Skeletal Muscle Measurements Based on Abdominal Computerized Tomography (CT) Predict Risk of Osteoporosis in Incident...

Objective: Osteoporosis is prevalent in patients with chronic kidney disease (CKD), with risk increasing as CKD progresses, subsequently elevating fracture risk. While previous studies have shown a link between low skeletal muscle mass and osteoporosis in the general population, there is limited research exploring this relationship in patients with advanced CKD (stages 3-5D). This study aimed to evaluate whether skeletal muscle area (SMA), as measured by abdominal CT, is correlated with bone mineral density (BMD) in advanced CKD patients beginning hemodialysis. Methods: This single-center, retrospective cohort study included patients who started maintenance hemodialysis at Daejeon St. Mary's Hospital from January 2018 to September 2021. Patients who underwent abdominal CT and BMD assessments within three months of dialysis initiation were enrolled, resulting in a sample of 87 individuals. Baseline characteristics were analyzed, with patients stratified by sex and SMA quartiles. Pearson's correlation and multivariate regression analyses were conducted to the relationship between SMA and BMD T-scores. Results: The study cohort had an average age of 65.4 years, with 52.9% of participants being male. Male patients exhibited significantly higher SMA and BMD T-scores in both the lumbar spine and femur compared to female patients. SMA showed the strongest positive correlation with BMD at both sites (lumbar spine, r = 0.424; femur, r = 0.514; p < 0.001). Multivariate analysis identified SMA as an independent positive predictor of BMD, while alkaline phosphatase (ALP) was independently associated with lower femur BMD. In the SMA-based subgroup analysis, patients with lower SMA had significantly lower BMD T-scores and a higher risk of osteoporosis. Logistic regression indicated that patients in the lowest SMA quartile had substantially increased odds of osteoporosis compared to those in the highest quartile, with an adjusted odds ratio of 30.59 (p = 0.008). Conclusions: Lower skeletal muscle mass is significantly associated with lower bone density and a higher risk of osteoporosis in advanced CKD patients initiating hemodialysis. SMA, as measured by abdominal CT, may serve as a useful marker for identifying patients at elevated osteoporosis risk in this population.