Muscular strength and physical function in elderly adults 6-18 months after a 12-week resistance exercise program.

AIMS: Benefits of resistance exercise in elderly people are well documented; however, sustaining these benefits can be difficult and adherence is often poor. Muscular strength and physical function usually decline after a supervised resistance exercise program (REP). We investigated these changes in older adults during an observational follow-up and whether leisure time physical activity (LTPA) or unsupervised resistance exercise (RE) limit these changes. METHODS: Subjects (N = 236, 73.7 ± 5.7 years, 58.2% female) had participated in a supervised 12-week REP. Quadriceps strength and timed-up-and-go performance (TUG) at follow-up were compared to values before and after REP. Multivariate statistics were used to predict changes in strength or function. RESULTS: Two hundred and eleven (90.3%) participants completed REP and 149 (63.1%) completed follow-up (11.4 ± 2.9 months). Quadriceps strength at follow-up decreased significantly compared to after REP (-27N), but was higher than before REP (+ 30N). TUG did not decrease during follow-up and was better than before REP (-0.9 seconds). LTPA (+ 38.0N, p < 0.001) and RE (+31.6N, p = 0.006) predicted strength at follow-up, although they did not completely prevent loss of strength during follow-up. CONCLUSIONS: quadriceps strength declines after a 12-week resistance exercise program in older adults. Neither LTPA nor RE completely prevents loss of quadriceps strength during follow-up, although they limited the loss. TUG did not change during follow-up and was better at follow-up than before the start of the resistance exercise program.

Dietary protein intake is associated with lean body mass in community-dwelling older adults.

Lean body mass (LBM) is important to maintain physical function during aging. We hypothesized that dietary protein intake and leisure-time physical activity are associated with LBM in community-dwelling older adults. To test the hypothesis, participants (n = 237; age, 65-92 years) did 3-day weighed food records and reported physical activity. Body composition was assessed using dual-energy x-ray absorptiometry. Protein intake was 0.98 ± 0.28 and 0.95 ± 0.29 g/kg body weight in male and female participants, respectively. Protein intake (in grams per kilogram of body weight) was associated with LBM (in kilograms); that is, the differences in LBM were 2.3 kg (P < .05) and 2.0 kg (P = .054) between the fourth vs the first and the fourth vs the second quartiles of protein intake, respectively. Only a minor part of this association was explained by increased energy intake, which follows an increased protein intake. Our study shows that dietary protein intake was positively associated with LBM in older adults with a mean protein intake higher than the current recommended daily allowance of 0.8 g/kg per day. Leisure-time physical activity, predominantly consisting of endurance type exercises, was not related to LBM in this group.

Glomerular filtration rate after a 12-wk resistance exercise program with post-exercise protein ingestion in community dwelling elderly.

OBJECTIVE: Increased protein intake and resistance exercise can be beneficial for maintenance of lean body mass (LBM) in older adults. However, these factors could also negatively affect renal function. We investigated changes in renal function after a 12-wk resistance exercise program combined with protein supplementation in community dwelling older adults. METHODS: Patients (N = 237, 73.7 ± 5.7 y, 58.2% female) participated in a 12-wk resistance exercise program (3 times/wk) designed to increase strength and muscle mass of major muscle groups. Participants were randomly assigned to one of three dietary supplements consumed directly after training: whey protein drink (20 g whey protein, 20 g carbohydrates), milk protein drink (20 g milk protein, 20 g carbohydrates), or carbohydrate drink (40 g carbohydrates). Renal function was estimated as glomerular filtration rate (GFR, Cockcroft-Gault formula), and dietary intake was measured as 3-d-weighed food record at baseline and endpoint. RESULTS: During the intervention, energy intake did not increase. Carbohydrate intake increased in the carbohydrate group and protein intake increased in the milk group, both approximately in accordance with the supplementation. In the whey group, protein intake did not increase, but carbohydrate intake did. GFR increased after the intervention (+4.4 mL/min/1.73 m2; P < 0.001), and the changes were similar in men and women or in the age quartiles. Changes in GFR at endpoint were not associated with LBM, dietary supplements, or total protein intake. CONCLUSIONS: A 12-wk resistance exercise program combined with protein supplementation in community dwelling older adults does not negatively affect GFR. The supplementation had only minor effects on total dietary intake.

[Dietary habits and their association with blood pressure among elderly Icelandic people]. / Fæduvenjur og fylgni vid blódthrýsting medal eldri Íslendinga.

OBJECTIVE: Prevalence of hypertension, which is the most common risk factor for cardiovascular disease in elderly people, increases with age. The aim of the study was to investigate the association between diet and blood pressure in elderly Icelanders, with focus on cod liver oil, and to compare their diet to dietary guidelines. MATERIAL AND METHODS: Diet was assessed using three-day weighed food records and blood pressure was measured after a 12-hour-fast in 236, 65-91 years old, Icelanders living in the capital area of Iceland. 99 men (42%) and 137 women (58%) participated in the study. RESULTS: According to Nordic nutrition recommendations, intake of nutrients was above lower intake levels among the majority of participants. However, 19% were under this level for vitamin-D, 13% for iodine, 17% of men for vitamin-B6, and 26% and 12% of men and women, respectively, for iron. Systolic blood pressure was inversely associated with cod liver oil intake, even when adjusted for age, body mass index, gender, and antihypertensive medications (P=0.01). Intake of long-chain omega-3 fatty acids correlated with blood pressure in a similar way. Other dietary factors were not associated with blood pressure. CONCLUSION: The results indicate that intake of cod liver oil is associated with lower blood pressure among elderly people and may therefore have beneficial effects on health. A notable proportion of participants was at risk of vitamin D, vitamin B6, iodine, and iron deficiency.

Gender difference in the prediction of weight loss by leptin among overweight adults.

BACKGROUND/AIM: Leptin plays an important role in energy metabolism. The primary objective of the study was to investigate whether baseline leptin levels predict weight loss during a dietary intervention in overweight and obese individuals. METHODS: A total of 324 individuals (138 men and 186 women, aged 20-40 years, BMI 27.5-32.5) were recruited in Iceland, Ireland and Spain. The intervention lasted for 8 consecutive weeks, and subjects were instructed to follow a diet, energy restricted by 30%. Anthropometric variables were assessed before and after the intervention. Leptin concentration was measured at baseline and corrected for fat mass. Linear models were used to find out which variables predicted weight loss. RESULTS: At end point, significant weight loss was observed (5.16 +/- 3.06 kg, p < 0.001). High baseline leptin concentrations were a significant negative predictor of weight loss in men (p = 0.028), with a predicted difference of 1.8 kg between the lowest and highest leptin quartile. CONCLUSION: Our study underlines the importance of leptin in energy metabolism. Plasma leptin concentrations at baseline are a predictor of weight loss in overweight men after an 8-week dietary intervention. The same effect was not observed in overweight women, which suggests that the role of leptin in the regulation of weight is gender specific.