Association between apolipoprotein E genetic polymorphism and the development of diabetic nephropathy in type 2 diabetic patients.
BACKGROUND
In recent studies, apolipoprotein E (apo E) genetic polymorphism in association with dyslipidemia have been proposed as the one of the risk factors for the development of diabetic nephropathy. We found that type 2 diabetic patients with microalbuminuria (MA) had higher plasma triglyceride levels than those with normoalbuminuria (NA) in our previous study. Therefore, we aimed for investigating the association among apo E genetic polymorphism, dyslipidemia and the development of diabetic nephropathy in type 2 diabetic patients.


METHODS
We included 58 subjects with normoalbuminuria and 36 subjects with microalbuminuria in analysis. They were all Korean and type 2 diabetic patients who had normal renal function, history of diabetes longer than 10 years and the data of urine albumin excretion rate at 10th year diabetes duration. Mean HbA1c, plasma total cholesterol and triglyceride levels for 10 years and several clinical characteristics were examined. Apo E genotypes were confirmed by real time PCR.


RESULTS
The frequency of e3/e4 genotype (20.7% versus 5.6%, p=0.045) and E4 carrier (22.8% versus 5.9%, p=0.035) was significantly higher in NA group than in MA group. On logistic regression analysis, crude odds ratio of E2 carrier and E4 carrier were 0.833 (95% CI: 0.245-2.833) and 0.205 (95% CI: 0.043-0.986), respectively. However, after adjusted by HbA1c, hypertension, total cholesterol and triglyceride, odds ratio of E2 carrier and E4 carrier were 0.664 (95% CI: 0.134-3.289) and 0.365 (95% CI: 0.061-2.187) and the association became weak. There were no correlation between apo E carrier and lipid profile. HbA1c (7.6+/-1.3% versus 7.0+/-0.9%, p=0.012) and mean creatinine (1.2+/-0.7 mg/dL versus 1.0+/-0.2mg/dL, p=0.004) levels were significantly higher in MA group than in NA group as expected.


CONCLUSIONS
These data suggest that E4 carrier might be associated with the protection for the development of diabetic nephropathy in type 2 diabetic patients without respect to dyslipidemia.
Kwon
Mi-Kwang
MK
Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
Rhee
Sang Youl
SY
Chon
Suk
S
Oh
Seungjoon
S
Woo
Jeong-taek
JT
Kim
Sung-Woon
SW
Kim
Jin-Woo
JW
Kim
Young Seol
YS
Jeong
Kyung-Hwan
KH
Lee
Sang-Ho
SH
Lee
Tae-won
TW
Ihm
Chun-Gyoo
CG
D000368:Aged; D001057:Apolipoproteins E / Q000235:genetics*; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000235:genetics*; D003928:Diabetic Nephropathies / Q000235:genetics*; D005260:Female; D006580:Genetic Carrier Screening; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012016:Reference Values; D014280:Triglycerides / Q000097:blood
D001057:Apolipoproteins E; D014280:Triglycerides; D002784:Cholesterol