Arm span, serum IGF-1 and IGFBP-3 levels as screening parameters for the diagnosis of growth hormone deficiency in patients with myelomeningocele--preliminary data

Abstract

Short stature is a common problem in patients with myelomeningocele (MMC) and hydrocephalus. We evaluated auxological and laboratory parameters to differentiate short stature due to neurological defect from short stature additionally caused by growth hormone deficiency (GHD). In a group of 38 prepubertal patients with MMC and hydrocephalus aged 3.8-11.0 years, auxological parameters, including arm span and bone age, and serum insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) levels were measured. Patients with normal supine length (n = 15) had normal arm span. Serum IGF-1 and IGFBP-3 levels were normal (> or = 10th percentile) in 14/15 patients. Twenty-three MMC patients had short stature (height SDS < -2), 11/23 patients had reduced arm span (SDS < -2), and 12/23 had normal arm span. Serum IGF-1 and IGFBP-3 levels were normal in 10/12 of short statured patients with normal arm span, but low (< 10th percentile) in those patients with reduced arm span (IGF-1: 8/11 patients, P < 0.05; IGFBP-3: 9/11 patients, P < 0.005). In 7/11 short statured MMC patients with reduced arm span and low serum IGF-1 and IGFBP-3 levels, growth hormone secretion was investigated. All had a disturbed growth hormone secretion (GHD: n = 4; neurosecretory dysfunction: n = 3).

Conclusion: Arm span, serum IGF-1 and IGFBP-3 levels are estimated to be appropriate screening parameters for GHD in patients with MMC. Initiating growth hormone therapy should be considered not only according to endocrine findings but also with respect to neurological and orthopaedic anomalies.