Background: Hereditary hypophosphatemic rickets (HHR) is a rare genetic disease characterized by renal phosphate wasting, caused by elevated circulating FGF23. Despite the current available treatment complications include short stature, hyperparathyroidism, pseudofractures, bone pain, bone demineralization and osteoporosis, nephrocalcinosis and enthesopathies. Elevated circulating FGF23 was recently involved in glucose metabolism and cardiovascular function.
Objective and hypotheses: Our objective was to prospectively evaluate complications of the disease and patients metabolism.
Method: Twenty-eight patients with HHR were prospectively evaluated (six males and 22 females).
Results: Mean age (min-max) of adult HHR patients was 39 years (19.469.3). The mean height for males was 160.6 cm and for female 147.0 cm. 9 (32.1%), 9 (32.1%), and 10 (35.8%) patients were obese, over weighted and had a normal BMI respectively. Two patients had glucose intolerance. One patient had a parathyroid adenoma. Two patients had renal lithiasis, none had nephrocalcinosis. The spinal T score correlated with FGF23 values. Femoral neck T score was higher in patients who received vitamin D analogues during childhood.
|All patients||Treated||Non treated||P*|
|Blood pressure systolic/diastolic (mmhg)||116/72||108/65||120/74||0.1044|
|Urinary calcium (mg/kg per day) (n<4)||2.5||1.8||2.8||0.1365|
|PTH (pg/ml) (n 1560)||36.0||46.5||52.5||0.7082|
|L1L4 T score||2.4||2.7||2.3||0.4980|
|Femoral neck T score||−0.1||0.7||−0.4||0.0174|
Conclusion: Overweight and obesity is frequent in HHR patients. Vitamin D analogues treatment improves cortical bone mineral density. Complications like nephrocalcinosis and hyperparathyroidism are rare.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology