리튬을 사용한 병력이 없는 양극성장애 환자에서의 갑상선기능저하증

Objectives：Hypothyroidism is highly reported in bipolar patients. However it is controversial that the cause of hypothyroidism in bipolar patients is lithium or affective disorder itself. This study aims to exam the prevalence of hypothyroidism in lithium naive bipolar patients and also to exam the predictor of hypothyroidism in lithium naive bipolar patients. Methods：We retrospectively reviewed medical charts of 394 bipolar patients who visited Psychiatric Outpatient clinic of Ulsan university hospital between March 1, 2011 and February 28, 2013 and have never been exposed to lithium before they visit the clinic. Sex, age, number of previous episode, duration of illness, bipolar diagnostic subtype, rapid cycling pattern, Free T4 and TSH levels at first visit was evaluated from charts. Results：The proportion of total thyroid abnormality was 50(12.7%). Among them hypothyroidism was 29(7.4%). There are no differences between different sex, age distribution, duration of illness, number of previous episode, rapid cycling and diagnostic subtypes. There is no demographic and clinical variable which predict hypothyroidism in bipolar patients significantly. Conclusion：Lithium may contributed as a confounding variable to the hypothyroidism in bipolar patients. Our data do not support the previous finding of higher rate of hypothyroidism in female and rapid cycling bipolar patients. Further study is necessary to explore the relationship between lithium associated hypothyroidism and various demographic and clinical variables.