Exploring biomarkers of osteosarcopenia in older adults attending a frailty clinic

Osteosarcopenia is a new definitional approach that can increase the risk of falls and fractures in elderly compared with that of osteoporosis and sarcopenia alone. However, biomarkers for osteosarcopenia have not been well identified. Thus, we aimed to explore the biomarkers of osteosarcopenia, including bone, muscle, and geriatric markers. Outpatients attending a frailty clinic were enrolled in the study. Osteosarcopenia was defined as the coexistence of osteoporosis and sarcopenia. Osteoporosis was defined according to the criteria of the Japan Osteoporosis Society. Sarcopenia was defined according to the Asian Working Group for Sarcopenia consensus (2019). We selected 35 blood/serum pathological parameters, including bone, inflammation, nutritional, and aging markers for the study. Logistic regression analysis for osteosarcopenia was performed to explore the biomarkers of osteosarcopenia. Of the total 600 patients with a mean age of 76.6 years, 595 were enrolled in the registry during the study period. Logistic regression analysis for osteosarcopenia showed that elevated thyroid stimulating hormone (TSH) (odds ratio [OR]:1.375; 95 % confidence interval [CI]: 1.092-1.731), bone-specific alkaline phosphatase (BAP) (OR: 1.059; 95 % CI: 1.002-1.120), and estimated glomerular filtration rate (eGFR) (OR: 1.029; 95 % CI: 1.007-1.053) increased the likelihood of osteosarcopenia. On the other hand, elevated 25hydroxyvitamin D (25OHD) (OR: 0.905; 95 % CI: 0.841-0.974), blood urea nitrogen (BUN) (OR: 0.895; 95 % CI: 0.829-0.966) and K (OR: 0.241; 95 % CI: 0.081-0.717) decreased the likelihood of osteosarcopenia. It is worthwhile to examine these biomarkers for older adult outpatients attending a frailty clinic for screening osteosarcopenia. Further studies are needed to investigate the effects of other markers of bone metabolism.