Emerging pattern of asymptomatic hyperparathyroidism in South India – a six-year retrospective study

Introduction : Primary hyperparathyroidism (PHPT) is a common endocrine disease with a variable presentation. There is a recent increase in the number of asymptomatic cases due to the use of multichannel automated analyzers. Aim : To analyze the changing trend of PHPT patients from South India. Materials and methods : We collected the data on clinical presentation, biochemistry, radiological features, and operative findings of patients with PHPT treated in our hospital over a period of six years and looked at the differences between symptomatic and asymptomatic PHPT. Results : Our study included 80 patients. A significant proportion (~41%; n=33) of the patients were asymptomatic. Fifty-seven percent of asymptomatic patients were females. Mean age at presentation of asymptomatic patients was 50.58 (±14.67) compared to 47.28 (±14.78) for the symptomatic group, which was not statistically significant ( p =0.34). The mean levels of serum calcium, phosphorous, 25(OH)D, iPTH, and 24-hour urinary calcium in symptomatic vs. asymptomatic patients were 12.47 (±2.26) mg/dl vs. 12.27 (±1.82) mg/dl ( p =0.70), 2.59 (±0.74) mg/dl vs. 2.38 (±0.77) mg/dl ( p =0.27), 12 (±1.2) ng/ml vs. 10.85 (±1) ng/ml ( p =0.78), 1212.5 pg/ml vs. 678.5 pg/ml ( p =0.31), and 292.6 mg/day vs. 262 mg/day ( p =0.64), respectively. When Ca and gland weight were compared with variations in the iPTH levels, there was a significant positive correlation with PTH >600 pg/ml ( p =0.001) with no between-group differences. The adenoma weight increased by 0.5291 mg for every unit increase in iPTH in the entire cohort, with no between-group differences ( p =0.52). Conclusion : Asymptomatic hyperparathyroidism is increasingly being identified in clinical practice and constitutes a significant proportion of primary hyperparathyroidism. Though asymptomatic PHPT is expected to be milder, such a difference in presentation was not obvious in our study.