in frail older adults. We assessed whether the greater increase in lean body mass can be attributed to muscle fiber type specific hypertrophy with concomitant changes in satellite cell (SC) content. Design: A total of 34 frail elderly individuals (77 ± 1 years, n = 12 male adults) participated in this randomized, double-blind, placebo-controlled trial with 2 arms in parallel. Intervention: Participants performed 24 weeks of progressive resistance-type exercise training (2 sessions per week) during which they were supplemented twice-daily with milk protein (2 × 15 g) or a placebo. Methods: Muscle biopsies were taken at baseline, and after 12 and 24 weeks of intervention, to determine type I and type II muscle fiber specific cross-sectional area (CSA), SC content, and myocellular characteristics. Results: In the placebo group, a trend for a 20% ± 11% increase in muscle fiber CSA was observed in type II fibers only (P = .051), with no increase in type I muscle fiber CSA. In the protein group, type I and II muscle fiber CSA increased by 23% ± 7% and 34% ± 10% following 6 months of training, respectively (P < .01). Myonuclear domain size increased over time in both groups and fiber types (P < .001), with no significant differences between groups (P > .05). No changes in myonuclear content and SC contents were observed over time in either group (both P > .05). Regression analysis showed that changes in myonuclear content and domain size are predictive of muscle fiber hypertrophy. Conclusions: Protein supplementation augments muscle fiber hypertrophy following prolonged resistance-type exercise training in frail older people, without changes in myonuclear and SC content.

The impact of dietary protein or amino acid supplementation on muscle mass and strength in elderly people : Individual participant data and meta-analysis of RCT’s
Tieland, M. ; Franssen, R. ; Dullemeijer, C. ; Dronkelaar, C. van; Kim, H.K. ; Ispoglou, T. ; Zhu, K. ; Prince, R.L. ; Loon, L.J.C. van; Groot, Lisette C.P.G.M. de - \ 2017
Journal of Nutrition, Health and Aging 21 (2017)9. - ISSN 1279-7707 - p. 994 - 1001.

Objectives: Increasing protein or amino acid intake has been promoted as a promising strategy to increase muscle mass and strength in elderly people, however, long-term intervention studies show inconsistent findings. Therefore, we aim to determine the impact of protein or amino acid supplementation compared to placebo on muscle mass and strength in older adults by combining the results from published trials in a metaanalysis and pooled individual participant data analysis. Design: We searched Medline and Cochrane databases and performed a meta-analysis on eight available trials on the effect of protein or amino acid supplementation on muscle mass and strength in older adults. Furthermore, we pooled individual data of six of these randomized double-blind placebo-controlled trials. The main outcomes were change in lean body mass and change in muscle strength for both the meta-analysis and the pooled analysis. Results: The meta-analysis of eight studies (n=557) showed no significant positive effects of protein or amino acid supplementation on lean body mass (mean difference: 0.014 kg: 95% CI -0.152; 0.18), leg press strength (mean difference: 2.26 kg: 95% CI -0.56; 5.08), leg extension strength (mean difference: 0.75 kg: 95% CI: -1.96, 3.47) or handgrip strength (mean difference: -0.002 kg: 95% CI -0.182; 0.179). Likewise, the pooled analysis showed no significant difference between protein and placebo treatment on lean body mass (n=412: p=0.78), leg press strength (n=121: p=0.50), leg extension strength (n=121: p=0.16) and handgrip strength (n=318: p=0.37). Conclusions: There is currently no evidence to suggest that protein or amino acid supplementation without concomitant nutritional or exercise interventions increases muscle mass or strength in predominantly healthy elderly people.

