Influence of educational level on test and treatment for incident hypothyroidism

Outdoor light at night exposure was associated with hypothyroidism in pregnant women: A national study in China

BACKGROUND

Evidence on the influence of outdoor artificial light at night (ALAN) on hypothyroidism in pregnant women is scarce. We aimed to investigate the association between outdoor ALAN exposure and hypothyroidism in pregnancy.

METHODS

81,820 pregnant women from the China Birth Cohort Study (CBCS) were analyzed, which recruited from 18 provinces and autonomous regions in China between February 2018 and December 2020. Hypothyroidism was defined based on clinical diagnosis by physicians. Outdoor ALAN exposure (nW/cm2/sr) within 1500 m was estimated using VIIRS/DNB satellite data based on the participants' residential address. The Outdoor ALAN was divided in quartiles, with the lowest quartile (Q1) serving as the reference group. Generalized linear mixed models were employed to estimate the association between ALAN exposure and hypothyroidism.

RESULTS

Among the 81,120 pregnant women, 3902 (4.77 %) were diagnosed hypothyroidism. Pregnant women with hypothyroidism had significantly higher median (IQR, interquartile range) outdoor ALAN levels during pregnancy compared to those without hypothyroidism (30.97 (18.15) vs. 29.14 (20.21) nW/cm2/sr, p < 0.01). After adjusting for covariates, we found that each quartile increment of outdoor ALAN exposure was associated with an adjusted Odds Ratio (aOR of 1.15 (95 % Confidence Interval [95 % CI]: 1.03-1.27), 1.15 (1.05-1.28), and 1.12 (1.00-1.25) for hypothyroidism, respectively from Q2 to Q4. Additionally, stratified analyses revealed that pre-pregnancy BMI was a significant modifier in the association between outdoor ALAN and hypothyroidism in pregnancy, with stronger effects observed among those who were overweight before pregnancy (1.21 [95 % CI, 1.05-1.39] vs. 1.03 [95 % CI, 0.97-1.10], p for interaction = 0.01).

CONCLUSIONS

Outdoor ALAN exposure is positively associated with hypothyroidism in pregnancy. To benefit maternal and infant health and well-being, recommendations for mitigating ALAN pollution and effective measures to avoid excessive light exposure should be developed.

The Copenhagen Primary Care Laboratory (CopLab) Database

Background

The Copenhagen General Practice Laboratory (CGPL) was founded in 1922 to provide paraclinical analyses to the primary health-care sector in Copenhagen. At the end of 2015, CGPL was closed and the CopLab database was established to make CGPL data available for research.

Methods

We isolated tests performed at the CGPL with clinically relevant test results. The database was linked to national registers containing health, social, and demographic information. Results are presented with descriptive statistics showing counts, percentages, medians, and interquartile ranges (IQR).

Results

The CopLab database includes 1,373,643 unique individuals from primary care with test results from laboratory analyses of blood/urine/semen as well as cardiac and lung function tests collected by CGPL from greater Copenhagen from 2000 to 2015. The CopLab database holds nearly all test results requested by general practitioners throughout years 2000 to 2015 for residents in the greater Copenhagen area. The median age of the individuals was 51 years and 59.7% were females. Each individual has a median of 4 requisitions. More than 1 million participants are currently alive and living in Denmark and may be followed in national registries such as the Danish National Patient Registry, Laboratory Database, National Prescription Database etc.

A Cross-Sectional Study of the Relationship Between Perceived Stress and Thyroid Function Among Apparently Normal Women in the Reproductive Age

BACKGROUND

A substantial majority of women in India report experiencing stress frequently, with a significant number indicating a lack of time for relaxation. Women within a central productive age bracket often report higher stress levels. Chronic stress can lead to the development of autoimmune disorders affecting the thyroid gland.

OBJECTIVE

To evaluate the relationship between perceived stress and thyroid function among apparently normal women of reproductive age.

