Prevalence of left ventricular hypertrophy in Type I diabetic patients with diabetic nephropathy

The increased mortality of patients with diabetic nephropathy is mainly due to cardiovascular disease and end stage renal failure. Left ventricular hypertrophy is an independent risk factor for myocardial ischaemia and sudden death. The aim of our cross-sectional study was to evaluate left ventricular structure and function in Type I (insulin-dependent) diabetic patients with diabetic nephropathy. M-mode and Doppler echocardiography were done on 105 Type I diabetic patients with diabetic nephropathy [61 men, age (means +/- SD) 44+/-9 years, and albuminuria [median(range)] 567(10-8188) mg/24 h, serum creatinine 109 (53-558) micromol/l], and 140 Type I diabetic patients with persistent normoalbuminuria [79 men, 47+/-10 years, urinary albumin excretion rate 8 (0-30) mg/24 h, and serum creatinine 81 (55-121) micromol/l]. Patients with and without nephropathy were comparable with respect to sex, body mass index, and duration of diabetes. Arterial blood pressure was slightly higher in patients with nephropathy: 140/79 +/- 17/9 mm Hg vs 134/78 +/- 15/8 mm Hg, p < 0.01, and the majority of proteinuric patients received antihypertensive drugs, 84 vs 17 %, respectively, p < 0.001. Left ventricular mass index was increased in the nephropathic group (means +/- SD) 100.6+/-23.9 g/m2 compared with the normoalbuminuric group 91.4+/-21.9 g/m2, p = 0.002. Left ventricular hypertrophy was found more often in patients with nephropathy 23 (14-31)% compared with patients with normoalbuminuria 9 (5-14)%, p < 0.005. Diastolic function, assessed by the ratio between the peak diastolic velocity and the peak atrial systolic velocity (E/A ratio) and isovolumic relaxation time, was reduced in patients with vs without nephropathy: 1.17+/-0.29 vs 1.34+/-0.32, and 81.7+/-16.5 vs 74.6+/-14.5, p < 0.001 and p = 0.002, respectively. Systolic function was about the same and normal in both groups. Our study suggests that an increase in left ventricular mass index and a decrease in diastolic function occurs early in the course of diabetic nephropathy.