Abstract
Background:The link between insulin and sarcopenia among older adults in China is not yet fully understood. This study seeks to investigate this association using data from a nationally representative large-scale survey.
Methods: The study utilized data from two waves of the China Health and Nutrition Survey (CHNS) conducted in 2009 and 2015. Subjects meeting the inclusion criteria were classified according to the Asia Working Group for Sarcopenia2019 criteria. The study employed ordinary least squares (OLS) regression models to analyze the cross-sectional association between muscle mass and insulin. Additionally, logistic regression models were utilized to examine the longitudinal association between sarcopenia and insulin.
Results: In 2009, a cross-sectional association study enrolled a total of 2329 participants aged over 60 years, with 53.1% women and a median age of 68.00 years. The prevalence of sarcopenia in the study population was 30.83%, with a higher prevalence in females (60.03%). In the adjusted OLS regression model based on blood biomarker, insulin was positively associated with muscle mass (β=0.075, 95% confidence interval (CI): 0.034 - 0.117, P <0.01). In 2009, individuals without sarcopenia were divided into two groups based on the median value of insulin in the total population. When 944 individuals were followed up in 2015 to assess the incidence of sarcopenia, a significant difference was found between the two groups (12.44% vs 7.45%, P=0.01). The adjusted logistic regression models indicated that higher insulin levels were associated with a reduced incidence of sarcopenia (Hazard ratio =0.958, 95% CI: 0.925 - 0.989, P=0.01).
Conclusions: Adequate insulin could potentially serve as a protective factor in preserving healthy muscle mass among Chinese adults aged 60 and above.