Elevated thyroid-stimulating hormone levels are associated with poor sleep: a cross-sectional and longitudinal study

The interplay between subclinical hypothyroidism and poor sleep quality: A systematic review

BACKGROUND

The relationship between subclinical hypothyroidism (SHYPO) and sleep disturbances is still poorly investigated. This systematic review aims to critically appraise the existing literature to provide more insights in understanding whether SHYPO favors sleep disturbances or it is the sleep disturbance per se that affects the hypothalamus-pituitary-thyroid axis regulation.

METHODS

Original studies on sleep quality and duration in patients with SHYPO were searched in the PubMed/MEDLINE, Embase, Web of Science and Scopus databases. Two reviewers independently screened articles for inclusion, extracted data, and assessed the quality of included studies.

RESULTS

Eight studies, including 2916 patients with SHYPO and 18,574 healthy controls, were retrieved. An overall agreement (7 out of 8 studies), about a positive correlation between decreased sleep quality and/or duration and SHYPO was observed. Five studies investigated sleep quality through self-reported surveys; only two studies explored both subjective and objective assessment of sleep quality with actigraphy (n = 1) or polysomnography (n = 1); finally, one study assessed subjective evaluation of sleep quality through a single question regarding the number of sleeping hours. A high level of heterogeneity among studies was manifest due to differences in population source, sleep measure assessment and criteria for diagnosing SHYPO.

DISCUSSION

Overall, the existing literature data suggest a link between SHYPO and sleep disturbances, but further studies on larger populations of patients with homogeneous study designs and outcomes are warranted.

Thyroid Function and Sleep Patterns: A Systematic Review

Hypothyroidism, defined as a low metabolic function of the thyroid gland that results in low thyroid hormone levels, and insomnia, a condition with the inability to sleep, are two distinct conditions with little overlap that have been extensively established. Both conditions have been studied independently in terms of epidemiology, pathophysiology, diagnosis, and management. The exact causal relationship between the two conditions has yet to be elucidated, and a direct underlying pathophysiology has not been pinpointed. To gain further insight into the relationship between hypothyroidism and insomnia, we performed a systematic review to explore this relationship using predetermined guidelines. Out of 59 studies assessed, four studies evaluated the mechanisms of these two potentially comorbid conditions. Our findings suggest that hypothyroidism and insomnia may have a bidirectional relationship, with symptomatic overlap that is tied to increased metabolic comorbidities and hormonal dysregulation. These findings warrant further research to verify these early findings and gain further insight into the relationship between these conditions. A better understanding of the pathophysiology of overlap between these two conditions will help improve diagnosis and target treatment more effectively.

The Diagnostic Value of Gut Microbiota Analysis for Post-Stroke Sleep Disorders

BACKGROUND

Gut microbiota have been associated with many psychiatric disorders. However, the changes in the composition of gut microbiota in patients with post-stroke sleep disorders (PSSDs) remain unclear. Here, we determined the gut microbial signature of PSSD patients.

METHODS

Fecal samples of 205 patients with ischemic stroke were collected within 24 h of admission and were further analyzed using 16 s RNA gene sequencing followed by bioinformatic analysis. The diversity, community composition, and differential microbes of gut microbiota were assessed. The outcome of sleep disorders was determined by the Pittsburgh Sleep Quality Index (PSQI) at 3 months after admission. The diagnostic performance of microbial characteristics in predicting PSSDs was assessed by receiver operating characteristic (ROC) curves.

RESULTS

Our results showed that the composition and structure of microbiota in patients with PSSDs were different from those without sleep disorders (PSNSDs). Moreover, the linear discriminant analysis effect size (LEfSe) showed significant differences in gut-associated bacteria, such as species of Streptococcus, Granulicatella, Dielma, Blautia, Paeniclostridium, and Sutterella. We further managed to identify the optimal microbiota signature and revealed that the predictive model with eight operational-taxonomic-unit-based biomarkers achieved a high accuracy in PSSD prediction (AUC = 0.768). Blautia and Streptococcus were considered to be the key microbiome signatures for patients with PSSD.

CONCLUSIONS

These findings indicated that a specific gut microbial signature was an important predictor of PSSDs, which highlighted the potential of microbiota as a promising biomarker for detecting PSSD patients.

Short night-time sleep duration is associated with thyroid nodules: A community-based survey from Guangzhou, China

BACKGROUND

Sleep plays a critical role in maintaining human health. This study aimed to explore the association between sleep status and thyroid nodules.

METHODS

A total of 2414 individuals aged 18 or older with euthyroidism were enrolled in this community-based survey. Sleep status was self-reported. Thyroid ultrasonography was performed to measure nodules. Multiple logistic analyses were applied to adjust for confounding factors.

RESULTS

The percentages of thyroid nodules among individuals who slept <5 hours, 5-8 hours, and >8 hours per night were 57.79% (115/199), 44.19% (833/1885) and 42.73% (141/330), respectively (p = 0.001). Individuals who slept <5 hours per night had a significantly higher percentage of thyroid nodules than those who slept 5-8 hours per night (57.79% vs. 44.19%, p = 0.001) or >8 hours per night (57.79% vs. 42.73%, P < 0.001). However, no similar result was shown between individuals who slept >8 hours and 5-8 hours per night (42.73% vs. 44.19%, p = 0.621). Multiple logistic analysis showed that a sleep duration of <5 hours per night was significantly associated with thyroid nodules (odds ratio (OR) 1.643, 95% confidence interval (CI) 1.084-2.490, p = 0.019) when compared to a sleep duration of >8 hours per night. However, a sleep duration of <5 hours per night was not associated with thyroid nodules compared to a sleep duration of 5-8 hours (OR 1.294, 95% CI 0.918-1.824, p = 0.141). Similarly, no significant differences were seen among sleep duration per day, time of falling asleep, habit of daytime napping or thyroid nodules in multiple logistic analyses (all p > 0.05).

