Longitudinal changes in insulin sensitivity and body composition of small-for-gestational-age adolescents after cessation of growth hormone treatment

Cerebrovascular Abnormalities in Adults Born SGA at 12 Years After Growth Hormone Cessation Compared to Controls

CONTEXT

Increased cerebrovascular morbidity was reported in adults born small for gestational age (SGA) who were treated with growth hormone (GH) during childhood compared to the general population. However, previous studies did not have an appropriate control group, which is a major limitation.

OBJECTIVE

To study cerebrovascular abnormalities (aneurysms, previous intracerebral hemorrhages and microbleeds) using magnetic resonance imaging (MRI) in adults born SGA at 12 years after cessation of childhood GH treatment (SGA-GH) compared to appropriate controls.

METHODS

In this single-center, prospective study, brain MRIs were performed between May 2016 and December 2020 on a 3T MRI system. MRI images were scored by 2 neuroradiologists who were blinded to patient groupings. Participants included adults born SGA previously treated with GH and 3 untreated control groups: adults born SGA with persistent short stature (SGA-S), adults born SGA with spontaneous catch-up growth to a normal height (SGA-CU) and adults born appropriate for gestational age with a normal height (AGA). The intervention was long-term GH treatment during childhood and the main outcome measure was cerebrovascular abnormalities.

RESULTS

A total of 301 adults were investigated. Aneurysms were found in 6 adults: 3 (3.6%) SGA-GH, 1 (2.9%) SGA-S and 2 (2.2%) AGA adults, without differences between SGA-GH adults and the controls. Previous intracerebral hemorrhages were only found in 2 SGA-S adults (4.8%). Microbleeds were found in 17 adults: 4 (4.3%) SGA-GH, 4 (9.5%) SGA-S, 3 (4.3%) SGA-CU and 6 (6.3%) AGA adults, without differences between SGA-GH adults and the controls.

CONCLUSION

Our findings suggest that SGA-GH adults at 12 years after GH cessation have no increased prevalence of cerebrovascular abnormalities compared to appropriate controls. Further research is needed to confirm our findings.

What is the evidence for beneficial effects of growth hormone treatment beyond height in short children born small for gestational age? A review of published literature

Background An increasing body of evidence supports the view that both an adverse intrauterine milieu and rapid postnatal weight gain in children born small for gestational age (SGA) contribute towards the risk for the development of chronic diseases in adult life. Content The aim of this review was to identify and summarize the published evidence on metabolic and cardiovascular risk, as well as risk of impaired cardiac function, intellectual capacity, quality of life, pubertal development and bone strength among children born SGA. The review will then address whether growth hormone (GH) therapy, commonly prescribed to reduce the height deficit in children born SGA who do not catch up in height, increases or decreases these risks over time. Summary Overall, there are limited data in support of a modest beneficial effect of GH therapy on the adverse metabolic and cardiovascular risk observed in short children born SGA. Evidence to support a positive effect of GH on bone strength and psychosocial outcomes is less convincing. Outlook Further evaluation into the clinical relevance of any potential long-term benefits of GH therapy on metabolic and cardiovascular endpoints is warranted.

Children Born Small for Gestational Age: Differential Diagnosis, Molecular Genetic Evaluation, and Implications

Children born small for gestational age (SGA), defined as a birth weight and/or length below -2 SD score (SDS), comprise a heterogeneous group. The causes of SGA are multifactorial and include maternal lifestyle and obstetric factors, placental dysfunction, and numerous fetal (epi)genetic abnormalities. Short-term consequences of SGA include increased risks of hypothermia, polycythemia, and hypoglycemia. Although most SGA infants show catch-up growth by 2 years of age, ∼10% remain short. Short children born SGA are amenable to GH treatment, which increases their adult height by on average 1.25 SD. Add-on treatment with a gonadotropin-releasing hormone agonist may be considered in early pubertal children with an expected adult height below -2.5 SDS. A small birth size increases the risk of later neurodevelopmental problems and cardiometabolic diseases. GH treatment does not pose an additional risk.

Impact of discontinuation of growth hormone treatment on lipids and weight status in adolescents

BACKGROUND

While the main role of growth hormone (GH) replacement therapy in children is to promote linear growth, GH has also an effect on lipids and body composition. There is an ongoing discussion whether discontinuation of GH treatment is associated with deterioration of lipids.

