Parâmetros lipídicos na população adulta brasileira: intervalos de referência, prevalência de hipercolesterolemia familiar e fatores associados

Abstract

The population diagnosis of dyslipidemia resulting from elevated levels of LDL-Cholesterol (LDL-Cholesterol) is essential for the prevention of cardiovascular disease. Determining proper reference intervals is important, because are influenced by biological variables such as race and ethnicity and differing between subpopulations. In Brazil, there are few studies on the population prevalence of increased LDL-Cholesterol and familial hypercholesterolemia and factors associated with these conditions. The aim of this research was to estimate reference intervals and factors associated with lipids parameters in the adult Brazilian population. This is a cross-sectional study with data from the National Health Survey, between 2014 and 2015, with 8,952 adults. To determine the associations between LDL-Cholesterol and sociodemographic, anthropometric, lifestyle, chronic disease and self-rated health variables, Poisson Regression models were used and prevalence ratios (PR) were calculated. Next, the population prevalence of possible cases of familial hypercholesterolemia and the factors associated with the disease were estimated. Prevalences and 95% confidence intervals (95%CI) were calculated and the logistic regression model was used to calculate the Odds Ratio (OR). To determine the reference intervals, the non-parametric method was adopted, considering the lower limits linked to the 2.5th percentile and the upper limit linked to the 97.5. Distribution percentiles from 1 to 99 were calculated. Lipid parameter values were compared with the Adult Treatment Panel study (ATP III). Differences were evaluated using the Mann Withney, Kruskal Wallis and Kolmogorov-Smirnov tests (p≤0.05). The results showed that the prevalence of increased LDL-Cholesterol was 18.58%. Factors positively associated with increased LDL-C were: age between 30 to 44 years (PR 1.99; 95%CI 1.58-2.54), 45 to 59 years (PR 2.89; 95%CI 2.29-3 .64) and 60 years or older (PR 2.90; 95%CI 2.29-3.68), living in the Northeast region (PR 1.16; 95%CI 1.02-1.32), being overweight (PR 1.32; 95%CI 1.15-1.51) and obesity (PR 1.41; 95%CI 1.19-1.65); and negatively, having anemia (PR 0.66; 95%CI 0.54-0.80). The prevalence of FH in adults in the country was 0.96%. Positively associated with FH, regular health self-assessment (OR 1.96; 95%CI 0.99-3.84) and poor or very bad (OR 3.02; 95%CI 1.30-7.03); and negatively, black race/color (OR 0.10; 95%CI 0.02-0.46) and having higher education, complete elementary education and incomplete high school (OR 0.47; 95%CI 0.23-0.98) and complete medium and more (OR 0.45; 95%CI 0.21-0.95). For reference intervals, women had higher concentrations of high-density lipoprotein (HDL-C) cholesterol levels (29-74 mg/dL) than men (25-67 mg/dL). In males, the reference intervals of total cholesterol (TC) and LDL-Cholesterol were higher after 60 years, (125-252 and 64-156 mg/dL) compared to 20 to 29 years (115-239 and 51-151 mg/dL), respectively. In women, TC and LDL-cholesterol parameters increased with age, 20-39 years: 118-248; 56-148; 40 to 59 years: 129-256; 58-165; 60 years or older:128.5-264; 59-172 mg/dL, respectively, and HDL-Cholesterol values were higher between 40-59 years (29-75 mg/dL) compared to 20-39 years (29-75 mg/dL) and in the breed /white color (29-75 mg/dL) compared to brown (29-73 mg/dL). The values of lipid parameters according to sex in this study were lower compared to ATP III (p ≤0.05). It is concluded that in Brazilian adults, increased LDL-Cholesterol is associated with aging, living in the Northeast region, having anemia, overweight and obesity. Familial hypercholesterolemia affects 1 in every 104 adults and was associated with self-assessment of regular and poor/very poor health, race/black color and education. Differences were evidenced for lipid parameters according to sex, age, race/color, reaffirming possible geographic and ethnic-rational influences on the analyzed analytes.