Progressive rise in the prevalence of asymptomatic primary hyperparathyroidism in India: Data from PHPT registry

Primary hyperparathyroidism (PHPT), a third common endocrine disorder, varies from asymptomatic disease, mostly seen in the West where routine biochemical screening is practiced, to the classical symptomatic disease mostly seen in the Eastern countries. We aimed to compare the demographic, clinical, biochemical measurements in patients with asymptomatic and symptomatic PHPT from the Indian PHPT registry.

Data of PHPT patients from the last 25 years (1995-2019) were analyzed for demographic, clinical presentation and biochemical measurements, and compared these characteristics between asymptomatic and symptomatic PHPT patients.

Of the 554 patients, 54 (10%) patients had asymptomatic PHPT. There was a sharp rise in the proportion of asymptomatic PHPT patients of 3% in the first decade to 13% in the second decade of the century (p = 0.003). Patients with asymptomatic PHPT were significantly older (50 vs. 42 years; p < 0.0001) and had higher mean body mass index (27.8 vs. 23.5 kg/m²; p < 0.0001) compared to the symptomatic PHPT group. In addition, asymptomatic PHPT patients had significantly lower median plasma iPTH (180 vs. 370 pg/mL; p < 0.0001), serum alkaline phosphatase (119 vs. 172 IU/L; p < 0.0001), and parathyroid adenoma weight (1.0 vs. 2.62 g; p = 0.006) compared to the symptomatic PHPT group.

Although symptomatic PHPT is still most prevalent (> 90%) in India with higher indices of the disease and tumor weights, there is a progressive rise in the prevalence of asymptomatic PHPT patients in the last decade. Improvements in calcium and vitamin D nutrition might account for this change as in the Western series.