Associations of Body Composition Biomarkers with Survival, Cardiovascular Events, and Progression in Persons with...

Low muscle mass and increased visceral fat are associated with increased mortality and adverse health outcomes, but measurement of components of body composition is not routine. The creatinine muscle index (CMI) has been described as a novel surrogate marker for muscle mass. The waist-to-hip ratio (WHR) is a recognised surrogate marker for visceral adiposity. We sought to study the associations of CMI and WHR with survival, cardiovascular events, and chronic kidney disease (CKD) progression.

This was a prospective observational cohort study of 1,732 people with CKD category G3 and followed up for 5 years. The primary outcomes were time to cardiovascular events and all-cause mortality over a 5-year period, and secondary outcome was progression of CKD.

Participants in the higher tertiles of CMI were younger, more likely to be male, and had higher serum albumin, lower BMI, and lower WHR. Two hundred forty-eight participants (14.3%) died prior to their visit in year 5. In the multivariable Cox proportional hazards model for mortality at 5 years, each one-standard-deviation decrease in CMI was associated with 28% higher risk in mortality (HR 1.277, 95% CI 1.086-1.502, p = 0.003). Cardiovascular events occurred in 605 (34.9%) participants. Each standard deviation increase in WHR was significantly associated with 16% higher risk of cardiovascular events at 5 years (HR 1.160, CI 1.037-1.298, p = 0.009). Three hundred six (24.8%) participants evidenced CKD progression. In a multivariable binary logistic regression analysis, lower CMI was associated with a higher risk of progression of CKD at 5 years (OR 1.230, CI 1.028-1.471, p = 0.024).

Lower CMI was independently associated with higher mortality and CKD progression, whereas higher WHR was independently associated with increased risk of cardiovascular events. These simple and inexpensive surrogate biomarkers of sarcopenia and visceral adiposity can be easily incorporated into daily practice to enhance risk stratification in people with CKD and inform therapeutic interventions to improve their clinical outcomes.