Cardiac hyperfunction in insulin-dependent diabetic patients developing microvascular complications

Cardiac function was studied by echocardiography in 80 insulin-dependent diabetic patients with no signs of ischemic heart disease and in 40 healthy control subjects. Echocardiographic findings were related to the urinary albumin excretion rate (UAE). In the diabetes group, fractional shortening of the left ventricle (FS) was 37.3% versus 34.3% (P less than .01) in the control group, whereas indices of preload and afterload were at the same levels as in control subjects. In diabetic patients with preclinical nephropathy (UAE 20-200 micrograms/min), FS was 41.1% compared to 37.0% (P less than .002) in patients with no signs of nephropathy (UAE less than 20 micrograms/min) and 34.8% (P less than .001) in patients with clinical nephropathy (UAE less than 200 micrograms/min). Furthermore, in patients with preclinical nephropathy, afterload was significantly decreased, whereas preload was at the same level as in the other two groups of UAE. In conclusion, a condition of cardiac hyperfunction has been found in diabetic patients with no signs of ischemic heart disease and seems pronounced in diabetic patients developing microvascular disease (patients with preclinical nephropathy), probably secondarily to a condition of hyperperfusion in these patients.