Patterns of protein consumption throughout adulthood and physical capability in later life

Abstract

Sarcopenia is a geriatric syndrome characterised by low muscle mass and low muscle function, caused by an imbalance between muscle protein synthesis and degradation. It has a multifactorial aetiology, but primary causes include a sedentary lifestyle and poor nutrition. Sarcopenia is associated with an increased risk of disability and mortality. This project aimed to test the hypothesis that adulthood patterns of protein consumption influence physical capability in later life. Dietary and physical capability data were obtained from the MRC National Survey of Health and Development, a British birth cohort comprising ~5000 individuals born in 1946. Dietary data were collected by 5d food diary in 1982, 1989 and 1999 when participants were 36, 43 and 53 y. Hand grip strength, chair rise time and timed up and go were measured in 2006/10 when participants were 60/64 y. Anthropometric, physical activity and socioeconomic variables were also provided. Using data for those participants who provided dietary information in all years, relationships between adulthood patterns of protein consumption and measures of physical performance were investigated using hierarchical linear regression. Concurrent measures of height, body composition and abdominal circumference were the strongest determinants of hand grip strength in males. In females, health status was also predictive. Health status, abdominal circumference and physical activity were predictive of chair rise time in males and females. In sensitivity analyses, low protein consumption in males was associated with a significantly poorer performance. Health status was the strongest determinant of timed up and go performance in males and females. In sensitivity analyses, low protein consumption in males was associated with a significantly poorer performance and socioeconomic position became significant. In this cohort, protein consumption was high. After excluding predicted misreporters, protein intakes averaged 1.2 g/kg/d. Meanwhile rates of obesity/abdominal circumference increased significantly, accompanied by declining levels of physical activity.