Introduction 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. Creatinine Muscle Index (CMI) has been described as a novel surrogate marker for muscle mass. Waist-hip ratio (WHR) is a recognised surrogate marker for visceral adiposity. We sought to study the associations of CMI and WHR on survival, cardiovascular events and CKD progression. Methods This was a prospective observational cohort study of 1732 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. Results Participants in the higher tertiles of CMI were younger, more likely to be male, had higher serum albumin, lower BMI and lower waist-to-hip ratio. 248 participants (14.3%) died prior to their year 5 visit. In 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%) of 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). 306 (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). Conclusion Lower CMI was independently associated with higher mortality and CKD progression whereas higher WHR 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.
Randhay et al. (Tue,) studied this question.