In vitro insulin-like growth factor-I, growth hormone, and insulin resistance occurs in symptomatic human immunodeficiency virus-1-infected children

Physical growth and sexual maturation of perinatally HIV-infected adolescent males in a southeast Nigerian tertiary hospital: a comparative cross-sectional study

Background

The advent of highly-active anti-retroviral therapy (HAART) has resulted in the survival of children with Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) into adolescence. Their prolonged survival has translated into co-morbidities like endocrine deficiencies which may manifest as growth and pubertal delay. This study aimed to determine the physical growth and sexual maturation of perinatally HIV-infected adolescent males and compare them with those of age-matched HIV-negative controls.

Methods

We conducted a comparative cross-sectional study of 104 perinatally HIV-infected males on HAART aged 10 to 19 years, and 104 age-matched HIV-negative males who served as controls. The subjects and controls were enrolled and assessed at a Nigerian tertiary hospital over six months. Anthropometric measurements such as weight, height, and BMI were obtained and Z scores for age were derived for weight, height, and BMI to determine physical growth using WHO AnthroPlus software. Sexual maturation was assessed using the method proposed by Marshall and Tanner. Data analysis and appropriate statistics were conducted with the Statistical Package for Social Sciences (SPSS) version 25 Chicago IL. A p-value < 0.05 was adopted as the level of statistical significance.

Results

The mean height, weight, and BMI Z scores of the subjects were all lower than those of the controls. The difference between the mean weight of the subjects (44.60 ± 13.32 kg) and the controls (49.97 ± 13.58 kg) was statistically significant (t = 2.88, p = 0.004). Similarly, the difference between the mean BMI Z-scores of the subjects (-0.96 ± 1.95) and the controls (-0.10 ± 0.86) was statistically significant (t = 4.10, p = < 0.001). The subjects showed a delay in pubic hair and testicular development for Stages 1, 2, and 3. Duration of HAART did not significantly affect the BMI of subjects who were in three groups: undernutrition, normal nutrition, and overnutrition (Kruskal-Wallis test, p = 0.30).

Conclusion

Perinatal HIV infection negatively affects physical growth and the onset of pubic-hair development (PH 2) despite the duration of HAART. We recommend that screening for weight deficit or pubertal delay should form part of the management protocol for HIV-infected male children on HAART.

Insulin-Like Growth Factor Is Associated with Changes in Body Composition with Antiretroviral Therapy Initiation

Growth hormone (GH)/insulin-like growth factor (IGF)-1 axis abnormalities have been associated with body composition changes among HIV-infected persons with wasting or lipodystrophy. Little is known of GH/IGF-1 axis alterations with antiretroviral therapy (ART) initiation or differing ART therapies. The AIDS Clinical Trials Group Prospective Evaluation of Antiretrovirals in Resource-Limited Settings (PEARLS) study was a prospective, randomized clinical trial of ART initiation with emtricitabine/tenofovir + efavirenz (FTC/TDF+EFV) versus lamivudine/zidovudine + efavirenz (3TC/ZDV+EFV) in HIV-1-infected individuals from resource-diverse settings. IGF-1 was measured from baseline, week 48, and week 96 stored serum samples. Multivariate models were constructed. 415 participants were included: 170 (41%) were randomized to FTC/TDF+EFV and 245 (59%) to 3TC/ZDV+EFV. The mean age was 35 years, 60% were black, 42% women. The mean IGF-1 level did not change significantly from baseline to week 96 (-0.65 ng/ml; 95% confidence interval (CI) -5.18-3.87), p = .78 and there were no differences by treatment arm at week 96, p = .74. Lower baseline IGF-1 was associated with age, non-white race, greater waist-hip ratio (WHR), low CD4 count, and lower baseline albumin (all p < .01) but not plasma HIV-1 RNA, body mass index, or treatment arm. Greater change in IGF-1 from baseline to 96 weeks was associated with female sex, smaller WHR change, lower baseline albumin, and higher baseline HIV-1 RNA (all p < .01). ART initiation with either ZDV or TDF did not significantly impact overall IGF-1 levels. Baseline and on-treatment changes in IGF-1 with ART initiation may be related to the body composition changes that occur after ART initiation.

Endocrinopathies in children infected with human immunodeficiency virus

Endocrine changes (including adrenal insufficiency, disorders of growth and puberty, thyroid dysfunction, metabolic abnormalities and osteopenia) accompany human immunodeficiency virus (HIV) infection in pediatric patients. The cause of these changes is multifactorial and includes direct viral effects of HIV, and effects of antiretroviral therapy. These effects may be of particular importance in childhood given the critical developmental processes that occur during this time period and the likelihood of prolonged exposure to the virus and medications.

Pubertal onset in children with perinatal HIV infection in the era of combination antiretroviral treatment

OBJECTIVE

To evaluate associations of perinatal HIV infection, HIV disease severity, and combination antiretroviral treatment with age at pubertal onset.

DESIGN

Analysis of data from two US longitudinal cohort studies (IMPAACT 219C and PHACS AMP), conducted during 2000-2012, including perinatally HIV-infected (PHIV) and HIV-exposed but uninfected (HEU) youth. Tanner stage assessments of pubertal status (breast and pubic hair in girls; genitalia and pubic hair in boys) were conducted annually.

