Psoas muscle measurement as a marker of sarcopenia predicts risk of Grade 4 or 5 baseline chronic kidney disease and its progression

Abstract Background Psoas muscle area (PMA) has recently been found to be an appropriate surrogate for whole‐body skeletal muscle mass and a measure of sarcopenia. Sarcopenia, which includes a decreased muscle mass and correlated with physical disability, morbidity, and mortality, is prevalent in and has deleterious consequences for patients with chronic kidney disease (CKD). The current study investigates the association of PMA, as a marker of sarcopenia, with baseline kidney function and CKD progression. Methods A retrospective cohort study was conducted in a community hospital nephrology clinic setting. For this study, sarcopenia was defined as standardized PMA measured at the L3 level either as below 25th percentile or below the median. Progression of CKD was measured by estimated glomerular filtration rate (eGFR) decline rate and change in proteinuria. To assess sarcopenia as a predictor of baseline CKD Grade 4 or 5, a multivariate logistic regression model was applied using standardized PMA < 25th percentile. To assess sarcopenia as a predictor for eGFR slope, a multivariate generalized linear model was applied using PMA < median. Results Among the 230 patients studied, the median age was 74 (31–92) years, 56.52% (130/230) were male patients, and the majority was Caucasian 62.61% (144/230). The body mass index classes of <18.5, 18.5–24.9, 25.0–29.9, and >29.9 kg/m2 were categorized by 4.8% (11/229), 24.89% (57/229), 33.19% (76/229), and 37.12% (85/229), respectively. Sarcopenia as a predictor of baseline CKD Grade 4 or 5 had an unadjusted odds ratio of 1.46 (0.87–2.63) and an adjusted odds ratio of 2.45 (1.13–5.31). Sarcopenia as a predictor for eGFR slope had an unadjusted odds ratio of 1.01 (1.00–1.04) and an adjusted odds ratio 1.03 (1.00–1.05). Conclusions Sarcopenia, as measured by PMA, predicts a significant risk of more severe baseline CKD grade and progression. Future studies should examine sex‐specific muscle mass tools as a predictor of renal function to create more targeted interventions.