Improvement of left ventricular function after starting insulin treatment in patients with non-insulin-dependent diabetes.

ABSTRACT

Left ventricular function was evaluated noninvasively before and three months after starting insulin treatment in nine patients (mean age 61.8 years, range 51-68 years) with non-insulin dependent diabetes showing an impaired insulin secretion capacity. After starting insulin treatment, fasting blood glucose decreased from 12.9 +/- 0.5 mmol/l (mean +/- SEM) to 9.8 +/- 1.2 mmol/l (p = 0.03), but the decrease of glycosylated haemoglobin Alc was not significant (9.0 +/- 0.4% vs. 8.3 +/- 0.6%). On systolic time intervals, PEP/LVET ratio improved from 0.44 +/- 0.03 to 0.37 +/- 0.02 (p = 0.03). On M-mode echocardiography, E-F slope became steeper (89 +/- 6 mm/sec vs. 103 +/- 8 mm/sec; p = 0.01) but no significant changes were observed in other variables reflecting diastolic or systolic function. On equilibrium radionuclide angiocardiography, the left ventricular ejection fraction at rest was similar before and after starting insulin treatment (48.6 +/- 3.2% vs. 49.2 +/- 2.8%) but during peak exercise the left ventricular ejection fraction improved significantly (51.0 +/- 5.3% vs. 59.9 +/- 4.7%; p = 0.02). The change of PEP/LVET ratio correlated significantly with the changes of blood glucose and glycosylated haemoglobin Alc levels, but the correlation between these metabolic variables and the change of left ventricular ejection fraction during exercise did not reach statistical significance. In conclusion, the left ventricular function improved concomitantly with improved metabolic control after starting insulin treatment in middle-aged patients with non-insulin-dependent diabetes having an impairment in insulin secretion capacity. This finding suggests that metabolic factors are involved in the left ventricular dysfunction observed in diabetes.