Pathophysiology of GHRH-growth hormone-IGF1 axis in HIV/AIDS

A Machine Learning Approach to Predict Weight Change in ART-Experienced People Living With HIV

INTRODUCTION

The objective of the study was to develop machine learning (ML) models that predict the percentage weight change in each interval of time in antiretroviral therapy-experienced people living with HIV.

METHODS

This was an observational study that comprised consecutive people living with HIV attending Modena HIV Metabolic Clinic with at least 2 visits. Data were partitioned in an 80/20 training/test set to generate 10 progressively parsimonious predictive ML models. Weight gain was defined as any weight change >5%, at the next visit. SHapley Additive exPlanations values were used to quantify the positive or negative impact of any single variable included in each model on the predicted weight changes.

RESULTS

A total of 3,321 patients generated 18,322 observations. At the last observation, the median age was 50 years and 69% patients were male. Model 1 (the only 1 including body composition assessed with dual-energy x-ray absorptiometry) had an accuracy greater than 90%. This model could predict weight at the next visit with an error of <5%.

CONCLUSIONS

ML models with the inclusion of body composition and metabolic and endocrinological variables had an excellent performance. The parsimonious models available in standard clinical evaluation are insufficient to obtain reliable prediction, but are good enough to predict who will not experience weight gain.

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.

Advances in the detection of growth hormone releasing hormone synthetic analogs

The administration of growth hormone releasing hormone (GHRH) and its synthetic analogs is prohibited by the World Anti-Doping Agency (WADA). Although there is evidence of their use, based on admissions and intelligence, they do not appear to have been found in anti-doping samples by WADA accredited laboratories. This might be due to their small concentration in urine and limited knowledge about their metabolism, especially for unapproved synthetic analogs. This study investigates the in vitro metabolism and detection of four of the larger GHRH synthetic analogs (sermorelin, tesamorelin, CJC-1295, and CJC-1295 with drug affinity complex) in fortified urine. Nineteen major in vitro metabolites were identified, selected for synthesis, purified, and characterized in house. These were used as reference materials to spike into urine together with commercially available parent peptides and a metabolite of sermorelin (sermorelin(3-29)-NH₂ ) to develop a sensitive liquid chromatography-tandem mass spectrometry method for their detection to help prove GHRH administration. Limits of detection of the target peptides were generally 1 ng/ml (WADA required performance limit) or less.

HIV and the Pituitary Gland: Clinical and Biochemical Presentations

Human immunodeficiency virus (HIV) can have profound impact on the function of the pituitary gland. We have performed an electronic literature search using the following database: PubMed, Medline, Scopus, and Google Scholar. These databases were searched using the keywords HIV, pituitary glands, cancer, pituitary apoplexy, and infertility. HIV can cause hypopituitarism and also can lead to diabetes insipidus. The impact can be slow and insidious, and diagnosis depends on high index of clinical suspicion. The effect on anterior pituitary gland can be associated with growth hormone deficiency, hypothyroidism, adrenal insufficiency, premature menopause, erectile dysfunction, and infertility. HIV can cause pituitary apoplexy, and this should be treated as an endocrine emergency. Importantly, HIV can be associated with pituitary lymphoma and pituitary cancer. Therefore, joined management between HIV physicians, clinical biochemists and endocrinologists may help in establishing pituitary dysfunction.

Combination of resistance and aerobic exercise for six months improves bone mass and physical function in HIV infected individuals: A randomized controlled trial

