Thyroid Function, Cardiovascular Risk Factors, and Incident Atherosclerotic Cardiovascular Disease: The Atherosclerosis Risk in Communities (ARIC) Study (original) (raw)
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Thyroid dysfunction and serum lipids: a community-based study
Clinical Endocrinology, 2005
Objective It is uncertain whether subclinical hypothyroidism (SCH) is associated with hypercholesterolaemia, particularly in subjects with SCH and serum TSH ≤ 10 mU/l. Design, patients and measurements Cross-sectional study of 2108 participants in a 1981 community health survey in Busselton, Western Australia. Serum total cholesterol and triglycerides were measured in all subjects and high density lipoprotein cholesterol (HDL-C) measured (and low density lipoprotein cholesterol (LDL-C) calculated) in a subgroup of 631 subjects at the time of the survey. In 2001, TSH and free T4 concentrations were measured on archived sera stored at − 70 ° C. Serum lipid concentrations in subjects with thyroid dysfunction and euthyroid subjects were compared using linear regression models. Results In the group as a whole, serum total cholesterol was higher in subjects with SCH ( N = 119) than in euthyroid subjects ( N = 1906) (mean ± SD 6·3 ± 1·3 mmol / l vs. 5·8 ± 1·2 mmol / l, P < 0·001 unadjusted, P = 0·061 adjusted for age, age 2 and sex). Serum total cholesterol was similarly elevated in subjects with SCH and TSH ≤ 10 mU/ l ( N = 89) (6·3 ± 1·3 mmol / l, P < 0·001 unadjusted, P = 0·055 adjusted for age, age 2 and sex). In the subgroup analysis, LDL-C was higher in subjects with SCH ( N = 30) than in euthyroid subjects ( N = 580) (4·1 ± 1·2 mmol / l vs. 3·5 ± 1·0 mmol / l, P < 0·01 unadjusted, P = 0·024 adjusted for age, age 2 and sex). LDL-C was significantly increased in subjects with SCH and TSH ≤ 10 mU/ l ( N = 23) (4·3 ± 1·3 mmol / l, P < 0·001 unadjusted, P = 0·002 adjusted for age, age 2 and sex). Conclusion SCH is associated with increased serum LDL-C concentrations, which is significant after adjustment for age, age 2 and sex.
Relationship between Thyroid Function and Coronary Artery Disease Severity
Annals of Tropical Medicine and Public Health, 2020
Aim: The aim of this study was to assess the relationship between thyroid function and coronary artery disease severity. Cardiovascular disease and related mortality has emerged as a major health burden worldwide with atherosclerosis being the major cause. Thyroid dysfunction results in changes in cardiac contractility, cardiac output, myocardial oxygen consumption, systemic vascular resistance, and blood pressure. The relationship between abnormal thyroid function and coronary artery disease has been recognized for a long time, especially in hypothyroidism status due to the associated hypercholesterolemia and hypertension. Design/Methods: This is a randomised, double-blinded parallel arm study with a total 300 patients diagnosed coronary artery disease and thyroid dysfunction. Patients were blockrandomised based on third party allocation (1:1).Concealment was done through SNOSE (Sequentially Numbered Opaquely Sealed Envelope) Results: Presence of overt hypothyroidism was significantly more in high risk syntax score 28.1% compared to intermediate risk 17 %. Presence of subclinical hypothyroidism was significantly more in high risk syntax score 18.8% compared to intermediate risk 11.4 %. Presence of euthyroid was significantly higher in low risk 85.6% compared to intermediate risk 71.6% and high risk 53.1 % Conclusions: In the present study showed that the Free T4 was more strongly associated with CAD and severity of atherosclerosis than TSH in the entire study population. We conclude that Overt and Subclinical hypothyroidism patients had more severe Coronary atherosclerosis than Euthyroid study population.
Frontiers in Endocrinology
BackgroundThyroid hormones are important modulators of cardiovascular function. Both hypothyroidism and hyperthyroidism are known to contribute to an increased cardiovascular risk. It remains uncertain whether thyroid hormones level within the euthyroid range are associated with cardiometabolic risk. We aimed to evaluate the association between thyroid function levels within the euthyroid range and cardiovascular risk in a population-based cohort.MethodsEight hundred thirty-five subjects aged ≥45 years from the EPIPorto population-based cohort were included. We excluded participants with TSH, free T4 (FT4), or free T3 (FT3) outside of the reference range, or with previous cardiovascular or thyroid disease. The associations between thyroid function, cardiovascular risk factors and the 10-year estimated risk of cardiovascular events (using SCORE2 and SCORE2-OP) were evaluated in linear and logistic regression models, crudely and adjusting for age, sex, BMI, diabetes, and smoking.Resul...
