TY - JOUR
T1 - IGFALS gene dosage effects on serum IGF-I and glucose metabolism, body composition, bone growth in length and width, and the pharmacokinetics of recombinant human IGF-I administration
AU - Högler, Wolfgang
AU - Martin, David D.
AU - Crabtree, Nicola
AU - Nightingale, Peter
AU - Tomlinson, Jeremy
AU - Metherell, Lou
AU - Rosenfeld, Ron
AU - Hwa, Vivian
AU - Rose, Stephen
AU - Walker, Joanna
AU - Shaw, Nicholas
AU - Barrett, Timothy
AU - Frystyk, Jan
PY - 2014/4
Y1 - 2014/4
N2 - 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-g/kg) in four ALS-deficient patients, compared with severe PIGFD, moderate PIGFD, and controls. Intravenous glucose tolerance tests, fasting bloodlevels,dual-energyX- rayabsorptiometry,peripheralquantitativecomputedtomography,andmetacarpal 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,andmetacarpal width.Boneanalysisshowedthat 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 comparedwith severe PIGFD, ALS-deficient patients cannotmountasimilar response. Alternativeways of rhIGF-I administration should be sought.
AB - 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-g/kg) in four ALS-deficient patients, compared with severe PIGFD, moderate PIGFD, and controls. Intravenous glucose tolerance tests, fasting bloodlevels,dual-energyX- rayabsorptiometry,peripheralquantitativecomputedtomography,andmetacarpal 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,andmetacarpal width.Boneanalysisshowedthat 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 comparedwith severe PIGFD, ALS-deficient patients cannotmountasimilar response. Alternativeways of rhIGF-I administration should be sought.
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U2 - 10.1210/jc.2013-3718
DO - 10.1210/jc.2013-3718
M3 - Article
C2 - 24423360
AN - SCOPUS:84898444840
SN - 0021-972X
VL - 99
SP - E703-E712
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 4
ER -