Association of Bioelectrical Impedance Phase Angle with Physical Performance and Nutrient Intake of Older Adults.

In recent years, the phase angle (PhA) as a raw bioelectrical impedance analysis variable has gained attention to assess cell integrity and its association to physical performance in either sports-related or clinical settings. However, data on healthy older adults are scarce. Therefore, data on body composition, physical performance and macronutrient intake from older adults (n = 326, 59.2% women, 75.2 ± 7.2 years) were retrospectively analyzed. Physical performance was evaluated by the Senior Fitness Test battery, gait speed, timed up and go and handgrip strength. Body composition was determined by the BIA and dual-energy X-ray absorptiometry (from a subgroup of n = 51). The PhA was negatively associated with the timed up and go test and age (r = -0.312 and -0.537, p < 0.001), and positively associated with the 6 min walk test, 30 s chair stand, handgrip strength, gait speed and physical performance score (r = 0.170-0.554, p < 0.05), but not protein intake (r = 0.050, p = 0.386). Hierarchical multiple regression analysis showed that especially age, sex, BMI, but also the PhA predicted the performance test outcomes. In conclusion, the PhA seems to be an interesting contributor to physical performance, but sex- and age-specific norm values still need to be determined.

The influence of vitamin D supplementation and strength training on health biomarkers and chromosomal damage in community-dwelling older adults.

Older adults lack of proper physical activity which is often accompanied by vitamin D deficiency. Those factors are known to contribute to health issues in the later years of life. The main goal of this intervention study was to investigate the effect of different vitamin D supplementation strategies for 4 weeks solely or combined with a 10-week strength training program on chromosomal stability in peripheral blood mononuclear cells in community-dwelling older people. One hundred women and men (65-85 years) received either vitamin D3 daily (800 IU), a monthly dose (50.000 IU) or placebo for 17 weeks. All groups received 400 mg calcium daily. The fitness status of the study participants was measured using the 30- second chair stand test, the handgrip strength test and the 6-min walk test. The cytokinesis block micronucleus cytome (CBMN) assay was applied to analyze chromosomal anomalies, including cytotoxic and genotoxic parameters. Changes in antioxidant markers were measured in plasma. Walking distance and chair stand performance improved significantly. Increased levels of the parameters of the CBMN assay were detected for all intervention groups at study end. At baseline micronuclei (MNi) frequency correlated significantly with BMI in both sexes (females: r = 0.369, p = 0.034; males: r = 0.265, p = 0.035), but not with vitamin D serum levels. In females, body fat (r = 0.372, p < 0.001) and functional parameter using the 30-s chair stand test (r = 0.311, p = 0.002) correlated significantly with MNi frequency. Interestingly, not vitamin D supplementation but 10 weeks of resistance training increased MNi frequency indicating elevated chromosomal instability and also adverse effects on antioxidant markers including glutathione and FRAP were detected in the group of community-dwelling older adults.

The plasma proteome is favorably modified by a high protein diet but not by additional resistance training in older adults: A 17-week randomized controlled trial.