Endocrine
Purpose Although thyroid hormones are irrefutably implicated in cardiovascular physiology, the impact of within-reference range variations of thyroid function on cardiovascular disease (CVD) remains unclear. Elucidating this is important, since it could foster preventive treatment and reduce global CVD burden. We therefore investigated the impact of within-reference range variations of thyroid function on all-cause and cardiovascular mortality. Methods We included community-dwelling individuals aged 28–75 years from a prospective cohort study, without known use of thyroid-affecting therapy and with thyrotropin within reference range. Associations of thyroid function with mortality were quantified using Cox models and adjusted for sociodemographic and cardiovascular risk factors. Results Mean (SD) age of the 6,054 participants (52.0% male) was 53.3 (12.0) years. During 47,594 person-years of follow-up, we observed 380 deaths from all causes and 103 from CVDs. Although higher thyrotro...
Cardiovascular Risk in Patients of Thyroid Disorders
Background: Hypothyroidism is a common condition; it causes symptoms that reduce the functional capacity of the bodily systems and negatively affects the quality of life. The risk of CHD and other forms of atherosclerotic vascular disease increases with elevated plasma levels of cholesterol. So, we have designed the study to see the effects of thyroid dysfunction on lipid parameters and cardiovascular disease (CVD) risk factors. Material & Methods: A Case Control Study was conducted on Patients with thyroid disorder, attending both OPD and IPD in the Department of Medicine in Mahatma Gandhi Medical College, Jaipur, Rajasthan between December 2015 to December 2016. A total of 80 Subjects, 40 subjects with thyroid disorder and 40 euthyroid controls were included in the study. Presence of thyroid dysfunction was defined as per American Thyroid Association's Guidelines. Results: In our study it was observed that 77.5% cases were below 45 years of age as compared to 57.5% in control group. A significant decline in TSH levels was noted after treatment (9.523±3.954 µIU/ml v/s 3.107±1.973 µIU/ml; P<0.0001***). However, there was no significant difference between before treatment and after treatment in cases when mean value of FT3 & FT4 were compared. 60% patients had RWMA abnormalities on 2D-Echo evaluation for cardiovascular disease. None in the control group showed such findings. Conclusion: The study showed a higher prevalence of thyroid disorders in elderly females. Patients with both, clinical and subclinical, hypothyroidism showed dyslipidemic abnormalities. Also a large percentage of hypothyroid patients showed 2-D echocardiographic abnormalities as a marker of underlying CV disease; thus suggesting the need for detailed cardiovascular evaluation of all such patients.
Biological Systems: Open Access, 2015
Introduction: Hypothyroidism, metabolic syndrome and central obesity are common diseases known as the risk factors for atherosclerotic cardiovascular disease. The coexistence of thyroid dysfunction in obese patients might substantially increase the cardiovascular risk. The objective of the study was to evaluate the effect of hypothyroidism on the main cardiovascular risk factors in patients with obesity and cardiovascular syndrome. Material and methods: In a cross-sectional clinical study we examined 202 patients with central obesity and metabolic syndrome (160 women, 42 men, aging 43 ± 13 yrs) with BMI ≥ 30 kg/m 2 divided in two groups-101 patients with subclinical or overt hypothyroidism (gr. A-hypot) and 101 eythyroid patients (gr B-eut), diagnosed by TSH, FT4,TPO-Ab. Laboratory assessment included: total cholesterol (TChol), HDL,LDL, triglycerides (3-glyc), serum glucose, standard oral glucose tolerance test (OGTT) and insulin resistance by Homeostasis Model Assessment of Insiline Resistance (HOMA-IR). Serum leptin and C-reactive proteins were estimated in 20 patients of each patients group and in a control group of 20 healthy persons with BMI <25 kg/m 2. The supplementation Levothyroxine therapy was carried out of patients with overt and subclinial hypothyroidism. Results: Both compared groups showed similar BMI (mean 37 kg/m 2) and HOMA-IR value 3.1 and 3.15, respectively Mean TSH value was found 4-fold higher in gr. A than in gr. B. which significantly correlated with TChol, 3-glyc, CRP and serum leptin The prevalence of arterial hypertension (AH), diabetes type2 or impaired glucose tolerance (IGT) in gr A was 86% and 67% vs. 80% and 70% in gr B, respectively. Significant correlations were established between TSH, TChol, atherogenic lipoproteins, 3-glyc. in patients gr. A but not in gr B. The same parameters decreased significantly after adequate levothyroxin supplementation. The significant positive nonparametric correlations were found also between BMI, TSH, leptin and CRP (p<0.05). Conclusion: Our data demonstrate that hypothyroidism significantly aggravates the lipid metabolisms in patients with obesity or MetS. These disturbances co-existing with higher prevalence of arterial hypertension, DM-T2 or IGT determine the substantially increased cardiovascular risk which correlated with increased insulin resistance, higher levels of leptin and CRP as a marker of chronic inflammation. Consequently clinicians shouid be particularly alert in the possibility of thyroid disfunction in obese patients.
