TY - JOUR
T1 - Smoking cessation is followed by a sharp but transient rise in the incidence of overt autoimmune hypothyroidism - A population-based case-control study
AU - Carlé, Allan
AU - Pedersen, Inge Bülow
AU - Knudsen, Nils
AU - Perrild, Hans
AU - Ovesen, Lars
AU - Rasmussen, Lone Banke
AU - Jørgensen, Torben
AU - Laurberg, Peter
N1 - © 2012 Blackwell Publishing Ltd.
PY - 2012/11
Y1 - 2012/11
N2 - Background Current smoking is associated with a low prevalence of thyroid autoantibodies. On the other hand, smoking withdrawal enhances thyroid autoantibody level and may be a risk factor for the development of hypothyroidism. The aim of this study was to assess the association between smoking habits (smoking cessation in particular) and development of autoimmune hypothyroidism. Design Population-based, case-control study. Participants Cases (n = 140) newly diagnosed with primary autoimmune overt hypothyroidism were identified prospectively by population monitoring (2 027 208 person-years of observation) of all thyroid function tests performed in the two well-defined geographical areas. Individually, age-, sex- and region-matched euthyroid controls (n = 560) were simultaneously included from the same population. Measurements Participants gave details on smoking habits including smoking withdrawal and other lifestyle factors. Smoking habits were verified by measuring urinary cotinine (a nicotine metabolite). Results Incident hypothyroidism was very common in people who had recently stopped smoking: OR vs never smokers (95%-CI); quit smoking <1 years, 7·36 (2·27-23·9); 1-2 years, 6·34 (2·59-15·3); 3-10 years, 0·75 (0·30-1·87); >10 years, 0·76 (0·38-1·51). Results were consistent in both sexes and irrespective of age. Within two years after smoking cessation, the percentage of hypothyroid cases attributable to cessation of smoking was 85%. The current smoking was not associated with altered risk of developing overt hypothyroidism [OR, 0·92 (0·57-1·48)]. Conclusions The risk of having overt autoimmune hypothyroidism diagnosed is more than 6-fold increased the first 2 years after cessation of smoking. Clearly, smoking cessation is vital to prevent death and severe disease. However, awareness of hypothyroidism should be high in people who have recently quit smoking, and virtually any complaint should lead to thyroid function testing.
AB - Background Current smoking is associated with a low prevalence of thyroid autoantibodies. On the other hand, smoking withdrawal enhances thyroid autoantibody level and may be a risk factor for the development of hypothyroidism. The aim of this study was to assess the association between smoking habits (smoking cessation in particular) and development of autoimmune hypothyroidism. Design Population-based, case-control study. Participants Cases (n = 140) newly diagnosed with primary autoimmune overt hypothyroidism were identified prospectively by population monitoring (2 027 208 person-years of observation) of all thyroid function tests performed in the two well-defined geographical areas. Individually, age-, sex- and region-matched euthyroid controls (n = 560) were simultaneously included from the same population. Measurements Participants gave details on smoking habits including smoking withdrawal and other lifestyle factors. Smoking habits were verified by measuring urinary cotinine (a nicotine metabolite). Results Incident hypothyroidism was very common in people who had recently stopped smoking: OR vs never smokers (95%-CI); quit smoking <1 years, 7·36 (2·27-23·9); 1-2 years, 6·34 (2·59-15·3); 3-10 years, 0·75 (0·30-1·87); >10 years, 0·76 (0·38-1·51). Results were consistent in both sexes and irrespective of age. Within two years after smoking cessation, the percentage of hypothyroid cases attributable to cessation of smoking was 85%. The current smoking was not associated with altered risk of developing overt hypothyroidism [OR, 0·92 (0·57-1·48)]. Conclusions The risk of having overt autoimmune hypothyroidism diagnosed is more than 6-fold increased the first 2 years after cessation of smoking. Clearly, smoking cessation is vital to prevent death and severe disease. However, awareness of hypothyroidism should be high in people who have recently quit smoking, and virtually any complaint should lead to thyroid function testing.
U2 - 10.1111/j.1365-2265.2012.04455.x
DO - 10.1111/j.1365-2265.2012.04455.x
M3 - Journal article
C2 - 22651374
SN - 0300-0664
VL - 77
SP - 764
EP - 772
JO - Clinical Endocrinology
JF - Clinical Endocrinology
IS - 5
ER -