Background: The age-related loss of muscle mass significantly contributes to the development of chronic diseases, loss of mobility and dependency on others, yet could be improved by an optimized lifestyle. Objective: The goal of this randomized controlled trial was to compare the influence of a habitual diet (CON) with either a diet containing the recommended protein intake (RP) or a high protein intake (HP), both with and without strength training, on the plasma proteome in older adults. Methods: One hundred and thirty-six women and men (65-85 years) were randomly assigned to three intervention groups. CON continued their habitual diet; participants of the HP and RP group consumed either high protein or standard foods. After 6 weeks of dietary intervention, HP and RP groups additionally started a strength training intervention twice per week for 8 weeks. Twenty-four hours dietary recalls were performed every 7-10 days. Body composition was assessed and blood taken. Plasma proteomics were assessed with LC-MS. Results: Participants of the HP group doubled their baseline protein intake from 0.80 ± 0.31 to 1.63 ± 0.36 g/kg BW/d; RP increased protein intake from 0.89 ± 0.28 to 1.06 ± 0.26 g/kg BW/d. The CON group kept the protein intake stable throughout the study. Combined exercise and HP initiated notable changes, resulting in a reduction in bodyfat and increased muscle mass. Proteomics analyses revealed 14 significantly affected proteins by HP diet, regulating innate immune system, lipid transport and blood coagulation, yet the additional strength training did not elicit further changes. Conclusions: Combined HP and resistance exercise in healthy older adults seem to induce favorable changes in the body composition. Changes in the plasma proteome due to the high protein diet point to a beneficial impact for the innate immune system, lipid transport and blood coagulation system, all of which are involved in chronic disease development. Clinical trial registration: The study was registered at ClinicalTrials.gov (NCT04023513).

Effects of an increased habitual dietary protein intake followed by resistance training on fitness, muscle quality and body composition of seniors: A randomised controlled trial.

BACKGROUND & AIMS: Resistance training and a sufficient amount of dietary protein have been suggested to build up and maintain muscle mass, strength and function into old age. As there is still no consensus on the optimum amount of protein intake in older people, this study aims to evaluate first whether it is achievable to double the recommended amount, which is 1 g/kg BW/d in German speaking countries, via food administration and secondly whether this would lead to stronger improvements when subsequently combined with resistance training. METHODS: In total, 136 community-dwelling older adults (54% females, 72.9 ± 4.8 yrs) were randomly assigned to one of the three study groups: observational control (CON), recommended protein (RP + T) and high protein (HP + T) intake groups. After six weeks of observation or nutritional counselling to achieve the respective protein target levels, eight weeks of resistance training (2x/week) were applied in RP + T and HP + T groups. Parameters indicative for muscle mass, strength and function were measured at baseline (t1), before (t2) and after the training period (t3). RESULTS: Baseline protein intake for the different groups were 0.83 (CON), 0.97 (RP + T) and 0.78 (HP + T) g/kg BW/d and increased by 0.18 ± 0.31 (RP + T, p = 0.003) and 0.83 ± 0.33 (HP + T, p > 0.001) g/kg BW/d between t1 and t3 while CON remained unchanged. Most of the physical performance parameters improved over time, but no interaction effects between group and time could be observed. While body fat mass initially increased from t1 to t2 (0.8 ± 2.3 kg, p = 0.001), skeletal muscle mass decreased (-0.5 ± 1.9 kg, p = 0.025), a trend which was reversed from t2 to t3 only in HP + T group (body fat mass: -0.47 ± 2.12 kg, p = 0.041; muscle mass: 0.51 ± 1.57 kg, p = 0.021). CONCLUSION: The findings suggest that a substantial increase of habitual protein intake above the currently recommended levels is achievable within 17 weeks in community-dwelling older adults, whereby the extra amount of protein led to minor changes in body composition but not physical performance or muscle quality (NCT04023513).

The Effect of Elevated Protein Intake on DNA Damage in Older People: Comparative Secondary Analysis of Two Randomized Controlled Trials.

A high protein intake at old age is important for muscle protein synthesis, however, this could also trigger protein oxidation with the potential risk for DNA damage. The aim of this study was to investigate whether an increased protein intake at recommended level or well above would affect DNA damage or change levels of reduced (GSH) and oxidised glutathione (GSSG) in community-dwelling elderly subjects. These analyses were performed in two randomized intervention studies, in Austria and in New Zealand. In both randomized control trials, the mean protein intake was increased with whole foods, in the New Zealand study (n = 29 males, 74.2 ± 3.6 years) to 1.7 g/kg body weight/d (10 weeks intervention; p < 0.001)) in the Austrian study (n = 119 males and females, 72.9 ± 4.8 years) to 1.54 g/kg body weight/d (6 weeks intervention; p < 0.001)). In both studies, single and double strand breaks and as formamidopyrimidine-DNA glycosylase-sensitive sites were investigated in peripheral blood mononuclear cells or whole blood. Further, resistance to H2O2 induced DNA damage, GSH, GSSG and CRP were measured. Increased dietary protein intake did not impact on DNA damage markers and GSH/GSSG levels. A seasonal-based time effect (p < 0.05), which led to a decrease in DNA damage and GSH was observed in the Austrian study. Therefore, increasing the protein intake to more than 20% of the total energy intake in community-dwelling seniors in Austria and New Zealand did not increase measures of DNA damage, change glutathione status or elevate plasma CRP.

