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Prevalence and risk of thyroid diseases in myasthenia gravis
Author(s) -
Chou ChengChe,
Huang ManHsu,
Lan WenChing,
Kong ShuSing,
Kuo ChangFu,
Chou IJun
Publication year - 2020
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/ane.13254
Subject(s) - medicine , cumulative incidence , myasthenia gravis , odds ratio , thyroid , hazard ratio , thyroid disease , confidence interval , incidence (geometry) , population , graves' disease , pediatrics , cohort , physics , environmental health , optics
Objectives To estimate the prevalence of thyroid diseases and the cumulative risk of thyroid diseases during a follow‐up period after myasthenia gravis (MG) diagnosis compared with non‐MG controls. Materials and Methods We used the Taiwan National Health Insurance Database linked to Registry of Catastrophic Illness database to identify patients with MG. The controls were composed of those who did not have MG and were matched with the MG patients by sex, age, and the index date. We recorded thyroid disease histories before and after the index date. Results Our study included 5813 MG patients and 29 065 controls. The prevalence of thyroid diseases in the MG patients at diagnosis was 18.4%, which was nearly 3.9‐fold greater than that in the control group. (Odds ratio [OR] 3.895, 95% Confidence interval [CI] 3.574‐4.246) After excluding pre‐existing thyroid diseases, the incidence of comorbid thyroid diseases was 8.7% in the MG patients and 4% in the control group. The MG patients had a 2.36‐fold increased risk of developing thyroid diseases compared to the control group. (crude hazard ratio [HR] 2.360, 95% CI 2.095‐2.659) The cumulative probabilities of developing thyroid diseases at 1, 5, and 10 years after the index date were 21.6%, 24.9%, and 28.7%, respectively, in the MG patients, while the cumulative probabilities were 6.5%, 8.8%, and 11.8%, respectively, in control group (log‐rank test <0.0001). Conclusions The current population‐based study showed a higher prevalence of pre‐existing thyroid diseases and a higher cumulative probability of thyroid diseases during follow‐up after MG diagnosis than in the general population.