Associations between cardiovascular risk, insulin resistance, β-cell function and thyroid dysfunction: a cross-sectional study in She ethnic minority group of Fujian Province in China

Abstract

Objective: To investigate the associations between cardiovascular risk, insulin resistance (IR), b-cell function and thyroid dysfunction in She ethnic minority group in China. Methods: We enrolled 5080 participants of She ethnicity in this analysis eventually. We measured serum TSH and thyroid peroxidase antibody (TPOAb) concentrations, blood glucose and insulin levels in both fasting and 2-h postprandial states, serum lipid levels, blood pressure (BP), brachial-ankle pulse wave velocity (baPWV), electrophysiological parameters, including T peak -T end interval (T p-e ), QT interval and height of the R wave in lead aVL (RaVL), and anthropometric parameters. Results: The total prevalence of thyroid dysfunction in this population is 12.1%. Hyperthyroid subjects had shorter T p-e interval and QT interval in electrocardiogram (ECG), while hypothyroid subjects had shorter T p-e interval and longer QT interval in ECG than euthyroid subjects. Neither hyperthyroid nor hypothyroid subjects showed significant difference in BP, pulse pressure, and baPWV compared with euthyroid subjects. RaVL was slightly higher in hyperthyroid subjects, though the difference did not reach statistical significance (PZ0.08). Subjects with TSH!0.3 mIU/l had higher blood glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and b-cell function (HOMA-b), whereas subjects with TSHO10 mIU/l had lower insulin, HOMA-IR, and HOMA-b than the reference group. There was a significant negative correlation, albeit weak, between TSH and HOMA-IR, HOMA-b after adjustment for confounding factors. Conclusions: Hypothyroid subjects may carry higher cardiovascular risk than euthyroid subjects. Moreover, IR and b-cell function are inversely correlated with TSH, which may be explained by the decreasing insulin-antagonistic effects of thyroid hormones along with increasing TSH.

Fatty liver largely explains associations of subclinical hypothyroidism with insulin resistance, metabolic syndrome, and subclinical coronary atherosclerosis

“…The results from previous studies investigating the association of mild thyroid failure with insulin resistance, MS, and CHD are conflicting. SCH subjects have been shown to have similar (13), higher (7,8), or lower (12) insulin and HOMA-IR levels, compared with euthyroid control subjects. Similarly, Garduño-Garcia et al (13) found that the prevalence of MS was not different between SCH subjects and individuals with normal thyroid function, while another study demonstrated that the syndrome was significantly more prevalent in subjects with both overt thyroid failure and SCH than in euthyroid subjects (9).…”

“…Although some studies have reported associations of SCH with insulin resistance (7,8), metabolic syndrome (MS) (7,9), and CHD (10,11), not all previous findings have been consistent (12,13,14). Recent studies in adults (9,15,16) and children (7) have shown that SCH is closely associated with NAFLD independent of potential confounders.…”

Altred Fructosamine and Lipid Fractions in Subclinical Hypothyroidism

“…Hypothyroidism is also associated with hyperinsulinaemia [13]. The slowed metabolic state of hypothyroidism not only slows the rate of glucose absorption from the gastro intestinal tract, but it also reduces the glucose utilization because of the insulin resistance [13,14]. In the current study, the significantly higher FPG of this group in comparison with that of the reference group, pointed to the possibility that hyperinsulinaemia and insulin resistance may be causing small excursions in the glucose levels in the prandial and the post prandial states.…”

Prevalence of Thyroid Disease among the Diabetic Patients: A Meta Analysis

“…[3] [4] But in diabetics patients, the prevalence is still greater and varies from 10 to 24% [4] [5] .These differences can be explained by different diagnostic criteria of thyroid dysfunction, degree of iodine intake in different people and different sensitivities of TSH and the large population diversity [6] .Thyroid diseases is a pathological state that adversely affect diabetics control and is commonly found in form of DM(diabetes mellitus) which is associated with advanced age in Type2 diabetes and autoimmune diseases in Type1 diabetes.DM appears to influence thyroid function in two sites ;firstly at the level of hypothalamic control of TSH release and secondly at the conversion of to in the peripheral tissue. The WHO estimate of diabetes prevalence for all age group worldwide was 2.8% in 2000 to 366 million in 2030 [7] .…”