Association between oral health and thyroid disorders: A population-based cross-sectional study

Periodontal disease in patients with thyroid diseases: A systematic review with meta-analysis

PURPOSE

The imbalance of thyroid hormones affects the metabolic activity of various tissues, including periodontium. Also, autoimmune diseases present an increased tendency to suffer from periodontal disease. Therefore, our systematic review was designed to answer the question "Is there a relationship between thyroid diseases and periodontal disease?".

MATERIALS AND METHODS

Following the inclusion and exclusion criteria, 10 studies were included in this systematic review using the databases PubMed, Scopus and Web of Science (according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines).

RESULTS

Based on the meta-analysis, patients with thyroid diseases (especially with hypothyroidism) demonstrated significantly worse periodontal status than systemically healthy controls. Moreover, according to the cross-sectional studies, 5.74 ​% of periodontitis patients reported the concomitance of thyroid diseases.

CONCLUSIONS

In summary, the included studies suggest a potential relationship between thyroid diseases and periodontal disease. However, further research is necessary to reliably assess the oral health in patients with hypothyroidism and hyperthyroidism.

Periodontitis and thyroid function: A bidirectional Mendelian randomization study

BACKGROUND AND OBJECTIVE

Previous studies suggest interaction between periodontitis and thyroid function, while the causality has not yet been established. We applied the Mendelian randomization (MR) method to assess bidirectional causal association between periodontitis and thyroid-related traits, including free thyroxine (FT4), thyroid stimulating hormone (TSH), hypothyroidism, hyperthyroidism and autoimmune thyroid disease (AITD).

METHODS

Genetic instruments were extracted from large-scale genome-wide association studies on normal-range FT4 (N = 49 269) and TSH (N = 54 288) levels, TSH in full range (N = 119 715); hypothyroidism (discovery/replication cohorts: N = 53 423/334 316), hyperthyroidism (discovery/replication cohorts: N = 51 823/257 552), AITD (N = 755 406) and periodontitis (N = 45 563). Here, the inverse variance weighted (IVW) method was applied as the primary analysis, and robustness of results were assessed by several pleiotropic-robust methods. Results were adjusted for Bonferroni correction thresholds with significant p < .004 (0.05/13) and suggestive p between .004 and .05.

RESULTS

The IVW analysis revealed a suggestively causal linkage between genetic predisposition to periodontitis and the increased risk of hypothyroidism (discovery cohort: odds ratio [OR] = 1.24, 95% confidence interval [CI] = 1.05-1.46, p = .012; replication cohort: OR = 1.06, 95% CI = 1.01-1.11, p = .011). No evidence was found for supporting the impact of periodontitis on hyperthyroidism and AITD risks (associated p ≥ .209), as well as thyroid-related traits on periodontitis risk (associated p ≥ .105). These findings were robust and consistent through sensitivity analysis with other MR models.

CONCLUSION

This bidirectional MR reveals periodontitis should not be attributed to variations in thyroid function but it has potential causal effect on hypothyroidism risk, which provides a better understanding of the relationship between periodontitis and thyroid function, and potential evidence for the clinical intervention of hypothyroidism. Further investigations are warranted to elucidate the nature and underlying mechanisms of this finding.

Prevalence and Trends of Thyroid Disease Among Adults, 1999-2018

BACKGROUND

Thyroid disease is a prominent endocrine disorder, yet the clinical epidemiology of this condition remains unclear. This study aims to describe the recent trends in the prevalence of thyroid disease in US adults from 1999-2018.

METHODS

This cross-sectional study used nationally representative data collected through the National Health and Nutrition Examination Survey (NHANES) from January 1, 1999 to December 31, 2018. Patients with thyroid disease were defined as patients who reported having a thyroid disease and were on thyroid-related treatment. Age-standardized prevalence of thyroid disease was calculated within 4-year survey periods (1999-2002, 2003-2006, 2007-2010, 2011-2014, and 2015-2018).

