THYROID-DISEASE IN MIDDLE-AGED AND ELDERLY SWEDISH WOMEN - THYROID-RELATED HORMONES, THYROID-DYSFUNCTION AND GOITER IN RELATION TO AGE AND SMOKING

The prevalence of thyroid disease and the concentration of thyroid hormones and thyrotropin were studied in a random population sample of 1154 women, aged 50-72 years, with special reference to the effect of age and smoking. The prevalence of spontaneous hypothyroidism was 3.3% (previously unknown overt and mild disease 1.3%) and the prevalence of hyperthyroidism was 2.5% (previously unknown disease 0.2%). Clinically suspected hyper- or hypothyroidism (very weak to strong) was recorded in 288 women, but was only verified in three cases. The prevalence of visible and palpable thyroid enlargement was 2.1% and 13-14%, respectively. Total thyroxine concentrations increased and free tri-iodothyronine levels decreased significantly with age (P < 0.001). The serum thyrotropin concentrations were lower in smoking women than in non-smokers in the 50- and 58-year age groups (P < 0.05). There was no increase in the prevalence of thyroid disease or goitre in the women who were smokers at the time of the study.