Translation of a tailored nutrition and resistance exercise intervention for elderly people to a real-life setting: adaptation process and pilot study
Dongen, E.J.I. van; Leerlooijer, J.N. ; Steijns, J.M. ; Tieland, C.A.B. ; Groot, C.P.G.M. de; Haveman-Nies, A. - \ 2017
BMC Geriatrics 17 (2017). - ISSN 1471-2318
Combining increased dietary protein intake and resistance exercise training for elderly people is a promising strategy to prevent or counteract the loss of muscle mass and decrease the risk of disabilities. Using findings from controlled interventions in a real-life setting requires adaptations to the intervention and working procedures of healthcare professionals (HCPs). The aim of this study is to adapt an efficacious intervention for elderly people to a real-life setting (phase one) and test the feasibility and potential impact of this prototype intervention in practice in a pilot study (phase two).
The Intervention Mapping approach was used to guide the adaptation in phase one. Qualitative data were collected from the original researchers, target group, and HCPs, and information was used to decide whether and how specified intervention elements needed to be adapted. In phase two, a one-group pre-test post-test pilot study was conducted (n = 25 community-dwelling elderly), to elicit further improvements to the prototype intervention. The evaluation included participant questionnaires and measurements at baseline (T0) and follow-up (T1), registration forms, interviews, and focus group discussions (T1). Qualitative data for both phases were analysed using an inductive approach. Outcome measures included physical functioning, strength, body composition, and dietary intake. Change in outcomes was assessed using Wilcoxon signed-rank tests.
The most important adaptations to the original intervention were the design of HCP training and extending the original protein supplementation with a broader nutrition programme aimed at increasing protein intake, facilitated by a dietician. Although the prototype intervention was appreciated by participants and professionals, and perceived applicable for implementation, the pilot study process evaluation resulted in further adaptations, mostly concerning recruitment, training session guidance, and the nutrition programme. Pilot study outcome measures showed significant improvements in muscle strength and functioning, but no change in lean body mass.
The combined nutrition and exercise intervention was successfully adapted to the real-life setting and seems to have included the most important effective intervention elements. After adaptation of the intervention using insights from the pilot study, a larger, controlled trial should be conducted to assess cost-effectiveness.
Seasonal variation in vitamin D status in elite athletes: a longitudinal study
Backx, E.M.P. ; Avoort, Cindy van der; Tieland, C.A.B. ; Maase, K. ; Kies, Arie ; Loon, L.J.C. van; Groot, C.P.G.M. de; Mensink, M.R. - \ 2017
International Journal of Sport Nutrition & Exercise Metabolism 27 (2017)1. - ISSN 1526-484X - p. 6 - 10.
Studies monitoring vitamin D status in athletes are seldom conducted for a period of 12 months or longer, thereby lacking insight into seasonal fluctuations. The objective of the cur-rent study was to identify seasonal changes in total 25-hydroxyvitamin D (25(OH)D) concen-tration throughout the year. Fifty-two, mainly Caucasian athletes with a sufficient 25(OH)D concentration (>75 nmol/L) in June were included in this study. Serum 25(OH)D concentra-tion was measured every three months (June, September, December, March, June). Addition-ally, vitamin D intake and sun exposure were assessed by questionnaires at the same time points. Highest total 25(OH)D concentrations were found at the end of summer (113±26 nmol/L), whereas lowest concentrations were observed at the end of winter (78±30 nmol/L). Although all athletes had a sufficient 25(OH)D concentration at the start of the study, nearly 20% of the athletes were deficient (<50 nmol/L) in late winter.
The impact of 1-year vitamin D supplementation on vitamin D status in athletes : a dose–response study
Backx, E.M.P. ; Tieland, M. ; Maase, K. ; Kies, A.K. ; Mensink, M. ; Loon, L.J.C. van; Groot, C.P.G.M. de - \ 2016
European Journal of Clinical Nutrition 70 (2016). - ISSN 0954-3007 - p. 1009 - 1014.

