A POLYMORPHISM IN THE GENE FOR THE ATRIAL-NATRIURETIC-PEPTIDE AND DIABETIC NEPHROPATHY

Background. Atrial natriuretic peptide is involved in blood pressure r egulation via its vasodilating and natriuretic actions. Since diabetic nephropathy and hyper tension are closely related, ANP is a reasonabl e candidate gene for diabetic nephropathy (DN). Methods. We genotyped 410 patients with type I diabetes (without DN n = 307; with DN n = 103 ) and 658 patients with type II diabetes (without DN n = 464; with DN n = 194). In the patients the duration of diabetes was at least 10 yea rs, Diabetic nephropathy was defined as urinary albumin excretion of g reater than or equal to 30 mg/24 h. The HpaII polymorphism in intron 2 of the ANP gene was determined using PCR amplification followed by re striction digest. Alleles were separated on agarose gels stained with ethidium bromide. Results. We compared genotype distribution and aliel e frequencies between patients with and without nephropathy. No signif icant difference was observed either in type I (allele frequency witho ut DN H1, 0.02/H2, 0.98 vs with DN I-Il, 0.05/H2, 0.95; P = 0.132) or in type II diabetes (allele frequency without DN I-Il, 0.04/H2, 0.96 v s with DN H1, 0.05/H2, 0.95; P = 0.551). Conclusions. The polymorphism in the gene for the atrial natriuretic peptide does not seem to play a major role in the development of diabetic nephropathy in either type I or in type II diabetes.