Effects of Vitamin D3 Supplementation and Resistance Training on 25-Hydroxyvitamin D Status and Functional Performance of Older Adults: A Randomized Placebo-Controlled Trial.

Vitamin D status is associated with muscle strength and performance in older adults. To examine the additive effects of vitamin D3 supplementation during resistance training, 100 seniors (65-85 years) participated in a 16-week intervention. Besides a daily dose of 400 mg of calcium, participants received either 800 IU vitamin D3 per day (VDD), 50,000 IU vitamin D3 per month (VDM) or nothing (CON). After the initial loading phase of four weeks, all groups started a 10-week resistance training program. Assessments of 25-hydroxyvitamin D (25(OH)D) status, muscle strength endurance (30-s chair stand and arm curl tests), aerobic capacity (6-min walk test) and functional mobility (gait speed and timed up and go test) were undertaken at baseline, after four weeks and at the end of the study. 25(OH)D status significantly improved in VDD and VDM, but not in CON (time x group: p = 0.021), as 15.2% of CON, 40.0% of VDD and 61.1% of VDM reached vitamin D sufficiency (>30 ng/mL; p = 0.004). Chair stand test, arm curl test, 6-min walk test, gait speed and timed up and go test improved over the whole intervention period (p < 0.05), however only chair stand and arm curl test were selectively affected by resistance training (p < 0.001). Neither muscle strength endurance, nor functional mobility or aerobic capacity were modulated by vitamin D supplementation. Therefore, the mere amelioration of 25(OH)D status of older adults does not lead to an additive effect on muscular performance during RT.

Data on the highly diverse plasma response to a drink containing nutrients.

Bioavailability of nutrients is highly diverse and depends on a variety of endogenous and exogenous factors in humans. This data article reports on the plasma response of 10 human subjects (5 females, 5 males) to a single dose of a multivitamin drink within 6h (blood taken after 1, 2, 4, and 6h). Nutrients, which were considered in the assessment, were folate (Radioimmuno Assay), vitamin B12 (Radioimmuno Assay) and resveratrol and its plasma metabolites resveratrol-3-O-glucuronide (R3G), resveratrol-4'-O-glucuronide (R4G), resveratrol-3-O-sulfate (R3S) and resveratrol-3-O-4'-O-disulfate (RD, all HPLC). Biological outcome measures were malondialdehyde (MDA, HPLC) and Ferric Reducing ability potential (FRAP, Microplate reader). Mean plasma concentration increased over time significantly for folate (p < 0.05, maximum concentration (Tmax) after 2h), R3G, R4G, R3S (all p < 0.05, Tmax after 1h), RD (p < 0.05, Tmax after 2h) as well as MDA, which decreased (p < 0.05, Tmax after 2h). No significant change was observed for vitamin B12 and FRAP. Within this mean development, individual changes of participants were highly diverse such as for folate from +42 to +422%, for MDA from -49 to +30% or vitamin B12 from -4 to +33%. For R4G 4 out of 10 subjects showed even no increase in plasma at all. For R4G plasma response ranged from 0 to 36 ng/ml, for R3G from 0 to 53 ng/ml or for R4S from 62 to 265 ng/ml. There was no gender difference regarding the plasma response.