Association of Hypothyroidism and Hyperprolactinaemia with the Risk of Benign Breast Disease: A Case–Control Study

A bstract Context: Benign breast disease (BBD) is a common condition amongst women of reproductive age. Hormonal imbalances, particularly involving prolactin and thyroid function, may play a role in its development. Aims: This study aimed to investigate the co-occurrence of hypothyroidism and hyperprolactinaemia in individuals diagnosed with BBD, and to elucidate the potential correlation between serum prolactin concentrations and thyroid-stimulating hormone (TSH) levels in this patient population. Settings and Design: A case–control study conducted in the surgical department from December 2022 to May 2024 was included in this study. Materials and Methods: Seventy females of reproductive age diagnosed with BBD were included as cases. Age- and sex-matched healthy women without BBD served as controls. Serum prolactin and TSH levels were measured and compared between these groups. Statistical Analysis Used: Median values and interquartile ranges (IQR) were compared using appropriate statistical tests. A P value of <0.05 was considered statistically significant. Results: Amongst 70 cases, 92.86% presented with breast lumps, with fibroadenoma comprising 90% of diagnoses. Median serum prolactin levels were significantly higher in cases than controls (11.34 ng/mL, IQR: 6.70–120.77 vs. 8.33 ng/mL, IQR: 1.12–25.43; P = 0.01). No significant difference was observed in TSH levels between groups (2.82 µIU/mL, IQR: 0.48–23.02 vs. 3.26 µIU/mL, IQR: 0.38–9.12; P = 0.22). Hyperprolactinaemia emerged as an independent risk factor for BBD. Conclusions: BBD appears to be more closely associated with abnormal prolactin secretion than thyroid dysfunction. Routine prolactin monitoring in BBD patients may enhance disease management.