Prescribed Medications and Sarcopenia Development in Community-Dwelling Older Adults in Japan: A Kashiwa Cohort Study

Background: Clinical evidence demonstrating a longitudinal association between prescribed medications and sarcopenia onset is lacking. We investigated the association of polypharmacy (the use of five or more medications) and potentially inappropriate medications (PIMs) with sarcopenia risk in community-dwelling older adults. Methods In this longitudinal population-based cohort study, 2,044 older residents with no long-term care needs were randomly selected from a community in Kashiwa, Japan. Baseline data collection was conducted in 2012, with follow-ups in 2013, 2014, 2016, 2018, and 2021. Prescribed medications and PIMs (drugs listed in the Screening Tool for Older Person’s Appropriate Prescriptions for the Japanese or potentially muscle-wasting drugs) were identified through interviews. New-onset sarcopenia was identified according to the 2019 criteria of the Asian Working Group for Sarcopenia over a 9-year period and analyzed as an event using generalized estimating equations with repeated measures. Results Of the 1,549 participants without sarcopenia at baseline (mean age, 72.5 ± 5.5 years; 49.1% women; 6,256 total measurements over the 9-year follow-up; median and interquartile range, 6.0 [4.0–9.0] years), 230 experienced 260 events of new-onset sarcopenia during the follow-up. After adjusting for potential confounders, the prescription of ≥ 5 medications with PIM use was strongly associated with new-onset sarcopenia (adjusted odds ratio, 1.71; 95% confidence interval, 1.13–2.60; P =  0.011). No significant associations were observed for either PIM use or polypharmacy alone. Conclusions The combination of polypharmacy and PIM use was associated with an increased risk of new-onset sarcopenia over the 9-year follow-up period. Limiting polypharmacy and imposing the prescription of appropriate medications may facilitate sarcopenia prevention.