Effects of growth hormone treatment on body proportions and final height among small children with X-linked hypophosphatemic rickets.
BACKGROUND
X-linked hypophosphatemic rickets (XLH) is characterized by rickets, disproportionate short stature, and impaired renal phosphate reabsorption and vitamin D metabolism. Despite oral phosphate and vitamin D treatment, most children with XLH demonstrate reduced adult height.


OBJECTIVE
To determine the beneficial effects of recombinant human growth hormone (rhGH) therapy on body proportions and adult height among patients with XLH.


METHODS
Three initially prepubertal short children (age, 9.4-12.9 years) with XLH were treated with rhGH for 3.1 to 6.3 years until adult height was attained.


RESULTS
rhGH treatment led to sustained increases in standardized height for all children. The median adult height was 0.9 SD (range: 0.5-1.3 SD) greater than that at the initiation of rhGH treatment and exceeded the predicted adult height by 6.2 cm (range: 5.3-9.8 cm). However, longitudinal growth of the trunk was stimulated more than leg growth. During rhGH treatment, the standardized sitting height increased by 1.6 SD (range: 1.1-2.7 SD), compared with baseline values. In contrast, the median subischial leg length did not change consistently (median change: 0.3 SD; range: -0.1 to 0.6 SD).


CONCLUSIONS
The increase in final height after rhGH treatment is of potential benefit for children with XLH. However, the exaggeration of disproportionate truncal growth observed for our prepubertal patients is a potential negative effect of treatment and should be confirmed with additional studies.
Haffner
Dieter
D
Department of Pediatric Nephrology, University Hospital Charité, Berlin, Germany.
Nissel
Richard
R
Wühl
Elke
E
Mehls
Otto
O
D001827:Body Height / Q000187:drug effects*; D002648:Child; D005260:Female; D006128:Growth / Q000187:drug effects; D006130:Growth Disorders / Q000188:drug therapy* / Q000209:etiology; D019382:Human Growth Hormone / Q000627:therapeutic use*; D006801:Humans; D007015:Hypophosphatemia, Familial / Q000150:complications / Q000188:drug therapy*; D008297:Male
D019382:Human Growth Hormone