The goal of eliminating iodine deficiency has been successfully achieved in China. However, the prevalence and spectrum of thyroid disorders has increased, reflecting possible adverse effects of increased iodine intake.

Abstract. To explore the relationship between serum thyrotropin and components of metabolic syndrome in a Chinese cohort. A total of 1534 adult inhabitants in DaDong district of Shenyang were asked to fulfill the questionnaire, complete physical examination and OGTT. Blood samples were collected to test thyrotropin (TSH), fasting plasma glucose (FPG), OGTT 2h PG, fasting insulin (FINS), triglyceride (TG) and high density lipoprotein cholesterol (HDL-C). Serum TSH in metabolic syndrome group was higher than that in the non-metabolic syndrome group (2.54 mIU/L vs. 2.22 mIU/L, p<0.05). TG level increased significantly in subclinical hypothyroid group compared with euthyroid subjects (1.73±0.12 mmol/L vs.1.47±0.03 mmol/L, p<0.05), and HDL-C decreased significantly in patients with subclinical hypothyroidism compared with euthyroid subjects (1.26±0.27 mmol/L vs. 1.33±0.27 mmol/L, p<0.05). The prevalence of hypertension was higher in the subclinical hypothyroid group than that in euthyroid group (42.86% vs. 33.2%, p<0.05). The serum TSH within the reference range was positively related with the prevalence of overweight/obesity. Slight increase in serum TSH maybe a risk factor for metabolic syndrome.

ObjectivesOur study aimed to distinguish the ability of anthropometric indices to assess the risk of metabolic syndrome (MetS).DesignProspective cohort study.SettingShenyang, China.ParticipantsA total of 379 residents aged between 40 and 65 were enrolled. 253 of them were free of MetS and had been followed up for 4.5 years.MethodsAt baseline, all the participants underwent a thorough medical examination. A variety of anthropometric parameters were measured and calculated, including waist circumference (WC), body mass index (BMI), a body shape index (ABSI), abdominal volume index (AVI), body adiposity index, body roundness index, conicity index, waist-to-hip ratio and visceral adiposity index (VAI). After 4.5 year follow-up, we re-examined whether participants were suffering from MetS. A receiver operating characteristic (ROC) curve was applied to examine the potential of the above indices to identify the status and risk of MetS.OutcomesOccurrence of MetS.ResultsAt baseline, 33.2% participants suffered from MetS. All of the anthropometric indices showed clinical significance, and VAI was superior to the other indices as it was found to have the largest area under the ROC curve. After a 4.5 year follow-up, 37.8% of men and 23.9% of women developed MetS. ROC curve analysis suggested that baseline BMI was the strongest predictor of MetS for men (0.77 (0.68–0.85)), and AVI was the strongest for women (0.72 (0.64–0.79)). However, no significant difference was observed between WC and both indices. In contrast, the baseline ABSI did not predict MetS in both genders.ConclusionsThe present study indicated that these different indices derived from anthropometric parameters have different discriminatory abilities for MetS. Although WC did not have the largest area under the ROC curve for diagnosing and predicting MetS, it may remain a better index of MetS status and risk because of its simplicity and wide use.

Objective: With the introduction of iodized salt worldwide, more and more people are exposed to more than adequate iodine intake levels with median urinary iodine excretion (MUI 200-300 mg/l) or excessive iodine intake levels (MUI O300 mg/l). The objective of this study was to explore the associations between more than adequate iodine intake levels and the development of thyroid diseases (e.g. thyroid dysfunction, thyroid autoimmunity, and thyroid structure) in two Chinese populations. Design: A population-based cross-sectional study was conducted in two areas in which people are exposed to different levels of iodine intake (Rongxing, MUI 261 mg/l; Chengshan, MUI 145 mg/l). A total of 3813 individuals were recruited by random sampling. Thyroid hormones, thyroid autoantibodies in serum, and iodine levels in urine were measured. B-mode ultrasonography of the thyroid was also performed for each participant. Results: The prevalence of subclinical hypothyroidism was significantly higher for subjects who live in Rongxing than those who live in Chengshan (5.03 vs 1.99%, P!0.001). The prevalence of positive anti-thyroid peroxidase antibody (TPOAb) and positive anti-thyroglobulin antibody (TgAb) was significantly higher for subjects in Rongxing than those in Chengshan (TPOAb: 10.64 vs 8.4%, PZ0.02; TgAb: 10.27 vs 7.93%, PZ0.01). The increase in thyroid antibodies was most pronounced in the high concentrations of TPOAb (TPOAb: R500 IU/ml) and low concentrations of TgAb (TgAb: 40-99 IU/ml) in Rongxing. Conclusions: More than adequate iodine intake could be a public health concern in terms of thyroid function and thyroid autoimmunity in the Chinese populations.European Journal of Endocrinology 164 943-950

It is still controversial whether subclinical hypothyroidism and euthyroidism affect blood pressure. The study aimed to explore the relationship between different levels of thyroid-stimulating hormone (TSH) and blood pressure in the participants with subclinical hypothyroidism and euthyroidism. A total of 1319 participants were administered a questionnaire survey, and their blood pressure, height and body weight measurements were taken. Blood samples were taken to test serum TSH. FT3 and FT4 were further examined if TSH was abnormal. Participants were divided into euthyroid group and subclinical hypothyroidism group. Euthyroid group was further divided into three groups: group A (TSH 0.3-0.99 mIU l À1 ), group B (TSH 1.0-1.9 mIU l À1) and group C (TSH 1.91-4.8 mIU l À1 ). Results showed that different levels of serum TSH had no relation with systolic blood pressure (SBP) and diastolic blood pressure (DBP). The prevalence of hypertension in subclinical hypothyroidism group was significantly higher than euthyroid group in females (41.3 vs 25.6%, Po0.05). The risk of hypertension in subclinical hypothyroidism group was significantly higher than that in the euthyroid group after adjusted for age, gender, smoking status, HOMA-IR (homoeostasis model assessment of insulin resistance) and body mass index (odds ratio (OR) ¼ 1.753, 95% confidence interval (CI) 1.067-2.879, P ¼ 0.027). This association was stronger in females (OR ¼ 3.545, 95% CI 1.576-7.975, P ¼ 0.004), but there was no statistical significance in males. Within normal range of TSH, both SBP and DBP were similar among the three groups. The prevalence and risk of hypertension were also similar among the three groups. In conclusion, the prevalence of hypertension in subclinical hypothyroidism group was significantly higher than in euthyroid group in females. Change of TSH in normal range did not affect blood pressure.

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Metabolic syndrome (MetS), a cluster of metabolic disturbances that increase the risk for cardiovascular disease and diabetes, was because of genetic susceptibility and environmental risk factors. To identify the genetic variants associated with MetS and metabolic components, we conducted a genome‐wide association study followed by replications in totally 12,720 participants from the north, north‐eastern and eastern China. In combined analyses, independent of the top known signal at rs651821 on APOA5, we newly identified a secondary triglyceride‐associated signal at rs180326 on BUD13 (P combined = 2.4 × 10−8). Notably, by an integrated analysis of the genotypes and the serum levels of APOA5, BUD13 and triglyceride, we observed that BUD13 was another potential mediator, besides APOA5, of the association between rs651821 and serum triglyceride. rs671 (ALDH2), an east Asian‐specific common variant, was found to be associated with MetS (P combined = 9.7 × 10−22) in Han Chinese. The effects of rs671 on metabolic components were more prominent in drinkers than in non‐drinkers. The replicated loci provided information on the genetic basis and mechanisms of MetS and metabolic components in Han Chinese.

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