Predictive value of serum NT-proBNP levels in type 2 diabetic people with diabetic nephropathy

Abstract

Objective: The serum N-terminal fragment of pro brain natriuretic peptide (NT-proBNP) level in type 2 diabetic subjects with or without diabetic nephropathy (DN) is still unclear. We aimed to evaluate the relationship between serum NT-proBNP levels and different stages of diabetic nephropathy, and identify probable factors predicting serum NT-proBNP level.

Subjects and methods: This cross-sectional study included 20 normoalbuminuric (Group-I), 28 microalbuminuric (Group-II), 20 macroalbuminuric type 2 diabetic patients (Group-III), and 20 healthy volunteers (Group-IV). Serum NT-proBNP levels were measured with highly sensitive and specific immunoassay.

Results: Mean NT-proBNP levels were 32 ± 55, 91 ± 95, 331 ± 297, 42 ± 34 pg/ml for Groups I-IV, respectively. When patients with LVH were excluded, mean logNT-proBNP was still significantly higher in Group-III than all other groups. The three diabetic groups were similar in age, BMI, HbA1c, fasting serum glucose, and GFR. In a multivariate linear regression model, adjusting for factors significantly correlated with NT-proBNP levels, the patient group, presence of LVH, and hemoglobin remained as an independent predictor of serum NT-proBNP. These variables explained 68% of the variability of NT-proBNP (adjusted R(2)=0.683).

Conclusions: Mean serum NT-proBNP level of macroalbuminuric diabetic patients was higher than normoalbuminuric and microalbuminuric diabetic patients, and healthy control subjects even after exclusion of LVH. NT-proBNP may be a useful and predictive marker of diabetic nephropathy.