Clinical Performance of Phase Angle in Screening for Osteosarcopenia Among Older Adults with Type 2 Diabetes

Background: This study aimed to determine the prevalence of osteosarcopenia and evaluate the diagnostic performance of phase angle, derived from bioelectrical impedance analysis, in identifying osteosarcopenia among older adults with type 2 diabetes mellitus. Method: A cross-sectional study was conducted with 147 participants aged 60 years or older, recruited from an outpatient clinic in Thailand between during 2024. Osteosarcopenia was diagnosed when criteria for both sarcopenia, defined by low skeletal muscle mass and either reduced handgrip strength or impaired physical performance, and osteoporosis, defined by a T-score of −2.5 or lower on dual-energy X-ray absorptiometry, were met. Participant characteristics, physical function, laboratory values, and body composition data were collected. Univariable Firth’s penalized logistic regression identified low body mass index and a lower phase angle as independent predictors of osteosarcopenia. Results: The overall prevalence of osteosarcopenia was 7.5 percent. Receiver operating characteristic curve analysis showed strong diagnostic performance of phase angle, with an area under the curve of 0.865. A cutoff value of less than 4.0 degrees achieved 100% sensitivity, 62.5% specificity, and 100% negative predictive value. These findings suggest that phase angle may be a practical, noninvasive screening tool for identifying older adults with type 2 diabetes mellitus who are at risk for osteosarcopenia. Its application in routine clinical settings could enable earlier intervention and reduce long-term complications associated with musculoskeletal decline in this vulnerable population.