Hypertriglyceridemia is the second most common, although non–mandatory, criterion of metabolic syndrome. Despite the growing body of evidence about its independent impact on cardiovascular risk and mortality, currently this dyslipidemia is considered to be a factor of residual risk after low density lipoprotein (LDL) cholesterol and non-high density lipoprotein cholesterol. The purpose of the study was to elucidate peculiarities of clinical manifestations, metabolic disorders, and long–term cardiovascular complications in patients with coronary artery disease and metabolic syndrome. Materials and methods: totally 107 patients with established coronary artery disease and ≥ 3 criteria of metabolic syndrome underwent anthropometry, transthoracic echocardiography, abdominal ultrasonography, and laboratory tests, including lipid profile, HbA1c, and oral glucose tolerance test with parallel detection of serum insulin and C–peptide levels and calculation of insulin sensitivity indices. According to serum triglyceride levels <1.7 and ≥1.7 mmol/L patients were divided into group 1 (n=49, 28 men, 21 women) and group 2 (n=58 with mail–to–female ratio 1:1; 35 cases of mild and 23 cases of moderate hypertriglyceridemia). Fisher’s exact test or Mann–Whitney U–test was used to compare the groups. The survival was analyzed by Kaplan–Meier’s method with calculation of cumulative proportion surviving, using Cox’s F–test for comparison; p values <0.05 were considered significant. Results and discussion. The prevalence of atrial fibrillation and atrioventricular regurgitation was more common among group 1 patients (24.5% vs. 10.3%, p=0.07 and 59.2% vs. 32.7%, p=0.007, respectively). Higher levels of Log (triglyceride / high density lipoprotein cholesterol), lipid accumulation product (both p <0.0001), fasting insulin and C–peptide levels (p <0.003), glycaemia in all points of oral glucose tolerance test (p<0.02), and HOMA index (p <0.002), but lower median values of Matsuda and deFronzo indices (p <0.005), as well as higher prevalence of liver steatosis (81% vs. 55%, p = 0.01) and gallbladder abnormalities (55.2% vs. 34.7%, p = 0.051) were observed in group 2 patients. Surgical menopause due to prior hysterovariectomy was observed in 55.2% of women in group 2 vs. 34.7% in group 1 (p = 0.018). During the period of observation, 27 new cases of diabetes were detected (23.8% in group 1 and 41.5% in group 2; cumulative proportion surviving 72.8% and 35.4%, respectively, p=0.039). Despite the long–term atorvastatin therapy at daily doses of 20–40 mg, 53 cases of hospitalizations due to acute coronary syndrome, heart failure or paroxysmal arrhythmias were documented during 50–months follow–up period, three of which were fatal (30.6% in group 1 and 65.5% in group 2), cumulative proportion surviving were 69.0% and 30.7%, respectively (p=0.0002). Furthermore, among patients with hypertriglyceridemia cardiovascular events appeared even in individuals with LDL-cholesterol levels <1.8 mmol/L. Conclusions. Patients with lower serum lipid levels were more likely to develop dilatation of cardiac chambers that explains higher prevalence of both atrial fibrillation and atrioventricular regurgitation. Hypertriglyceridemia was associated with fasting hyperinsulinemia and impaired postprandial insulin secretion, more severe hyperglycaemia, and lower tissue insulin sensitivity that explain higher risk of diabetes. In combination with qualitative lipid abnormalities (e.g., predominance of small dense LDL particles) and ectopic lipid deposition, these metabolic disorders predispose to typical comorbidity, i.e., liver steatosis, biliary sludge and increased bile lithogenicity. In women, hypertriglyceridemia often resulted from hysterovariectomy. Despite statin therapy with achievement of LDL-cholesterol levels <1.8 mmol/L, patients with hypertriglyceridemia had a higher risk of cardiovascular complications.
Full text: PDF (Ukr) 322K