Sarcopenia in older adults with diabetes may encompass clinically distinct phenotypes. We examined whether body composition-defined phenotypes differed in diabetes complications, insulin resistance-related metabolic features, and continuous glucose monitoring (CGM)-derived glycemic profiles.

This cross-sectional study included 109 adults aged 70 years or older with diabetes and frailty. Sarcopenia was defined according to the European Working Group on Sarcopenia in Older People 2 criteria; adiposity was defined using body mass index, body fat percentage, and central obesity. Analyses were mainly descriptive; exploratory logistic regression assessed poor CGM time in range (TIR), defined as TIR below 70%.

Sarcopenia was identified in 86 participants (78.9%). After exclusion of 2 participants in a small non-sarcopenic with adiposity subgroup, 107 participants formed three phenotypes. Sarcopenic obesity showed an insulin resistance-related cluster comprising greater central adiposity, higher triglycerides and TyG index, metabolic syndrome in all participants, and greater insulin requirements. Sarcopenia without adiposity showed more neuropathy, albuminuria, cerebrovascular disease, and lower TIR despite similar glycated hemoglobin. Glycated hemoglobin was the only independent correlate of poor TIR; phenotype was not significant overall.

Phenotypes showed distinct clinical, insulin resistance-related, and CGM profiles. These preliminary findings support phenotype-aware assessment but require confirmation in larger longitudinal studies before informing management.