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Objective: ATP binding cassette transporter A1 (ABCA1) controls the reverse cholesterol transport. Some ABCA1 variants are correlated with serum high-density lipoprotein cholesterol (HDL-C) and other lipid concentrations. We aimed to explore the relationship of ABCA1 gene with both the lipid profile and coronary heart disease (CHD) risk. Methods: Selected 627 individuals of the Turkish Adult Risk Factor Study were genotyped for ABCA1 R219K polymorphism using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) method. Student's t-test, one-way ANOVA, Chi-square test, linear and logistic regression was used for statistical analysis. Results: We demonstrated a gender-specific effect of the R219K polymorphism on plasma lipids and CHD. In men, while homozygosity of the K allele was associated with increased plasma low-density lipoprotein cholesterol (LDL-C) (p<0.05) and total cholesterol concentrations (p<0.05), carriage of this allele was associated with higher HDL-C concentrations (p<0.05) after adjustment for associated risk factors, but not with CHD. In women, however, without being related to HDL-C levels, each 219K allele was associated with 10% higher triglycerides (TG) concentrations (p<0.05). R219K heterozygosity in women independently doubled (95% CI 1.00; 3.80) the odds ratio for CHD risk in regression models, after adjustment for several variables. Interaction of TG elevation (>140 mg/dL) with CHD was demonstrated in female 219RK genotype carriers. Conclusion: R219 allele of the ABCA1 gene independently confers CHD risk in heterozygote Turkish women, not via reduced HDL-C, but interacting with elevated TG expressed by the 219K allele, but not in men. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relative roles of serum apolipoprotein (apo) B and low density lipoprotein (LDL)-cholesterol levels in predicting incident coronary heart disease (CHD). Whether apo B/apo A-I ratio has advantage over apo B in this prediction constitutes a secondary aim. Methods: Prospective evaluation of 1138 men and 1210 women, aged 28–74 years participating in the TEKHARF survey 1997/98 with a mean 5.9-years' follow-up in whom serum apo B was determined. Tertiles of LDL-cholesterol were formed by cut points of 130 and 100 mg/dl, and of apo B by 120 and 95 mg/dl. Metabolic syndrome was defined by modified ATPIII criteria. Nonfatal CHD diagnosis was based on history of angina and myocardial revascularization, physical examination of the cardiovascular system and Minnesota coding of resting electrocardiograms. Results: Apolipoprotein B showed significant correlations with a greater number of parameters than did LDL-cholesterol. Incident CHD was not significantly predicted in age-adjusted logistic regression by LDL-cholesterol but by apo B concentrations in men with a relative risk (RR) 1.005. Apolipoprotein B level >120 vs <95 mg/dl retained significance in both genders combined, even after adjustment for waist girth and log C-reactive protein. The top (>1.02) compared with the bottom bracket of apo B/A-I ratio, though not reaching significantly predictive values among women, did significantly predict in men incident CHD with a RR 1.89. Conclusions: Apolipoprotein B, which marks small, dense LDL particles in plasma is a better predictor of incident CHD than LDL-cholesterol among Turkish adults. While in the prediction of CHD apo B level should be preferred in women, an apo B/A-I ratio >1.02 has advantages over the latter in men. It is time to create the environment (at least in our cities) for measuring in equipped laboratories apo B, which has advantages over measurements that permit calculation of LDL-cholesterol. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the relative values in the prediction of type 2 diabetes and coronary heart disease (CHD) by the metabolic syndrome (MS) as defined by the ATPIII and by its modification of the Turkish Adult Risk Factor Study (TEKHARF-def) and selection of most appropriate definition. Methods: Prospective evaluation of 1683 men and 1718 women, aged ≥28 years participating in the TEKHARF study surveys 1997/98 and 2002/03 with a mean follow-up of 5.9 years. The modification involved especially abdominal obesity (≥95 cm in men, ≥91 cm in women). Results: After exclusion of participants with diabetes at baseline and adjustment for sex and age, both MS definitions predicted the development of diabetes with virtually identical relative risks (RR) (ATPIII 2.85 [95%CI 2.14; 3.80]; TEKHARF 2.84 [95%CI 2.13; 3.81]. After similar exclusion and adjustments, both MS definitions predicted significantly the development of CHD with similar RRs (ATPIII 2.10 [95%CI 1.64; 2.68] in 36% of the cohort; TEKHARF-def 1.90 [95%CI 1.49; 2.43] in 39.6% of the cohort. For both outcomes, the TEKHARF-def provided higher predictive values in men, and (because of the high density lipoprotein (HDL)-cholesterol cutoff) the ATPIII definition in women. Absolute annual CHD risk in individuals with MS exceeded on average 2%, while age ≥50 years constituted the most appropriate indicator of further elevated risk in both genders. Most suitable modifications of the ATPIII definition are proved to be impaired fasting glucose (IFG) ≥100 mg/dl and in men ≥95 cm of waist circumference. Most CHD cases afŞicting Turkish adults (namely 61% in men and 69% in women) originated from the latter definition of MS. Conclusions: In predicting diabetes and CHD risk, the TEKHARF-def MS is more valuable in men; the ATPIII definition modified for IFG (≥100 mg/dl) should be adopted in women. In 2 out of every 3 cases, CHD originates from MS among Turks, and age ≥50 years is a good indicator of higher risk in both genders. [ABSTRACT FROM AUTHOR]