Creatinine Clearance, Walking Speed, and Muscle Atrophy: A Cohort Study

Abstract

Background Chronic kidney disease (CKD) is associated with malnutrition and inflammation. These processes may lead to loss of skeletal muscle and reduced physical performance. Associations of kidney function with muscle composition and longitudinal measures of physical performance are unknown. Study Design Prospective cohort study. Setting & Participants We evaluated 826 community-dwelling older adults enrolled in the Invecchiare in Chianti (InCHIANTI) Study free of baseline stroke or activities of daily living disability. Predictor Baseline creatinine clearance (Clcr) based on a 24-hour urine collection. Outcomes Cross-sectional and longitudinal trajectories of physical performance measured by 7-meter usual gait speed, 400-meter fast gait speed, and knee extension strength using isometric dynamometry. Calf muscle composition assessed by quantitative CT. Results Mean age of participants was 74 ± 7 (SD) years with 183 having Clcr < 60ml/min/1.73m2. After adjustment each 10ml/min/1.73m2 decrement in Clcr was associated with 0.01 (95% CI, 0.004–0.017) m/s slower 7-meter usual walking speed and 0.008 (95% CI, 0.002–0.014) m/s slower 400-meter walking speed. Each 10 ml/min/1.73m2 decrement in Clcr was associated with 28mm2 (95% CI, 0.8–55) lower muscle area and 0.15mg/cm3 (95% CI, 0.04–0.26) lower muscle density. After adjustment, lower Clcr was associated with slower mean 7-meter (P=0.005) and 400-meter (P=0.02) walk and knee extension strength (P=0.001) over the course of follow-up. Over a mean follow-up of 7.1 ±2.5 years, each 10 ml/min/1.73m2 lower baseline Clcr was associated with 0.024 (95% CI, 0.01–0.037) kg/year greater decline in knee strength. Limitations Single baseline measurement of Clcr and 3-year interval between follow-up visits may lead to non-differential misclassification and attenuation of estimates. Conclusions: Among older adults, lower Clcr is associated with muscle atrophy, reduced walking speed and more rapid declines in lower extremity strength over time.

Visit-to-visit blood pressure variability and future functional decline in old age

“…Furthermore, higher BPV has been longitudinally associated with deterioration of kidney function [39][40][41]. Diminished kidney function, even within the normal range, has been associated with muscle atrophy, reduced walking speed and steeper decline in lower-extremity strength in older adults [42]. Nonetheless, evidence from observational studies cannot prove a causal relationship between BPV and subclinical cardiac and kidney damage.…”

“…We measured functional status at 18 months, after the assessment of BPV, and subsequently at 30,36,39,42,45 or 48 months. Functional decline in ADL and IADL was defined as the difference between the last measured score and the score at 18 months, divided by the time interval.…”

Association of Muscle Endurance, Fatigability, and Strength With Functional Limitation and Mortality in the Health Aging and Body Composition Study

“…Standard encouragement was provided during the test. We defined maximal isometric strength as the maximum value from the three trials as per previous analyses (6,7,12). The isometric test was specifically designed to measure maximal quadriceps strength.…”

Gait Speed in Patients With Kidney Failure Treated With Long-term Dialysis

“…Studies of community-dwelling older adults have indicated that lower kidney function was associated with lower ambulatory muscle density, slower gait speed, 11 and faster declines in ambulatory muscle strength over time. 13 Patients with stages 2 to 4 CKD had substantially diminished lower-extremity physical performance compared to the general population. 14 Regardless of the test, patients with CKD who had worse lower-extremity physical performance were at substantially increased risk of death and dialysis therapy initiation even after accounting for demographics and comorbid conditions.…”