[Association between dietary energy and protein intake and sarcopenia among the elderly in 8 cities across China].

Objective: To explore the association between energy and protein intake and sarcopenia among elder people from eight cities across China.
Methods: The current study is based on a previous research conducted in 2016 which was named "Chinese Urban Adults Diet and Health Study". A total of 427 participants aged 65 and older were enrolled. Questionnaire was conducted to obtain the socio-demographic characteristics of participants. 24 h dietary recall was used to assess the dietary intake and energy and protein intake was calculated according to China Food Composition. The subjects were then divided into four groups(Q1, Q2, Q3, Q4) according to their energy intake(<1197. 6 kcal/d, 1197. 6-1531. 4 kacl/d, 1531. 4-1984. 0 kcal/d, ≥1984. 1 kacl/d) and protein intake(<36. 8 g/d, 36. 8-50. 4 g/d, 50. 4-68. 6 g/d, ≥68. 6 g/d). Bioelectrical impedance analysis was used to measure the skeletal muscle mass, hand-held grip strength meter was used to measure the skeletal muscle strength, and four-meter gait speed test was used to measure the skeletal muscle performance. According to the criteria of Asian Working Group for Sarcopenia, the health status of the skeletal muscle was evaluated.
Results: Compared with the Q1 group, there was no significant difference in skeleton muscle mass, grip strength, walking speed and the detection rate of sarcopenia among the energy intake groups(Q2-Q4). Compared with the Q1 group, the Q2 protein intake group had greater grip strength(β=0. 12, 95%CI 0. 03-0. 21, P=0. 009) and faster gait speed(β=0. 20, 95%CI 0. 07-0. 34, P=0. 003).
Conclusion: The level of protein intake is associated with the grip strength and gait speed of the elderly in China, but has no significant effect on the detection rate of sarcopenia.