Significance of BMI for diagnosing sarcopenia is equivalent to slow gait speed in Japanese subjects with type 2 diabetes: Cross-sectional study using outpatient clinical data.

AIMS/INTRODUCTION This study examined the association between body mass index (BMI) and risk of sarcopenia in Japanese type 2 diabetes patients. MATERIALS AND METHODS Patients with type 2 diabetes who visited an outpatient clinic comprised the study's participants. Sarcopenia was defined using the definition of the Asian Working Group for Sarcopenia 2014. The area under the curves (AUC) was examined for the presence of sarcopenia based on the receiver operating characteristic curve (ROC) of BMI. RESULTS Among 1137 patients, 210 were diagnosed with low grip strength, 78 with slow gait speed, 444 with low muscle mass, and 142 with sarcopenia. The optimal cut-off point of BMI level for risk of sarcopenia was 24.4 kg/m2 (AUC 0.729, 95%CI, 0.688-0.770, sensitivity = 0.587, specificity = 0.789). Furthermore, the ROC of BMI for sarcopenia did not significantly differ (P=0.09) from that of gait speed, an established marker of sarcopenia. In both male and female groups, there was no difference between the ROCs of BMI and gait speed for sarcopenia. (P=0.23 and 0.40, respectively). CONCLUSIONS These results suggest that a BMI lower than 24 kg/m2 among Japanese patients with type 2 diabetes could increase their risk of sarcopenia, the extent of which is equivalent to the risk for sarcopenia from slow gait speed in this study. Further prospective investigation, however, is needed.