To evaluate the effect of combined resistance and aerobic training (RT+AT) on regional bone mineral density (BMD) and physical performance in people living with HIV (PLWH). Forty PLWH (20 men and 20 women) were randomized into RT+AT group (n = 20; age = 38.3 ± 4.9) or non-exercise control group (n = 20; age = 37.9 ± 5.1). The RT+AT group was required to perform a nonlinear periodized resistance training program targeting large muscle groups followed by 20 min aerobic exercise at 65-80% of maximal heart rate. Participants in RT+AT performed three supervised sessions per week for 6-months, whereas participants in the control group were instructed to continue with their current lifestyle habits. The primary outcome was bone mineral density (lumbar spine (L2-L4), femoral neck, and distal 1/3 radius). Secondary outcomes included physical function, anthropometry, inflammatory markers, and growth factors. The RT+AT group demonstrated a significant increase in BMD at follow-up for the Lumbar spine (L2-L4), femoral neck, and 1/3 radius (all, P < .05), and There were no gender differences in the training response between men and women for any of the BMD regions. Similar findings were also observed for lean body mass, IGF1and Adiponectin (P < .001). We observed a decrease in percent body fat, fat mass, IL-6, TNF-α, and myostatin in the RT+AT group (P < .001). Finally, there was a significant increase in handgrip strength and gait speed for both women and men in the RT+AT group (P < .001). A combination of resistance and aerobic training appears to be a feasible and effective means for counteracting bone loss and improving various inflammatory markers, physical function, and growth hormones in PLWH.

The treatment effect of novel hGHRH homodimer to male infertility hamster

Extra-hypothalamic growth hormone-releasing hormone (GHRH) plays an important role in reproduction. To study the treatment effect of Grin (a novel hGHRH homodimer), the infertility models of 85 male Chinese hamsters were established by intraperitoneally injecting 20 mg/kg of cyclophosphamide once in a week for 5 weeks and the treatment with Grin or human menopausal gonadotropin (hMG) as positive control was evaluated by performing a 3-week mating experiment. 2-8 mg/kg of Grin and 200 U/kg of hMG showed similar effect and different pathological characteristics. Compared to the single cyclophosphamide group (0%), the pregnancy rates (H-, M-, L-Grin 26.7, 30.8, 31.3%, and hMG 31.3%) showed significant difference, but there was no difference between the hMG and Grin groups. The single cyclophosphamide group presented loose tubules with pathologic vacuoles and significant TUNEL positive cells. Grin induced less weight of body or testis, compactly aligned tubules with little intra-lumens, whereas hMG caused more weight of body or testis, enlarging tubules with annular clearance. Grin presented a dose-dependent manner or cell differentiation-dependentincrease in testicular GHRH receptor, and did not impact the levels of blood and testicular GH, testosterone. Grin promotes fertility by proliferating and differentiating primitive cells through up-regulating testicular GHRH receptor without triggering GH secretion, which might solve the etiology of oligoasthenozoospermia.

Novel hGHRH homodimer promotes fertility of female infertile hamster by up-regulating ovarian GHRH receptor without triggering GH secretion

Extra-hypothalamic growth hormone-releasing hormone (GHRH) plays an important role in infertility. The female infertility models were formed by intraperitoneally injecting cyclophosphamide in 5-week-old Chinese hamster once in a week for 5 weeks. All the models mated with healthy male hamster in the ratio of 1:1 in the experimental 6-8th week and the couples were separated to breed in the 9-10th week. 20 mg/kg of cyclophosphamide induced temporary interference of reproduction and did not cause significant difference in the weight of body, bilateral ovaries, or liver. By intramuscularly injecting twice in a week during the experimental 4-10th week, 2, 4, 8 mg/kg of Grin induced 30, 42.9, 60% of total pregnancy rates in a dose-dependent manner whereas 200 U/kg of hMG induced 50% of total pregnancy rates. The single cyclophosphamide dose caused strongly eosinophilic ovarian cells, scattered early follicles, many atretic follicles, and no corpora luteum was observed. The hMG group individually presents many follicles at all levels, especially secondary ones in the ovarian cortex and medulla. Much of loose connective tissue, vacuoles, and sparse interstitial cells distribute in the medulla. Grin induced many follicles at all dose levels and corpora lutea in the cortex, and the compactly aligned interstitial cells occurred in the whole ovarian tissue. The less TUNEL staining and higher expression of ki67 showed the proliferation and protection effect of Grin on ovarian cells. Grin obviously promotes fertility by up-regulating ovarian GHRH receptor and strengthening the development and maturation of follicles without triggering central and ovarian GH secretion.

