The D allele of angiotensin-converting enzyme polymorphism as a predictor of renal function decline over 4 years in an apparently healthy Chinese population aged 60 and older.

OBJECTIVES

To test the association between angiotensin-converting enzyme (ACE) insertion or deletion (I/D) polymorphism and decline of renal function in people aged 60 and older.

DESIGN

Population-based prospective study with 4-year follow-up.

SETTING

Department of Internal Medicine and Family Medicine, Kaohsiung Medical University (KMU) Hospital and Graduate Institute of Medicine and Public Health, KMU.

PARTICIPANTS

Of 1,500 people screened, 193 subjects were enrolled, and 144 completed 4 years of follow-up, 112 non-diabetic normotensive elderly people were analyzed.

MEASUREMENTS

Subjects received biochemistry examination at baseline and at 2- and 4-year follow-ups. Serum creatinine and calculated renal parameters, including the Cockroft-Gault (CG) formula, the Jelliffe formula, and the Modification of Diet in Renal Disease (MDRD) Study equation, were used. Genetic polymorphism was analyzed according to the polymerase chain reaction.

RESULTS

The mean age+/-standard deviation of the subjects was 71.9+/-3.7 (range 60-81). Serum creatinine, CG creatinine clearance (CrCl), Jelliffe CrCl, and MDRD glomerular filtration rate (GFR) were significantly lower at the 2- and 4-year follow-ups (all P < or = .001). At the 4-year follow-up, the magnitude of declines of the above four renal parameters was significantly higher in subjects with the ACE D allele than in the non-D-allele carriers (P = .01, .01, .04, and .01 for creatinine, CG CrCl, Jelliffe CrCl, and MDRD GFR, respectively). This association was still significant in multivariate analyses (P < or = .02 for all parameters).

CONCLUSION

This longitudinal study showed the ACE I/D gene polymorphism might modulate renal function decline in elderly Chinese. This provides further knowledge essential in the assessment of renal disease and determination of renal function in older Chinese.