@article {8825, title = {Urine creatinine concentration and clinical outcomes in older adults: The Cardiovascular Health Study.}, journal = {J Am Geriatr Soc}, year = {2021}, month = {2021 Aug 07}, abstract = {

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 < 0.001) and lower mortality risk (0.92 [0.88, 0.97]; p < 0.001), while a one standard deviation increase in muscle mass derived from DEXA had no such significant association. Ucr levels were not associated with incident diabetes mellitus risk (0.97 [0.85, 1.11]; p~=~0.65).

CONCLUSION: A higher spot Ucr concentration was favorably associated with muscle mass and strength and with health outcomes in older community-living adults. The ease of obtaining a spot Ucr makes it an attractive analyte to use for gauging the health of older adults.

}, issn = {1532-5415}, doi = {10.1111/jgs.17388}, author = {Barzilay, Joshua I and B{\r u}zkov{\'a}, Petra and Shlipak, Michael G and Lyles, Mary F and Bansal, Nisha and Garimella, Pranav S and Ix, Joachim H and Kizer, Jorge R and Strotmeyer, Elsa S and Djouss{\'e}, Luc and Biggs, Mary L and Siscovick, David and Mukamal, Kenneth J} }