Delay in sexual maturation in perinatally HIV-infected youths is mediated by poor growth

OBJECTIVE

To evaluate the association between HIV infection and sexual maturation, and mediation of this association by HIV effects on growth.

DESIGN

Pooled data were analyzed from two longitudinal cohort studies, the International Maternal Pediatric Adolescent AIDS Clinical Trials P219/219C Study (1993-2007) and the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol (2007-2015), including perinatally HIV-infected (PHIV) and HIV-exposed uninfected (PHEU) youths.

METHODS

We evaluated age at sexual maturity among 2539 PHIV and PHEU adolescents based on annual physician-assessed pubertal staging measures. Interval-censored regression models were used to evaluate associations of HIV infection with age at maturity. Mediation analyses accounting for height and BMI Z-scores at specific ages were used to estimate direct and indirect effects of HIV infection on age at sexual maturity.

RESULTS

Mean ages at sexual maturity for PHIV girls (n = 1032) were 15.5 years for both female breast and pubic hair and 15.9 and 15.8 years for PHIV boys (n = 1054) for genitalia and pubic hair, respectively. PHIV youths matured approximately 6 months later on average than PHEU (n = 221 girls and 232 boys), and this difference persisted after adjustment for race/ethnicity and birth cohort. BMI and height Z-scores mediated the association between HIV infection and later maturation in girls, accounting for up to 74% of the total HIV effect. Only height Z-scores mediated the effect of HIV on male age at maturity, accounting for up to 98% of the HIV effect.

CONCLUSION

PHIV youths attain sexual maturity later on average than PHEU youths. Much of this difference may be attributable to deficient growth, suggesting directions for future interventions.

Growth hormone deficiency and human immunodeficiency virus

Treatment with highly active antiretroviral drugs (HAART) is associated with several endocrine and metabolic comorbidities. Pituitary growth hormone (GH) secretion seems to be altered in human immunodeficiency virus (HIV) infection, and about one-third of patients have biochemical GH deficiency (GHD). We undertake a historical review of the functioning of the GH/insulin-like growth factor-1 (IGF-1) axis in patients with acquired immunodeficiency syndrome, and provide an overview of the main changes of the GH/IGF-1 axis occurring today in patients with HIV. Both spontaneous GH secretion and GH response to provocative stimuli are reduced in patients with HIV infection, especially in those with HIV-related lipodystrophy. The role of fat accumulation on flattened GH secretion is discussed, together with all factors able to potentially interfere with the pituitary secretion of GH. Several factors contribute to the development of GHD, but the pathophysiologic mechanisms involved in the genesis of GHD are complex and not yet fully elucidated owing to the difficulty in separating the effects of HIV infection from those of HAART, comorbidities and body changes. An update on the putative mechanisms involved in the pathogenesis of altered GH secretion in these patients is provided, together with an overview on the therapeutic strategies targeting the GH/IGF-1 axis to counteract fat redistribution associated with HIV-related lipodystrophy. The clinical significance of GHD in the context of HIV infection is discussed. The administration of tesamorelin, a GH releasing hormone analogue, is effective in reducing visceral fat in HIV-infected patients with lipodystrophy. This treatment is promising and safer than treatment with high doses of recombinant human growth hormone, which has several side-effects.

Frailty in HIV: Epidemiology, Biology, Measurement, Interventions, and Research Needs

Frailty is a critical aging-related syndrome marked by diminished physiologic reserve and heightened vulnerability to stressors, predisposing to major adverse clinical outcomes, including hospitalization, institutionalization, disability, and death in the general population of older adults. As the proportion of older adults living with HIV increases in the era of antiretroviral therapy, frailty is increasingly recognized to be of significant clinical and public health relevance to the HIV-infected population. This article reviews current knowledge on the epidemiology and biology of frailty and its potential role as a target for reducing disparities in outcomes in HIV; conceptual frameworks and current approaches to frailty measurement; existing data on frailty interventions; and important areas for future research focus necessary to develop and advance effective strategies to prevent or ameliorate frailty and its marked adverse consequences among people living with HIV.

