Age-related change in kidney function, its influencing factors, and association with asymptomatic carotid atherosclerosis in healthy individuals-A 5-year follow-up study

Objectives: To better define the longitudinal changes in renal function, to examine the associated risk factors, and to investigate whether there is an independent association of decline in renal function with presence of carotid plaque in a middle-aged and elderly healthy population. Methods: 245 healthy individuals (98 males, 147 females) evaluated at baseline and 5 years later. Results: Over five years, estimated glomerular filtration rate (eGFR) decreased from 98.1 +/- 15.6 to 90.4 +/- 17.3 mL/min/1.73 m(2). There are three kinds of change in eGFR (elevated, stable and decreased) during follow-up, accounting for 14%, 29% and 57%, respectively. Multivariate analysis of cross-sectional data showed that gender, age, and serum uric acid (UA) were major factors which consistently affected eGFR at both baseline and follow-up, and that higher systolic blood pressure (SBP) and presence of plaque were involved in lower eGFR at the follow-up point. In longitudinal analysis, five baseline factors - age, SBP, low-density lipoprotein cholesterol (LDL-C), serum transferrin (TRF) and eGFR - independently predicted a greater variability in renal function. In addition, presence of plaque was an independent risk factor for a faster decline of eGFR. Conclusions: Cross-sectional analysis demonstrates that renal function declines with increasing age. However, 43% of participants did not experience a decline in eGFR during follow-up. Besides older age and higher initial eGFR, presence of atherosclerotic carotid plaque, higher SBP, higher LDL-C and lower TRF are independent risk factors to predict a rapid decline of renal function in the healthy Chinese population. (c) 2012 Elsevier Ireland Ltd. All rights reserved.