OBJECTIVE Diabetic nephropathy increases the risk of premature cardiovascular disease and sudden death, particularly in type 1 diabetic patients. One possible mechanism for this risk may be left ventricular hypertrophy. In our study, we aimed to evaluate left ventricular structure and function in normotensive type 1 diabetic patients with and without nephropathy.

RESEARCH DESIGN AND METHODS M-mode and Doppler echocardiography was performed in 17 type 1 diabetic patients with nephropathy (albuminuria [median (range)], 345 (135–2,846) mg/24 h) and compared with 34 normotensive, normoalbuminuric (10 [3–30] mg/24 h) type 1 diabetic patients matched for arterial blood pressure (mean ± SD) ([134/77] ± [13/7] vs. [129/78] ± [12/7] mmHg), age (40 ± 11 vs. 42 ± 10 years), duration of diabetes (28 ± 7 vs. 28 ± 6 years), and BMI (24.2 ± 4.2 vs. 24.6 ± 2.4 kg/m²).

RESULTS Left ventricular mass (LVM) index was significantly higher in patients with nephropathy compared with patients with normoalbuminuria (100.8 ± 10.3 vs. 88.2 ± 21.0 g/m², respectively; P = 0.02). Greater ventricular septum width was demonstrated in the nephropathic group compared with the control group (9.4 ± 1.0 vs. 8.2 ± 1.3 mm, respectively; P = 0.002). No significant difference in posterior wall thickness was apparent. The nephropathic group tended to have reduced diastolic function (E/A ratio, 1.2 ± 0.3 vs. 1.4 ± 0.4; P = 0.09). Fractional shortening was normal and about the same in the two groups. The groups did not differ with respect to serum creatinine or hemoglobin, while metabolic control (assessed by HbA_1c) and plasma renin and prorenin levels were elevated in the nephropathic group compared with the normoalbuminuric group.

CONCLUSIONS A blood pressure-independent increase in LVM may contribute to the increased cardiac morbidity and mortality in normotensive type 1 diabetic patients with diabetic nephropathy. Glycemic abnormalities and activation of the renin-angiotensin system may lead to the ventricular enlargement.