Acquired von Willebrand disease secondary to hypothyroidism: a rare cause for postextraction hemorrhage

Genetic insights and therapeutic avenues: unraveling the role of polyunsaturated fatty acids as mediators between hypothyroidism and Von Willebrand disease through Mendelian randomization

Background

Previous observational studies have shown that Hypothyroidism is associated with Von Willebrand Disease (VWD), but the causal relationship has not been confirmed because of conflicting findings and confounding by mixing factors. There are also some studies suggesting that polyunsaturated fatty acids (PUFA) may be one of the potential mediators. In this study, we used a Mendelian randomization study to analyze the causal relationship between Hypothyroidism and VWD and to investigate whether polyunsaturated fatty acids mediate the effects of Hypothyroidism on VWD.

Methods

Using a large publicly available genome-wide association study of predominantly European ancestry to obtain data on Hypothyroidism, VWD, and PUFA, we conducted a two-sample Mendelian randomization study to assess the causal relationship between Hypothyroidism and VWD and assess the potential role of Polyunsaturated fatty acids in mediating the causal pathway between Hypothyroidism and VWD. Finally, we also inferred reverse causality between VWD and Hypothyroidism. Inverse variance weighting (IVW) was the primary analytical method.

Results

We found that Hypothyroidism may be negatively causally associated with the development of VWD and that PUFA have a role in mediating role in this process (the ratio of the mediating effect: 24.33%). The causal effects of Hypothyroidism and PUFA on VWD remained significant (p < 0.05) after correction of each other by MVMR.

Conclusion

Our study unveils a novel negative correlation between hypothyroidism and VWD, further enriched by the discovery of partial mediation by PUFA. This groundbreaking finding not only advances our comprehension of VWD etiology but also opens promising avenues for its control and treatment. By elucidating the intricate interplay between hypothyroidism, PUFA, and VWD, our research pioneers a paradigm shift in therapeutic approaches, offering fresh perspectives for the management of this complex disorder.

Asphyxial death related to postextraction hematoma in an elderly man

We here report an autopsy case of a man in his seventies who died from asphyxia due to compression of the trachea caused by postextraction bleeding after extraction of his left mandibular third molar by a dentist in private practice. On the morning after the tooth extraction, he had complained of dyspnea and became unconscious at home. Although he was brought to the emergency room by ambulance, he died 7 days later without regaining consciousness. Autopsy examination revealed that the lingual side of the alveolar bone was fractured at the extraction socket. Moreover, subcutaneous bleeding that extended from the extraction socket to the thyrohyoid ligament in the cervical region and deviation of the epiglottis due to the bleeding were observed. Histological findings revealed liver cirrhosis; there were no significant findings in other organs. On the basis of these findings, we concluded that alveolar bone fracture occurred during the extraction and that the bleeding spread to the cervical region. Thus, the patient had died from asphyxia resulting from airway obstruction caused by cervical subcutaneous bleeding derived from postextraction bleeding. We emphasize that tooth extraction may cause fatal complications in patients with bleeding tendencies, particularly in the elderly.

Congenital von Willebrand's disease and clinical hypothyroidism

Data from case reports and systematic reviews suggest an association of Hypothyroidism and Acquired von Willebrand's syndrome. It is not known if congenital von Willebrand's disease is associated with hypothyroidism in a similar way. The aim of this study was to identify the association of congenital von Willebrand's disease (VWD) with clinical hypothyroidism. A total of 350 cases of congenital VWD were initially screened from our institution database from 1985 to 2010. A careful review of patient records was carried out to see if patients truly had congenital VWD and coexisting clinical hypothyroidism. Patients with uncertain diagnoses or other bleeding disorders were excluded, leading to 197 patients remaining in the final sample. A random age- and sex-matched parallel control group was also obtained from the hospital database. Of 197 patients (mean age 43.8 ± 17.5 years, women 72%) of congenital VWD, 32/197 (16%) were diagnosed with clinical hypothyroidism, while only 11/197 (5.6%) of the matched controls were clinically hypothyroid. Univariate and multivariate analysis demonstrated that VWD was an independent predictor of developing clinical hypothyroidism (OR 3.45; 95% CI 1.65-7.22, P = 0.001). The proportion of patients diagnosed with clinical hypothyroidism was more in the VWD group (P < 0.0001). Our analysis shows a strong association of clinical hypothyroidism in patients with congenital VWD, but future studies will be required to delineate a pathological mechanism. In our opinion, clinicians should consider checking thyroid function in the newly diagnosed and established cases of congenital VWD.