Relationship between TSH Levels and the Advanced Lipoprotein Profile in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

PURPOSE/AIMS: The relationship between thyroid-stimulating hormone (TSH) and lipoprotein subfractions by Vertical Auto Profile (VAP) is unclear. We aimed to evaluate lipoprotein profiles according to TSH levels in euthyroid individuals.Material and Methods: Cross-sectional analysis of 3,525 participants from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) with no previous thyroid disease and who were not on lipid-lowering medication. Total-cholesterol and its fractions, lipoprotein subfractions, triglycerides, and triglyceride-rich lipoprotein cholesterol [TRL-C (VLDL1+2-C, VLDL3-C, IDL-C)] were determined by VAP. Associations between TSH quintiles and lipoprotein subfractions were evaluated by crude and adjusted linear regression models.Results: For the total sample, significant beta-coefficients in full adjusted models for the 5th quintile of TSH (compared to 1st) were found for the following VAP lipids and lipoproteins: IDL-C (ß: 0.90; 0.11 to 1.69); VLDL-C (ß: 2.80; 1.51 to 4.08), triglycerides (ß: 18.66; 8.07 to 29.25), non-HDL-C (ß: 4.63; 0.50 to 8.75 mg/dl), TRL-C (ß:1.93;0.70 to 3.17), VLDL3-C (ß: 1.04; 0.50 to 1.57), as well as, TC/HDL-C (ß: 0.15; 0.03 to 0.26) and TG/HDL-C ratio (ß: 0.49;0.21 to 0.77). In women, similar results were found for VLDL-C, triglycerides, non-HDL-C, TRL-C, VLDL3-C, TC/HDL-C and TG/HDL-C-ratios. In men, we also found positive associations between the highest quintile of TSH with VLDL-C, triglycerides, VLDL3-C and TG/HDL-C.Conclusions: In the ELSA-Brasil, the highest TSH levels were mostly positively associated with lipoprotein levels, particularly TG, TRL and their remnants. Notwithstanding, our findings suggest that TSH levels within the normal range have little impact on the atherogenic profile.

The impact of diabetes and subclinical hypothyroidism association with coronary artery calcium: results from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

Objective: We aimed to analyze the association of diabetes and subclinical hypothyroidism with subclinical atherosclerosis measured by coronary artery calcium (CAC) in the baseline of the ELSA-Brasil study. Materials and methods: CAC was measured using a 64-detector computed tomographic scanner. The association of CAC > 0 was presented as an odds ratio (OR) and 95% confidence intervals (95%CI) in logistic models and as ß (95%CI) in linear models after multivariable adjustment for confounders. Results: We analyzed 3,809 participants (mean-age (SD) 50.5 (8.8); 51.7% women). In the main analysis, we did not find an association of diabetes and subclinical hypothyroidism with CAC. However, in stratified analysis according to age strata, we found no significative interaction terms, an important heterogeneity between the groups, with the younger age strata showing an association of the group with both diseases and CAC > 0 (OR 7.16; 95%CI, 1.14; 44.89) with a wide but significative 95%CI, suggesting that the smaller number of participants in the younger group may influence the results. Our findings also showed an association of CAC > 0 and log (CAC+1) with diabetes in logistic (OR, 1.31; 95%CI, 1.05-1.63) and linear models (ß, 0.24, 0.16, 0.40), respectively. Diabetes was independently associated with CAC > 0 in linear models. Discussion: In conclusion, our results showed a great heterogeneity in stratified analysis based on age in the younger age strata. Although we found no significant interaction factors, the smaller sample size for the analysis may influence the negative findings.