Paget's disease of bone: experience from a centre in southern India.

BACKGROUND: Paget's disease is a localized disorder of the skeleton characterized by increased osteoclastic activity. While the prevalence in the Western Population is 1-2%, the prevalence in India is not known. We studied the clinical profile, biochemical parameters, bone scans, therapeutic details and follow up data of patients with Paget's disease, attending the Endocrinology outpatient clinic in our institution.
METHODS: A retrospective review was done of the medical records of 51 patients seen in a tertiary referral centre in Southern India from 1995 to 2003. The data was analyzed using SPSS 9.0 software package.
RESULTS: There were a total of 51 patients (41 male and 10 female). The mean age at presentation was 56 years and the mean duration of symptoms was 43 months. At least 6 months of follow-up was available in 31 patients and longer term (>2 years) follow-up in 22 patients. The symptoms at presentation were bone pain in 65%, low backache in 37%, skeletal deformities in 33%, pathological fractures in 20%, neurogenic claudication in 4%, deafness and head enlargement in 7% and renal stones in 4% of subjects. Five patients (9.8%) were asymptomatic and were incidentally diagnosed during evaluation of an elevated alkaline phosphatase. The mean serum alkaline phosphatase (range and SD) at the time of presentation was 690 IU/L (91-3873 U/L, 698 U/L). There was no statistically significant difference in the serum alkaline phosphatase values between female and male patients (576 U/L versus 718 U/L). Polyostotic involvement was seen in 90.2% of the patients. The pattern of skeletal involvement was very similar to that described in the Western literature. Twenty patients were started on Calcitonin and of these, 13 patients were later changed over to bisphosphonates to induce remission. In all, thirty six subjects received Alendronate and of them, 31 received lower doses (10-20mg/day). All the treated patients showed a good clinical and biochemical improvement. Two patients with severe Pagetic involvement of the bone who also had neurologic symptoms (root pains in one and cauda equina lesion in the other) needed intravenous Pamidronate to obtain a rapid response in the initial phase of treatment.
CONCLUSIONS: In our series, Paget's disease had a male predominance. The clinical presentation and the pattern of skeletal involvement was similar to the Western series. Serum alkaline phosphatase declined by 40% at 6 months of therapy and by 64% by one year of treatment in patients who were on lower doses of Alendronate (10-20 mg/day) in our series, which is similar to what has been described with conventional doses (40 mg per day) in the Western series.