METHODS

We compared the timing of pubertal onset (Tanner stage ≥2) between PHIV and HEU youth using interval-censored models. For PHIV youth, we evaluated associations of HIV disease severity and combination antiretroviral treatment with age at pubertal onset, adjusting for race/ethnicity and birth cohort.

RESULTS

The mean age at pubertal onset was significantly later for the 2086 PHIV youth compared to the 453 HEU children (10.3 vs. 9.6, 10.5 vs. 10.0, 11.3 vs. 10.4, and 11.5 vs. 10.7 years according to female breast, female pubic hair, male genitalia, and male pubic hair staging, respectively, all P < 0.001). PHIV youth with HIV-1 RNA viral load above 10, 000 copies/ml (vs. ≤10, 000 copies/ml) or CD4% below 15% (vs. ≥15%) had significantly later pubertal onset (by 4-13 months). Each additional year of combination antiretroviral treatment was associated with a 0.6-1.2-month earlier mean age at pubertal onset, but this trend did not persist after adjustment for birth cohort.

CONCLUSION

Pubertal onset occurs significantly later in PHIV than in HEU youth, especially among those with more severe HIV disease. However, in the current era, combination antiretroviral treatment may result in more normal timing of pubertal onset.

In vitro and in vivo effects of IGF-I on adiposity in HIV-associated metabolic disease: a pilot study

BACKGROUND AND AIMS

We tested the effects of recombinant insulin-like growth factor-I (IGF-I) in an adipocyte model of HIV lipodystrophy and in an open label study on body composition and metabolism in patients with HIV lipodystrophy.

METHODS

The effects of IGF-I on ritonavir-induced adipocyte cell death were studied in vitro. We assessed lipid accumulation, IGF signaling, apoptosis, and gene expression. We conducted a 24-week open label trial of recombinant IGF-I in ten adults with HIV associated lipoatrophy. Laboratory assessments included glucose, insulin, lipids, and IGF-I. At weeks 0 and 24, body composition studies were performed including skinfold measurement, dual-energy x-ray absorptiometry, and computed tomography of the abdomen and thigh.

RESULTS

In vitro, ritonavir increased delipidation and apoptosis of adipocytes, whereas co-treatment with IGF-I attenuated the effect. In the clinical study, subcutaneous adipose tissue did not increase in patients after treatment with IGF-I; however, there was a decrease in the proportion of abdominal fat (39.8 ± 7% vs. 34.6 ± 7%, p = 0.007). IGF-I levels increased with treatment (143 ± 28 μg/L at week 0 vs. 453 ± 212 μg/L at week 24, p = 0.002), whereas IGFBP-3 levels declined (3.554 ± 1.146 mg/L vs. 3.235 ± 1.151 mg/L, p = 0.02). Insulin at week 12 decreased significantly (90.1 ± 39.8 pmol/L vs. 33.2 ± 19.6 pmol/L, p = 0.002). There was a nonsignificant decrease in visceral adipose tissue (155.2 ± 68 cm² at week 0 vs. 140.6 ± 70 cm² at week 24, p = 0.08).

CONCLUSIONS

Use of recombinant IGF-I may lower fasting insulin and abdominal fat in patients with lipoatrophy associated with HIV infection. Further evaluation of this agent for treatment of HIV-associated lipodystrophy may be warranted.

Growth hormone: the expansion of available products and indications

Growth hormone is a widely used hormone. This article describes its historical use, current indications and studies for possible future uses.

Impact of antiretroviral therapy on growth, body composition and metabolism in pediatric HIV patients

Highly active antiretroviral therapy improves survival and growth in children with HIV infection. However, its use can be associated with adverse changes in body composition and metabolism. Bone mineral density can be adversely affected in HIV-positive children due to nutritional compromise or certain antiretrovirals. HIV-associated lipodystrophy, consisting of redistribution of adipose tissue, insulin resistance, and dyslipidemia, has also been described in children. Pediatric HIV patients may be at greater risk for these problems because of their longer potential lifetime exposure to these agents and because childhood is normally a period of rapid growth and tissue accretion. Healthcare providers for children with HIV infection must be aware of the potential complications associated with HIV antiretrovirals so that their antiviral efficacy can be balanced against their risk for side effects. In this review, we discuss the alterations in childhood growth and body composition that occur in HIV-infected children, and describe the impact of antiretroviral therapy on these outcomes. The problem of HIV-associated lipodystrophy syndrome in children is also discussed. Children with HIV should have their growth and body composition systematically monitored. Antiretroviral regimens should be tailored to optimize adherence and viral suppression while minimizing the potential for adverse side effects.

Growth hormone: the expansion of available products and indications

Growth hormone is a widely used hormone. This article describes its historical use, current indications and studies for possible future uses.

