Enhanced albuminuric response to atrial natriuretic peptide in normoalbuminuric patients with Type 1 diabetes mellitus – a pilot study

Abstract

ANP increases urine albumin excretion rate in normoalbuminuric Type 1 DM patients, and this effect is more pronounced than in healthy volunteers.

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

“…In humans, the albuminuric action of ANP was first reported in healthy individuals, who were infused with extremely high doses of the hormone [26], though subsequent studies in young controls failed to demonstrate a significant albuminuric response to intravenous infusions of low dose ANP [10,12]. Our data demonstrates a non-significant trend towards an albuminuric response to low dose ANP in an older control group.…”

“…The rises in urinary cGMP and urine sodium excretion were similar and there was an almost identical diuresis between the diabetic and control groups. Previous studies have shown either blunted or normal diuretic and natriuretic responses to ANP in type-1 diabetic patients [10,12,20]. We were careful to exclude patients with microalbuminuria, so our data clearly shows normal renal sensitivity to the natriuretic effects of ANP in type-2 diabetes in the absence of microalbuminuria.…”

“…Pretreatment of the rats with either antiserum to ANP, or an ANP receptor antagonist, reduced both the glomerular hyperfiltration and increased UAER that occurs after the onset of diabetes [8,13], suggesting that the rise in plasma concentrations of ANP caused the changes in renal haemodynamics. In humans, ANP increases UAER in both normoalbuminuric and microalbuminuric subjects with type-1 diabetes [10][11][12], as well as in non-diabetic patients with hypertension [21], nephrotic syndrome [22] or nephritic syndrome [23]. ANP appears therefore to accentuate abnormalities of glomerular permeability in a variety of conditions that are already associated with glomerular damage.…”

“…Log transformations were derived prior to conducting the analysis. The power calculation was based on data from previous work examining the albuminuric response to ANP in normoalbuminuric subjects with type-1 diabetes and controls [10]. One-sided-sample size calculations with a power of 80% were used.…”

“…The pathogenesis of microalbuminuria is multifactorial and hyperglycaemia [3], glomerular hyperfiltration [4], nitric oxide [5], angiotensin II [6], kinins [7], prostaglandins [8] and transforming growth factor-B [9] have all been shown to influence the rate of urinary albumin excretion. It has been hypothesised that ANP contributes to the development of microalbuminuria in type-1 diabetes, on the basis of human [10][11][12] and animal data [13], which has shown that ANP increases urine albumin excretion. However, the role of ANP in the development of microalbuminuria in type-2 diabetes is less well understood.…”