Metabolic bone disease in patients receiving home parenteral nutrition: a Canadian study and review

Metabolic bone disease (MBD) is a significant complication in patients receiving long-term home parenteral nutrition (HPN). Pamidronate has been poorly studied in this population. We examine the prevalence and risk factors for MBD and examine changes in bone mineral density (BMD) after pamidronate administration.

First, a chart review of patients receiving HPN for >1 year was performed, and Pearson correlations were used to assess associations between MBD (defined as t score<-1) and risk factors. Second, the effect of IV pamidronate on BMD was studied prospectively in 11 HPN patients. Results were compared using a t-test.

Charts were reviewed in 25 patients (15 F, 10 M): age, 56.9+/-3.1 years; body mass index (BMI), 21.2+/-0.57 kg/m2; months receiving HPN, 113.2+/-0.09; and days per week receiving HPN, 5.08+/-0.39. MBD was present in 33% of patients for the spine and hip and in 50% for the femoral neck; 24% had previous fractures. There was a significant negative correlation between the duration of HPN and BMD (r=-0.40) for all measurements. From those patients, 11 received IV pamidronate for a mean of 22.2+/-5.4 months. At baseline, their mean HPN treatment duration was 10.6+/-6.3 years. Overall, BMD results showed a trend toward improvement in the mean t score of the spine and hip postpamidronate therapy (pre, -3.1+/-0.75; post, -2.9+/-0.69; p=.07). After excluding 2 patients receiving corticosteroids, the mean t score of the spine showed significant improvement (prepamidronate -3.4+/-0.57 vs post-pamidronate -3.1+/-0.65, p=.036).

In our HPN population, 76% had MBD and 24% had previous fractures. The results suggest that these patients may benefit from pamidronate. More studies are needed to assess the efficacy of pamidronate.