Growth and puberty in children with HIV infection

Children with perinatal HIV infection may present with clinical features of endocrine dysfunction such as growth failure and pubertal delay. Pediatric care providers and pediatric endocrinologists should implement appropriate preventive, screening, and therapeutic strategies to maximize survival and quality of life in these children. Growth and pubertal delay can be exacerbated by a variety of treatable infectious, endocrine, nutritional, and immunological disorders. Timely diagnosis and appropriate treatment of these conditions may lead to improvement or even normalization of growth and puberty. HIV-infected children with advanced disease should undergo periodic growth evaluation, including GH levels, IGF-I, IGF binding protein 3 and androgens, in order to identify subclinical endocrine dysfunction. However, little is known about the association between HIV infection and endocrine dysfunction in children. Highly active antiretroviral therapy may also be associated with endocrine dysfunction with consequences on growth and puberty. Growth retardation and pubertal delay are always seen in children with advanced HIV infection and are often related to the proinflammatory milieu found in advanced AIDS. Growth and pubertal impairment are markers of advanced disease and require proper evaluation. A dysregulation of the hypothalamic-pituitary axis, toxic or allergic drug reactions may play a role in growth and pubertal delay of HIV-infected children. These dysfunctions require careful monitoring, in order to assess metabolic alterations that may be important in regulation of growth among HIV infected children. Better understanding of the mechanisms leading to impairment of growth and puberty in children with perinatal HIV-1 infection might lead to appropriate treatment when required.

Monitoring insulin-like growth factors in HIV infection and AIDS

There is a close association between the growth hormone (GH)-insulin-like growth factor I (IGF-I) axis, infection and immunity. Infection with the human immunodeficiency virus (HIV) is often associated with a decrease of the concentrations of IGF-I, IGF-II, IGF-binding protein 3 (IGFBP-3) and an increase of IGFBP-1 and -2. Many investigators have studied the relationship between the GH-IGF-I system and some of the most common characteristics of disease progression, such as decreased CD4 cell counts, weight loss and fat redistribution. Although conditions for restoration of thymic function and lymphopoiesis with GH or IGF-I are still not well defined, many studies led to the development of clinical trials on the therapeutic use of GH, IGF-I and GHRH for the treatment of weight loss or fat redistribution, two problems which persist despite the introduction of highly active antiretroviral therapy. Monitoring IGF-I concentrations during treatment with GH and GHRH is likely to become an essential component of their therapeutic use. IGF-I levels are the first indicator of treatment efficacy and can be used to monitor compliance. High levels of IGF-I are a warning sign for the increased risk of potential adverse effects, such as acromegalic-like symptoms or malignancy. This could lead to a reduction of the therapeutic dose or the temporary interruption of treatment until IGF levels reach a safe range. IGF-I levels are also likely to increase with other hormones used in HIV patients, such as erythropoietin for the treatment of anemia or anabolic androgens in HIV-infected women.

Perspective on HIV infection and aging: emerging research on the horizon

A greater prevalence of human immunodeficiency virus (HIV)-infected individuals aged >50 years is projected. This epidemiologic trend will continue to increase as a result of not only greater survival rates among HIV-infected patients who receive treatment, but also of delayed recognition of older individuals with occult HIV disease. Historically, it was thought that, despite viral responses to highly active antiretroviral therapy (HAART) among older individuals that approximate those of younger individuals, older persons infected with HIV could not mount as vigorous an immune response as do younger HIV-infected individuals. However, recent evidence suggests that older HIV-infected individuals may do just as well, because they may be more compliant with their antiretroviral regimens. Limited data are available on the safety and tolerability of HAART in this population. Emerging evidence suggests that metabolic, neuropsychiatric, and cardiovascular morbidities could be exacerbated by use of antiretrovirals or by HIV infection itself. Additional research is needed to optimize the care of older HIV-infected patients.

Changed bone status in human immunodeficiency virus type 1 (HIV-1) perinatally infected children is related to low serum free IGF-I

INTRODUCTION

Adults and children affected by human immunodeficiency virus type-1 (HIV-1) infection show bone demineralization. Little is known about skeletal status using a quantitative high-frequency ultrasound (QUS) technique in these patients.

OBJECTIVE

To evaluate the bone quality and assess the role of the IGF system in the bone metabolism and skeletal status of HIV-1 perinatally infected children.

PATIENTS AND METHODS

Serum free and total IGF-I, IGFBP-3, serum osteocalcin level, urinary deoxypyridinoline concentration, spontaneous interleukin-6 (IL-6) release and broadband ultrasound attenuation (BUA) were evaluated in 44 prepubertal children who had perinatal HIV-1 infection. The patients were divided into two groups depending on the severity of their clinical condition: group 1 (23 children with no or mild clinical symptoms, mean age 8.0 +/- 2.9 years) and group 2 (21 children with severe clinical symptoms, mean age 8.58 +/- 2.47 years). Fifty-five healthy age- and sex-matched controls were analysed for comparison.

