The Association Between NT ‐Pro BNP , Nephropathy and Endothelial Dysfunction in Patients With Type 2 Diabetes Mellitus

BACKGROUND: N-terminal pro-B-type natriuretic peptide (NT-Pro BNP) is an established biomarker of heart failure and has been recommended for cardiovascular risk stratification in type 2 diabetes mellitus (T2DM). However, its relationship with diabetic nephropathy and endothelial dysfunction across varying stages of kidney impairment remains unclear. This study examined the associations of NT-Pro BNP, renal impairment, albuminuria and endothelial dysfunction in patients with T2DM without overt heart failure. METHODS: ). NT-Pro BNP was considered abnormal at a cut-off of ≥ 125 pg/mL. Albuminuria was categorized using the urinary albumin-to-creatinine ratio (uACR). Endothelial function was assessed by brachial artery flow-mediated dilatation (FMD). Logistic regression analysis was performed to identify independent factors of elevated NT-Pro BNP, with p-values < 0.05 considered statistically significant. RESULTS: NT-Pro BNP levels were significantly higher in the lower eGFR groups compared with normal eGFR (204.3 vs. 96.8 vs. 62.2 pg/mL, p < 0001). A weak but significant positive correlation was observed between NT-Pro BNP and uACR (r = 0.31, p < 0.001). However, no significant association was found between NT-Pro BNP and FMD (p = 0.388). Following multivariable adjustments, older age (adjusted OR 1.14, 95% CI: 1.06-1.23, p < 0.001), higher systolic blood pressure (adjusted OR 1.05, 95% CI: 1.02-1.08, p = 0.010), lower eGFR (adjusted OR 0.97, 95% CI: 0.95-0.99, p = 0.003) and beta-blocker use (adjusted OR 4.65, 95% CI: 1.61-13.45, p < 0.001) were independently associated with elevated NT-Pro BNP. CONCLUSION: In patients with T2DM without overt heart failure, elevated NT-Pro BNP showed a statistically significant association with lower eGFR and higher albuminuria. Moderate to severe albuminuria becomes an independent factor for elevated NT-Pro BNP after adjustment excluding eGFR. The lack of association with endothelial dysfunction suggests that NT-Pro BNP may reflect different pathophysiological pathways. NT-Pro BNP may serve as a useful biomarker for early cardiovascular risk stratification and identification of individuals at risk of pre-heart failure in diabetic kidney disease.