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.

Death by Suicide in Graves' Disease and Graves' Orbitopathy: A Nationwide Danish Register Study.

BACKGROUND: Graves' disease (GD) is associated with excess morbidity and mortality, but little is known about unnatural manners of death and the potential relation with Graves' orbitopathy (GO). This study investigated the risk of unnatural death in Graves' patients with and without orbitopathy compared to matched control populations. METHODS: This was a cohort study covering all adult Danes (≥18 years) diagnosed with GD or GO during 1995-2012. Median follow-up time was 7.9 years (range 0-17.5 years). Utilizing the Danish Register of Causes of Death and the Danish National Patient Registry, 28,461 subjects with GD and 3965 with GO were identified and matched for age and sex with four subjects from the background population. The manner of death was identified, and hazard ratios (HR) for mortality due to unnatural deaths (accident, suicide, violence/homicide, and unknown) were calculated using Cox regression analyses, adjusted for pre-existing somatic and psychiatric morbidity. RESULTS: In Graves' disease overall (GD + GO), there was an increased risk of death from unknown unnatural manners (HR = 2.01 [confidence interval (CI) 1.17-3.45], p = 0.012) and of suicide, although the latter difference was not with certainty statistically significant (HR = 1.43 [CI 1.00-2.04], p = 0.053). There was no significant difference in risk of death from suicide in GD subjects compared to their controls (HR = 1.27 [CI 0.85-1.89], p = 0.253). However, GO patients had a significantly higher risk of death from suicide (HR = 2.71 [CI 1.16-6.32], p = 0.022). CONCLUSIONS: Mortality by suicide was increased in Graves' disease overall, most significantly in patients with GO, also after adjustment for pre-existing somatic and psychiatric disease. These findings indicate that GD and GO may have a significant role in the pathophysiological mechanisms of suicidal behavior. Beyond independent confirmation, reasons for this need to be explored in order to introduce preventive measures.