Relationship between protein intake and dynapenia in postmenopausal women.

Objective: The purpose of this study was to investigate the relationship between protein intake and dynapenia.

Design: A cross-sectional/observational study.

Setting: Department of Kinanthropology at the University of Quebec at Montreal.

Participants: Seventy-two non-frail postmenopausal women aged between 50 to 75 years were recruited.

Measurements: Body weight (BW), lean body mass (LBM; %) and skeletal muscle mass (bio-electrical impedancemetry analysis), maximum voluntary handgrip strength (using hand dynamometer), aerobic capacity (VO2peak) and dietary intake were measured. Women were divided according to dynapenia criteria.

Results: The strongest correlation between muscle strength and protein intake was observed when we express the amount of protein in g/d/BW. No differences for age, BMI, status of menopause, fat mass and VO2peak were observed between non-dynapenic, type I dynapenic and type II dynapenic women, independently of the criteria used. We observed significant differences in protein intake (g/d/BW) between non-dynapenic and type II dynapenic (p<0.01) as well as between type I dynapenic and type II dynapenic (p<0.01) when dynapenia was expressed in kg/BW and in kg/LBM, respectively. It should be noted that no differences in LBM between the three groups were observed when dynapenia was expressed in kg/BW and kg/LBM. Protein intake for all groups respected the RDA of 0.8 to 1.2 g/d/BW (non-dynapenic: 1.44/1.38; type I dynapenic: 1.30/1.33; type II dynapenic: 1.05/1.08 g/d/BW).

Conclusions: Protein intake seems to play a role in the development of dynapenia particularly at the level of type II dynapenia. Therefore, an increase in the recommended daily allowance for protein intake may be warranted.