Abstract P098: Slower Gait Speed is Associated with Increased Mortality Risk in Chronic Kidney Disease.

Abstract

Objective: Skeletal muscle dysfunction (sarcopenia) is an under-recognized complication of chronic kidney disease (CKD) that may have important clinical consequences. Gait speed is associated with sarcopenia and comorbid disease burden among older adults; however, little is known about the prognostic significance of gait speed in CKD. We determined the association of gait speed with all-cause mortality in a prospective cohort of non-dialysis CKD patients. Methods: We measured usual gait speed over 4-meters in 309 participants from a prospective study of non-dialysis CKD. Included subjects had an estimated glomerular filtration rate (eGFR ckdepi ) <90mL/min/1.73m 2 , were stroke-free and did not require a wheelchair for ambulation. Study coordinators assessed mortality during follow-up by phone contacts, medical record review, and the social security death index. We evaluated gait speed continuously, and using a cut point of 0.8 m/s, consistent with previous studies. We used Cox's proportional hazards to estimate the association of gait speed with mortality after adjustment for age, sex, race, smoking, diabetes, pre-existing CAD, BMI, eGFR and hemoglobin. Results: Median follow-up time was 2.7 years; range 27 days to 4.8 years. The mean age was 58.9 ± 13 years and mean eGFR by cystatin C (eGFR cysc ) was 48.5 ± 23mL/min/1.73m 2 . There were a total of 31 deaths (10.4%) during follow-up. Unadjusted mortality rates were 23 and 80 deaths per 1,000 person-years among participants who had a gait speed of >0.8m/s versus ≤0.8m/s, respectively. After full adjustment, gait speed ≤0.8m/s was associated with a 2.8-fold greater risk of death compared to a gait speed >0.8 m/s. Gait speed was also strongly associated with mortality when analyzed as a continuous variable ( Table ) and a stronger predictor of death than age, history of CAD, or diabetes. No. Deaths (%) Model 1 + Model 2 # Hazard Ratio 95% CI Hazard Ratio 95% CI Gait speed * 32(10) 0.74 (0.64-0.86) 0.75 (0.64-0.87) >0.8m/s 13 (6) Reference Reference ≤0.8m/s 19(19) 3.49 (1.54-7.95) 2.84 (1.25-6.48) * Gait speed analyzed continuously per 10cm/s increase in speed. +Model 1: Adjusted for age, sex, race, study site #Model 2: adds smoking, BMI, eGFR cysc , diabetes, prevalent coronary disease. Conclusion: Gait speed is strongly associated with death in a cohort of middle-aged CKD patients.