METHODS

We analyzed weight status [as body mass index-standard deviation score (BMI-SDS)], insulin like growth factor (IGF)-1, triglycerides, total, low-density liporptoein (LDL)- and high-density lipoprotein (HDL)-cholesterol at the end of GH treatment and in mean 6 months later in 90 adolescents (53 with GH deficiency, 16 with Turner syndrome [TS] and 21 born small-for-gestational age [SGA]).

RESULTS

After stopping GH treatment, total cholesterol (+10±24 mg/dL vs. -4±13 mg/dL) and LDL-cholesterol (+15±20 mg/dL vs. -6±12 mg/dL) increased significantly higher in severe (defined by GH peak in stimulation test <3 ng/mL) compared to moderate GHD. In patients with TS, total cholesterol (+19±9 mg/dL), LDL-cholesterol (+9±12 mg/dL) and HDL-cholesterol (+4.3±3.5 mg/dL) increased significantly. In adolescents born SGA, triglycerides increased (+34±51 mg/dL) and HDL-cholesterol decreased significantly (-3.8±7.1 mg/dL). In multiple linear regression analyses, changes of total and LDL-cholesterol were significantly negatively related to peak GH in stimulation tests, but not to gender, age at GH start, duration of GH treatment, observation time, changes of BMI-SDS or IGF-1 after the end of GH treatment. The BMI-SDS did not change after the end of GH treatment.

CONCLUSIONS

Discontinuation of GH treatment leads to a deterioration of lipids in TS, SGA and severe but not moderate GHD.

Risk of Diabetes Treated in Early Adulthood After Growth Hormone Treatment of Short Stature in Childhood

CONTEXT

Growth hormone (GH) is known to be diabetogenic, but the risk of diabetes in individuals treated with GH in childhood has been little evaluated, and conflicting results have been obtained.

OBJECTIVE

To investigate the prevalence of diabetes and gestational diabetes in a population-based cohort of patients treated with GH for short stature in childhood in France.

DESIGN, SETTING, AND PARTICIPANTS

Participants were a population-based cohort of 5100 children with idiopathic isolated GH deficiency, idiopathic short stature, or short stature in children born short for gestational age who started GH treatment between 1985 and 1996. Data on the delivery of diabetes drugs in 2009 and 2010 were obtained from the French national health insurance database. Cases in patients and controls were identified from diabetes drugs deliveries.

MAIN OUTCOME MEASURE

The prevalence of diabetes was calculated and compared with that in the general population, determined on the basis of data from the same source, with the same definition.

RESULTS

At a mean age of 30 years, no difference in the prevalence of treated diabetes (oral drugs or insulin) was found between subjects treated with GH and the general population in France, regardless of sex. Similarly, the risk of insulin-treated gestational diabetes was similar in patients and in the reference population.

CONCLUSIONS

No difference in the risk of diabetes was found between GH-treated patients and the reference population. These results are reassuring, but further studies with a longer follow-up are required to evaluate the risk of diabetes with age in these patients.

Effects of size at birth, childhood growth patterns and growth hormone treatment on leukocyte telomere length

BACKGROUND

Small size at birth and rapid growth in early life are associated with increased risk of cardiovascular disease in later life. Short children born small for gestational age (SGA) are treated with growth hormone (GH), inducing catch-up in length. Leukocyte telomere length (LTL) is a marker of biological age and shorter LTL is associated with increased risk of cardiovascular disease.

OBJECTIVES

To investigate whether LTL is influenced by birth size, childhood growth and long-term GH treatment.

METHODS

We analyzed LTL in 545 young adults with differences in birth size and childhood growth patterns. Previously GH-treated young adults born SGA (SGA-GH) were compared to untreated short SGA (SGA-S), SGA with spontaneous catch-up to a normal body size (SGA-CU), and appropriate for gestational age with a normal body size (AGA-NS). LTL was measured using a quantitative PCR assay.

RESULTS

We found a positive association between birth length and LTL (p = 0.04), and a trend towards a positive association between birth weight and LTL (p = 0.08), after adjustments for gender, age, gestational age and adult body size. Weight gain during infancy and childhood and fat mass percentage were not associated with LTL. Female gender and gestational age were positively associated with LTL, and smoking negatively. After adjustments for gender, age and gestational age, SGA-GH had a similar LTL as SGA-S (p = 0.11), SGA-CU (p = 0.80), and AGA-NS (p = 0.30).

