No evidence of a causal relationship between hypothyroidism and glaucoma: A Danish nationwide register-based cohort study

Thyroid disorders and their role in the pathogenesis of glaucoma

The literature analysis confirms the interrelationship of thyroid gland pathology and glaucoma. Patients with diffusetoxic goiter (DTG) and endemic goiter have an especially high risk of developing glaucoma, while those with autoimmune thyroiditis face a moderate risk. The prevalence of primary open angle glaucoma (POAG) in patients over 40 with endocrine ophthalmopathy is reliably associated with the male gender and the duration of the disease longer than 60 months. An increased risk of POAG is noted in men with hypothyroidism averagely aged 69. In most cases, ophthalmic hypertension that accompanies endocrine pathology does not need any topical hypotensive treatment. The main pathogenetically validated therapy of thyroid disorders results in a reduction of IOP level and an improvement of fluid outflow from the eye.

Death by unnatural causes, mainly suicide, is increased in patients with Hashimoto's thyroiditis. A nationwide Danish register study

PURPOSE

Hashimoto's thyroiditis (HT) is associated with excess psychiatric in addition to reduced quality of life. However, little is known about risk of unnatural manners of death in HT. We investigated the risk of death by accidents, suicide, violence/homicide, and unknown causes in patients with HT, compared to a matched control population.

METHODS

Register study covering all adult Danes diagnosed with HT during 1995-2012. In total, 111,565 HT cases were identified and matched for age and sex with four euthyroid controls. The hazard ratios (HR) for mortality were calculated using Cox regression analyses, adjusted for pre-existing morbidity. Median follow-up time was 5.9 years (range 0-17.5).

RESULTS

Compared to controls, HT patients had an increased frequency of death by suicide (0.10% vs 0.07%, p < 0.001) and unknown manners (0.05% vs 0.02%, p < 0.001). There were no significant differences between controls and HT patients in risk of death by accidents (0.36% vs 0.37%, p = 0.384) or violence (0.004% vs 0.005%, p = 0.749). After adjustment for pre-existing somatic and psychiatric morbidity HT patients still had an increased risk of suicide and death by unknown causes, whereas risk of death caused by accidents was reduced.

CONCLUSIONS

Mortality due to suicide and unknown causes, but not accidents and violence, was increased in HT. This indicates that HT may have a significant role in the pathophysiological mechanisms of suicidal behavior. This suggests that physicians caring for HT patients should be vigilant when facing expressions of suicidal ideation or signs and symptoms of self-harm as a first step towards prevention.