Background: Sarcopenia research may be hampered by the heterogeneity of populations and outcome measures used in clinical studies.
Aim: The aim of this study was to describe the inclusion/exclusion criteria and outcome measures used in ongoing research in sarcopenia.
Methods: All active intervention studies registered in the World Health Organization with the keyword sarcopenia were included. Study design, type of intervention, inclusion/exclusion criteria and outcome measures were registered and classified.
Results: In April 2014, 151 studies on sarcopenia were registered in the WHO database. One hundred twenty-three were intervention studies. Most trials (94.3 %) were single centre and randomized (93.5 %), 51.2 % were double blind. Nutritional interventions (36.6 %), physical exercise (12.2 %) or both (19.5 %) were the most common interventions tested. Only 54.4 % included subjects of both genders, and 46.3 % had an upper age limit. Definition of the target populations was heterogeneous, with 57.7 % including healthy subjects and none using recent definitions of sarcopenia. Lifestyle and the degree of physical activity of subjects were not described or considered in most cases (79.7 %). Subjects with cardiovascular, neuropsychiatric or metabolic disorders and those with physical disability were usually excluded. Muscle mass and muscle strength were the primary outcome variables in 28.5 and 29.5 % of studies and physical performance in 19.5 %, but only 4.1 % used the three variables used the three of them. An additional 26.8 % used biological outcome variables. Little information and agreement existed in the way muscle and physical performance parameters were measured.
Conclusions: We found a large heterogeneity in trial design, definition of populations and outcome measures in present research.
Keywords: Clinical trials; Inclusion/exclusion criteria; Outcomes; Sarcopenia.