CONCLUSIONS

Short nighttime sleep duration was associated with thyroid nodules in our community-based population. Screening for thyroid nodules among these individuals is recommended.

Association of sleep problems with urinary concentrations of personal care and consumer product chemicals: a nationally representative, population-based study

Sleep problems are common in modern society and may be related to environmental chemicals. The objective of this study is to investigate the association between exposure to personal care and consumer product chemicals (PCCPCs) and sleep-related disorders. Nationally representative data from the National Health and Nutrition Examination Survey (NHANES) were used in this study (N=2415). Sleep-related variables, including sleep duration, snoring, and self-reported sleep problems, were included as outcome variables to assess sleep quality. Urinary PCCPC concentrations were used to assess the association of PCCPCs with sleep problems and adjusted for variables similar to those used in related studies. PCCPC levels were analysed as quartiles. Multivariate logistic regression and weighted quantile sum (WQS) regression were used to analyse the association of urinary PCCPCs with sleep problems. Nine of the 12 kinds of PCCPCs with a detection rate greater than 50% were included in our study. Specifically, the concentrations of bisphenol A (BPA), bisphenol F (BPF), methyl paraben (MP) and triclosan (TCS) were significantly related to insufficient sleep. Based on the WQS model, combined exposure to PCCPCs was also significantly related to insufficient sleep; TCS, BPA, and MP were the compounds with the greatest impact regarding combined exposure. A variety of PCCPCs were associated with insufficient sleep in participants but were not significantly associated with the other sleep problems reported in the NHANES. As poor quality sleep is associated with multiple adverse health outcomes, our study provides insight into the health risks of PCCPC exposure.

The association between electronic cigarettes, sleep duration, and the adverse cardiovascular outcomes: Findings from behavioral risk factor surveillance system, 2020

The joint effect of electronic cigarette smoking and insufficient sleep duration on cardiovascular disease (CVD) was unclear. This cross-sectional study aimed to evaluate the association between electronic cigarettes, sleep duration, and risk of CVD among American adults. The participants who completed the survey from the behavioral risk factor surveillance system in 2020 were included in this study. The status of electronic cigarette smoking was divided into never, former, and current use. The duration of sleep was categorized into insufficient (<6 h), appropriate (6–9 h), and excessive (>9 h) groups. The CVD group was defined as a patient having any of the following conditions: heart attack, coronary heart disease, or stroke according to self-report. The multivariate logistic regression model was adopted to determine the association between electronic cigarettes, sleep duration, and the risk of CVD. Sensitivity analyses were performed to assess the joint effects on the risk of CVD subtypes, including heart attack, coronary heart disease, and strokes, respectively. Subgroup analyses were performed to estimate the joint effects within the stratum of the age group. The total number of participants included in the present study was 253,561. Of which, 22,908 patients had CVD. In total, 61,293 participants had previously or currently used electronic cigarettes and 37,429 participants had inappropriate sleep duration. Former electronic cigarette users had a 10.8% increased risk of having CVD (OR = 1.108, 95% CI: 1.001–1.227) compared to users who never had electronic cigarettes. Insufficient and excessive sleep durations are associated with increased risks of CVD (OR = 1.592, 95% CI: 1.460–1.735; OR = 1.523, 95% CI: 1.320–1.758). The participants with current vaping status and lack of sleep had a 159.6% increased risk of CVD (OR = 2.596, 95% CI: 1.810–3.723). Sensitivity analyses found similar joint effects of current vaping and insufficient sleep on the risk of heart attack, coronary heart attack, and stroke. The subgroup analyses across each age stratum found that the middle-aged group is most vulnerable to the joint effect of current vaping and insufficient sleep. This study found that both current vaping and inappropriate sleep duration were associated with CVD. Additionally, there was a significant joint effect of current vaping and insufficient sleep on the risk of CVD, especially for middle-aged participants.

Relationship Between TSH Levels and Cognition in the Young Adult: An Analysis of the Human Connectome Project Data

CONTEXT

The nature of the relationship between serum thyrotropin (TSH) levels and higher cognitive abilities is unclear, especially within the normal reference range and in the younger population.

OBJECTIVE

To assess the relationship between serum TSH levels and mental health and sleep quality parameters (fluid intelligence [Gf], MMSE (Mini-Mental State Examination), depression scores, and, finally, Pittsburgh Sleep Quality Index (PSQI) scores (working memory, processing speed, and executive function) in young adults.

METHODS

This was a retrospective analysis of the data from the Human Connectome Project (HCP). The HCP consortium is seeking to map human brain circuits systematically and identify their relationship to behavior in healthy adults. Included were 391 female and 412 male healthy participants aged 22-35 years at the time of the screening interview. We excluded persons with serum TSH levels outside the reference range (0.4-4.5 mU/L). TSH was transformed logarithmically (log TSH). All the key variables were normalized and then linear regression analysis was performed to assess the relationship between log TSH as a cofactor and Gf as the dependent variable. Finally, a machine learning method, random forest regression, predicted Gf from the dependent variables (including alcohol and tobacco use). The main outcome was normalized Gf (nGf) and Gf scores.

RESULTS

Log TSH was a significant co-predictor of nGF in females (β = 0.31(±0.1), P < .01) but not in males. Random forest analysis showed that the model(s) had a better predictive value for females (r = 0.39, mean absolute error [MAE] = 0.81) than males (r = 0.24, MAE = 0.77).

CONCLUSION

Higher serum TSH levels might be associated with higher Gf scores in young women.