Wolfgang Högler1, David D Martin, Nicola Crabtree, Peter Nightingale, Jeremy Tomlinson, Lou Metherell, Ron Rosenfeld, Vivian Hwa, Stephen Rose, Joanna Walker, Nicholas Shaw, Timothy Barrett, Jan Frystyk. 1. Departments of Endocrinology and Diabetes (W.H., N.S., T.B.) and Nuclear Medicine (N.C.), Birmingham Children's Hospital, B4 6NH Birmingham, United Kingdom; Department of Paediatric Endocrinology and Diabetes (D.D.M.), University Children's Hospital, D-72074 Tübingen, Germany; Wellcome Trust Clinical Research Facility (P.N.), Queen Elizabeth Hospital, Birmingham B15 2TH, United Kingdom; School of Clinical and Experimental Medicine (J.T., T.B.), University of Birmingham, Birmingham B15 2TT, United Kingdom; William Harvey Research Institute (L.M.), Barts and the London School of Medicine, Queen Mary University of London, London E1 1BB, United Kingdom; Department of Paediatrics (R.R.), Oregon Health Sciences University, Portland, Oregon 97239; Department of Paediatrics (S.R.), Heartlands Hospital, B9 5SS Birmingham, United Kingdom; Department of Paediatrics (J.W.), Portsmouth Hospital, Portsmouth PO6 3LY, United Kingdom; and Medical Research Laboratory (J.F.), Department of Clinical Medicine, Faculty of Health, Aarhus University, and Department of Endocrinology and Internal Medicine, Aarhus University Hospital, DK-8000 C Aarhus, Denmark.
Abstract
CONTEXT: Acid labile subunit (ALS) deficiency, caused by IGFALS mutations, is a subtype of primary IGF-I deficiency (PIGFD) and has been associated with insulin resistance (IR) and osteopenia. Whether patients respond to recombinant human IGF-I (rhIGF-I) is unknown. OBJECTIVE AND DESIGN: This study determined the 14-hour pharmacokinetic response of free and total IGF-I and IGF binding protein 3 (IGFBP-3) to a single sc dose of rhIGF-I (120 μg/kg) in four ALS-deficient patients, compared with severe PIGFD, moderate PIGFD, and controls. Intravenous glucose tolerance tests, fasting blood levels, dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and metacarpal radiogrammetry were performed in the four patients and 12 heterozygous family members. RESULTS: IGF-I and IGFBP-3 increased above baseline (P < .05) for 2.5 hours, returning to baseline 7 hours after rhIGF-I injection. Mean (SD) IGF-I Z-score increased by 2.49 (0.90), whereas IGFBP-3 Z-score increased by 0.57 (0.10) only. IGF-I elimination rates in ALS deficiency were similar, but the IGF-I increment was lower than those for severe PIGFD. Significant gene dosage effects were found for all IGF-I peptides, height, forearm muscle size, and metacarpal width. Bone analysis showed that ALS deficiency creates a phenotype of slender bones with normal size-corrected density. Abnormal glucose handling and IR was found in three of four patients and 6 of 12 carriers. CONCLUSIONS: These gene dosage effects demonstrate that one functional IGFALS allele is insufficient to maintain normal ALS levels, endocrine IGF-I action, full growth potential, muscle size, and periosteal expansion. Similar gene dosage effects may exist for parameters of IR. Despite similar IGF-I elimination compared with severe PIGFD, ALS-deficient patients cannot mount a similar response. Alternative ways of rhIGF-I administration should be sought.
CONTEXT: Acid labile subunit (ALS) deficiency, caused by IGFALS mutations, is a subtype of primary IGF-I deficiency (PIGFD) and has been associated with insulin resistance (IR) and osteopenia. Whether patients respond to recombinant human IGF-I (rhIGF-I) is unknown. OBJECTIVE AND DESIGN: This study determined the 14-hour pharmacokinetic response of free and total IGF-I and IGF binding protein 3 (IGFBP-3) to a single sc dose of rhIGF-I (120 μg/kg) in four ALS-deficient patients, compared with severe PIGFD, moderate PIGFD, and controls. Intravenous glucose tolerance tests, fasting blood levels, dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and metacarpal radiogrammetry were performed in the four patients and 12 heterozygous family members. RESULTS: IGF-I and IGFBP-3 increased above baseline (P < .05) for 2.5 hours, returning to baseline 7 hours after rhIGF-I injection. Mean (SD) IGF-I Z-score increased by 2.49 (0.90), whereas IGFBP-3 Z-score increased by 0.57 (0.10) only. IGF-I elimination rates in ALS deficiency were similar, but the IGF-I increment was lower than those for severe PIGFD. Significant gene dosage effects were found for all IGF-I peptides, height, forearm muscle size, and metacarpal width. Bone analysis showed that ALS deficiency creates a phenotype of slender bones with normal size-corrected density. Abnormal glucose handling and IR was found in three of four patients and 6 of 12 carriers. CONCLUSIONS: These gene dosage effects demonstrate that one functional IGFALS allele is insufficient to maintain normal ALS levels, endocrine IGF-I action, full growth potential, muscle size, and periosteal expansion. Similar gene dosage effects may exist for parameters of IR. Despite similar IGF-I elimination compared with severe PIGFD, ALS-deficient patients cannot mount a similar response. Alternative ways of rhIGF-I administration should be sought.
Authors: Helen L Storr; Sumana Chatterjee; Louise A Metherell; Corinne Foley; Ron G Rosenfeld; Philippe F Backeljauw; Andrew Dauber; Martin O Savage; Vivian Hwa Journal: Endocr Rev Date: 2019-04-01 Impact factor: 19.871