Moderate alcohol consumption may protect against overt autoimmune hypothyroidism: a population-based case-control study.
OBJECTIVE
Alcohol consumption is an important protective risk factor for many autoimmune diseases. We wished to study the association between alcohol consumption and autoimmune hypothyroidism.


METHODS
Population-based, case-control study, 1997-2001, Denmark.


METHODS
Patients with newly diagnosed autoimmune overt hypothyroidism (n=140) were prospectively identified in a population (2 027 208 person-years of observation), and their matched controls with normal thyroid function (n=560) were recruited simultaneously from the same population. Participants gave information on alcohol intake, smoking, previous diseases, education, and family history of hypothyroidism. The association between alcohol intake and development of hypothyroidism was analyzed in conditional regression models.


RESULTS
Hypothyroid cases had reported a lower alcohol consumption than controls (median units of alcohol (12 g) per week: 3 vs 5, P=0.002). In a multivariate regression model, alcohol consumption was associated with a reduction in risk for development of overt autoimmune hypothyroidism. Odds ratios (95% confidence interval) compared with the reference group with a recent (last year) consumption of 1-10 units of alcohol per week were as follows: 0 units/week, 1.98 (1.21-3.33); 11-20 units/week, 0.41 (0.20-0.83); and ≥21 units/week, 0.90 (0.41-2.00). Similar results were found for maximum previous alcohol consumption during a calendar year. No interaction was found with type of alcohol consumed (wine vs beer), sex, or region of inhabitancy.


CONCLUSIONS
Alcohol consumption seems to confer considerable protection against development of overt autoimmune hypothyroidism irrespective of sex and type of alcohol consumed.
Department of Endocrinology and Medicine, Aalborg Hospital, Aarhus University Hospital, DK-9000 Aalborg, Denmark. carle@dadlnet.dk
Allan
A
Carlé
Inge Bülow
IB
Pedersen
Nils
N
Knudsen
Hans
H
Perrild
Lars
L
Ovesen
Lone Banke
LB
Rasmussen
Torben
T
Jørgensen
Peter
P
Laurberg
D000293:Adolescent; D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000453:epidemiology*; D000434:Alcoholic Beverages; D000465:Algorithms; D016022:Case-Control Studies; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011153:Population; D012307:Risk Factors; D013967:Thyroiditis, Autoimmune / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control*; D055815:Young Adult
D000431:Ethanol