Serum TSH levels are associated with cardiovascular risk factors in overweight and obese adolescents

The Relationship of Thyroid Functions With ADMA, IMA, and Metabolic Laboratory Parameters in Euthyroid Adults With and Without Autoimmune Thyroiditis

OBJECTIVE

To investigate the relationship between thyroid functions and asymmetric dimethylarginine (ADMA), ischemia-modified albumin (IMA), and other metabolic laboratory markers in euthyroid adults and whether narrower thyroidal targets are required for lower metabolic risk.

MATERIALS AND METHODS

Thyroid functions, antithyroid autoantibodies, and metabolic parameters were measured for 115 patients. Forty-seven had autoimmune thyroiditis (AIT). Analyses were performed according to cutoff values of 1, 2, 2.5, and 3 mIU/L for thyrotropin, 0.84 ng/dL for free thyroxine (fT4), and 3.59 ng/dL for free tri-iodothyronine (fT3).

RESULTS

There was no relationship between thyrotropin and fT3 cutoff values and metabolic parameters. Only C-reactive protein was lower in the group with thyrotropin ≤2.5 μIU/L. A weak positive correlation was found between fT4 with IMA and IMA corrected for albumin (r = 0.187, P = .05; r = 0.204, P = .034, respectively). There was no difference between AIT and the metabolic laboratory parameters examined in the study.

CONCLUSION

This study is the first to evaluate ADMA in AIT. Narrower thyroid function targets are not required for better metabolic control in euthyroid adults.

Interplay between metabolic and thyroid parameters in obese pubertal children. Does visceral adipose tissue make the first move?

Objectives: The mechanisms of obesity-associated thyroid dysfunction in children are incompletely deciphered. We aimed to evaluate whether visceral adipose tissue (VAT), insulin resistance (IR), inflammation, oxidative stress (OS) are involved in thyroid morpho-functional changes in pubertal obese children. Methods: We recruited 43 obese pubertal children without history of thyroid pathology. Metabolic and thyroid parameters (visceral fat thickness [VFT], waist/hip ratio [WHR], waist/height ratio [WHtR], insulin, glucose, liver parameters, thyroid stimulation hormone [TSH], free thyroxine [FT4], free triiodothyronine [FT3], thyroid and abdominal ultrasonography) were evaluated. Serum monocyte chemoattractant protein-1 (MCP-1) and malondialdehyde (MDA) levels were quantified as markers of inflammation and OS. Results: VFT correlated positively both with WHR (p= 0.034) and the presence of thyroid nodules (p= 0.036). WHR associated with TSH (p= 0.005), FT3/FT4 (p= 0.033) and was independently associated with FT3/FT4 increase (p< 0.001). HOMA-IR increased with visceral obesity (waist circumference, p= 0.001; WHR, p= 0.018; WHtR: p< 0.001), hepatic impairment (alanine aminotransferase, p= 0.019) and hepatic steatosis (HS; p= 0.013) and correlated positively with FT3/FT4 (p= 0.036). TSH was significantly higher in subjects with HS versus those without HS (p= 0.007) and logistic regression analysis identified TSH as a risk factor for HS (p= 0.014). MDA correlated positively with MCP-1 (p= 0.021). Conclusion: VAT and IR may be responsible for changes in thyroid parameters associated with obesity: elevated TSH, FT3/FT4 levels and increased prevalence of thyroid nodules. WHR was predictive of increased FT3/FT4. In obese children, there is an interdependent relationship between HS and thyroid function.

Reference Range and Sociodemographic Characteristics of TSH among Reproductive Age Women in Rural China

Appropriate reference range of thyroid-stimulating hormone (TSH) is important to interpreting the results of thyroid functional tests. However, the reference range and sociodemographic characteristics of TSH based on large-scale studies are yet to be declared in rural China. To clarify reference range and sociodemographic characteristics of TSH in reproductive age of women from rural China. A nationwide population-based study was conducted as The National Free Preconception Health Examination Project (NFPHEP). Nearly 400,000 (n = 392,659) of Chinese rural women aged 15-55 years were randomly recruited. Predetermined strict exclusion criteria made a number of 359,895 as the reference population. Serum TSH was evaluated with enzyme-linked immunosorbent assay (ELISA). The reference range of TSH on overall and reference population was 0.39-5.20 and 0.39-5.13 uIU/ml (2.5th-97.5th percentiles), respectively. In the reference population, the range (2.5th to 97.5th percentile) of serum TSH in different age groups was 0.40-5.03 uIU/ml, 0.39-5.15 uIU/ml, 0.37-6.10 uIU/ml, and 0.44-7.03 uIU/ml, respectively. The mean TSH value in women aged 26-35 years was 2.26 uIU/ml, significantly lower than those aged 36-45 (p < 0.001). The mean TSH values for eastern, central, and western regions were 2.28 uIU/ml, 2.29 uIU/ml, and 2.24 uIU/ml respectively. The mean of serum TSH concentration was significantly higher in central region than that in western region (p ≤ 0.001). The TSH value 0.39-5.13 uIU/ml (2.5th-97.5th percentiles) was derived as a reference range of reproductive age women from rural China. We use the TSH ranges from reference population to diagnose hyperthyrotropinemia or hypothyroidism in different areas in China. The reference ranges for eastern, central, and western regions were 0.33-5.61 uIU/ml, 0.40-5.04 uIU/ml, and 0.40-4.98 uIU/ml (2.5th-97.5th percentiles) respectively. The value of serum TSH was associated with age, living region, smoking, drinking, educational level, and interpersonal tension, as well as life and economic pressure, but irrelevant to ethnicity or occupation.

The Association between Oligomenorrhea, Onset of Menopause and Metabolic Syndrome in Thai Postmenopausal Women

Objectives

This study explored the association between a history of oligomenorrhea and onset of menopause and metabolic parameters.

Methods

The study population was 605 postmenopausal women who were patients at the Menopause Clinic, Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand between February 2015 and December 2015. A questionnaire was used to ask all women about their history of oligomenorrhea. The study also collected medical data, including weight, height, waist circumference, blood pressure, and blood glucose and lipid profile.

Results

Of the 231 postmenopausal women with a complete data record, 31 had a history of oligomenorrhea and 200 did not. The age of onset of menopause was around 48 years in both groups. Prevalence of metabolic syndrome was 12.1%. More women with a waist circumference larger than 80 cm had a history of oligomenorrhea at the interview than women who had not, but a history of oligomenorrhea did not relate to other metabolic parameters. The adjusted odds ratio of a history of oligomenorrhea to waist circumference was 3.69 (95% confidence interval, 1.17–11.64).

Conclusions

A history of oligomenorrhea did not affect the age at menopause, but was associated with waist circumference during menopause.

Waist Circumference and Subclinical Thyroid Dysfunction in a Large Cohort of Chinese Men and Women

OBJECTIVE

The association between subclinical thyroid dysfunction and waist circumference (WC) is still controversial, especially from the perspective of sex differences. We aimed to explore the impact of sex on this relationship in a large Chinese cohort.

METHODS

This cross-sectional study recruited 13,505 healthy participants (8,346 males, 5,159 females) who were enrolled in a health check program. Clinical data were collected. The association between subclinical thyroid dysfunction and WC of both sexes was analyzed separately after dividing WC into quartiles. Odds ratios (ORs) were calculated by binary logistic regression models, and linear regression analysis was also performed.

RESULTS

The prevalence rates of subclinical hyper-and hypothyroidism were significantly lower in males. Binary logistic regression models showed that WC in females with subclinical hypothyroidism had a detrimental effect with an OR of 1.011, but the effect disappeared when we included other covariates. The other ORs indicated no significant effects. The weak negative relationship between WC and thyrotropin was also indicated by linear regression analyses with very low R² values.

CONCLUSION

The current research did not show WC as a risk factor for subclinical thyroid dysfunction in either sex. Regional and ancestral origin differences may account for the variations with other studies.

ABBREVIATIONS

ALT = alanine aminotransferase; BMI = body mass index; FT3 = free triiodothyronine; FT4 = free thyroxine; TG = triglycerides; TSH = thyroid-stimulating hormone; UA = uric acid; WC = waist circumference.

The impact of micronutrient status on health: correlation network analysis to understand the role of micronutrients in metabolic-inflammatory processes regulating homeostasis and phenotypic flexibility

Background

Vitamins and carotenoids are key micronutrients facilitating the maintenance of health, as evidenced by the increased risk of disease with low intake. Optimal phenotypic flexibility, i.e., the ability to respond to a physiological challenge, is an essential indicator of health status. Therefore, health can be measured by applying a challenge test and monitoring the response of relevant phenotypic processes. In this study, we assessed the correlation of three fat-soluble vitamins, (i.e., vitamin A or retinol, vitamin D₃, two homologues of vitamin E) and four carotenoids (i.e., α-carotene, β-carotene, β-cryptoxanthin, and lycopene), with characteristics of metabolic and inflammatory parameters at baseline and in response to a nutritional challenge test (NCT) in a group of 36 overweight and obese male subjects, using proteomics and metabolomics platforms. The phenotypic flexibility concept implies that health can be measured by the ability to adapt to a NCT, which may offer a more sensitive way to assess changes in health status of healthy subjects.

Results

Correlation analyses of results after overnight fasting revealed a rather evenly distributed network in a number of relatively strong correlations per micronutrient, with minor overlap between correlation profiles of each compound. Correlation analyses of challenge response profiles for metabolite and protein parameters with micronutrient status revealed a network that is more skewed towards α-carotene and γ-tocopherol suggesting a more prominent role for these micronutrients in the maintenance of phenotypic flexibility. Comparison of the networks revealed that there is merely overlap of two parameters (inositol and oleic acid (C18:1)) affirming that there is a specific biomarker response profile upon NCT.

Conclusions

Our study shows that applying the challenge test concept is able to reveal previously unidentified correlations between specific micronutrients and health-related processes, with potential relevance for maintenance of health that were not observed by correlating homeostatic measurements. This approach will contribute to insights on the influence of micronutrients on health and help to create efficient micronutrient intervention programs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12263-017-0553-7) contains supplementary material, which is available to authorized users.