Long-term control of Paget’s disease of bone with low-dose, once-weekly, oral bisphosphonate preparations, in a “real world” setting

Abstract

We thank Liel Y et al. [1] for sharing their significant study indicating that in a large proportion of “real world” Paget’s bone disease patients, remission can be achieved with once-weekly, “osteoporosis doses” of alendronate or risedronate. In this study, 21 patients (7 women and 14 men) were followed for a mean of 11.9 years. Out of 96 treatment courses with amino-bisphosphonates were observed, among them 85 with alendronate and 11 with risedronate. We have several concerns with the study. The authors used serum total alkaline phosphatase (ALP) in combination with liver function tests for determining PDB activity. Although ALP is recommended in many guidelines as the first-line biochemical screening test, one of recently published study in evaluating the utility of bone turnover markers in PDB patients showed that procollagen type 1 N-terminal propeptide (P1NP) may be the best markers in following patients with Paget’s disease before and after treatment [2]. Thus, if possible, P1NP should be monitored when the patients were investigated. Furthermore, bone turnover markers always differ by calcium and vitamin D nutrition status, since secondary hyperparathyroidism induced by vitamin D insufficiency or deficiency would significantly influence bone metabolism. The author emphasized that all the patients received regular calcium and vitamin D supplementations, but it is still reasonable to show both 25(OH) D and intact-parathyroid hormone level at the time of each initiation, cessation of bisphosphonate treatment and duration of remission. Finally, there were about 50% percent of patients aged over 65-years-old and three patients over 80 years in this study. How many patients had osteoporosis or osteopenia or normal bone mineral density? What was the impact of bisphosphonate treatment on their bone mass? We recommend the author should specify the possible effect of long-term antiresorptive treatment on patient’s bone, especially in very old people [3].