Association between estimated glomerular filtration rate and asymmetric dimethylarginine concentrations among the elderly in a rural community

Abstract

Background: Reduction of glomerular filtration rate is one of common disorders in elderly people. The high concentrations of asymmetric dimethylarginine (ADMA) is also prevalent in the elderly and have been reported as a risk factor of cardiovascular disease (CVD). However, most of studies that examined the association between the two conditions were performed in patients with renal dysfunction, but not for general healthy population. Thus, this study investigated an association between eGFR and ADMA concentration among communitydwelling older Koreans.

Method: A cross-sectional study was conducted on 269 men and 382 women (mean age, 71.6 years) enrolled in the Korean Social Life, Health, and Aging Project (KSHAP), a population-based longitudinal study of health determinants in elderly Koreans. I classified participants into three statuses according to estimated glomerular filtration rate (eGFR) reduction: normal to minimally-reduced (≥60 mL/min/1.73m², n=198), moderatelyreduced (30-<60 mL/min/1.73m², n=407), and severely-reduced eGFR(<30 mL/min/1.73m², n=46). Plasma ADMA concentration was divided into two groups by 75 percentile. The association between eGFR reduction and ADMA elevation was analyzed by multivariable logistic regression models. A multiple linear regression analyses was performed to confirm the association of eGFR and ADMA concentrations in the general elderly after excluding severe eGFR reduction group.

Results: The mean ADMA level was significantly higher in the severely-reduced eGFR (0.715 ㎛ol/L, p=0.002) than in the normal to minimally-reduced eGFR reduction (0.659 ㎛ol/L). The negative association between eGFR and ADMA concentrations was significant in general participants, excluding those with severely-reduced eGFR (β=-0.0016, p<0.01). Compared to people with normal to minimally-reduced eGFR, the unadjusted odds ratio (OR) for having ADMA elevation (95% CI) was 2.4 (1.2-4.7) in people with the severelyreduced eGFR. Even after adjusting for sex, age, body mass index, blood pressure, total and HDL cholesterol, diabetes, smoking, and drinking, the adjusted OR for the ADMA elevation was 3.6 (1.5-8.9) in people with severely-reduced eGFR, compared with normal to minimally-reduced eGFR.

Conclusion: The findings of this study suggest that an inverse association between eGFR and ADMA concentrations among the Korean elderly in a rural community.