E L T van den Akker

The melanocortin-4 receptor as target for obesity treatment: a systematic review of emerging pharmacological therapeutic options

Obesity is one of the greatest public health challenges of the 21st century. Obesity is currently responsible for ∼0.7–2.8% of a country’s health costs worldwide. Treatment is often not effective because weight regulation is complex. Appetite and energy control are regulated in the brain. Melanocortin-4 receptor (MC4R) has a central role in this regulation. MC4R defects lead to a severe clinical phenotype with lack of satiety and early-onset severe obesity. Preclinical research has been carried out to understand the mechanism of MC4R regulation and possible effectors. The objective of this study is to systematically review the literature for emerging pharmacological obesity treatment options. A systematic literature search was performed in PubMed and Embase for articles published until June 2012. The search resulted in 664 papers matching the search terms, of which 15 papers remained after elimination, based on the specific inclusion and exclusion criteria. In these 15 papers, different MC4R agonists were studied in vivo in animal and human studies. Almost all studies are in the preclinical phase. There are currently no effective clinical treatments for MC4R-deficient obese patients, although MC4R agonists are being developed and are entering phase I and II trials.

Socioeconomic status in children is associated with hair cortisol levels as a biological measure of chronic stress

INTRODUCTION Low socioeconomic status (SES) may be associated with a high risk of lifestyle-related diseases such as cardiovascular diseases. There is a strong association between parental SES, stress and indicators of child health and adult health outcome. The exact mechanisms underlying this association have not yet been fully clarified. Low SES may be associated with chronic stress, which may lead to activation of the hypothalamic-pituitary-adrenal (HPA)-axis, resulting in a higher circulating level of the stress hormone cortisol. Therefore, chronic stress may mediate the association between low SES and elevated cortisol levels and its adverse outcomes. AIM We investigated whether SES was associated with a chronic measure of cortisol exposure in a child population. METHODS Cortisol and cortisone were measured in scalp hair in 270 children and adolescents, aged 4-18 years, enrolled through school visits. Neighborhood level SES was based on a score developed by the Netherlands Institute for Social Research using postal codes, and this includes neighborhood measures of income education and unemployment. Maternal and paternal education level were used as indicators of family SES. RESULTS Neighborhood level socioeconomic status score was significantly associated with hair cortisol (β=-0.103, p=0.007, 95%CI [-0.179, -0.028]) and hair cortisone (β=-0.091, p=0.023, 95%CI [-0.167, -0.015]), adjusted for age and sex. Additionally, hair cortisol was significantly correlated with maternal education level and hair cortisone was significantly correlated with paternal education level. CONCLUSION The results of our study suggest that the widely shown association between low family SES and adverse child health outcomes may be mediated by chronic stress, given the chronically higher levels of cortisol in children and adolescents in families with low SES. It is especially notable that the association between SES and cortisol was already found in children of young age as this can have major consequences, such as increased risk of cardio metabolic diseases in later life.

Minor disturbances in central nervous system function in familial neurohypophysial diabetes insipidus

Familial neurohypophysial diabetes insipidus (FNDI) is caused by a defect in vasopressin synthesis and release as a result of a heterozygous mutation in the gene for the vasopressin prohormone. The predominant characteristic of FNDI is excessive thirst and urine production. However, vasopressin not only has peripheral endocrine effects, but also regulates numerous brain functions. We investigated whether central functions are affected in FNDI, by studying neuropsychological functioning of 23 affected members (15 males, 8 females) of a large family carrying a T/G transition mutation at nucleotide 2110 (codon 116) of the vasopressin prohormone gene (Cys116Gly). The relatively large number of family members with FNDI made it possible to compare cognitive and other CNS effects in these subjects with those of family members without FNDI. Thirty-seven adult volunteers (20 males, 17 females) from the same family and 11 non-family members (2 males, 9 females) from northern part of The Netherlands were tested. The mean age of the subjects was 35+/-12 years. Of the 63 quantified neuropsychological parameters few were statistically different between the subjects with FDNI and control subjects. Memory retrieval processes and sustained attention were worse in the subjects with FDNI. Moreover, these individuals reported significantly fewer symptoms of agoraphobia and miscellaneous symptoms, and had significantly lower scores on a scale measuring anger. The performance of FNDI subjects on an auditory verbal learning test (the 15-word test learning trial) was worse, but not significantly so, than that of the subjects without FDNI. There were subjective complaints of forgetfulness and slow recalls and those were observed in daily life by non-affected family members. These moderate differences in neuropsychological performance indicate that in human FNDI parvocellular vasopressin systems that supply the brain may be less affected or give no such serious disabilities, than the magnocellular hypothalamo-neurohypophysial system that provides vasopressin for endocrine regulation of water homeostasis.

