Is Paget Disease of Bone more Common in South India? Clinical Characteristics, Therapeutic Outcome and follow-up of 66 Patients from Tamil Nadu.

INTRODUCTION

Paget disease of bone (PDB) is a disorder of altered bone remodeling mainly characterized by increased osteoclastic activity. While the exact Indian prevalence remains unknown, a clustering of published cases suggests South Indian predominance.

OBJECTIVE

To study the clinico-biochemical profile and therapeutic response of patients with PDB and briefly review the epidemiology of PDB from an Indian perspective.

MATERIALS AND METHODS

Retrospective data was collected from the charts of patients who have been seen in endocrine out-patient clinics in Tamil Nadu over a 12-year period. Published literature on PDB from India was reviewed.

RESULTS

A total of 66 patients (71% males) predominantly from Tamil Nadu were studied. The mean age at presentation was 67 ± 8 years. Polyostotic involvement was seen in 89% and familial occurrence of PDB in 5 patients. Symptoms at presentation mainly included bone pain (51%) and skeletal deformities (18%). Scalp vein sign (21%) and sensorineural hearing loss (64%) were also noted. Incidental PDB detection by raised serum alkaline phosphatase (SAP) levels was observed in 17% and by abnormal fluorodeoxyglucose-positron emission tomography (FDG-PET) scan in 6% of cases. Mean SAP at presentation was 606 ± 438 IU/L (Normal, 76-140). Major skeletal site involvement includes pelvis (62.1%) and spine (34.8%). Mean (range) follow-up of the cohort was 3.4 yrs (1-12 yrs). In all, 64 subjects received zoledronate and two received alendronate, and mean (SD) SAP at 1-year was 73 ± 42 IU/L. All but two showed remission at the end of 1 year. Two had pathological fractures and two had sarcomas. A review of epidemiology of PDB in Indian literature clearly showed a South Indian predilection for unclear reasons.

CONCLUSION

In our cohort of PDB, male gender, polyostotic involvement, and hearing impairment were noted in more than two-thirds of patients and single-dose intravenous zoledronate was effective in normalizing SAP in almost all patients. PDB is intriguingly more common in South India and this needs more exploration.