Enaldo V. Melo

Longevity in Untreated Congenital Growth Hormone Deficiency Due to a Homozygous Mutation in the GHRH Receptor Gene

CONTEXTnReduced longevity observed in hypopituitarism has been attributed to GH deficiency (GHD). It is, however, unclear whether GHD or other confounding factors cause this early mortality.nnnOBJECTIVEnThe aim was to study longevity in subjects from a large kindred with untreated, lifetime isolated GHD (IGHD) due to a homozygous mutation in the GHRH receptor gene and in heterozygous carriers of the mutation.nnnDESIGN, SETTING, AND PARTICIPANTSnWe carried out a retrospective cohort study on three groups. We first compared mortality risk of 65 IGHD individuals and their 128 unaffected siblings from 34 families. We then compared mean age of death of the IGHD to the general population. A transversal study was carried out to compare the rate of heterozygosity for the mutation in two groups of young (20-40 yr old) and old (60-80 yr old) normal-appearing subjects from the same county.nnnMAIN OUTCOME MEASUREnWe measured longevity.nnnRESULTSnThe risk of death of IGHD subjects was not different from their siblings. Life span in IGHD individuals was shorter than the general population. When stratified by sex, this difference persisted only in females, due to a high frequency of IGHD deaths in females aged 4-20. There was no significant difference in life span between IGHD subjects and siblings or the general population when analyzing subjects who reached age 20. The prevalence of heterozygosity did not differ in young and old groups, suggesting no survival advantage or disadvantage.nnnCONCLUSIONSnIn a selected genetic background, lifelong untreated IGHD does not affect longevity.

Heme Oxygenase-1 Promotes the Persistence of Leishmania chagasi Infection

Visceral leishmaniasis (VL) remains a major public health problem worldwide. This disease is highly associated with chronic inflammation and a lack of the cellular immune responses against Leishmania. It is important to identify major factors driving the successful establishment of the Leishmania infection to develop better tools for the disease control. Heme oxygenase-1 (HO-1) is a key enzyme triggered by cellular stress, and its role in VL has not been investigated. In this study, we evaluated the role of HO-1 in the infection by Leishmania infantum chagasi, the causative agent of VL cases in Brazil. We found that L. chagasi infection or lipophosphoglycan isolated from promastigotes triggered HO-1 production by murine macrophages. Interestingly, cobalt protoporphyrin IX, an HO-1 inductor, increased the parasite burden in both mouse and human-derived macrophages. Upon L. chagasi infection, macrophages from Hmox1 knockout mice presented significantly lower parasite loads when compared with those from wild-type mice. Furthermore, upregulation of HO-1 by cobalt protoporphyrin IX diminished the production of TNF-α and reactive oxygen species by infected murine macrophages and increased Cu/Zn superoxide dismutase expression in human monocytes. Finally, patients with VL presented higher systemic concentrations of HO-1 than healthy individuals, and this increase of HO-1 was reduced after antileishmanial treatment, suggesting that HO-1 is associated with disease susceptibility. Our data argue that HO-1 has a critical role in the L. chagasi infection and is strongly associated with the inflammatory imbalance during VL. Manipulation of HO-1 pathways during VL could serve as an adjunctive therapeutic approach.

Insulin Sensitivity and β-Cell Function in Adults with Lifetime, Untreated Isolated Growth Hormone Deficiency