IMPORTANCE Some experts suggest that serum thyrotropin levels in the upper part of the current reference range should be considered abnormal, an approach that would reclassify many individuals as having mild hypothyroidism. Health hazards associated with such thyrotropin levels are poorly documented, but conflicting evidence suggests that thyrotropin levels in the upper part of the reference range may be associated with an increased risk of coronary heart disease (CHD). OBJECTIVE To assess the association between differences in thyroid function within the reference range and CHD risk. DESIGN, SETTING, AND PARTICIPANTS Individual participant data analysis of 14 cohorts with baseline examinations between July 1972 and April 2002 and with median follow-up ranging from 3.3 to 20.0 years. Participants included 55 412 individuals with serum thyrotropin levels of 0.45 to 4.49 mIU/L and no previously known thyroid or cardiovascular disease at baseline. EXPOSURES Thyroid function as expressed by serum thyrotropin levels at baseline. MAIN OUTCOMES AND MEASURES Hazard ratios (HRs) of CHD mortality and CHD events according to thyrotropin levels after adjustment for age, sex, and smoking status. RESULTS Among 55 412 individuals, 1813 people (3.3%) died of CHD during 643 183 person-years of follow-up. In 10 cohorts with information on both nonfatal and fatal CHD events, 4666 of 48 875 individuals (9.5%) experienced a first-time CHD event during 533 408 person-years of follow-up. For each 1-mIU/L higher thyrotropin level, the HR was 0.97 (95% CI, 0.90-1.04) for CHD mortality and 1.00 (95% CI, 0.97-1.03) for a first-time CHD event. Similarly, in analyses by categories of thyrotropin, the HRs of CHD mortality (0.94 [95% CI, 0.74-1.20]) and CHD events (0.97 [95% CI, 0.83-1.13]) were similar among participants with the highest (3.50-4.49 mIU/L) compared with the lowest (0.45-1.49 mIU/L) thyrotropin levels. Subgroup analyses by sex and age group yielded similar results. CONCLUSIONS AND RELEVANCE Thyrotropin levels within the reference range are not associated with risk of CHD events or CHD mortality. This finding suggests that differences in thyroid function within the population reference range do not influence the risk of CHD. Increased CHD risk does not appear to be a reason for lowering the upper thyrotropin reference limit.
International Journal of Cardiology, 2008
Background: Previous studies have suggested that sub-clinical thyroid states may have detrimental effects on the coronary heart disease (CHD). Whether subclinical thyroid dysfunction is a risk factor for the above is controversial. Methods: A systemic search of the literature using Pubmed, Medline and Ovid online tool was performed to identify relevant studies. Amongst the clinical studies, crossectional study and studies with follow-up period ranging between 4 and 20 yr were identified (Walsh JP, Bremner AP, Bulsara MK, et al. Subclinical thyroid dysfunction as a risk factor for cardiovascular disease. Arch Intern Med 2005 Nov 28;165 (21):2467-72.; Rodondi N, Newman AB, Vittinghoff E, et al. Subclinical hypothyroidism and the risk of heart failure, other cardiovascular events, and death. Arch Intern Med 2005 Nov 28; 165 (21):2460-6.; Rotterdam study, Imaizumi M, Akahoshi M, Ichimaru S, et al. Risk for coronary heart disease and all-cause mortality in subclinical hypothyroidism. J Clin Endocrinol Metab 2004 Jul; 89 (7):3365-70.; Capolla et al.; Parle JV, Maisonneuve P, Sheppard MC, Boyle P, Franklyn JA. Prediction of all-cause and cardiovascular mortality in elderly people from one low serum thyrotropin result: a 10-year cohort study. Lancet 2001 Sep 15; 358 (9285):861-5). Results: Sub-clinical hypothyroidism: The pooled estimate of the relative risk of CHD revealed significant difference both at baseline [RR with 95% CI: 1.533 (1.312-1.791), P b 0.05] and at follow-up [RR with 95% CI: 1.188 (1.024-1.379), P b 0.05]. The relative risk of allcause mortality at follow-up revealed no significant difference. However, the relative risk of death from cardiovascular causes at follow-up was significantly higher [RR with 95% CI: 1.278 (1.023-1.597), P b 0.05]. Sub-clinical hyperthyroidism: The pooled estimate of the relative risk of CHD revealed no significant difference both at baseline [RR with 95% CI: 1.156 (0.709-1.883)] and at follow-up [RR with 95% ].The relative risk of death from cardiovascular causes at follow-up was also not significantly higher. Conclusion: The present meta-analysis indicates that sub-clinical hypothyroidism is associated with both, a significant risk of CHD at baseline and at follow-up. In addition, mortality from cardiovascular causes is significantly higher at follow-up. Sub-clinical hyperthyroidism is not associated with CHD or mortality from cardiovascular causes.