Significant Fracture Burden, Psychological Comorbidities Associated With Hypophosphatasia

Patients with probable hypophosphatasia (HPP) were found to have a significant number of fractures and psychological comorbidities including depression and anxiety, according to study results presented at ENDO 2017: the 99th Annual Meeting & Expo, April 1-4, in Orlando, Florida.

To determine the fracture burden in this population, Joseph Biskupiak, PhD, MBA, of the University of Utah in Salt Lake City, and colleagues screened pediatric and adult patients using the University of Utah Health Care electronic health record (EHR) database, which contained data from 1.6 million patients from 1990 to 2014, looking for indicators of probable HPP including disorders of phosphorous metabolism or low age- or sex-adjusted serum alkaline phosphatase (ALP).

Patients identified were further checked for clinical, biochemical, and radiographic evidence of HPP, including seizures and respiratory failure in children younger than 5; elevated urine phosphoethanolamine; radiographic evidence of hypomineralization, osteopenia or rickets; and history of multiple, nontraumatic fractures, among others. 

Fracture burden was determined by Kaplan-Meier analysis, assessing time to incident fracture and time to subsequent fractures with comorbidities.

The researchers identified 83 patients, 29 children and 54 adults, with probable HPP based on low age- or sex-adjusted ALP and accompanying symptoms.

During a mean 5.7-year follow-up, 78 (94%) patients had 1 or more fractures with a cumulative total of 477 fractures.

Kaplan-Meier analysis showed that the median time to the first fracture was 2.88 years and 7.32 years for the third fracture.

Other comorbidities reported included skeletal complications other than fractures (96.4%), pain (61.4%), and depression and anxiety in children (62.1%) and adults (90.7%).

“Patients with probable HPP had a significant burden of disease associated with skeletal manifestations such as high proportion of fractures and pain with comorbidities of depression and anxiety,” the researchers concluded.

Disclosures: Joseph Biskupiak, Casey Tak, Minkyoung Yoo, and Diana Brixner report receiving research funding from Alexion Pharmaceuticals, Inc. Ioannis C. Tomazos, Gilbert L’Italien, Bonnie Donato, and Andrew E. Denker are employees of Alexion Pharmaceuticals, Inc.

Reference

Biskupiak J, Tak C, Yoo M, et al. Fracture burden in patients with probable hypophosphatasia – identified within an electronic health record database. Presented at: ENDO 2017; April 1-4, 2017; Orlando, Florida.