RESULTS

Compared with group 1 and the controls, group 2 patients showed a significantly reduced BUA Z-score (P < 0.001), and significantly reduced concentrations of serum osteocalcin (P < 0.001) and urinary deoxypyridinoline (P < 0.001 and P < 0.05, respectively). Group 2 patients also showed significantly reduced serum free IGF-I (P < 0.001) and total IGF-I (P < 0.05) levels compared with the controls, but not with group 1. No statistically significant differences were found between the three groups with regard to IGFBP-3. Group 2 patients showed significantly higher spontaneous IL-6 release than group 1 patients and controls (P < 0.001). BUA Z-scores displayed a significant correlation with free IGF-I in group 2 (r = 0.96; P < 0.001), group 1 (r = 0.56; P = 0.005) and controls (r = 0.50; P < 0.001).

CONCLUSION

Our study shows that only patients affected by perinatal HIV-1 infection with severe clinical manifestations present significant changes in bone quality and bone metabolism. Our data also show that impairment of skeletal status is related to reduction in serum total and free IGF-I. Children with perinatal HIV-1 infection, because of a considerable improvement in life expectancy, seem at great risk of not obtaining an optimal bone mass. A possible therapeutic approach should be considered in these children.

From hormones to immunity: the physiology of immunology

Discoveries in the physiology of immunology have increased at an increasing rate during the past two decades. It is now recognized that the immune system is just another physiological system that regulates, and is regulated by, other physiological systems such as the brain. These advances make it clear that recent findings in genomic biology must be interpreted in the context of the environment in which animals and humans live. Lack of a strong genetic basis for significant human mental health disorders, such as major depression, points to the critical importance of interactions. Several examples of environmental x genetic x disease interactions are presented. Regulation of cells of the hematopoietic lineage by two genes that control over 80% of postnatal growth, growth hormone and IGF-I, are then highlighted. The reciprocal relationship of how proinflammatory cytokines from the immune system regulate the growth hormone/IGF-I axis is also summarized. Particular emphasis is placed upon TNFalpha-induced IGF-I resistance in neurons, muscle cells and epithelial cells. This cytokine regulation of hormone action may ultimately be more important for human and animal health than direct effects of growth hormone and IGF-I on hematopoietic cells. Wasting of AIDS patients is given as an important clinical example of how TNFalpha from an activated immune system reduces IGF-I sensitivity in multiple physiologic systems, including muscle, nervous and hematopoietic tissues.

Impaired growth hormone secretion correlates with visceral adiposity in highly active antiretroviral treated HIV-infected adolescents

BACKGROUND

HIV-infected adults with lipodystrophy, characterized by excess accumulation of intra-abdominal adipose tissue (IAT), showed impaired growth hormone (GH) secretion. Data are lacking in paediatric lipodystrophy with the same features.

METHODS

Twenty-five pubertal HIV-infected children were assessed for GH response (GH-AUC(0-120 min)) to arginine + GHRH testing, insulin-like growth factor-1 (IGF-1), IGF binding protein 3 (IGFBP-3), insulin, glucose, cholesterol, triglycerides, free fatty acids and nitric oxide levels. Body composition and IAT content were evaluated by dual-energy x-ray-absorptiometry and magnetic resonance imaging. An excess accumulation of IAT was defined as a value > 41 cm2. Differences between children with (V+) and without (V-) excess IAT were assessed by non-parametric tests and multivariate analysis. RESULTS Ten V+ (mean IAT, 82.5 cm2) and 15 V- (mean IAT, 26.8 cm2) were identified; they were similar for age (13.8 versus 14.8 years), body mass index (20.2 versus 19.5 kg/m2), male : female ratio (3/7 versus 8/7), months on highly active antiretroviral therapy (54.5 versus 55 months). V+ showed lower GH-AUC(0-120 min) (16.4 versus 31.6 microg x h/l; P = 0.002), lower IGF-1 concentrations (384 versus 515 ng/ml; P = 0.03) and higher insulin levels (17.8 versus 10.5 microIU/ml; P = 0.01) than V-. V+, as compared to V-, showed lower lean mass (total, P = 0.025; arms, P = 0.024; legs, P = 0.008) and higher fat mass (total, P = 0.0038; arms, P = 0.028; trunk, P < 0.0001). Lipid profile and glucose, IGFBP-3, nitric oxide and free fatty acids levels were similar in the two groups. GH-AUC(0-120 min) correlated negatively with IAT content and insulin levels.

CONCLUSION

Impaired GH secretion is detectable in pubertal children with increased visceral adiposity and hyperinsulinemia. GH therapy should be considered in lipodystrophic HIV-infected children with excess IAT.

Cardiovascular and cerebrovascular events in patients treated for human immunodeficiency virus infection

BACKGROUND

Metabolic abnormalities associated with human immunodeficiency virus (HIV) infection, including dysglycemia and hyperlipidemia, are increasingly prevalent, and there is concern about the possibility of an association with accelerated cardiovascular and cerebrovascular disease.

METHODS

We conducted a retrospective study of the risk of cardiovascular and cerebrovascular disease among the 36,766 patients who received care for HIV infection at Veterans Affairs facilities between January 1993 and June 2001.

