Effects of Whey Protein Supplementation Pre- or Post-Resistance Training on Muscle Mass, Muscular Strength, and Functional Capacity in Pre-Conditioned Older Women: A Randomized Clinical Trial

Association between Geriatric Nutrition Risk Index and low muscle mass in Chinese elderly people

BACKGROUND/OBJECTIVES

The aim of the study was to evaluate the relationship between Geriatric Nutrition Risk Index (GNRI) and low muscle mass (LMM) in elderly people.

SUBJECTS/METHODS

A cross-sectional study was carried out in Chinese PLA General Hospital with 3240 participants who underwent a health check-up examination between February 2016 and February 2017. Linear regression and logistic regression were used to examine the relationship between GNRI and LMM.

RESULTS

The mean age of the participants in the study was 64.6 years. The mean appendicular skeletal muscle mass index (ASMI) was 8.92 ± 0.93 kg/m² in men and 7.62 ± 0.73 kg/m² in women. The incidences of LMM were 7.9% in men and 3.7% in women. Linear regression demonstrated that GNRIs were positively correlated with ASMIs in both men and women (β = 0.055 for men and 0.039 for women, all P < 0.001). The cut-off point of the GNRI in elderly people for LMM was 104.0 in men and 107.0 in women and were identified by Classification and Regression Trees (CART). Logistic regression showed that both men and women with decreased GNRIs had higher ratios of LMM [odds ratio (OR) = 3.904 for men and 4.486 for women, P < 0.001 and P = 0.001, respectively].

CONCLUSIONS

Elderly people with a low GNRI had a higher incidence of LMM, which suggested that GNRI had a close relationship with LMM and that it could be a good indicator in identifying senior people who need further nutritional support and physical activity.

Locomotive syndrome in Japan

The present aging rate in Japan of some 28% will continue to increase along with the advancing age of elderly persons. Therefore, the demand for care will also increase. Approximately 25% of the need for nursing-care defined by the Japanese long-term care insurance system is associated with disorders or deterioration of locomotive organs. Therefore, the prevention and treatment of diseases in the locomotor system and maintenance of motor function are important for extended healthy life span and to decrease the demand for long-term care. Based on this background, the Japanese Orthopaedic Association (JOA) proposed the concept of locomotive syndrome (LS) in 2007, which is defined as reduced mobility due to impaired locomotive organs. Changes in locomotion must be noticed early to ensure the timely implementation of appropriate checks and measures of locomotion can uncover risk of acquiring LS. The acquisition of an exercise habit, appropriate nutrition, being active and evaluating and treating locomotion-related diseases are important to delay or avoid LS. The JOA recommends locomotion training consisting of four exercises to prevent and improve LS. Countermeasures against LS should become a meaningful precedent not only for Japan, but for other countries with rapidly aging populations.

Whey Protein Concentrate WPC-80 Intensifies Glycoconjugate Catabolism and Induces Oxidative Stress in the Liver of Rats

The aim of this study was to evaluate the effect of whey protein concentrate (WPC-80) on glycoconjugate catabolism, selected markers of oxidative stress and liver inflammation. The experiment was conducted on male Wistar rats (n = 63). The animals from the study group were administered WPC-80 at a dose of 0.3 or 0.5 g/kg body weight for 7, 14 or 21 days, while rats from the control group received only 0.9% NaCl. In liver homogenates, we assayed the activity of N-acetyl-β-D-hexosaminidase (HEX), β-glucuronidase (GLU), β-galactosidase (GAL), α-mannosidase (MAN), α-fucosidase (FUC), as well as the level of reduced glutathione (GSH), malondialdehyde (MDA), interleukin-1β (IL-1β) and transforming growth factor-β1 (TGF-β1). A significantly higher activity of HEX, GLU, MAN and FUC were found in the livers of rats receiving WPC-80 compared to controls. Serum ALT and AST were significantly higher in the animals supplemented with WPC-80 at a dose of 0.5 g/kg body weight for 21 days. In the same group of animals, enhanced level of GSH, MDA, IL-1β and TGF-β1 were also observed. WPC-80 is responsible for intensive remodelling of liver tissue and induction of oxidative stress especially at a dose of 0.5 g/kg body weight.