Expanded spectrum of recombinant human growth hormone therapy

[Efficacy of different doses of recombinant human growth hormone in the treatment of short stature in children born small for gestational age]

OBJECTIVE

To investigate the efficacy and safety of different doses of recombinant human growth hormone (rhGH) in the treatment of short stature in children born small for gestational age (SGA).

METHODS

A total of 37 children with short stature born SGA were enrolled, and based on the dose of rhGH treatment, they were divided into low-dose rhGH group (0.1-0.15 IU/kg daily) and high-dose rhGH group (0.16-0.2 IU/kg daily). The changes in height standard deviation score (ΔHtSDS), height velocity (HV), serum levels of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3), and fasting blood glucose at 3, 6, 9, 12, and 24 months after treatment were compared between the two groups.

RESULTS

ΔHtSDS and HV both increased after the treatment with high- and low-dose rhGH, but ΔHtSDS and HV in the high-dose rhGH group were significantly higher than in the low-dose rhGH group 9, 12 and 24 months after treatment (P<0.05). Both high- and low-dose rhGH treatment increased serum levels of IGF-1 and IGFBP-3. Serum levels of IGF-1 and IGFBP-3 were positively correlated with HtSDS in both groups. One child each in the high- and low-dose rhGH groups experienced transient slight increase in fasting blood glucose (6.1 mmol/L). There were no cases of abnormal thyroid function.

CONCLUSIONS

rhGH has good efficacy in the treatment of short stature in children born SGA, with few adverse events, and high-dose rhGH has some advantages over low-dose rhGH.

Beyond antibodies: using biological principles to guide the development of next-generation protein therapeutics

Protein-based biologics, which leverage the inherent affinity and specificity of protein-protein interactions, offer an effective strategy for targeting and modulating disease pathways. Despite the broad diversity of the proteome, monoclonal antibodies have been the major focus of such drug discovery efforts. While antibodies have shown great clinical value, the breadth and complexity of human disease highlight the need for alternatives that expand the therapeutic repertoire beyond this single class of proteins. The elucidation of molecular mechanisms underlying human disease has provided new opportunities for protein-based drugs to address challenging clinical problems. Natural ligands and receptors, which inherently modulate complex biological processes, have emerged as promising candidates for protein-based drug discovery efforts. Protein engineering strategies, guided by biological principles, are allowing ligands and receptors to be developed as next-generation therapeutics with improved safety and efficacy.

Effects of 4 weeks recombinant human growth hormone administration on insulin resistance of skeletal muscle in rats

PURPOSE

Effect of recombinant human growth hormone (rhGH) administration on lipid storage, and its subsequent effect on insulin sensitivity have not yet been adequately examined. Thus, we investigated the effects of rhGH treatment on muscle triglyceride (TG) and ceramide content, and insulin sensitivity after 4 weeks of rhGH administration in rats.

MATERIALS AND METHODS

Fourteen rats were randomly assigned to two groups: rhGH injection group (GH, n = 7) and saline injection group (CON, n = 7). GH received rhGH by subcutaneous injections (130 microg.kg(-1).day(-1), 6 days.week(-1)) for 4 weeks, while CON received saline injections that were equivalent in volume to GH group. Intramuscular TG and ceramide content and hepatic TG content were measured. To determine insulin sensitivity, oral glucose tolerance test (OGTT) and muscle incubation for glucose transport rate were performed in rats, and used as indicators of insulin sensitivity. We also examined plasma lipid profiles.

RESULTS

After 4 weeks of rhGH treatment, the GH group had higher muscle and liver TG contents than the CON (p < 0.05). Ceramide content in GH was significantly greater than that in CON (p < 0.05). GH also had higher plasma levels of FFA (p < 0.05), glucose and insulin responses during OGTT (p < 0.05), and lower glucose transport rates in submaximal insulin concentration (p < 0.05) as compared with CON. Results indicate that rhGH treatment is associated with insulin resistance in rats.

CONCLUSION

rhGH treatment elevated muscle TG and ceramide content, and hepatic TG content. Thus, elevation of these compounded by rhGH treatment could contribute to the development of insulin resistance in rats.

Sex differences in patients referred for evaluation of poor growth

OBJECTIVES

The objective of this study was to compare sex differences among referrals for evaluation of poor growth.

STUDY DESIGN

This study was based on chart reviews of all new-patient encounters at Children's Hospital of Philadelphia Diagnostic and Research Growth Center for short stature or poor growth evaluations during 2001. Outcome measures were patient growth characteristics, frequency of underlying pathology, and frequency of laboratory and radiologic investigations before referral.

RESULTS

One hundred eighty-two boys and 96 girls were referred ( P < .0001). Girls were shorter, relative to the general population (median height z score, -2.4 vs -1.9 for boys, P = .02) and mid-parental target heights (median deficit, 1.9 vs 1.3 SD, P < .01). Differences were more pronounced starting at age 9 years. Median time to referral from initial fall-off on the growth curve was 35 months in girls and 24 months in boys (not significant). The percentage of girls (41%) with organic disease significantly exceeded that of boys (15%). Conversely, more boys (72%) than girls (48%) were of normal height or short but healthy ( P < .0001). Sex was not associated with frequency of tests before referral; neither was severity of short stature.

CONCLUSIONS

Sex differences in short stature referrals may delay diagnosis of diseases in girls while promoting overzealous evaluations of healthy boys who do not appear to be tall enough.