Association between the serum concentration of triiodothyronine with components of metabolic syndrome, cardiovascular risk, and diet in euthyroid post-menopausal women without and with metabolic syndrome

Abstract

PurposeTo determine the association between the serum concentration of triiodothyronine (T3) with components of metabolic syndrome (MetS), cardiovascular risk (CVR), and diet in euthyroid post-menopausal women without and with MetS.MethodsA cross-sectional study was performed in 120 voluntary women of an indigenous population from Tlaxcala-México. Euthyroid status was assessed measuring the serum concentration of thyrotropin (TSH) and thyroid hormones, while that of estradiol was measured to confirm the postmenopausal condition. MetS was diagnosed using the American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement (AHA/NHLBI) criterion. Estimation of CVR was calculated based on the Framingham scale. Diet components were evaluated based on survey applications. Correlations, logistic regression analyses, ANOVA or Kruskall-Wallis, and chi-square tests were used to determine significant differences (P ≤ 0.05) between women without MetS and women with MetS having different serum concentrations of T3.ResultsTriiodothyronine was positively correlated with insulin but negatively correlated with glucose, high-density lipoprotein cholesterol (HDL-C), and CVR. Compared to women without MetS, women with MetS and low-normal T3 concentration showed a high risk for hyperglycemia and moderate/high risk for CVR. In contrast, a high-normal T3 concentration increased the risk to have a big waist circumference, a high concentration of HDL-C, and insulin resistance. Diet analysis showed a high grade of malnutrition in women from all groups. The intake of calories was positively affected by the T3 concentration, albeit it did not affect the extent of malnutrition.ConclusionsIn contrast to concentrations of TSH, total thyroxin (T4), and free T4, the concentration of serum T3 was strongly correlated with cardio-metabolic variables in euthyroid postmenopausal women. In comparison to women without MetS, a high-normal serum concentration of T3 in women with MetS is positively associated with reduced glycaemia and CVR but negatively related to body mass index (BMI), insulin, insulin resistance, and HDL-C. Although the analyzed population had a nutritional deficiency, both calories and iron intake were positively affected by the T3 concentration. Our results suggest the necessity of health programs monitoring T3 in old people in order to treat hyperglycemia, cardio-metabolic components, and the ageing anorexia.

Moderate‐to‐high normal levels of thyrotropin is a risk factor for urinary incontinence and an unsuitable quality of life in women over 65 years

“…Women were invited to the enrolment of our survey. This community forms part from the Otomies indigenous of México, and has a low income, low educational level, and nutritional deficiency …”

“…The BMI was calculated as the quotient of the body weight (kg) divided by the square of the height (m 2 ). Due to elderly subjects being commonly are shorter and slimmer as compared to their younger counterparts, the height was estimated by the half arm span . Fat mass was measured using a device to analyze the bioelectrical impedance (Tanita BC‐534, Inner Scan, IL, USA).…”

A Low-Normal Free Triiodothyronine Level Is Associated with Adverse Prognosis in Euthyroid Patients with Heart Failure Receiving Cardiac Resynchronization Therapy

“…It suggested that fT3 level was correlated to the severity of HF in patients receiving CRT, which agreed with the previous studies. [17][18][19][20] Low fT3 level in HF reduced metabolic demand, which was seen as an adaptive process for HF. 21) But persistently low fT3 represented a maladaptive mechanism in favor of structural and functional cardiac remodeling, which had a key role in the pathogenesis of HF.…”

“…Low fT3 level reduced ejection fraction, and further caused enlarged heart chambers, lower velocity in the left atrial appendage and severe mitral regurgitation, which finally reduced cardiac systolic function. Thirdly, low-normal fT3 could affect several arteriosclerotic risk factors, such as diabetes mellitus, 17) insulin resistance, 20) serum lipid levels 23) and artery stiffness, 24) all of them above had been proved to have adverse effects on progress of HF. Fourthly, low fT3 status was independently correlated to peak oxygen uptake and functional exercise capacity in severe HF, which made recurrence of HF more frequent and remission period shorter than those with normal range of fT3.…”

Thyroid Hormone Regulation and Insulin Resistance: Insights From Animals Naturally Adapted to Fasting

“…Several other studies have reported that increases in TSH levels are associated with insulin resistance and clearly demonstrate that hypothyroidism is linked to increases in insulin resistance (9,134). Even modest increases in TSH are associated with subclinical hypothyroidism, and are correlated with insulin resistance and hyperlipidemia (15,59,68,77). TSH has the capacity to directly induce adipogenesis, and PPAR␥ receptor agonism can potently stimulate TSH receptor expression and adipogenesis (125).…”