Background/Objectives:To assess the prevalence of vitamin D deficiency in Dutch athletes and to define the required dosage of vitamin D3 supplementation to prevent vitamin D deficiency over the course of a year.Subjects/Methods:Blood samples were collected from 128 highly trained athletes to assess total 25(OH)D concentration. Of these 128 athletes, 54 male and 48 female athletes (18–32 years) were included in a randomized, double blind, dose–response study. Athletes with either a deficient (

Physical activity energy expenditure and sarcopenia in black South African urban women
Kruger, Herculina S. ; Havemann-Nel, Lize ; Ravyse, Chrisna ; Moss, Sarah J. ; Tieland, Michael - \ 2016
Journal of Physical Activity and Health 13 (2016)3. - ISSN 1543-3080 - p. 296 - 302.
Aging - Body composition

Background: Black women are believed to be genetically less predisposed to age-related sarcopenia. The objective of this study was to investigate lifestyle factors associated with sarcopenia in black South African (SA) urban women. Methods: In a cross-sectional study, 247 women (mean age 57 y) were randomly selected. Anthropometric and sociodemographic variables, dietary intakes, and physical activity were measured. Activity was also measured by combined accelerometery/heart rate monitoring (ActiHeart), and HIV status was tested. Dual energy x-ray absorptiometry was used to measure appendicular skeletal mass (ASM). Sarcopenia was defined according to a recently derived SA cutpoint of ASM index (ASM/height squared) <4.94 kg/m2. Results: In total, 8.9% of the women were sarcopenic, decreasing to 8.1% after exclusion of participants who were HIV positive. In multiple regressions with ASM index, grip strength, and gait speed, respectively, as dependent variables, only activity energy expenditure (β = .27) was significantly associated with ASM index. Age (β = -.50) and activity energy expenditure (β = .17) were significantly associated with gait speed. Age (β = -.11) and lean mass (β = .21) were significantly associated with handgrip strength. Conclusions: Sarcopenia was prevalent among these SA women and was associated with low physical activity energy expenditure.

Dose-response effects of supplementation with calcifediol on serum 25(OH)D status in older adults
Vaes, A.M.M. ; Tieland, M. ; Regt, M.F. de; Wittwer, Jonas ; Loon, Luc J.C. Van; Groot, C.P.G.M. de - \ 2016
The muscle metabolome differs between healthy and frail older adults
Fazelzadeh, P. ; Hangelbroek, R.W.J. ; Tieland, C.A.B. ; Groot, C.P.G.M. de; Verdijk, L. ; Loon, L.J.C. van; Smilde, A.K. ; Alves Rolo, Rodrigo ; Vervoort, J.J.M. ; Müller, M.R. ; Duynhoven, J.P.M. van; Boekschoten, M.V. - \ 2016
Journal of Proteome Research 15 (2016)2. - ISSN 1535-3893 - p. 499 - 509.
Populations around the world are aging rapidly. Age-related loss of physiological functions negatively affects quality of life. A major contributor to the frailty syndrome of aging is loss of skeletal muscle. In this study we assessed the skeletal muscle biopsy metabolome of healthy young, healthy older and frail older subjects to determine the effect of age and frailty on the metabolic signature of skeletal muscle tissue. In addition, the effects of prolonged whole-body resistance-type exercise training on the muscle metabolome of older subjects were examined. The baseline metabolome was measured in muscle biopsies collected from 30 young, 66 healthy older subjects and 43 frail older subjects. Follow-up samples from frail older (24 samples) and healthy older subjects (38 samples) were collected after 6 months of prolonged resistance-type exercise training. Young subjects were included as a reference group. Primary differences in skeletal muscle metabolite levels between young and healthy older subjects were related to mitochondrial function, muscle fiber type, and tissue turnover. Similar differences were observed when comparing frail older subjects with healthy older subjects at baseline. Prolonged resistance-type exercise training resulted in an adaptive response of amino acid metabolism, especially reflected in branched chain amino acids and genes related to tissue remodeling. The effect of exercise training on branched-chain amino acid-derived acylcarnitines in older subjects points to a downward shift in branched-chain amino acid catabolism upon training. We observed only modest correlations between muscle and plasma metabolite levels, which pleads against the use of plasma metabolites as a direct read-out of muscle metabolism and stresses the need for direct assessment of metabolites in muscle tissue biopsies.
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