A case-control study of the association between ulcerative colitis and hyperthyroidism in an Asian population.
OBJECTIVE
Ulcerative colitis (UC) is a chronic relapsing inflammatory disease with significant clinical diversity. However, the aetiology, pathogenesis and optimal treatment of UC remain unclear. The purpose of this case-control study was to investigate the association between previously diagnosed hyperthyroidism and UC using a large population-based data set in Taiwan.


METHODS
The data for this population-based case-control study were retrieved from the Taiwan Longitudinal Health Insurance Database 2005. We included 2709 patients with UC as cases and 8127 sex- and age-matched patients without UC as controls. A conditional logistic regression analysis was conducted to compute the odds ratio (OR) and corresponding 95% confidence interval (CI) for the association between UC and prior hyperthyroidism.


RESULTS
We found that, in total, 327 of the 10 836 sampled patients (3.02%) had previously been diagnosed with hyperthyroidism. There was a higher proportion of prior hyperthyroidism among cases than controls (4.10% vs 2.66%, P<.001). A conditional logistic regression showed that the OR of prior hyperthyroidism was 1.57 (95% CI=1.24-1.98) compared to controls. Similarly, after adjusting for monthly income, geographic location and urbanization level, cases were still more likely to have previously been diagnosed with hyperthyroidism than controls (OR=1.61, 95% CI=1.27-2.05). Furthermore, we analysed the ORs of prior hyperthyroidism between cases and controls according to age group. We found that of the youngest group of sampled patients (18-39 years), cases had the greatest adjusted OR for having previously been diagnosed with hyperthyroidism than controls (OR=1.98, 95% CI=1.04-3.79).


CONCLUSIONS
This study demonstrated an association between UC and hyperthyroidism.
Division of Gastroenterology, Department of Internal Medicine, Hsinchu Cathay General Hospital, Hsinchu, Taiwan.
Ming-Chieh
MC
Tsai
School of Health Care Administration, Taipei Medical University, Taipei, Taiwan.
Herng-Ching
http://orcid.org/0000-0003-4661-959X
HC
Lin
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Cha-Ze
CZ
Lee
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000209:etiology*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000150:complications*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult