Class III Obesity as a Presenting Syndrome in Prolactinoma Patients: Insights Into Obesity and Metabolic Dysfunction in This Unique Group

Abstract

The occurrence of patients with lactotroph adenoma presenting with class III obesity is extremely rare. This study reports long-term outcomes of such patients treated with transsphenoidal surgery (TSS) or dopamine agonists (DAs) and integrates findings with existing literature to explore prolactin's (PRL) role in obesity pathophysiology. We analysed BMI and metabolic changes and compared findings with published case series. Four patients presented with class III obesity (BMI range, 40.0–43.1 kg/m²). The diagnostic work-up revealed hyperprolactinemia (PRL range, 56.1–4389 μg/L) and hypogonadism in all patients, with sellar MRI indicating a macroadenoma in all but one patient. Over a median follow-up of 31 months (range 24–144), both TSS (n = 2) and DAs (n = 2) effectively controlled hyperprolactinemia and hypogonadism. BMI changes (ΔBMI/year) were −1.4 ± 1.8 kg/m²/year (TSS) and −3.9 ± 3.4 kg/m²/year (DAs), with non-significant metabolic improvements. Analysis of 22 additional cases revealed similar trends. Higher baseline BMI and macroprolactinoma were risk factors for persistent obesity. Early PRL screening in patients with class III obesity, weight loss interventions and long-term hyperprolactinemia management are essential. Both TSS and DAs provide metabolic benefits, highlighting the need for a multidisciplinary approach in diagnosing and managing lactotroph adenomas with obesity.