Increased prevalence of subclinical hypothyroidism in females in mountainous valley of Kashmir

Indian J Endocrinol Metab. 2013 Mar;17(2):276-80. doi: 10.4103/2230-8210.109709.

Abstract

Background: Iodine-rich diet is necessary for proper thyroid gland function. Subclinical hypothyroidism (SCH) is associated with serious complications. Substantial numbers of patients have risk of SCH getting converted into primary hypothyroidism.

Objectives: The objectives of the present study are to survey dietary iodine intake pattern in ethnic population of Kashmir and to study the prevalence of SCH.

Materials and methods: A retrospective, cross-sectional referral hospital study was conducted. Sample size comprised of 2550 patients who were referred to Department of Biochemistry, Government Medical college, Srinagar diagnostic laboratory from OPD and IPD of associated SMHS hospital. Assessment of thyroid function over a period of one year from March 2010 to March 2011 in the serum has been performed by electro-chemiluminescence immunoassay method on ECLIA 2010 fully automatic analyzer. Interview cum questionnaire methods were used to record the patient history and dietary iodine intake pattern. Iodine status of these patients was assessed by measuring urinary iodine excretion.

Results: Total patients were 2550 comprising of 44.6% males and 56.4% females. Subjects with elevated and normal thyroid stimulating hormone (TSH) levels in the serum were 30.51 and 69.4% respectively. About 550 patients (21.56%) had subclinical hypothyroidism which includes both males and females. Prevalence of SCH was more in females (81.8%) than in males (18.2%). Most of the patients presenting with SCH were in the age group of 20-65 years.

Conclusion: The percentage of SCH amongst the study sample patients was 21.56%, which is much higher as compared to other parts of the world. The highest percentage of SCH was found in females (81.8%) as compared to males (18.2%). On the basis of the present study, we suggest that routine screening of selected populations, especially women between 20 and 65 years of age, may be advocated. Further community level awareness programs need to be organized wherein people in mountainous valley of Kashmir are motivated to take salt in iodized form and diet rich in iodine to ensure proper thyroid gland functioning.

Keywords: Dairy products; iodine rich food; strawberries; subclinical hypothyroidism; thyroid stimulating hormone; urinary iodine excretion.