Persistence of Increased Cardiovascular Risk in Patients with Cushing's Disease after Five Years of Successful Cure

Abstract

Patients with Cushing's disease (CD) mainly die because of cardiovascular accidents. The aim of this study was to evaluate whether patients with CD still have increased cardiovascular risk and suffer from premature atherosclerosis once cured. Fifteen patients cured from CD for a long term period (5 yr), 30 sex-and age-matched controls, and 30 body mass index (BMI)-matched controls were included in this study. BMI; waist to hip ratio (WHR); systolic (SBP) and diastolic (DBP) blood pressures; serum total, low density lipoprotein (LDL), and high density lipoprotein (HDL) cholesterol; serum triglycerides, fibrinogen, and lipoprotein(a) levels; prothrombin time; activated partial thromboplastine time; and basal and glucose load-stimulated insulin and glucose levels were measured in patients and controls. By echo-Doppler ultrasonography, the intima media thickness (IMT), systolic and diastolic media-media distances, blood systolic (SPV) and diastolic (DPV) peak velocity, systolic (SLD) and diastolic (DLD) lumen diameter, and distensibility coefficient (DC) were measured at both common carotid arteries where the presence, size, and location of atherosclerotic plaques were also evaluated. Compared with a sex- and age-matched control population, CD patients had BMI (P < 0.001), WHR (P < 0.001), SBP (P < 0.005), DBP (P < 0.05), fasting glucose (P < 0.001) and insulin (P < 0.05), glucose load-stimulated glucose and insulin levels (P < 0.05), total cholesterol (P < 0.05), LDL cholesterol (P < 0.01), fibrinogen (P < 0.01), and lipoprotein(a) (P < 0.05) levels higher and HDL cholesterol levels (P < 0.05) lower than controls. At ultrasonography, in the patients, IMT (P < 0.05), SPV (P < 0.05) and DPV (P < 0.001) were significantly increased whereas SLD (P < 0.001), DLD (P < 0.001), and DC (P < 0.05) were significantly decreased compared to controls. In addition, CD patients had higher WHR (P < 0.05), DBP (P < 0.05), glucose load-stimulated glucose and insulin levels (P < 0.05), and fibrinogen levels (P < 0.01) and lower HDL cholesterol (P < 0.05) levels than BMI-matched controls. At ultrasonography, increased common carotid arteries IMT (P < 0.05) and DPV (P < 0.05) and decreased DLD (P < 0.05) and DC (P < 0.05) were measured in patients compared to those in BMI-matched controls. Atherosclerotic plaques were found in 26.7% of patients, in none of the sex- and age-matched controls, and in 3.3% of the BMI-matched controls. In CD patients, a significant correlation was found between both WHR and fasting serum insulin levels and DBP (r = 0.52 and r = 0.55; P < 0.05), triglycerides levels (r = 0.56 and r = 0.77; P < 0.05), and IMT (r = 0.64 and r = 0.56; P < 0.05). Right (r = -0.70; P < 0.005) and left (r = -0.65; P < 0.01) DC were inversely correlated to the duration of CD in the patient group. At the multiple regression analysis, WHR was the best predictor of fasting insulin levels (beta = 0.77; P < 0.05), and vice versa, fasting insulin level was the best predictor of WHR (beta = 1.20; P < 0.05). In conclusion, patients cured from CD for a long term period have a high prevalence of atherosclerosis and maintain increased several cardiovascular risk factors of the active disease, probably due to a residual abdominal obesity and/or insulin resistance syndrome.