Association between apolipoprotein E genetic polymorphism and the development of microalbuminuria in type 2 diabetic patients

Kwon, Mikwang; Rhee, Sang Youl; Chon, Suk; Oh, Seungjoon; Woo, Jeong Taek; Kim, Sung Woon; Kim, Jin Woo; Kim, Young Seol

Abstract

BACKGROUND: Apo E genetic polymorphism has been proposed as the one of the risk factors for diabetic nephropathy. We studied the association between Apo E genetic polymorphism and the development of microalbuminuria, which is the early stage of diabetic nephropathy.
METHODS
Fifty eight subjects with normoalbuminuria and Thirty six subjects with microalbuminuria were enrolled. They were all type 2 diabetic patients who had normal renal function and a history of diabetes longer than a 10 years duration. We examined the mean HbA1c, total cholesterol and triglyceride levels for 10 years, and we also examined several clinical characteristics. We determined the Apo E genotype by performing real time PCR.
RESULTS
In the microalbuminuria group, compared with the normoalbuminuria group, the HbA1c (7.6+/-1.3% vs 7.0+/-0.9%, respectively, p=0.012) and mean creatinine (1.2+/-0.7 mg/dL vs 1.0+/-0.2 mg/dL, respectively, p=0.004) levels were significantly higher, and the frequencies of the e3/e4 genotype (5.6% vs 20.7%, respectively, p=0.045) and the E4 carriers (5.9% vs 22.8%, respectively, p=0.035) were significantly lower. On logistic regression analysis, the crude odds ratio of being an E2 carrier and being an E4 carrier were 0.833 (95% CI: 0.245-2.833) and 0.205 (95% CI: 0.043-0.986), respectively. However, the odds ratio after adjusted by HbA1c, hypertension, total cholesterol and triglyceride were 0.664 (95% CI: 0.134-3.289) and 0.365 (95% CI: 0.061-2.187), respectively. There were no correlations between being an Apo E carrier and the lipid levels in the healthy controls and diabetic patients.
CONCLUSIONS
Being an E4 carrier might play a role in protecting against the development of microalbuminuria in type 2 diabetic patients and there was no correlation among the Apo E genetic polymorphisms and the lipid levels.