CONCLUSIONS

Larger size at birth is positively associated with LTL in young adulthood. Growth patterns during infancy and childhood are not associated with LTL. Previously GH-treated young adults born SGA have similar LTL as untreated short SGA, SGA with spontaneous catch-up and AGA born controls, indicating no adverse effects of GH-induced catch-up in height on LTL.

Metabolic health of young adults who were born small for gestational age and treated with growth hormone, after cessation of growth hormone treatment: a 5-year longitudinal study

BACKGROUND

Growth hormone treatment reduces fat mass and insulin sensitivity and increases lean body mass. Data are only available for short-term longitudinal changes after cessation of growth hormone treatment in young adults born small for gestational age. We aimed to assess long-term changes over a 5-year period following cessation of growth hormone treatment.

METHODS

We did a longitudinal study of young adults born small for gestational age and previously treated with growth hormone. Individuals were followed up for 5 years after attainment of adult height, when growth hormone treatment was discontinued: assessments were done at cessation of growth hormone treatment and at 6 months, 2 years, and 5 years thereafter. Data 5 years after cessation of growth hormone were compared with untreated age-matched controls. We used dual-energy x-ray absorptiometry to assess body composition, and did frequently sampled intravenous glucose tolerance tests to assess insulin sensitivity, acute insulin response, and the disposition index (a measure of β-cell function). This study is registered with ISRCTN, numbers ISRCTN96883876 and ISRCTN65230311.

FINDINGS

Between April, 2004, and April, 2016, we followed up 199 young adults born small for gestational age and previously treated with growth hormone, during the 5 years after cessation of growth hormone treatment. Data at 5 years for these individuals were compared with those for 51 untreated adults born small for gestational age with short stature, 92 untreated adults born small for gestational age with spontaneous catch-up growth, and 142 adults born appropriate for gestational age and unexposed to growth hormone treatment. In young adults born small for gestational age and previously treated with growth hormone, 5 years after cessation of growth hormone treatment, there were increases in fat mass (estimated marginal mean 10·73 kg [95% CI 9·95-11·50] at cessation of treatment vs 16·12 kg [14·77-17·46] at 5 years; p<0·0001), trunk fat (5·34 kg [4·94-5·73] vs 7·86 kg [7·12-8·60]; p<0·0001), and limb fat (4·87 kg [4·49-5·25] vs 7·41 kg [6·78-8·05]; p<0·0001); furthermore, lean body mass had decreased (42·41 kg [95% CI 41·09-43·73] at cessation of treatment vs 41·42 kg [40·17-42·66] at 5 years; p=0·0013). Insulin sensitivity increased within 6 months of cessation and was sustained 5 years after treatment cessation (estimated marginal mean 4·14 mU/L [95% CI 3·79-4·53] at cessation of treatment vs 6·15 mU/L [5·21-7·24] at 5 years; p<0·0001), and acute insulin response was diminished at 6 months, which persisted at 5 year follow-up (597·63 mU/L [539·62-661·86] vs 393·69 mU/L [337·56-459·15]; p<0·0001). The disposition index was increased 6 months after treatment but values at 5 years were similar to those at cessation of treatment (2483·94 [95% CI 2233·43-2762·54] at cessation of treatment vs 2367·83 [2033·43-2757·22] at 5 years; p=0·49). 5 years after cessation of growth hormone treatment, adults born small for gestational age and previously treated with growth hormone had fat mass, insulin sensitivity, and disposition index similar to those of untreated adults born small for gestational age with short stature, but lean body mass (adjusted for sex and height) was lower (46·47 kg [44·95-48·00] in those born small for gestational age with short stature vs 44·32 kg [43·35-45·30] in those born small for gestational age and treated with growth hormone; p=0·007). In adults previously treated with growth hormone born small for gestational age, at 5 years after cessation of growth hormone treatment, compared with adults born small for gestational age with spontaneous catch-up growth and adults born appropriate for gestational age, lean body mass was lower and results from frequently sampled intravenous glucose tolerance tests were similar.

