Urine creatinine concentration and clinical outcomes in older adults: The Cardiovascular Health Study

• Published in: Journal of the American Geriatrics Society (JAGS) 2021-12, Vol.69 (12), p.3486-3496
• Main Authors: Barzilay, Joshua I., Buzkova, Petra, Shlipak, Michael G., Lyles, Mary F., Bansal, Nisha, Garimella, Pranav S., Ix, Joachim H., Kizer, Jorge R., Strotmeyer, Elsa S., Djousse, Luc, Biggs, Mary L., Siscovick, David, Mukamal, Kenneth J.
• Format: Article
• Language: English
• Subjects: Absorptiometry, Photon; Aged; Aged, 80 and over; Clinical outcomes; Creatinine; Creatinine - urine; Diabetes; Diabetes mellitus; Diabetes Mellitus - etiology; Dual energy X-ray absorptiometry; Female; Grasping; grip strength; Hand Strength; Health Surveys; Heart Disease Risk Factors; hospitalization; Hospitalization - statistics & numerical data; Humans; Independent Living - statistics & numerical data; lean muscle mass; Linear Models; Male; Mortality; Muscle, Skeletal - physiopathology; Muscular Atrophy - urine; Older people; Proportional Hazards Models; Risk Assessment; Standard deviation; Urine; urine creatinine
• ISSN: 0002-8614; 1532-5415
• DOI: 10.1111/jgs.17388

Purpose Loss of muscle mass and strength are associated with long‐term adverse health outcomes in older adults. Urine creatinine concentrations (Ucr; mg/dl) are a measure of muscle tissue mass and turnover. This study assessed the associations of a spot Ucr level with muscle mass and with risk of hospitalization, mortality, and diabetes mellitus in older adults. Methods We examined 3424 participants from the Cardiovascular Health Study who provided spot urine samples in 1996–1997 and who were followed through June 2015. All participants underwent baseline measurement of grip strength. In a sub‐cohort, 1331 participants underwent dual energy X‐ray absorptiometry (DEXA) scans, from which lean muscle mass was derived. Participants were followed for a median of 10 years for hospitalizations and mortality, and 9 years for diabetes mellitus. Results In linear regression analysis, a one standard deviation higher Ucr concentration (64.6 mg/dl) was associated with greater grip strength (kg force) β = 0.44 [0.16, 0.72]; p = 0.002) and higher lean muscle mass (kg) (β = 0.43 [0.08, 0.78]; p = 0.02). In Cox regression analyses, each standard deviation greater Ucr concentration was associated with lower rates of hospitalizations (0.94 [95% confidence interval, 0.90, 0.98]; p