The role of renal damage on cardiac remodeling in patients with diabetic nephropathy

Background: Cardiovascular damage and diabetic nephropathy are major complications in patients with Type 2 diabetic nephropathy (T2DN); however, the role of renal damage on cardiac remodeling is not yet fully known. Methods: A retrospective research was conducted in 254 T2DN patients. All were divided into three groups according to urinary albumin excretion (UAE): the normoalbuminuria group (UAE < 30 mg/g, n = 18), the microalbuminuria group (UAE 30 - 300 mg/g, n = 99) and the macroalbuminuria group (UAE >300 mg/g, n = 137). The parameters of cardiac remodeling, left atrial diameter (LAD), left ventricular diameter at the end of diastole (LVDd), interventricular septum (IVS), posterior wall of left ventricle (PWLV) and ejection fraction (EF), were determined by Doppler echocardiography. The effects of renal damage on cardiac remodeling were analyzed. Results: Among the 254 patients, LAD and LVDd enlargement was found in 180 (70.86%) and 53 (20.86%) patients, respectively; 46 cases (18.11%) suffered from both LAD and LVDd enlargement. Compared with normal LAD/LVDd groups, creatinine clearance (Ccr) and hemoglobin (Hb) were significantly lower in the left atrial (LA) and left ventricular (LV) dilated groups. LAD was positively correlated with mesangial sclerosis, tubular-interstitial lesions, interstitial fibrosis, as well as tubular basement membrane thickness (r = 0.273, 0.208, 0.176, 0.155, p < 0.05, respectively). Moreover, in comparison to patients with LA enlargement, more severe renal damage was detected in patients with LV enlargement. Conclusion: There is a strong correlation between echocardiographic parameters and kidney lesions in patients with T2DN in China; the more severe the renal damage, the more severe the cardiac structural alteration. Renal damage contributes to cardiac remodeling, which may provide new insights into the pathogenesis of cardiovascular complications in diabetes mellitus.