RESULTS

For antiretroviral therapy, 70.2 percent of the patients received nucleoside analogues, 41.6 percent received protease inhibitors, and 25.6 percent received nonnucleoside reverse-transcriptase inhibitors for a median of 17 months, 16 months, and 9 months, respectively. Approximately 1000 patients received combination therapy with a protease inhibitor for at least 48 months, and approximately 1000 patients received combination therapy with a nonnucleoside reverse-transcriptase inhibitor for at least 24 months. Between 1995 and 2001, the rate of admissions for cardiovascular or cerebrovascular disease decreased from 1.7 to 0.9 per 100 patient-years, and the rate of death from any cause decreased from 21.3 to 5.0 deaths per 100 patient-years. Patient-level regression analyses indicated that there was no relation between the use of nucleoside analogues, protease inhibitors, or nonnucleoside reverse-transcriptase inhibitors and the hazard of cardiovascular or cerebrovascular events, but the use of antiretroviral drugs was associated with a decreased hazard of death from any cause.

CONCLUSIONS

Use of newer therapies for HIV was associated with a large benefit in terms of mortality that was not diminished by any increase in the rate of cardiovascular or cerebrovascular events or related mortality. Fear of accelerated vascular disease need not compromise antiretroviral therapy over the short term. However, prolonged survival among HIV infected patients means that longer-term observation and analysis are required.

Endocrinologic and immunologic factors associated with recovery of growth in children with human immunodeficiency virus type 1 infection treated with protease inhibitors

INTRODUCTION

Growth failure is a common presenting sign in children with HIV disease and is a sensitive indicator of disease progression in children with AIDS. Highly active antiretroviral therapy (HAART) is associated with a significant decrease in viral load and a subsequent rise in CD4+ T cell counts in HIV-1-infected children and also with increased height and weight. The underlying mechanisms of catch-up growth during HAART are yet unknown.

METHODS

Height and weight measurements, blood sample analyses for HIV-1 RNA and peripheral blood CD4+ T cell counts were obtained twice within 1 month before the start of HAART and after 12, 24, 36 and 48 weeks of treatment. Serum concentrations of insulin-like growth factor I (IGF-1), IGFs complexed to specific, structurally homologous binding proteins (IGFBP-3), cortisol, free thyroxine and tumor necrosis factor alpha (TNF-alpha) were measured before the start of therapy and after 24 weeks. In addition serum IGF-1 and IGFBP-3 values were determined after 48 weeks.

RESULTS

Twenty-seven HIV-1-infected children with a median age of 5.5 years (range, 0.3 to 14.9 years) were included. Overall no significant changes in height and body mass index (BMI) z scores were observed. The median baseline plasma viral load of 68,800 copies/ml decreased to less than the detection limit of 500 copies/ml in 80% of the children after 48 weeks. TNF-alpha values were elevated (44 pg/ml) at baseline and decreased significantly to 37 pg/ml after 24 weeks. At baseline elevated TNF-alpha was observed in 78%, which decreased to 55% after 24 weeks. Baseline free thyroxine and cortisol values were normal and did not change during therapy. Baseline serum of IGF-1 and IGFBP-3 concentrations were normal, but IGF-1 tended to be lower than IGFBP-3. Both values increased significantly after the initiation of therapy. IGFBP-3 decreased after 48 weeks whereas IGF-1 stabilized. The increase in IGF-1 was significantly higher in children in whom the BMI and length (after correction for age and sex) increased the most.

CONCLUSION

Hypothyroidism and adrenal axis abnormalities are not associated with restoration of growth after the initiation of antiretroviral therapy in HIV-1-infected children. The combination of relatively high serum IGFBP-3 concentration and relatively lower serum IGF-1 suggests the presence of a growth hormone-resistant state. During treatment with a protease inhibitor-containing regimen, decreased serum IGFBP-3 and stabilization of IGF-1 after a significant initial increase suggest restoration of normal sensitivity to growth hormone and recovery to an anabolic condition.

Assessment of growth and immunologic function in HIV-infected and exposed children

Many children who are HIV infected grow poorly. An epidemiological framework guided a retrospective chart review assessing growth in three groups of children (n = 192): (a) children who were HIV infected secondary to maternal transmission (n = 77), (b) children who had been HIV-positive at birth but became seronegative and continue to be observed (seroreverters) (n = 84), and (c) HIV-infected children who had died (n = 31). Growth failure in the HIV-infected children was significantly greater than that expected in the general population. The seroreverters also demonstrated significantly more growth failure than that expected in the general population. Of the children who had linear growth failure, only 3 of 12 HIV-infected children and 2 of 11 seroreverters also had inadequate weight gain. However, 13 of 15 children with growth failure who subsequently died had poor weight gain. HIV classification was not significantly related to growth. These findings extend our understanding to a large, urban population of children in the United States including those who are older than children in other studies and who developed HIV through perinatal transmission. Nursing clinical practice and research implications are offered.

