Male gender differences in the thyroid ultrasound features, thyroid peroxidase antibodies and thyroid hormone levels: a large population-based study

Anti-thyroid antibodies and thyroid ultrasound (US) are currently the methods for diagnosing autoimmune thyroid disease. Few data exist on their utility in males. The aim of the study was to investigate the gender-specific relationship between the Anti-TPO levels, thyroid ultrasound features, and thyroid function in a population with no known thyroid disorder. Methods We studied 1,887 subjects, 20-80 years, 953 females, 934 males. Anti-TPO antibodies, TSH and FT4 were measured and ultrasound of the thyroid was performed. The subjects were divided into antibody-positive and antibody-negative, and into four US pattern groups. The prevalence of subclinical (SHT) and overt (OHT) hypothyroidism was determined. Results Antibody positivity was found in 23 % of females and 10 % of males (p < 0.01), being highest in the hypoechoic/non-homogenous subgroups [68 % Ab-positive females versus 41 % Ab-positive males (p < 0.001)]. Hypothyroidism was most prevalent in the antibody-positive subjects with hypoechoic non-homogenous pattern (35 %, both genders). Odds ratios for hypothyroidism were similar in males and females with hypoechoic non-homogenous pattern (5.91, 95 % CI 2.50, 13.96 vs. 6.27, 95 % CI 2.64, 14.91), but higher in Ab-positive females than males. SHT was found in 4.5 % of females and 2 % of males, OHT in 3.2 % of females and 1.1 % of males. 65 % of the females with SHT, 81 % of those with OHT, 26 % of the males with SCH and 60 % with OHT were Anti-TPO positive. Conclusion The prevalence and pattern of autoimmunerelated changes differed in the two genders. Hypothyroidism prevalence was similar in both genders when both hypoechoic/non-homogenous pattern and anti-TPO positivity were present.