CONTEXTnGH reduces insulin sensitivity (IS), whereas IGF-I increases it. IGF-I seems to be critical for the development of the β-cells, and impaired IS has been reported in GH deficiency (GHD).nnnOBJECTIVEnThe aim of the study was to assess IS and β-cell function in adult patients with untreated isolated GHD (IGHD) due to a homozygous mutation in the GHRH receptor gene.nnnDESIGN, SETTING, AND PATIENTSnWe conducted a cross-sectional study in 24 GH-naive adult IGHD subjects and 25 controls.nnnINTERVENTIONnWe performed an oral glucose tolerance test with glucose and insulin measurements at 0, 30, 60, 90, 120, and 180 min.nnnMAIN OUTCOME MEASURESnIS was assessed by homeostasis model assessment index of insulin resistance (IR), quantitative IS check index, oral glucose IS in 2 h (OGIS2) and 3 h (OGIS3). β-Cell function was assayed by homeostasis model assessment index-β, insulinogenic index, and area under the curve of insulin-glucose ratio.nnnRESULTSnDuring the oral glucose tolerance test, glucose levels were higher in IGHD subjects (P<0.0001), whereas insulin response presented a trend toward reduction (P=0.08). The number of individuals with impaired glucose tolerance was higher in the IGHD group (P=0.001), whereas the frequency of diabetes was similar in the two groups. Homeostasis model assessment index of IR was lower (P=0.04), and quantitative IS check index and OGIS2 showed a nonsignificant trend toward elevation (P=0.066 and P=0.09, respectively) in IGHD. OGIS3 showed no difference between the groups. Homeostasis model assessment index-β, insulinogenic index, and ratio of the areas of the insulin and glucose curves were reduced in the IGDH group (P=0.015, P<0.0001, and P=0.02, respectively).nnnCONCLUSIONSnAdult subjects with lifetime congenital untreated IGHD present reduced β-cell function, no evidence of IR, and higher frequency of impaired glucose tolerance.

Increased Visceral Adiposity and Cortisol to Cortisone Ratio in Adults With Congenital Lifetime Isolated GH Deficiency

CONTEXTnAdult-onset GH deficiency (GHD) increases visceral adiposity and the activity of the enzyme 11β-hydroxysteroid dehydrogenase, which converts cortisone (E) to cortisol (F), both linked to insulin resistance and increased cardiovascular risk. Conversely, we reported that adults with congenital isolated GHD (IGHD) have increased insulin sensitivity.nnnOBJECTIVEnTo assess the type of fat distribution and the amount of visceral and sc fat and to correlate them to the F/E ratio in adults with untreated IGHD due to a mutation in the GHRH receptor gene.nnnMETHODSnBody composition was assessed by dual-energy x-ray absorptiometry, thickness of sc and visceral fat was measured by sonography, and serum F and E were measured in 23 IGHD subjects and 21 age-matched controls.nnnRESULTSnWaist/hip ratio (WHR), trunk fat, and trunk/extremity fat (TR/EXT) ratio were higher in IGHD subjects. Visceral fat index (VFI) (but not sc fat index [SFI]) was higher in IGHD. F and F/E ratio were also higher in IGHD. In all 44 individuals, WHR correlated with TR/EXT ratio, thickness of visceral fat, VFI/SFI ratio, F, and F/E ratio. TR/EXT ratio correlated with visceral fat thickness, VFI/SFI ratio, and F. Age had a significant effect on VFI and on F/E ratio. Body mass index SD score and WHR have a similar significant effect on TR/EXT ratio and on F/E ratio.nnnCONCLUSIONSnLifetime congenital untreated IGHD causes increased visceral adiposity with a high F/E ratio. However, the increased insulin sensitivity suggests that visceral adiposity needs a minimal GH secretion to translate into increased insulin resistance.

Lifetime, untreated isolated GH deficiency due to a GH-releasing hormone receptor mutation has beneficial consequences on bone status in older individuals, and does not influence their abdominal aorta calcification.

The GH/IGF-I axis has essential roles in regulating bone and vascular status. The age-related decrease in GH secretion (“somatopause”) may contribute to osteoporosis and atherosclerosis, commonly observed in the elderly. Adult-onset GH deficiency (GHD) has been reported to be associated with reduced bone mineral density (BMD), increased risk of fractures, and premature atherosclerosis. We have shown the young adult individuals with isolated GHD (IGHD) due to a homozygous for the c.57+1G>A GHRH receptor gene mutation have normal volumetric BMD (vBMD), and not develop premature atherosclerosis, despite adverse risk factor profile. However, the bone and vascular impact of lifetime GHD on the aging process remains unknown. We studied a group of ten older IGHD subjects (≥60xa0years) homozygous for the mutation, comparing them with 20 age- and gender-matched controls (CO). Areal BMD was measured, and vBMD was calculated at the lumbar spine and total hip. Vertebral fractures and abdominal aortic calcifications (expressed as calcium score) were also assessed. Areal BMD was lower in IGHD, but vBMD was similar in the twoxa0groups. The percent of fractured individuals was similar, but the mean number of fractures per individual was lower in IGHD than CO. Calcium score was similar in the two groups. A positive correlation was found between calcium score and number of fractures. Untreated lifetime IGHD has beneficial consequences on bone status and does not have a deleterious effect on abdominal aorta calcification.