Insulin-like growth factor I (IGF-I) and IGF-binding protein 3 response to growth hormone is impaired in HIV-infected children

To better characterize the somatotropic axis in HIV-infected children the circadian rhythm of growth hormone (GH), and basal and stimulated (by an insulin-like growth factor I [IGF-I] generation test) plasma levels of IGF-I and insulin-like growth factor-binding protein 3 (IGFBP-3), were evaluated in 16 children (9 boys and 7 girls; age range, 7-11 years) with HIV infection. All patients were free from active opportunistic infection or liver disease at the time of the study. Sixteen age- and sex-matched healthy children (10 boys and 6 girls; age range, 7-11 years) served as control subjects. GH rhythmometric data were analyzed by single and population mean cosinor analysis. As regards the IGF-I generation test, biosynthetic human GH (hGH, 0.1 IU/kg, 0.033 mg/kg) was administered subcutaneously for 4 days and blood samples were taken from fasting subjects at baseline and on the morning after the last GH injection for measurement of IGF-I and IGFBP-3. Plasma GH levels fell within normal limits in the HIV-seropositive patients and were similar to those of healthy children (1.31 +/- 1.18 vs. 1.57 +/- 1.16 microg/liter, respectively; mean +/- SD). The population mean cosinor analysis shows that the GH circadian rhythm reached statistical significance both in the HIV-seropositive children and in the control group. Despite this, the IGF-I and IGFBP-3 levels were significantly lower in HIV-infected children than in the control group (75.6 +/- 57.2 vs. 233.3 +/- 52.5 ng/ml, p < 0.001 and 2.09 +/- 0.17 vs. 3.89 +/- 0.24 mg/liter, p < 0.01, respectively; mean +/- SD); moreover, the response of IGF-I and IGFBP-3 to the IGF-I generation test was significantly lower in HIV-infected children than in the control group (86.3 +/- 55.8 vs. 257.5 +/- 53.4 ng/ml, p < 0.001 and 3.14 +/- 0.43 mg/liter, p < 0.01, respectively; mean +/- SD). It appears that circadian GH secretion is normal in children with HIV infection, but the response to exogenous GH with regard to IGF-I and IGFBP-3 production is impaired, indicating a degree of GH insensitivity in such children.

Growth failure in children with HIV infection

Poor growth is reported in as many as 50% of HIV-infected children. HIV infection adversely affects pregnancy outcome; infants born to HIV-infected women have significantly lower mean birth weight and length, regardless of the infants' HIV status, compared with infants born to uninfected women. Pediatric HIV further reduces birth weight. Progressive stunting, that is, proportionately decreased linear and ponderal growth, appears to be the most common abnormality in perinatally infected children and is accompanied by preferential decreases of fat-free or lean body mass. Although data are inconsistent, deficiencies of several micronutrients with the potential to affect growth adversely have been identified, including that of vitamin A. Neuroendocrine abnormalities also occur, including abnormal thyroid, growth hormone/ insulinlike growth factor-1, and adrenal function; however, no consistent endocrine abnormality is observed in HIV-associated growth failure. Infections of the gastrointestinal tract and malabsorption of carbohydrates, fat, and protein are common, but no relationship between these disorders and poor growth has been demonstrated. Despite normal rates of resting and total energy expenditures, the mean daily dietary intake of children with growth failure (GF) appears to be inadequate. Inadequate dietary intake is not the sole cause of GF; dietary supplementation improves weight but does not correct deficits in lean tissue or height. Levels of HIV RNA are greater in children with poor growth compared with infected children with normal rates of growth. How HIV replication impedes growth has not been established but suppression of HIV appears to have a favorable effect on ponderal and linear growth. Further investigations are necessary to evaluate the potential role of anabolic agents for the management of HIV-associated growth failure.

Growth failure in children with HIV infection

Poor growth is reported in as many as 50% of HIV-infected children. HIV infection adversely affects pregnancy outcome; infants born to HIV-infected women have significantly lower mean birth weight and length, regardless of the infants' HIV status, compared with infants born to uninfected women. Pediatric HIV further reduces birth weight. Progressive stunting, that is, proportionately decreased linear and ponderal growth, appears to be the most common abnormality in perinatally infected children and is accompanied by preferential decreases of fat-free or lean body mass. Although data are inconsistent, deficiencies of several micronutrients with the potential to affect growth adversely have been identified, including that of vitamin A. Neuroendocrine abnormalities also occur, including abnormal thyroid, growth hormone/ insulinlike growth factor-1, and adrenal function; however, no consistent endocrine abnormality is observed in HIV-associated growth failure. Infections of the gastrointestinal tract and malabsorption of carbohydrates, fat, and protein are common, but no relationship between these disorders and poor growth has been demonstrated. Despite normal rates of resting and total energy expenditures, the mean daily dietary intake of children with growth failure (GF) appears to be inadequate. Inadequate dietary intake is not the sole cause of GF; dietary supplementation improves weight but does not correct deficits in lean tissue or height. Levels of HIV RNA are greater in children with poor growth compared with infected children with normal rates of growth. How HIV replication impedes growth has not been established but suppression of HIV appears to have a favorable effect on ponderal and linear growth. Further investigations are necessary to evaluate the potential role of anabolic agents for the management of HIV-associated growth failure.

