Atrial natriuretic peptide increases urinary albumin excretion in people with normoalbuminuric type-2 diabetes

Background  Atrial natriuretic peptide (ANP) is elevated in patients with type-2 diabetes and microalbuminuria. The purpose of this study is to evaluate if ANP increases Urinary Albumin Eaxcretion Rate (UAER) in type-2 diabetes. Methods  Eight normoalbuminuric diabetic subjects underwent a randomised single blind study of 60 min intravenous infusion of ANP or vehicle. Eight non-diabetic controls underwent ANP infusion alone. Seven normoalbuminuric type-2 diabetes subjects received further ANP infusions during euglycaemia and during hyperglycaemia. Results  ANP increased urinary sodium (191.3 ± 80.7 to 529.2 ± 263.4 μmol/min, mean ± SD, and P < 0.001) and UAER (72.2 ± 73.4 to 224.9 ± 182.9.5 μg/min, and P < 0.01) in diabetic subjects. In controls, UAER did not change significantly (P = 0.16); however, the natriuretic response to ANP was similar to diabetic subjects (P = 0.98). Hyperglycaemic did not enhance the albuminuric response to ANP (P = 0.88). Conclusion  ANP increases UAER in normoalbuminuric type-2 diabetic subjects.