Voice Formants in Individuals With Congenital, Isolated, Lifetime Growth Hormone Deficiency

OBJECTIVEnTo analyze the voice formants (F1, F2, F3, and F4 in Hz) of seven oral vowels, in Brazilian Portuguese, [a, ε, e, i, ɔ, o, and u] in adult individuals with congenital lifetime untreated isolated growth hormone deficiency (IGHD).nnnSTUDY DESIGNnThis is a cross-sectional study.nnnMETHODSnAcoustic analysis of isolated vowels was performed in 33 individuals with IGHD, age 44.5 (17.6) years (16 women), and 29 controls, age 51.1 (17.6) years (15 women).nnnRESULTSnCompared with controls, IGHD men showed higher values of F3 [i, e, and ε], Pxa0=xa00.006, Pxa0=xa00.022, and Pxa0=xa00.006, respectively and F4 [i], Pxa0=xa00.001 and lower values of F2 [u], Pxa0=xa00.034; IGHD women presented higher values of F1 [i and e] Pxa0=xa00.029 and Pxa0=xa00.036; F2 [ɔ] Pxa0=xa00.006; F4 [ɔ] Pxa0=xa00.031 and lower values of F2 [i] Pxa0=xa00.004. IGHD abolished most of the gender differences in formant frequencies present in controls.nnnCONCLUSIONSnCongenital, severe IGHD results in higher values of most formant frequencies, suggesting smaller oral and pharyngeal cavities. In addition, it causes a reduction in the effect of gender on the structure of the formants, maintaining a prepubertal acoustic prediction.

Prolactin and sex steroids levels in congenital lifetime isolated GH deficiency

Growth hormone (GH) and prolactin share similarities in structure and function. We have previously shown that women with congenital isolated GH deficiency (IGHD) caused by a homozygous mutation in the GHRH receptor gene (GHRHR) (MUT/MUT) have a short reproductive life, with anticipated climacteric. At climacteric, they have lower prolactin levels than normal controls (N/N). Because they are able to breast feed, we hypothesized that this prolactin reduction is limited to climacteric, as result of lower estradiol exposure of the lactotrophs. The purposes of this work were to assess prolactin levels in broader age adults homozygous and heterozygous (MUT/N) for the mutation and in normal controls (N/N), and to correlate them to sex steroids levels. We enrolled 24 GH-naïve MUT/MUT (12 female), 25 MUT/N (14 female), and 25xa0N/N (11 female) subjects, aged 25–65xa0years. Anthropometric data and serum prolactin, estradiol, total testosterone, and sex hormone binding globulin (SHBG) were measured. Free testosterone was calculated. Prolactin levels were similar in the three groups. In males, testosterone and SHBG levels were higher in MUT/MUT in comparison to N/N. There was no difference in free testosterone among groups. In all 74 individuals, prolactin correlated inversely with age (pxa0<xa00.0001) and directly with serum estradiol (pxa0=xa00.018). Prolactin levels in subjects with IGHD due to a homozygous GHRHR mutation are similar to heterozygous and normal homozygous, but total testosterone and SHBG are higher in male MUT/MUT, with no difference in free testosterone. The reduced prolactin level is limited to climacteric period, possibly due to reduced estrogen exposure.

