Primary Hyperparathyroidism: An Analysis Amid the Co-Occurrence of Type 2 Diabetes Mellitus

Apart from classical elements in primary hyperparathyroidism (PHPT), non-classical complications, including type 2 diabetes mellitus (T2DM), are reported in some patients, but currently, they do not represent a parathyroidectomy (PTx) indication.

to explore the latest data regarding glucose profile, particularly, T2DM and metabolic syndrome (MetS) in PHPT, including post-PTx.

PubMed-based review included English-published original studies between January 2020 and December 2024 (n = 20).

Studied population: 764,485 subjects (female-to-male ratio of 1.26:1; 23,931 were PHPT patients vs. 740,502 controls). T2DM prevalence (n = 13; N = 763,645 patients; 55.92% females): 4-60% (higher vs. controls); for the largest study (N = 699,157) of 31.3%. Age-based analysis: higher T2DM prevalence at >50 vs. <50 years (14.4% vs. 2.6%, p < 0.001), but not all studies agreed. Concurrent vitamin D deficiency as a contributor to a higher risk had limited evidence. The association MetS-PHPT (n = 2) had no clear conclusion. Post-PTx showed the following: lower glycaemia, fasting insulin, insulin resistance (HOMA-IR) improvement, and reduced rate (but not all studies agreed). PHPT patients with prediabetes might represent the population sub-group with the highest post-PTx benefit.

The panel of PHPT-T2DM interplay remains heterogeneous. Data regarding post-PTx improvement of glucose disorders are still conflicting, recent findings suggested that surgery has beneficial effects, especially in patients with confirmed pre-existing prediabetes. Patients with the normocalcemic variant seemed to be less affected by the glucose-related disturbances, but further studies are needed. A better understanding of the intricate relationship between PHPT and glucose metabolism anomalies will help in providing optimal management to reduce the overall disease burden.