INTERPRETATION

Significant changes in body composition and insulin sensitivity were recorded 5 years after cessation of growth hormone treatment in adults born small for gestational age, reflecting a loss of pharmacological effects of growth hormone. 5 years after cessation of treatment, fat mass, insulin sensitivity, and β-cell function of previously treated adults were similar to untreated adults born small for gestational age with short stature, indicating that long-term growth hormone treatment in children born small for gestational age has no unfavourable effects on metabolic health in early adulthood.

FUNDING

Novo Nordisk Farma BV (Netherlands).

Long-term metabolic risk among children born premature or small for gestational age

Accumulating evidence suggests that both the intrauterine environment and growth during early life can influence the development of chronic noncommunicable diseases, such as type 2 diabetes mellitus and cardiovascular disease, in adulthood. Here, we review the available human data supporting increased metabolic risk among children born premature or small for gestational age; the adrenal and pubertal modifications that contribute to this risk; metabolic changes that occur during adolescence and early adulthood; and approaches to potentially modify or decrease risk of metabolic disease. The risks associated with delivery at term or preterm are compared for each period of life. Knowledge of these associations is fundamental for the paediatric community to develop preventive strategies early during postnatal life.

Growth and Metabolism in Children Born Small for Gestational Age

Most children born SGA show spontaneous catch-up growth to a normal weight and height above -2 SDS; however, 10% remain short. GH treatment improves adult height and has positive effects on body composition, blood pressure and serum lipids. At 6.5 years after stopping GH treatment, body composition, blood pressure, and lipid levels are similar to untreated short SGA adults indicating that GH-induced catch-up in height has no unfavorable effects on metabolic health. GH-induced reduction in insulin sensitivity is reversible after stopping GH. It remains to be elucidated how metabolic health develops when these subjects become older.

The impact of long-term growth hormone treatment on metabolic parameters in Japanese patients with short stature born small for gestational age

BACKGROUND/AIMS

An examination of the effects of up to 260 weeks of growth hormone (GH) therapy on metabolic parameters in Japanese children born small for gestational age (SGA).

METHODS

Data were analysed from a 156-week extension of a 104-week multicentre, randomised, double-blind, parallel-group trial. Sixty-five children born SGA (age 3-<8 years) received 33 μg/kg/day (n = 31, 64.5% male) or 67 μg/kg/day (n = 34, 58.8% male) GH for 260 weeks. Changes in metabolic parameters - glucose, insulin, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol - were recorded. Alterations in weight, body mass index standard deviation score (BMI SDS) and vital signs were also evaluated.

RESULTS

Over 260 weeks of GH treatment, a positive correlation between Δheight SDS and Δinsulin-like growth factor-I SDS was observed. Insulin and glucose levels were generally unaffected. Favourable changes in lipid profiles were recorded, which were maintained for the study duration. No adverse alterations in weight, BMI SDS or vital signs were noted.

CONCLUSION

Long-term, continuous GH treatment in children born SGA appears to be efficacious, associated with potential benefits for several metabolic parameters and associated with no long-term safety concerns.

Baseline IGF-I levels determine insulin secretion and insulin sensitivity during the first year on growth hormone therapy in children born small for gestational age. Results from a North European Multicentre Study (NESGAS)

OBJECTIVE

Developmental programming alters growth and metabolic outcome in children born small for gestational age (SGA). We explored insulin and glucose metabolism in SGA children treated with a fixed GH dose over 1 year.

METHODS

In the North European Small for Gestational Age Study (NESGAS), 110 short SGA children received GH at 67 µg/kg/day for 1 year. Insulin secretion was assessed by acute insulin response (AIR), insulin sensitivity (IS) by HOMA and disposition index (DI) by insulin secretion adjusted for IS.

RESULTS

First-year GH therapy led to increases in height and IGF-I standard deviation score (SDS), and reductions in IS (p < 0.0001). Compensatory increases in AIR (p < 0.0001) were insufficient and resulted in reduced DI (p = 0.032). Children in the highest IGF-I SDS tertile at baseline were the least insulin sensitive at baseline (p = 0.024) and 1 year (p = 0.006). IGF-I responses after 1 year were positively related to AIR (r = 0.30, p = 0.007) and DI (r = 0.29, p = 0.005).

