Comparison Of Profile Of Primary Hyperparathyroidism With And Without Type 2 Diabetes Mellitus: Retrospective Analysis From The Indian PHPT Registry.

ABSTRACT PURPOSE To describe the prevalence and compare the clinico-biochemical profile of primary hyperparathyroidism (PHPT) patients with and without type 2 diabetes mellitus (T2DM) Material & Methods We conducted a retrospective observational study wherein details of PHPT patients with T2DM (PHPT-T2DM) and without diabetes mellitus were retrieved from the Indian PHPT Registry (www.indianphptregistry.com) between 2005-2019. We compared the clinical, biochemical and post-operative findings of PHPT-T2DM patients with age, sex and body mass index-matched PHPT patients without T2DM (1:2 ratio). Results Out of 464 PHPT patients, 54 (11.6%) had T2DM. We observed an increase in the prevalence of PHPT-T2DM cases over time; only 7.1% of the total PHPT cases had T2DM in 2005-2009 that increased to 12.8% in the last half-decade (2015-2019). PHPT-T2DM patients had a significantly lower prevalence of nephrolithiasis (18.5% vs. 36.1%, p=0.03) and a higher prevalence of pancreatitis (22.2% vs. 5.6%, p=0.007) than those without T2DM. Furthermore, intact parathyroid hormone levels (203 (139.8-437.3) vs. 285 (166-692) pg/ml, p=0.04) and serum creatinine (0.90 (0.67-1.25) vs. 1.10 (0.73-1.68)mg/dL, p=0.03) were significantly lower in PHPT-T2DM patients. Besides, tumor weight tended to be lower in PHPT-T2DM patients compared to non-T2DM counterparts (1.05 (0.5 – 2.93) vs. 2.16 (0.81-7.0) g, p=0.06). Conclusions The prevalence of T2DM in Asian-Indians with PHPT is 11.6%. PHPT-T2DM patients are characterized by a higher prevalence of pancreatitis, lower prevalence of nephrolithiasis and lower levels of iPTH/creatinine. Part of the clinical picture can be possibly explained by early detection of PHPT in T2DM patients consequent to more frequent screening.