High androgen levels protect against hypothyroidism

Area of Science:

• Endocrinology
• Reproductive Health
• Thyroidology

Background:

• Hypothyroidism is a prevalent endocrine disorder, disproportionately affecting women.
• Polycystic Ovary Syndrome (PCOS) is associated with hyperandrogenism, and its impact on hypothyroidism risk is not well-established.

Purpose of the Study:

• To investigate the hypothesis that hyperandrogenism, a hallmark of PCOS, may confer protection against the development of hypothyroidism.
• To compare the prevalence of hypothyroidism in women with PCOS, women with Turner syndrome, men, and the general female population.

Main Methods:

• Comparative analysis of data from prospective follow-up and register studies.
• Inclusion of cohorts: women with PCOS (n=25), women with Turner syndrome (n=217), a general female population sample (n=315), and men (n=95).
• Verification in a large cohort of females (n=553,716) and measurement of thyroid peroxidase antibodies (TPO).

Main Results:

• Hypothyroidism prevalence was significantly lower in women with PCOS (8% >50 years) and men (4%) compared to women with Turner syndrome (43%) and the general postmenopausal population (17%).
• Hypothyroidism incidence increased with age in most groups, except for PCOS women and men.
• Register study confirmed lower hypothyroidism rates in women with PCOS (5.5%) versus women without PCOS (6.8%) aged >25 years.

Conclusions:

• Hypothyroidism is less frequent in women with PCOS and men compared to the general female population and women with Turner syndrome.
• The protective effect against hypothyroidism in PCOS and men is not attributable to altered autoimmunity or the Y-chromosome.
• Findings support the hypothesis that androgens play a protective role against hypothyroidism.