Metabolic Risk Factors and Sarcopenia in Older Japanese Adults: The Bunkyo Health Study

The increasing prevalence of type 2 diabetes (T2DM) and sarcopenia in older Japanese adults presents significant health challenges. We investigated the following utilizing baseline data from the Bunkyo Health Study: The first study investigated determinants of diabetes in older adults, highlighting glucose tolerance declined with age in Japanese older adults, possibly due to age- related insulin resistance and β-cell deterioration associated with fat accumulation and elevated free fatty acid levels. In the second study, the relationship between diabetes/prediabetes and sarcopenia was explored, revealing diabetes as a significant risk factor in both sexes, with prediabetes also showing an association in men. Higher age, body fat percentage, and lower body mass index were identified as additional sarcopenia risk factors. The third study investigated the role of insulin resistance and low grip strength as potential surrogate markers for sarcopenic obesity in East Asians. Possible sarcopenia, identified by low handgrip strength, and insulin resistance, as measured by the triglyceride glucose (TyG) index, are independently associated with the prevalence of T2DM in older adults. The coexistence of these factors shows a particularly strong association with T2DM. Since handgrip strength and the TyG index can be easily measured in clinical settings, their coexistence might be a valuable indicator for assessing the risk of T2DM in older adults. These findings underscore the complexity of metabolic interactions in older Japanese adults and highlight the importance of targeted interventions to mitigate associated health risks.