Association of 2238T>C Polymorphism of the Atrial Natriuretic Peptide Gene With Coronary Artery Disease in Afro-Caribbeans With Type 2 Diabetes

BACKGROUND The atrial natriuretic peptide (ANP) is known mainly for its effects on kidney function and blood pressure homeostasis. We investigated the association between two ANP polymorphisms and pre-existing coronary artery disease (CAD) in patients of African descent with type 2 diabetes (T2D). METHODS We conducted a cross-sectional and retrospective study of 218 volunteer Afro-Caribbean patients with T2D. Two polymorphisms (rs5064, 708C>T; and rs5065, 2238T>C) of ANP were genotyped using PCR-restriction fragment length polymorphism analysis. ANCOVA, chi(2)-test, and logistic regression were used for statistical analysis. RESULTS Among these patients (92 men; 128 women), 67 (30.7%) had CAD, of whom 75% had had myocardial infarction. The frequency of rs5065-C carriers (TC/CC) was significantly lower in patients with CAD than in those without CAD (24 vs. 41%, P=0.01). The frequency of hypertension did not differ significantly according to genotype. Univariate logistic regression revealed that male sex, age, dyslipidemia, hypertension, and rs5065-C carrier status were associated significantly with CAD. After adjustment for the variables of interest, the odds ratio (ORs) of CAD for rs5065-C carriers (TC/CC) was 0.50 (0.26-0.96; P=0.038). No association was found between the rs5064 (708C>T) single-nucleotide polymorphisms (SNPs) and pre-existing CAD or cardiovascular risk factors. CONCLUSIONS The ANP rs5065 (2238T>C) C allele seems to exert a protective effect against CAD in T2D patients of African descent. The relevance of ANP polymorphisms for CAD should be determined in different populations.