Ghrelin Actions on Somatotropic and Gonadotropic Function in Humans

Ghrelin, a 28 amino-acid octanoylated peptide predominantly produced by the stomach, was discovered to be the natural ligand of the type 1a GH secretagogue receptor (GHS-R1a). It was thus considered as a natural GHS additional to GHRH, although later on ghrelin has mostly been considered a major orexigenic factor. The GH-releasing action of ghrelin takes place both directly on pituitary cells and through modulation of GHRH from the hypothalamus; some functional antisomatostatin action has also been shown. However, ghrelin is much more than a natural GH secretagogue. In fact, it also modulates lactotroph and corticotroph secretion in humans as well as in animals and plays a relevant role in the modulation of the hypothalamic-pituitary-gonadal function. Several studies have indicated that ghrelin plays an inhibitory effect on gonadotropin pulsatility, is involved in the regulation of puberty onset in animals, and may regulate spermatogenesis, follicular development and ovarian cell functions in humans. In this chapter ghrelin actions on the GH/IGF-I and the gonadal axes will be revised. The potential therapeutic role of ghrelin as a treatment of catabolic conditions will also be discussed.

Synthesis and biological evaluation of novel structure-related hGHRH agonistic analogs

Activity and half-life play key roles in the application of GHRH analogues. The GHRH monomers produced in a solid synthesizer were incubated, respectively, in NH4OH solution and lyophilized to obtain their dimers. The activities, specificities, and receptor affinities of the GHRH dimers were evaluated in rGH release/inhibition, rACTH/LH/PRL release, pituitary homogenate binding, and fluorescent staining. Compared to hGHRH(1-44)NH2 (S), PP-hGHRH(1-44)-GGC-CGG-hGHRH(44-1)-PP (2D), P-hGHRH(1-44)-GGC-CGG-hGHRH(44-1)-P (2E), (1)P-hGHRH(2-44)-GGC-CGG-hGHRH(44-2)-(1)P (2F), or hGHRH(1-44)-GGC-CGG-hGHRH(44-1) (2Y) had potency of 104 ± 16.7%, 94 ± 32.6%, 114 ± 16.6%, or 122 ± 14.5% and similar specificities. The inhibition effect of GHIH on rGH stimulated by GHRH dimer was in dose-/time-dependent manner. The staining of FITC-labeled dimer showed cytomembrane distribution and the binding ranking was 2F>2D>2Y>2E>S. 2F presents the strongest activity and the highest affinity to pituitary cells. The dimer with (1)Pro-GHRH stimulates stronger rGH release than that with (1)Tyr-GHRH and the N-terminal single cyclic amino acid is required for the stimulation.

Growth failure and nutrition considerations in chronic childhood wasting diseases

Growth failure is a common problem in many children with chronic diseases. This article is an overview of the most common causes of growth failure/growth retardation that affect children with a number of chronic diseases. We also briefly review the nutrition considerations and treatment goals. Growth failure is multifactorial in children with chronic conditions, including patients with cystic fibrosis, chronic kidney disease, chronic liver disease, congenital heart disease, human immunodeficiency virus, inflammatory bowel disease, short bowel syndrome, and muscular dystrophies. Important contributory factors to growth failure include increased energy needs, increased energy loss, malabsorption, decreased energy intake, anorexia, pain, vomiting, intestinal obstruction, and inflammatory cytokines. Various metabolic and pathologic abnormalities that are characteristic of chronic diseases further lead to significant malnutrition and growth failure. In addition to treating disease-specific abnormalities, treatment should address the energy and protein deficits, including vitamin and mineral supplements to correct deficiencies, correct metabolic and endocrinologic abnormalities, and include long-term monitoring of weight and growth. Individualized, age-appropriate nutrition intervention will minimize the malnutrition and growth failure seen in children with chronic diseases.

Gender differences in GH response to GHRH+ARG in lipodystrophic patients with HIV: a key role for body fat distribution

OBJECTIVE

Gender influence on GH secretion in human immunodeficiency virus (HIV)-infected patients is poorly known.

