Abstract
Background and Aims
Muscle wasting leads to poor outcomes in patient with chronic kidney disease (CKD). The serum creatinine to cystatin C (Cr/CysC) ratio has been reported as marker for muscle mass and may predict outcomes in chronic diseases. We hypothesized that the Cr/CysC ratio would be a predictor of outcomes in CKD.
Method
We investigated a total of 2142 patients (male 61%, aged 54±12 year) with CKD followed for a median of 3.74 years. We assessed the factors associated with Cr/CysC ratio and the relationship between Cr/CysC ratio and outcomes of end-stage renal disease (ESRD), cardiovascular event (CVE), and mortality.
Results
The Cr/CysC ratio significantly correlated with age (r=-0.18), estimated glomerular filtration rate (eGFR) (r=-0.21), serum albumin (r=0.11), 24-hour urine creatinine (r=0.38), and moderate to vigorous physical activity time (r=0.07). After adjusting for age, sex, eGFR, and log urine albumin creatinine ratio (model 1), the hazard ratios for ESRD, CVE, and mortality were 0.96 (95% CI, 0.86-1.07), 0.78 (95% CI, 0.61-0.99), and 0.72 (95% CI, 0.53-0.97) per 1 standard deviation Cr/CysC increase (0.21), respectively. After full adjustment for model 1 variables plus lifestyle factors, laboratory factors, and comorbidities (model 2), the hazard ratios for ESRD, CVE, and mortality were 0.99 (95% CI, 0.88-1.10), 0.84 (95% CI, 0.65-1.07), and 0.75 (95% CI, 0.55-0.99) per 1 standard deviation Cr/CysC increase (0.24), respectively. In subgroup of the elderly (age>65 year) and early stage CKD (eGFR>60 ml/min/1.73m2), the hazard ratios for CVE were significantly lower in patients with high Cr/CysC ratio.
Conclusion
Cr/CysC ratio correlates with muscle biomarkers and physical activity. A higher Cr/CysC ratio is associated with low CVE and mortality, but not ESRD in CKD.
Physical Exercise in People with Chronic Kidney Disease—Practices and Perception of the Knowledge of Health Professionals and Physical Activity and Sport Science Professionals about Their Prescription
