Absence of clinically overt atherosclerotic vascular disease and adverse changes in cardiovascular risk factors in 70 patients with insulinoma

Hyperinsulinemia has been assumed to contribute to the pathogenesis of atherosclerosis. To assess the reliability of such claim we planned a retrospective study on a cohort of patients with pancreatic insulin producing neoplasm. A correlation was sought between fasting insulin plasma levels and the metabolic profile emerging from those parameters known to be cardiovascular risk factors, i.e. plasma triglycerides and cholesterol, insulin resistance, hypertension. Special attention was paid to the duration of disease, because the time exposure to hyperinsulinemia could play an important role in developing cardiovascular disease. Seventy patients, 41 females and 29 males, aged 44.9 +/- 1.96 yr (range 15-80), with surgically proved insulinoma were included in the study. Chronic exposure to hyperinsulinemia was documented through the measurement of insulin plasma levels either in the fasting state or post-prandially, resulting in 44.7 +/- 3.28 and 149.9 +/- 12.22 microU/ml, respectively. Fasting glycemia in average was 45.3 +/- 1.34 mg/dl. Plasma triglycerides and cholesterol concentrations were 136.3 +/- 7.93 and 195.8 +/- 5.18 mg/dl, respectively, their distribution overlapping that anticipated for the general population. No correlation arose between the degree of hyperinsulinemia and the lipidic profile. Preoperative blood pressure was 136.9 +/- 2.87 mmHg, systolic and 81.9 +/- 1.32 mmHg, diastolic. Hypertension was present in 5 (7.1%) out of 70 patients and persisted after tumor removal. A condition of insulin resistance (M = 4.06 +/- 0.4 mg/kg min vs 7.41 +/- 0.21) was documented through the euglycemic hyperinsulinemic clamp technique in 20 patients and showed a positive and significant correlation with fasting insulinemia.(ABSTRACT TRUNCATED AT 250 WORDS)