SAT463 Hormonal Contraceptive Use and Hypothyroidism Risk

Disclosure: S. Gloe: None. T.B. Carroll: Consulting Fee; Self; Corcept Therapeutics. Research Investigator; Self; Corcept Therapeutics, Novartis Pharmaceuticals. Introduction: Thyroid dysfunction is one of the most common endocrine disorders, with an estimated 4.3% of the US affected by subclinical hypothyroidism and 0.3% affected by overt hypothyroidism. Chronic autoimmune thyroiditis is the most common cause of hypothyroidism in the US and is estimated to affect 5-10x more women than men. Given this higher incidence in women, it is possible that hormonal difference or hormonal medications may play a role in thyroid dysfunction. Nearly 15% of women aged 15-49 use oral contraceptive pills (OCP) and 10.4% use other long-acting reversible hormonal contraceptives. A recent study showed a 25% increased prevalence of hypothyroidism in women with prior OCP use and in women with more than 10 years of OCP use the risk of developing hypothyroidism was nearly 4 times as high. Methods: Using the TriNetX database, four distinct groups of women aged 18-45 were identified using data from 1/1/2010 -1/1/2020. The four groups were EPC (n=5849), POC (n=5052), IUD (n=1000), and controls without prior hormonal contraception use (n = 6677). Demographic data, date of diagnosis of hypothyroidism, alcohol use, tobacco use, and BMI was obtained for each subject. Exclusion criteria included thyroidectomy (partial or total), lack of sufficient medication data, and a hypothyroidism diagnosis prior to or within 90 days of the first contraceptive medication order. A logistic model was then created accounting for known risk factors for the development of hypothyroidism (race/ethnicity, alcohol use, smoking, and BMI).Results: Initial comparison of treatment groups to controls demonstrated an no difference in risk of developing hypothyroidism for the EPC group (OR=1.18, p=0.2), but the POC and IUD groups had decreased risk of hypothyroidism (OR=0.39, p=<0.001 and OR=0.45, p=0.029, respectively). Using the logistic model, all groups demonstrated a decreased risk of hypothyroidism as compared to the control group (EPC: OR=0.3, p=<0.001, POC: OR=0.14, p=<0.001, IUD: OR=0.12, p=<0.001). Additionally, individuals identifying as Black/African Americans were less likely to develop hypothyroidism when compared to white/Caucasian subjects (OR=0.25, p=<0.001). Finally, BMI showed a fairly weak but significant association with development of hypothyroidism (OR=1.04, p=< 0.0001). Conclusion: Contrary to prior research, our data suggests a potential protective effect against the development of hypothyroidism for EPC, POC, and IUD use. The data also confirms prior studies showing a lower incidence of hypothyroidism in individuals who identify as Black/African American and perhaps those with lower BMI. Presentation Date: Saturday, June 17, 2023