RESULTS

During the NHANES 1999-2018, a total of 57 540 participants were examined. The age-standardized prevalence of thyroid disease was 5.05% (95% CI, 4.55%-5.60%) from 2015-2018, signifying a significant increase from the 1999-2002 period (P <.0002). However, prevalent thyroid disease remained steady between 2003 and 2014. The highest prevalence of thyroid disease was observed in non-Hispanic Whites (8.1%; 95% CI, 7.3%-9.0%), individuals aged ≥60 years (15.4%; 95% CI, 13.3%-17.8%), and tended to be higher in women (7.6%; 95% CI, 6.8%-8.5%). Multiple regression analysis revealed that age, women sex, non-Hispanic White and Mexican American, body mass index, higher education and incomes were independently associated with increased risks of thyroid disease.

CONCLUSION

The age-standardized prevalence of thyroid disease among US adults increased from 1999-2003, remained stable between 2003 and 2014, and then saw an increase from 2014-2018, with the highest rate observed among elders, women, and non-Hispanic Whites.

Oral Microbiota Signatures in the Pathogenesis of Euthyroid Hashimoto’s Thyroiditis

One of the most prevalent autoimmune illnesses in the world is Hashimoto’s thyroiditis, whose pathogenesis is still unknown. The gut–thyroid axis is frequently examined, and although oral health affects thyroid functions, there are limited data on how oral microbiota is linked to Hashimoto’s thyroiditis. The study aims to identify the oral microbiota from saliva samples taken from treated (with levothyroxine) and untreated female euthyroid Hashimoto’s thyroiditis patients as well as healthy controls who were age- and sex-matched to compare the oral microbiota across the groups and to contribute preliminary data to the literature. This study was designed as a single-center cross-sectional observational study. Sixty (60) female patients with euthyroid Hashimoto’s thyroiditis (HT) and eighteen (18) age- and gender-matched healthy controls were included in this study. Unstimulated saliva samples were collected. After DNA isolation, sequencing was performed by targeting the V3-V4 gene regions of the 16S rRNA on the MiSeq instrument. R scripts and SPSS were used for bioinformatic and statistical analysis. No significant differences were found in the diversity indices. However, Patescibacteria phylum showed a significantly higher abundance (3.59 vs. 1.12; p = 0.022) in the oral microbiota of HT patients compared to HC. In the oral microbiota, the euthyroid HT group had approximately 7, 9, and 10-fold higher levels of the Gemella, Enterococcus, and Bacillus genera levels than healthy controls, respectively. In conclusion, the results of our study demonstrated that Hashimoto’s thyroiditis causes changes in the oral microbiota, whereas the medicine used to treat the condition had no such effects. Therefore, revealing the core oral microbiota and long-term follow-up of the HT process by conducting extensive and multicenter studies might provide some important data for understanding the pathogenesis of the disease.

Association between oral health behavior and chronic diseases among middle-aged and older adults in Beijing, China

OBJECTIVES

To evaluate the association between oral health behavior and multiple chronic diseases among middle-aged and older adults.

METHODS

We obtained data of the Beijing Health Service Survey and used multivariate logistic models to estimate the association between oral hygiene behavior and the risk of chronic diseases.

RESULTS

The risk of any chronic diseases (OR = 1.27, 95% CI: 1.18-1.37), cardiovascular diseases (CVD, OR = 1.30, 95% CI: 1.21-1.39), and endocrine or nutritional metabolic disorders (OR = 1.11, 95% CI: 1.01-1.22) was higher in those who with poor oral health behavior. There was no significant correlation between oral health behavior and the risk of diseases of the musculoskeletal, respiratory, digestive, and genitourinary systems.

CONCLUSIONS

Poor oral hygiene practices were associated with higher risk of chronic diseases, CVD and diabetes mellitus (DM) among middle-aged and older adults. These findings motivate further studies to evaluate whether improved oral health behavior may prevent the incidence of chronic diseases.