CONCLUSION

In SGA children treated with a high GH dose for 1 year, baseline IGF-I levels were related to IS whilst gains in height and IGF-I responses were associated with insulin secretion. Defining heterogeneity in IGF-I in SGA children may be useful in predicting growth and metabolic response.

Exacerbation of BMI after cessation of growth hormone therapy in patients with Prader-Willi syndrome

Long-term treatment with growth hormone (GH) in patients with Prader-Willi syndrome (PWS) improves not only height velocity, height standard deviation score, and final height, but also the degree of obesity and body composition abnormalities. Anecdotally, PWS patients tend to suffer from severe obesity and its complications after cessation of GH therapy. However, there have been no studies to investigate changes in body mass index (BMI) and adipose tissue distribution after cessation of GH therapy in young PWS patients. Therefore, we investigated changes in the BMI-standard deviation score (SDS) and adipose tissue distribution after cessation of GH therapy in PWS patients. We evaluated 14 PWS patients. BMI-SDS was calculated at 0, 6, 12, 18, and 24 months before and after cessation of GH treatment. We also evaluated subcutaneous adipose tissue (SAT) (cm(2)) and visceral adipose tissue (VAT) (cm(2)) area in 8 of the 14 study patients with single slice abdominal computed tomography at the level of the umbilicus. The BMI-SDS significantly increased at 6, 12, 18, and 24 months after cessation of GH therapy (P = 0.039, P = 0.008, P = 0.003, P = 0.003, respectively). There was a tendency toward increases in VAT at 12 and 24 months after cessation of GH therapy, but the increases did not reach statistical significance (P = 0.062, P = 0.125, respectively). Therefore, cessation of GH therapy in PWS patients worsened BMI. To maintain good body composition and prevent complications of obesity, long-term use of GH in adult PWS patients may be advisable.

Latin American consensus: children born small for gestational age

BACKGROUND

Children born small for gestational age (SGA) experience higher rates of morbidity and mortality than those born appropriate for gestational age. In Latin America, identification and optimal management of children born SGA is a critical issue. Leading experts in pediatric endocrinology throughout Latin America established working groups in order to discuss key challenges regarding the evaluation and management of children born SGA and ultimately develop a consensus statement.

DISCUSSION

SGA is defined as a birth weight and/or birth length greater than 2 standard deviations (SD) below the population reference mean for gestational age. SGA refers to body size and implies length-weight reference data in a geographical population whose ethnicity is known and specific to this group. Ideally, each country/region within Latin America should establish its own standards and make relevant updates. SGA children should be evaluated with standardized measures by trained personnel every 3 months during year 1 and every 6 months during year 2. Those without catch-up growth within the first 6 months of life need further evaluation, as do children whose weight is ≤ -2 SD at age 2 years. Growth hormone treatment can begin in SGA children > 2 years with short stature (< -2.0 SD) and a growth velocity < 25th percentile for their age, and should continue until final height (a growth velocity below 2 cm/year or a bone age of > 14 years for girls and > 16 years for boys) is reached. Blood glucose, thyroid function, HbA1c, and insulin-like growth factor-1 (IGF-1) should be monitored once a year. Monitoring insulin changes from baseline and surrogates of insulin sensitivity is essential. Reduced fetal growth followed by excessive postnatal catch-up in height, and particularly in weight, should be closely monitored. In both sexes, gonadal function should be monitored especially during puberty.

SUMMARY

Children born SGA should be carefully followed by a multidisciplinary group that includes perinatologists, pediatricians, nutritionists, and pediatric endocrinologists since 10% to 15% will continue to have weight and height deficiency through development and may benefit from growth hormone treatment. Standards/guidelines should be developed on a country/region basis throughout Latin America.

Growth hormone: health considerations beyond height gain

The therapeutic benefit of growth hormone (GH) therapy in improving height in short children is widely recognized; however, GH therapy is associated with other metabolic actions that may be of benefit in these children. Beneficial effects of GH on body composition have been documented in several different patient populations as well as improvements in lipid profile. Marked augmentation of bone mineral density also seems evident in many pediatric populations. Some of these benefits may require continued therapy past the acquisition of adult height. With long-term therapy of any kind, the adverse consequences of treatment should also be considered. Fortunately, long-term GH treatment seems to be safe and well-tolerated. This review describes the long-term metabolic effects of GH treatment in the pediatric population and considers how these may benefit children who are treated with GH.