MATERIALS AND METHODS

The present study was conducted at the Vijayanagar Institute of Medical Sciences (VIMS) after obtaining clearance from the Institutional Ethical Committee and informed written consent from the participants. One hundred and fourteen working women aged 20-49 who consented to the study and had no personal or family history of medical illness or thyroid disease were randomly selected. Stress levels were measured using a Perceived Stress Scale (PSS), and thyroid parameters (total triiodothyronine [T3], total thyroxine [T4], and thyroid-stimulating hormone [TSH]) in blood samples were assessed by the electrochemical luminescence immunoassay method. Anthropometric parameters such as age and body mass index (BMI), as well as vital parameters like pulse rate and blood pressure, were measured for all participants. A detailed history was also recorded, including marital status, duration of married life, education, number of children, type of family, per capita income, phase of menstrual cycle, and dietary habits.

RESULTS

The Statistical Package for the Social Sciences (SPSS) software version 22.0 was used for statistical analysis. The analysis used Pearson's chi-square test, Student's t-test, and binary logistic regression. A positive correlation was observed between PSS and TSH (correlation coefficient "r" value = 0.060) without a significant p-value. Participants were divided into two groups based on TSH values: those with normal thyroid function (TSH <4.2 international units [IU]) and those with subclinical hypothyroidism (SCH) (TSH >4.2 IU). Both groups had total T3 and T4 levels within the normal reference range. A highly significant difference was observed for age, BMI, TSH, marital status, and duration of married life between women with normal thyroid function and those with SCH. No significant difference was found between the two groups for PSS.

DISCUSSION

Both acute and chronic stress affect thyroid function through the hypothalamus-pituitary-thyroid (HPT) axis and the hypothalamus-pituitary-adrenal (HPA) axis. Psychological and physiological stressors induce immune modulations that can lead to autoimmune thyroid diseases, resulting in hypothyroidism.

CONCLUSION

The study examined the link between stress and thyroid health in women of childbearing age, revealing a trend where higher stress levels corresponded with increased TSH levels, though not significantly. It also found that older age, higher BMI, and longer duration of marriage were linked to a greater occurrence of SCH. These findings underscore the potential influence of lifestyle factors and stress on thyroid function, suggesting that stress management and demographic factors should be considered in managing thyroid health. For women of reproductive age under high stress, routine monitoring of thyroid function could be beneficial for overall health maintenance.

Socioeconomic influence on treatment with liothyronine and desiccated thyroid extract in Denmark

Introduction

High compared with low educational level increases the odds of starting levothyroxine (L-T4) with a normal thyroid-stimulating hormone - the mechanism is most likely patient request. The use of liothyronine (L-T3) and desiccated thyroid extract (DTE) is also speculated to be initiated at patients' request. Therefore, the primary aim of this study was to evaluate if educational level influences treatment with L-T3 and DTE.

Material and methods

In this register-based cross-sectional study, we included all Danish citizens ≥30 years with redeemed prescription of L-T4, L-T3, or DTE during 2017-2020. We defined educational levels as short, medium, and long (<10 years, 10-12 years, and above 12 years, respectively). The association between educational level and treatment with LT3 or DTE vs only LT4 was analyzed in logistic regression models adjusted for age and sex.

Results

We included 154,360 individuals using thyroid medication of whom 3829 were treated with L-T3 (2.48%) and 430 with DTE (0.28%). The usage was highest among women (3.15%) and the age group 40-49 (5.6%). Longer education compared with short increased the odds of being treated with DTE or L-T3 (medium education odds ratio (OR) 1.61 (95% CI 1.50-1.8) and long education OR 1.95 (95% CI 1.79-2.13)). Test for trend: OR: 1.37 (95% CI 1.31-1.42). Adjustment for other covariates did not affect the results substantially.

Conclusion

Persons with a longer compared to a shorter education are more often treated with either DTE or L-T3, and the usage of these drugs is limited to less than 3% of thyroid hormone users.