Interleukin-6 release by cultured peripheral blood mononuclear cells inversely correlates with height velocity, bone age, insulin-like growth factor-I, and insulin-like growth factor binding protein-3 serum levels in children with perinatal HIV-1 infection

Spontaneous and phytohemagglutinin (PHA)-stimulated interleukin (IL)-6 release by cultured peripheral blood mononuclear cells was related to height velocity, bone age, insulin-like growth factor-I (IGF-I), and IGF binding protein-3 (IGFBP-3) serum level standard deviation scores (SDS) of 32 children [aged 91 (median; range 13-151) months] with human immunodeficiency virus-type 1 (HIV-1) perinatal infection and severe disease. Spontaneous and PHA-stimulated IL-6 release inversely correlated with height velocity, bone age, IGF-I, and IGFBP-3 SDS. Ten children with height velocity SDS </= -2, compared to 22 children with height velocity SDS > -2, showed higher spontaneous and PHA-stimulated IL-6 release and lower IGF-I and IGFBP-3 SDS (irrespective of CD4-positive T-lymphocyte counts, viral load, liver disease, or nutrition status). IL-6 overproduction may be a mechanism of IGF-I and IGFBP-3 down-regulation and impaired linear growth in children with perinatal HIV-1 infection. Growth-promoting strategies, including targeted anticytokine treatments, could be devised for such children.

Fasting hyperinsulinemia and increased waist-to-hip ratios in non-wasting individuals with AIDS

OBJECTIVE

To identify metabolic and body composition changes associated with HIV-1 infection in a cross-sectional study of individuals stratified by immunologic status and body mass.

DESIGN

Metabolic abnormalities including glucose intolerance and changes in body morphology have recently been described in HIV-1-infected individuals following therapy with protease inhibitor-containing highly active anti-retroviral therapy. Although this is suggestive of a direct drug effect, the possibility that HIV infection may induce a tendency towards such underlying derangements should be considered. HIV-infected patients are heterogeneous with respect to immunologic status and body mass. In examining the underlying effect of HIV-1 on metabolic and body composition parameters, stratification by various immunologic and body mass categories may give divergent results that would not be detected otherwise.

METHODS

Thirty male participants were categorized into four cohorts: non-wasting HIV-seronegative controls, non-wasting HIV-infected patients with relatively intact immune function (CD4 cell count > 500 x 10(6)/l); non-wasting individuals with AIDS (CD4 cell count < 200 x 10(6)/l); and individuals with AIDS wasting.

RESULTS

Increased fasting plasma insulin and waist-to-hip ratios were found specifically in non-wasting individuals with AIDS compared with HIV-negative controls.

CONCLUSIONS

Our study emphasises the importance of both body mass and immune function in studying metabolic and body composition abnormalities associated with HIV-1 infection. The association of increased waist-to-hip ratios and hyperinsulinemia suggestive of insulin resistance in non-wasting individuals with AIDS suggest that the tendency towards these metabolic abnormalities may be related to the HIV infectious process or to factors associated with immunologic dysfunction.

Involvement of hormonal circadian secretion in the growth of HIV-infected children

OBJECTIVE

To evaluate the circadian secretion of hormones involved in the regulation of growth in childhood, namely growth hormone, insulin-like growth factor (IGF)-I, cortisol, adrenocorticotropin hormone (ACTH), and thyroid-stimulating hormone (TSH) in HIV-infected children.

DESIGN

The circadian secretory pattern of growth hormone, IGF-I, cortisol, ACTH and TSH was evaluated in 14 HIV-infected children; 13 healthy age- and sex-matched children were chosen as controls.

METHODS

Sampling was performed every 4 h from 0400 h to 2000 h and every 2 h from 2000 h to 0400 h. Rhythmometric data were analysed by single and population mean cosinor methods and by analysis of variance.

RESULTS

A statistically significant circadian rhythm for growth hormone, IGF-I and cortisol was detectable in HIV-seropositive children, but the mean basal IGF-I levels were below the normal range for age in 12 patients. A statistically significant circadian rhythm was not detectable for ACTH or TSH.

CONCLUSION

These results show that there is a loss of the physiological regulation of growth hormone-IGF-I axis and a modification of 24 h TSH profile in our HIV-infected children. These abnormalities might be involved in the altered growth mechanism leading to the failure to thrive that is a peculiar feature of HIV-infected children.

Effects of growth hormone and insulin-like growth factor I on T- and B-lymphocytes and immune function

The concept of a neuro-endocrine-immune axis was proposed more than 50 years ago. Growth hormone (GH), a central component of this axis has many functions at both a molecular and cellular level, including thymocyte proliferation, stimulation of the cytotoxic activity of natural killer cells and induction of lymphocyte proliferation. Binding of GH to its receptors on lymphocytes stimulates the production of insulin-like growth factor I (IGF-I), which mediates the effects of GH on cell proliferation. Other effects of GH on the immune system appear to be direct, such as priming monocytes for enhanced production of hydrogen peroxide in response to phorbol esters, and stimulating neutrophils to secrete superoxide anions associated with enhanced phagocytic activity. Many of the effects of GH are shared by IGF-I. Despite these observations, and the fact that GH is produced and secreted in immunological tissues such as the thymus and spleen, immune deficiency is not characteristic of GH deficiency in humans. The question remains as to whether GH and IGF-I could be used as immunotherapy. Currently, both agents have been used in adults to diminish wasting due to acquired immunodeficiency syndrome, and GH has been shown to stimulate CD8+ cell counts. However, they had little impact on CD4+ cell counts, which may be due to IGF-I and GH resistance in these individuals. The use of GH and IGF-I as immunotherapies merits further study.