DESIGN AND METHODS

To determine the effect of gender, we compared GH response to GH-releasing hormone plus arginine (GHRH+Arg), and body composition in 103 men and 97 women with HIV and lipodystrophy. The main outcomes were IGF1, basal GH, GH peak and area under the curve (AUC) after GHRH+Arg, body composition, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT).

RESULTS

Men had lower GH peak and AUC than women (P<0.001). Of the study population, 21% of women and 37% of men had biochemical GH deficiency (GHD; GH peak <7.5 μg/l). VAT-to-SAT ratio was higher in men than in women with GHD (P<0.05). Unlike women, VAT, SAT, and trunk fat were greater in men with GHD than in men without GHD. IGF1 was significantly lower in women with GHD than in women without GHD, but not in men. At univariate analysis, BMI, trunk fat mass, VAT, and total adipose tissue were associated with GH peak and AUC in both sexes (P<0.05). BMI was the most significant predictive factor of GH peak, and AUC at multiregression analysis. Overall, abdominal fat had a less pronounced effect on GH in females than in males.

CONCLUSIONS

These data demonstrate that GH response to GHRH+Arg is significantly lower in HIV-infected males than females, resulting in a higher percentage of GHD in men. Adipose tissue distribution more than fat mass per se seems to account for GH gender differences and for the alteration of GH-IGF1 status in these patients.

Metabolic disease in HIV infection

The treatment of metabolic disease is becoming an increasingly important component of the long-term management of patients with well controlled HIV on antiretroviral therapy (ART). Metabolic diseases probably develop at the intersection of traditional risk factors (such as obesity, tobacco use, and genetic predisposition) and HIV-specific and ART-specific contributors (including chronic inflammation and immune activation). This Review discusses present knowledge on adipose tissue dysfunction, insulin-glucose homoeostasis, lipid disturbances, and cardiovascular disease risk in people with HIV on ART. Although new antiretroviral drugs are believed to induce fewer short-term metabolic perturbations than do older drugs, the long-term effects of these drugs are not fully understood. Additionally, patients remain at increased risk of cardiovascular disease and other metabolic comorbidities. Research and treatment should focus on selection of ART that is both virologically effective and has minimum metabolic effects, minimisation of traditional risk factors for metabolic disease, and development of novel therapies to treat metabolic disease in patients with HIV, including use of anti-inflammatory and immunomodulatory drugs.

Assessment of serum IGF-1 and adipokines related to metabolic dysfunction in HIV-infected adults

PURPOSE

HIV/HAART associated metabolic syndrome (HAMS) seems to result from direct influence of HIV, adverse effects of combined antiretroviral therapy (cART) and individual genetic predisposition. This study aimed to assess the influence of HIV infection and cART on serum concentration of insulin-like growth factor-1 (IGF-1) and adipokines related to metabolic abnormalities.

METHODS

Seventy-two HIV infected patients including 48 HIV/HCV coinfected were enrolled in this study. Insulin resistance was evaluated by Homeostatic Model Assessment (HOMA) indexes. Serum concentrations of IGF-1, adiponectin, chemerin and visfatin were measured by ELISA.

RESULTS

Significant correlation between serum IGF-1 level and CD4 lymphocytes count was demonstrated and the lowest values were observed in subjects with CD4<200 cells/μL. Serum concentration of IGF-1 was significantly higher in patients treated with protease inhibitors based regimen compared to non-nucleoside reverse transcriptase inhibitors and healthy subjects. A significant negative correlation between serum concentration of adiponectin and waist-hip ratio as an indicator of central obesity, was found. There were significant positive correlations between serum concentration of chemerin and HOMA1-IR and serum IGF-1 concentration. Serum chemerin was increased in patients with insulin resistance vs. those with preserved insulin sensitivity.

CONCLUSIONS

According to these results HAMS is associated with insulin resistance and imbalance of adipokines serum concentration, therefore identification of pathways related to HAMS development might be helpful in management of the syndrome. Serum IGF-1 largely depends on level of immunodeficiency in HIV-infection and may provide a link between immune dysfunction and development of HIV-associated lipodystrophy, AIDS wasting syndrome, diabetes and/or cardiovascular diseases in HIV-infected patients.