SUN-384 Chronic Disease Prevalence Among Adults with Congenital Hypothyroidism

Abstract Disclosure: A.M. Lehman: None. Congenital hypothyroidism (CH) is an inborn defect in thyroid hormone synthesis, usually due to sporadic thyroid dysgenesis. Incidence is 1:2000-1:4000. Newborn screening began in the 1970s, allowing early initiation of levothyroxine and largely ameliorating CH as a cause of neurodevelopmental disability. The oldest adults with CH identified by newborn screen are now in their late 40s. CH studies have focused on childhood neurodevelopmental outcomes, and it remains largely unknown how adults with CH may differ from adults with acquired hypothyroidism. Our study seeks to increase understanding of CH outcomes in adults as the newborn screening cohort ages. We compared the prevalence of 20 chronic diseases in a deidentified population of 18-44 year olds with CH (n=114) to 18-44 year olds with acquired hypothyroidism (AH, n=9962) who sought care at a midwestern academic medical center between 2013-2023. Using the University of [State] Healthcare Enterprise Repository for Ontological Narration (HERON) database, we queried each group for 546 ICD-9 and ICD-10 codes for these diseases, then quantified how many unique patients in each group had one or more diagnosis code for each disease. We used Fisher’s exact test to compare prevalence between CH and AH groups. Prevalence of each diagnosis was also compared to the age 18-44 euthyroid population seen in 2023 (ET, n=149241). Type II diabetes was less prevalent in CH than AH (5.3% vs 11.8%, OR 0.42, p=0.0276) but not significantly different between CH and the ET population (4.08%), a finding which may be explored in future studies. Thyroid cancer was also less common in CH than AH patients (0.88% vs. 4.76%, OR 0.18, p=0.0449), as expected. Consistent with studies of children with CH, prevalence of hearing loss (12.3%), congenital heart defects (CHD, 6.1%) and autism spectrum disorders (ASD, 5.3%) were higher in CH than ET or AH. Anxiety disorders were the most prevalent comorbidities among all groups (CH 34.2%, AH 37.4%, ET 25.8%), higher among hypothyroid groups than the ET population, but not different between CH and AH. Hypertension, heart failure, arrhythmias, atherosclerotic heart disease, chronic kidney disease and asthma were also more prevalent in both hypothyroid groups than the ET population, but not different between CH and AH, including controlling for CHD. There was no difference in prevalence of hyperlipidemia, stroke, type I diabetes, obstructive pulmonary disease, non-thyroid cancers, osteoporosis, arthritis, substance use disorders, schizophrenia, or attention deficit hyperactivity disorder between CH and other groups. Our findings indicate that CH adults share increased risks for anxiety, asthma, and cardiovascular comorbidities with AH adults, but not for type II diabetes or thyroid cancer. CH adults are more likely to have hearing loss, CHD, and ASD than AH adults. Presentation: Sunday, July 13, 2025