Changes in muscle strength and physical performance are mostly used in finding sarcopenia cases. We investigated the relationship between physical performance and renal function test of older pre-dialysis CKD patients to explore whether we could better predict the risk of sarcopenia with a selection of these parameters.
Elderly CKD patients were screened with SARC-CalF and grouped as risk of sarcopenia (RS) if scored ≧11, or otherwise, non-sarcopenia (NS). Results of the most recent renal function test of the participants were obtained from their medical record, including estimated glomerular filtration rate (eGFR), urine protein (Upro), serum and urine creatinine level (Cr and UCr), urine protein and creatinine ratio (UPCR), haemoglobin (Hb), haematocrit (Hct), albumin, total cholesterol (TC), LDL cholesterol (LDL-C), and triglycerides (TG). Physical assessment was performed and consisted of measurement of handgrip strength, biceps and quadriceps strength, five times sit-to-stand test (FTSST), and timed up-and-go test (TUG). All parameters (11 clinical and 5 physical) were assigned as feature 1 to 16 and logistic regression was then used to see if certain combination of features could best classify the RS and NS groups.
In total 17.28% (33 of total 191) of the pre-dialysis CKD elderly were classified as RS group; comparing to the NS group they were significantly older (81.73±6.23 years vs 75.30±5.97 years respectively, p0.001), with lower BMI (23.05±2.81 kg.m-2 vs 25.60±4.55 kg.m-2 respectively, p0.02), but showed no significant difference in their CKD stages, time since diagnosis or comorbidities, and neither difference in any of the renal function test results. The physical assessment found the RS group was significantly weaker in all muscle tested, and moved slower in performing the FTSST (20.58±7.36s) and TUG (19.45±7.43s) than the NS group (14.54±5.56s and 12.70±4.06s respectively, p0.005). Good classification accuracy could be generated with only 2 out of 5 parameters of physical features (TUG and FTSST, ACC=64.1%), or 7 out of 11 clinical features (eGFR, Cr, UCr, UPCR, Hb, HCT and TG; ACC=71.8%). When all features were pooled, the accuracy was largely improved (ACC=76.9%) with 11 parameters (all physical features, plus eGFR, UPro, UPCR, Hb, TC and LDL-C). The coefficients derived from the logistic regression model found UPCR (65.9%) and TUG (54.5%) were most impactful among all parameters in the prediction.
Old age, lower BMI, and poorer physical performance, were associated with higher risk of sarcopenia in pre-dialysis CKD. To best predict the risk of sarcopenia, combining 5 physical performance and 6 clinical renal function test would be the best, with UPCR and TUG as the best determinants.
Awareness of clinical lab data could add value to PTs' physical assessment and sarcopenia care for CKD.
CKD
Physical assessment
