Symptom and Surgical Burden of X-Linked Hypophosphatemia in Adults

Even in adulthood, patients with X-linked hypophosphatemia (XLH) experience several musculoskeletal symptoms. However, Muhammad Kassim Javaid and colleagues felt that the disease burden of XLH needed further definition regarding musculoskeletal presentations and associated surgeries. In their study published in the Journal of Endocrinology and Metabolism, they concluded that “adults with XLH bear a substantial burden of multiple musculoskeletal features, emerging decades earlier than in the general population, as early as in their 20s, and progressively accumulating with age.”

The authors’ analysis included a total of 336 retrospective adult patients. Patients were either subjects of a clinical trial, respondents in an online survey, or a subgroup of the online survey participants who were deemed comparable to the clinical trial subjects based on worst pain scoring. Each group was stratified by participant age, and the rate of five prespecified musculoskeletal features and associated surgeries were recorded.

According to the authors, 43% to 47% of patients across all three groups had a history of fracture, with the proportion increasing with age. Overall, the prevalence of osteoarthritis was greater than 50% for all three groups, “with a rate of 23% to 37% in the 18- to 29-year-old group, and increasing with age,” noted the article. Reportedly, similar patterns were seen for osteophytes and enthesopathy. Notably, hip and knee arthroplasty was observed even in adults over 30 years of age. Prevalence of spinal stenosis was low but increased with age. Finally, the proportion of adults with two or more disease-related musculoskeletal features was 59.1%, 55.0%, and 61.3% for clinical trial, survey, and survey subgroup patients, respectively.

The authors ultimately concluded that the musculoskeletal and surgical burden of patients with XLH was significant, even in adult patients. They summarized that, “the findings from this study highlight the frequency of clinically important musculoskeletal features in adults with XLH and their early onset, illustrating a scenario of premature musculoskeletal morbidity compared with the general population.”