Immune checkpoint inhibitor-induced thyroid dysfunction is associated with higher body mass index

Abstract

Context: Obesity is a proinflammatory metabolic state that may play a role in the development of immune-related adverse events (irAEs) associated with immune checkpoint inhibitor therapy. Objective: To characterize the association between body mass index (BMI) and thyroid irAEs. Methods: We performed a single-center, retrospective analysis of 185 cancer patients treated with anti-PD-1/L1 from January 2014 to December 2018. Patients with normal thyroid function at baseline and available BMI were included. Main outcome measures: The primary endpoint was difference in BMI in patients who developed overt thyroid dysfunction versus those who remained euthyroid following anti-PD-1/ L1 initiation. Additional endpoints included any (overt or subclinical) thyroid dysfunction, overt thyrotoxicosis or overt hypothyroidism, and time to development of dysfunction according to BMI. Results: Any thyroid dysfunction developed in 72 (38.9%) patients and 41 (22.1%) developed overt thyroid dysfunction. Mean BMI was higher in those with overt thyroid dysfunction versus euthyroid (27.3 ± 6.0 vs 24.9 ± 4.5, P = .03). Development of overt thyrotoxicosis versus remaining euthyroid was associated with higher BMI (28.9 ± 5.9 vs 24.9 ± 4.5; P