Porvoo sarcopenia and nutrition trial: effects of protein supplementation on functional performance in home-dwelling sarcopenic older people - study protocol for a randomized controlled trial

Background: Age-related muscle loss (that is, sarcopenia) is a common health problem among older people. Physical exercise and dietary protein have been emphasized in prevention and treatment of sarcopenia. Rigorous trials investigating the effects of protein supplementation on physical performance in sarcopenic populations are still scarce. The aim of this study is to investigate the effects of protein supplementation along with simple home-based exercises on physical performance among home-dwelling sarcopenic older people. Methods/Design: During 2012 the entire 75 and older population (N = 3,275) living in Porvoo, Finland was contacted via a postal questionnaire. Persons at risk of sarcopenia are screened with hand grip strength and gait speed. Poorly performing persons are further examined by segmental bioimpendance spectroscopy to determine their skeletal muscle index. Sarcopenic patients (target N = 250) will be enrolled in a 12-month randomized controlled trial with three arms: 1) no supplementation, 2) protein supplementation (20 grams twice a day), and 3) isocaloric placebo. All the participants will receive instructions on simple home-based exercises, dietary protein, and vitamin D supplementation (20 mu g/d). The recruitment of patients will be completed during 2013. The primary endpoint of the trial is the change in short physical performance battery score and percentage of patients maintaining or improving their physical performance. Secondary endpoints will be, among other things, changes in muscle functions, nutritional status, body composition, cognition, quality of life, use of health care services, falls, and mortality. The assessment times will be 0, 6, 12 and 24 months. Discussion: To our knowledge, this is the first large scale randomized controlled trial among community dwelling older people with sarcopenia that focuses on the effects of protein supplementation on physical performance.