Delayed Puberty, Loss of Bone Density in EB, Analysis Shows
Researchers examined medical records of 186 epidermolysis bullosa patients
People with epidermolysis bullosa (EB) have an increased risk of delayed puberty and low bone mineral density (BMD), according to a medical records analysis.
Increased incidence of delayed puberty with associated low BMD was notably seen in those with the recessive dystrophic epidermolysis bullosa (DEB) subtype.
Predictors of BMD decline included puberty delays, older age, and body fat content, as assessed by the body mass index (BMI).
These findings highlight the need for puberty and bone health monitoring during childhood and adolescence in EB patients, the researchers said.
The medical records analysis, “Prevalence of delayed puberty and low bone density in patients with epidermolysis bullosa: Insight from a large single center’s experience,” was published in the journal Pediatric Dermatology.
EB is a group of rare skin disorders characterized by lack of proteins that anchor the outermost layer of skin (epidermis) to the underneath layer (dermis). As a result, people with the condition have fragile skin that tears and blisters easily.
Growing evidence suggests that delayed puberty, which can lead to impaired bone health and bone diseases such as osteoporosis, also is a significant concern for EB patients.
In this report, researchers described the natural history of bone health and puberty delays in EB patients who received care at the EB Center at Cincinnati Children’s Hospital Medical Center, in Ohio, over about 10 years.
Study design
Data were collected from the medical records of 186 individuals with EB, with 98 (52.7%) being diagnosed with recessive DEB. Among the others, 22 had dominant DEB, 43 had EB simplex (EBS), and 23 with junctional EB (JEB).
BMD of the lumbar (lower) spine was used to assess bone health, as measured by dual-energy X-ray absorptiometry (DXA) scans. BMD z-scores were calculated from bone scans, defined as the difference between a patient’s BMD and the average BMD at a given age in healthy individuals. BMD z-scores adjusted for height also were calculated.
At the last visit, 90 (48.4%) participants had reached an age where puberty could be classified. Delayed puberty was defined as no testicular growth by age 14 years or a prescription for testosterone in males, and in females, no breast development by age 13 years or no menses by age 16. In other cases, puberty delay was determined by a pediatric endocrinologist.
Among the 60 recessive DEB patients who reached puberty, 33% met the criteria for delayed puberty. Although delayed puberty was not seen in any other EB subtypes, most (65%) individuals with EBS or JEB were still too young to determine puberty status. The team noted only one of them had early puberty.
Bone scans were available for 55% of participants, with recessive DEB patients significantly more likely to have had a bone scan (78%). By age 10, 29% of recessive DEB patients had low lumbar spine BMD z-scores, and 26% had low BMD z-scores after height adjustments. Recessive DEB patients were more likely to be underweight compared to those with other types of EB.
Decreasing height-adjusted BMD scores were associated significantly with delayed puberty, older age, and predominant wheelchair use. After statistically adjusting for puberty and wheelchair use, disease type, BMI, and the use of feeding tubes were not related to BMD scores.
BMD in recessive DEB
Individuals with recessive DEB were more likely to have low BMD at any age during childhood than those with other EB types. Still, delays in puberty were linked with low height-adjusted BMD, regardless of EB subtype, as well as predominant wheelchair use compared to normal puberty (61% vs. 18%).
The most significant predictors of declining height-adjusted BMD scores were delayed puberty, older age, and BMI. Wheelchair use, disease type, and feeding tube status were no longer significant in predicting BMD after statistical adjustments.
“Patients with EB, especially [recessive DEB], are at risk for delayed puberty, and this may contribute to the increased prevalence of low BMD in these individuals,” the researchers concluded.
“While further investigation is necessary to determine the impact of low BMD on fracture, pain and osteoporosis risk in patients with EB,” they added, “this study highlights the need for pubertal screening and bone health monitoring during childhood and adolescence to address skeletal health concerns in this population.”
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