The consequences of growth hormone-releasing hormone receptor haploinsufficiency for bone quality and insulin resistance

Objectiveu2002 Growth hormone (GH)/insulin‐like growth factor (IGF) axis and insulin are key determinants of bone remodelling. Homozygous mutations in the GH‐releasing hormone receptor (GHRHR) gene (GHRHR) are a frequent cause of genetic isolated GH deficiency (IGHD). Heterozygosity for GHRHR mutation causes changes in body composition and possibly an increase in insulin sensitivity, but its effects on bone quality are still unknown. The objective of this study was to assess the bone quality and metabolism and its correlation with insulin sensitivity in subjects heterozygous for a null mutation in the GHRHR.

Infectious diseases and immunological responses in adult subjects with lifetime untreated, congenital GH deficiency

Growth hormone is important for the development and function of the immune system, but there is controversy on whether growth hormone deficiency is associated to immune disorders. A model of isolated growth hormone deficiency may clarify if the lack of growth hormone is associated with increased susceptibility to infections, or with an altered responsiveness of the immune system. We have studied the frequency of infectious diseases and the immune function in adults with congenital, untreated isolated growth hormone deficiency. In a cross-sectional study, 35 adults with isolated growth hormone deficiency due to a homozygous mutation in the growth hormone releasing hormone receptor gene and 31 controls were submitted to a clinical questionnaire, physical examination serology for tripanosomiasis, leishmaniasis, HIV, tetanus, hepatitis B and C, and serum total immunoglobulin G, M, E and A measurement. The immune response was evaluated in a subset of these subjects by skin tests and response to vaccination for hepatitis B, tetanus, and bacillus Calmette-Guérin. There was no difference between the groups in history of infectious diseases and baseline serology. Isolated growth hormone deficiency subjects had lower total IgG, but within normal range. There was no difference in the response to any of the vaccinations or in the positivity to protein Purified Derived, streptokinase or candidin. Adult untreated isolated growth hormone deficiency does not cause an increased frequency of infectious diseases, and does not alter serologic tests, but is associated with lower total IgG levels, without detectable clinical impact.

Efficacy and safety of available treatments for visceral leishmaniasis in Brazil: A multicenter, randomized, open label trial.

Background There is insufficient evidence to support visceral leishmaniasis (VL) treatment recommendations in Brazil and an urgent need to improve current treatments. Drug combinations may be an option. Methods A multicenter, randomized, open label, controlled trial was conducted in five sites in Brazil to evaluate efficacy and safety of (i) amphotericin B deoxycholate (AmphoB) (1 mg/kg/day for 14 days), (ii) liposomal amphotericin B (LAMB) (3 mg/kg/day for 7 days) and (iii) a combination of LAMB (10 mg/kg single dose) plus meglumine antimoniate (MA) (20 mg Sb+5/kg/day for 10 days), compared to (iv) standard treatment with MA (20 mg Sb+5/kg/day for 20 days). Patients, aged 6 months to 50 years, with confirmed VL and without HIV infection were enrolled in the study. Primary efficacy endpoint was clinical cure at 6 months. A planned efficacy and safety interim analysis led to trial interruption. Results 378 patients were randomized to the four treatment arms: MA (n = 112), AmphoB (n = 45), LAMB (n = 109), or LAMB plus MA (n = 112). A high toxicity of AmphoB prompted an unplanned interim safety analysis and this treatment arm was dropped. Per intention-to-treat protocol final analyses of the remaining 332 patients show cure rates at 6 months of 77.5% for MA, 87.2% for LAMB, and 83.9% for LAMB plus MA, without statistically significant differences between the experimental arms and comparator (LAMB: 9.7%; CI95% -0.28 to 19.68, p = 0.06; LAMB plus MA: 6.4%; CI95% -3.93 to 16.73; p = 0.222). LAMB monotherapy was safer than MA regarding frequency of treatment-related adverse events (AE) (p = 0.045), proportion of patients presenting at least one severe AE (p = 0.029), and the proportion of AEs resulting in definitive treatment discontinuation (p = 0.003). Conclusions Due to lower toxicity and acceptable efficacy, LAMB would be a more suitable first line treatment for VL than standard treatment. ClinicalTrials.gov identification number: NCT01310738. Trial registration ClinicalTrials.gov NCT01310738