Circadian secretory pattern of growth hormone, insulin-like growth factor type I, cortisol, adrenocorticotropic hormone, thyroid-stimulating hormone, and prolactin during HIV infection

The circadian rhythms of plasma growth hormone (GH), insulin-like growth factor type I (IGF-I), cortisol, adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), and prolactin (PRL) were evaluated in 13 HIV-seropositive patients (8 males and 5 females; mean age [+/-SD], 30 +/- 5 years), classified as CDC C2. Sixteen clinically healthy subjects (9 males and 7 females; mean age [+/-SD], 32 +/- 8 years) were chosen as control group. Samples were taken every 4 hr from 04:00 to 20:00 and every 2 hr from 20:00 to 04:00. Plasma GH was evaluated by IRMA procedure, plasma IGF-I by RIA (after separation of soluble IGF-I from IGF-I-binding proteins, using acid-ethanol extraction), plasma cortisol by a solid-phase RIA, plasma ACTH by double-antibody RIA, and serum TSH and serum PRL by a solid-phase two-site fluoroimmunometric assay. Rhythmometric data were analyzed by single and population mean cosinor analysis; the comparison of the parameters of the rhythm between patients and controls was carried out by the mesor test and the amplitude-acrophase Hotelling test. Alterations of the circadian pattern of GH, IGF-I, cortisol, ACTH, TSH, and PRL were demonstrated in HIV-seropositive patients. In fact, the circadian profiles of these hormones were clearly flattened and no statistically significant 24-hr rhythm was detectable (with the exception of cortisol). These results are consistent with the hypothesis that alterations of the circadian temporal structure may already be present in HIV-seropositive patients without wasting and infectious complications.

Endocrine implications of human immunodeficiency virus infection

Endocrine abnormalities occur frequently in HIV-infected patients. Although the majority of endocrine disorders reflect chronic infection, stress, and malnutrition, some disorders are characteristic of HIV infection or AIDS and deserve particular clinical attention. Identification of HIV patients at risk of frank endocrine disorders, rapid and correct diagnosis, and appropriate management are essential steps to minimize morbidity and mortality. Finally, increasing evidence from in vitro studies suggests that various hormones may influence HIV replication as well as the course of HIV disease and associated disorders. Future studies on the molecular mechanisms of hormones on HIV action and clinical studies on the effects of hormones as adjunctives to established forms of therapy may stimulate development of novel therapeutic strategies that will benefit HIV-infected patients.

Natural history of somatic growth in infants born to women infected by human immunodeficiency virus. Women and Infants Transmission Study Group

OBJECTIVE

To evaluate the nature and magnitude of the effect of congenitally or perinatally acquired human immunodeficiency virus (HIV) infection on somatic growth from birth through 18 months of age.

STUDY DESIGN

Anthropometry was performed serially in 282 term infants born to HIV-infected women in a multicenter prospective natural history cohort study. Repeated measures analysis was used to compare z-score anthropometric indexes of weight-for-age, length-for-age, weight-for-length, and head circumference-for-age between infected and uninfected infants, with adjustment for covariates including infant gender; maternal education; prenatal alcohol, tobacco, and/or illicit drug exposure; and mean prenatal CD4+ T-lymphocyte count. A separate repeated measures model was used to assess the effect of infant zidovudine treatment on growth.

RESULTS

Infants infected with HIV were an estimated average 0.28 kg lighter and 1.64 cm shorter than uninfected infants at birth, were 0.71 kg lighter and 2.25 cm shorter by 18 months of age, and had a sustained estimated average decrement of 0.70 to 0.75 cm in head circumference. Patterns of growth were similar in male and female infants. Infected infants had a progressive decrement in body mass index from birth through 6 months of age. Infection with HIV was associated with significant decrements across all standardized growth outcome measures after adjustment for covariates. Mean z scores were lower for weight by 0.612 (p < 0.001), for length by 0.735 (p < 0.001), for weight-for-length by 0.255 (p = 0.02), and for head circumference by 0.563 (p < 0.001) SD units compared with uninfected infants. Zidovudine treatment was not associated with improved growth.

CONCLUSION

The effect of congenitally or perinatally acquired HIV infection on infant growth is one of early and progressive decrements in attained linear growth and growth in mass, early and sustained decrements in head growth, and marked early decrements in body mass index.

Hypothalamic and pituitary function in AIDS

Clinically relevant HP dysfunction occurs infrequently in the course of HIV infection and AIDS, and is usually due to destruction or infiltration of the region by opportunistic infections. However, more subtle defects occur with much greater frequency. Since these impairments, especially in the gonadotrophic and corticotrophic axes, are observed in HIV patients before the development of ARC or AIDS, direct involvement of the hypothalamus or pituitary by the neurotropic HIV virus or by other HIV-mediated factors is possible. Further investigation of hypothalamic and pituitary hormones by provocative means, in addition to assessment of the pulsatile secretion of these hormones, at all stages of HIV infection will be needed to clarify the role of the virus in these individuals.