title: Prevalence of goitre in Isfahan, Iran, fifteen years after initiation of universal salt iodization.
abstract: This cross-sectional study investigated the prevalence of goitre in Isfahan, a centrally-located city in Iran, 15 years after the initiation of universal salt iodization. In total, 2,523 Isfahani adults (1,275 males, 1,248 females) aged > 20 years were selected by multi-stage cluster-sampling method. Goitre rate, serum thyroid-stimulating hormone (TSH), thyroxine (T4), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), and urinary iodine concentration (UIC) were measured and compared between the goitrous (n = 478) and the non-goitrous (n = 2,045) participants. The total goitre rate was 19% (n = 478) of the 2,523 adults. The rate of Grade I and II goitre was 12.4% (n = 312) and 6.6% (n = 166) respectively. The total goitre rate, Grade I and II goitre were more prevalent among women than among men. Hypothyroidism was observed in 6.4% (130/2,045) and 18.6% (89/478) of the non-goitrous and goitrous participants respectively [odds ratio (OR) = 3.6, 95% confidence interval (CI) 2.7-4.9, p = 0.001]. Hyperthyroidism was present in 0.8% (17/2,045) and 5.2% (29/478) of the non-goitrous and goitrous adults respectively (OR = 9.0, 95% CI 4.9-16.6, p = 0.001). Hypothyroidism was more prevalent in Grade II than in Grade I goitre and among those without goitre (31.3%, 14.1%, and 6.4% respectively) (p = 0.001). Positive TPOAb was observed in 24% (n = 50) of the non-goitrous and 33.5% (n = 84) of the goitrous subjects (p = 0.03). Positive TPOAb was observed in 24.6% (35 of 142) of the Grade I and 45% (49 of 109) of the Grade II goitrous adults (p = 0.001). Positive TgAb was observed in 21.6% (n = 45) of the non-goitrous and 35.9% (n = 90) of the goitrous adults (p = 0.001). Positive TgAb was observed in 30.3% (43 of 142) of the Grade I and 43.1% (47 of 109) of the Grade II goitrous adults (p = 0.04). The median UIC was 18 microg/dL (range 1-80 microg/dL). It was 17.9 microg/dL and 19 microg/dL in the non-goitrous and goitrous adults respectively. After 15 years of successful universal salt iodization in Isfahan, goitre is still endemic, which may be due to thyroid autoimmunity. However, other environmental or genetic factors may have a role.
authors.affiliation: Isfahan Endocrine and Metabolism Research Center, Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. aminorroaya@med.mui.ac.ir
authors.forename: Ashraf
authors.initials: A
authors.lastname: Aminorroaya
authors.forename: Massoud
authors.initials: M
authors.lastname: Amini
authors.forename: Silva
authors.initials: S
authors.lastname: Hovsepian
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006043:Goiter, Endemic / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control* / Q000652:urine; D006801:Humans; D007455:Iodine / Q000008:administration & dosage* / Q000652:urine; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018673:Nutrition Policy / Q000331:legislation & jurisprudence; D015995:Prevalence; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D017673:Sodium Chloride, Dietary; C006606:anti-thyroglobulin; C034024:iodized salt; D007455:Iodine
references.citation: East Mediterr Health J. 2008 Mar-Apr;14(2):325-32
references.pmid: 18561724
references.citation: Eur J Endocrinol. 2000 Nov;143(5):639-47
references.pmid: 11078988
references.citation: Thyroid. 1998 Sep;8(9):827-56
references.pmid: 9777756
references.citation: Int J Vitam Nutr Res. 2002 Oct;72(5):291-5
references.pmid: 12463103
references.citation: Thyroid. 2001 May;11(5):501-10
references.pmid: 11396709
references.citation: Thyroid. 2001 May;11(5):457-69
references.pmid: 11396704
references.citation: J Endocrinol Invest. 2002 May;25(5):409-13
references.pmid: 12035935
references.citation: Thyroid. 2003 Feb;13(2):199-203
references.pmid: 12699595
references.citation: J Clin Endocrinol Metab. 2000 Oct;85(10):3798-802
references.pmid: 11061541
references.citation: Eur J Clin Nutr. 1990 Jan;44(1):17-22
references.pmid: 2354688
references.citation: J Endocrinol Invest. 2003;26(2 Suppl):43-8
references.pmid: 12762640
references.citation: Natl Med J India. 1993 May-Jun;6(3):110-3
references.pmid: 8329988
references.citation: Eur J Endocrinol. 2006 Aug;155(2):219-28
references.pmid: 16868134
references.citation: J Clin Endocrinol Metab. 2003 Feb;88(2):617-21
references.pmid: 12574190
references.citation: J Endocrinol Invest. 2008 May;31(5):422-31
references.pmid: 18560260
references.citation: Arch Med Res. 2007 Jan;38(1):1-14
references.pmid: 17174717
references.citation: Baillieres Best Pract Res Clin Endocrinol Metab. 2000 Dec;14(4):577-600
references.pmid: 11289736
references.citation: J Endocrinol Invest. 2007 May;30(5):404-10
references.pmid: 17598973
references.citation: Indian J Pediatr. 1992 Sep-Oct;59(5):585-91
references.pmid: 1459681