Long-term glucocorticoid concentrations as a risk factor for childhood obesity and adverse body-fat distribution

Background:Childhood obesity is an important risk factor for premature development of the metabolic syndrome (MetS) at adulthood. There is need for understanding of the mechanisms underlying the MetS and obesity. Patients with Cushing’s disease suffer from similar metabolic complications, leading to the hypothesis that inter-individual cortisol variation may contribute to the onset of obesity. In addition, glucocorticoid receptor (GR)-gene polymorphisms resulting in differential glucocorticoid (GC) sensitivity, have been associated with an adverse metabolic profile.Aim:To study associations of GC levels in scalp hair, as a marker of long-term systemic GC concentrations, and genetically determined GC sensitivity with obesity and body-fat distribution in children.Methods:We performed a cross-sectional study of cortisol and cortisone concentrations over a 3-month period, measured by LC-MS/MS (Liquid Chromatography Tandem Mass Spectrometry) in hair of 3019 6-year-old children participating in the Generation R study. Genotyping of GR-gene polymorphisms was performed.Results:Of all children, 4.3% was obese and 13.4% overweight. Cortisol was significantly associated with risk of obesity (odd ratio (OR): 9.4 (3.3–26.9)) and overweight (OR: 1.4 (1.0–2.0)). Cortisone was associated with risk of obesity (OR: 1.9 (1.0–3.5)). Cortisol and cortisone were significantly positively associated with body mass index, fat mass (FM) index and android/gynecoid FM ratio. GR polymorphisms were not associated with adiposity parameters.Conclusion:Long-term cortisol concentrations are strongly associated with an increased risk of childhood obesity and adverse body-fat distribution. Future research may reveal whether these are causal relations and may be a target for therapy.

Bone age assessment by dual-energy X-ray absorptiometry in children: an alternative for X-ray?

OBJECTIVE The aim of the study was to validate dual-energy X-ray absorptiometry (DXA) as a method to assess bone age in children. METHODS Paired dual-energy X-ray absorptiometry (DXA) scans and X-rays of the left hand were performed in 95 children who attended the paediatric endocrinology outpatient clinic of University Hospital Rotterdam, the Netherlands. We compared bone age assessments by DXA scan with those performed by X-ray. Bone age assessment was performed by two blinded observers according to the reference method of Greulich and Pyle. Intra-observer and interobserver reproducibility were investigated using the intraclass correlation coefficient (ICC), and agreement was tested using Bland and Altman plots. RESULTS The intra-observer ICCs for both observers were 0.997 and 0.991 for X-ray and 0.993 and 0.987 for DXA assessments. The interobserver ICC was 0.993 and 0.991 for X-ray and DXA assessments, respectively. The mean difference between bone age assessed by X-ray and DXA was 0.11 years. The limits of agreement ranged from -0.82 to 1.05 years, which means that 95% of all differences between the methods were covered by this range. CONCLUSIONS Results of bone age assessment by DXA scan are similar to those obtained by X-ray. The DXA method seems to be an alternative for assessing bone age in a paediatric hospital-based population.

Glucocorticoid receptor gene haplotypes are not associated with birth anthropometry, blood pressure, glucose and insulin concentrations, and body composition in subjects born small for gestational age

OBJECTIVE Smaller size at birth has been associated with an increased risk of metabolic and cardiovascular disorders in adult life. Fetal programming of the hypothalamic-pituitary-adrenal axis has been suggested as a possible explanation. Fetal glucocorticoid (GC) overexposure has effects that suggest a role of GCs in this programming. The effects of GCs are mediated through the GC receptor (GR or NR3C1). Several functional polymorphisms have been described, which are associated with relative GC resistance or hypersensitivity. Our aim is to compare frequencies of GR haplotypes, characterized by the R23K, N363S, Bcl1, or 9β polymorphisms, in subjects born small for gestational age (SGA) and associate birth anthropometry data, response to GH treatment, blood pressure, glucose and insulin concentrations, and body composition with these haplotypes. DESIGN In total, 418 SGA subjects and 697 healthy controls were enrolled in this study. Methods Anthropometry data were obtained, as well as blood samples to determine fasting glucose and insulin concentrations. Dual energy X-ray absorptiometry scans were used to measure the amount of fat and lean mass. RESULTS No differences were found between GR haplotype frequencies in SGA children compared with healthy controls. No associations were found between GR haplotypes and birth length and birth weight, growth response during GH treatment, blood pressure, glucose and insulin concentrations, and body composition. CONCLUSION GR haplotypes and their effect on GC sensitivity do not seem to play a significant role in GH-induced catch-up growth and the risk factors of developing metabolic and cardiovascular disorders in adult life of SGA children.

Cushing syndrome as a presenting symptom of renal tumors in children

Cushing syndrome as the presenting symptom of a malignant renal tumor in children is rare. We report the first case of paraneoplastic Cushing syndrome due to a Wilms tumor, in which clinical and biological signs of hypercortisolism regressed during preoperative chemotherapy. Additionally, we reviewed the literature on paraneoplastic Cushing syndrome secondary to pediatric renal tumors. Pediatr Blood Cancer 2009;53:211–213.

Prenatal maternal psychopathology and stress and offspring HPA axis function at 6 years

OBJECTIVE Intrauterine exposures such as maternal psychopathology and stress are known to influence the physical and mental health of the offspring. One of the proposed pathways underlying these associations is dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity in the offspring. This study examined the relation of perinatal maternal symptoms of psychopathology and stress with offspring HPA axis activity at 6 years as measured by hair cortisol and cortisone concentrations. METHODS The study was part of the population-based Generation R Study, a prospective population-based cohort from fetal life onwards. 2546 children and their mothers formed the study population. Perinatal maternal psychopathology and stress were assessed by questionnaires in the second and third trimester. Principal components for both psychopathology and stress were created to reduce the number of explanatory variables. Child hair samples for cortisol and cortisone measurements were collected at the age of 6. Linear regression analysis, adjusted for covariates, was used to examine associations between maternal psychopathology and stress and child hair cortisol and cortisone levels. RESULTS The maternal psychopathology principal component was associated with higher child hair cortisone (adjusted B = 0.24, 95%CI 0.08;0.40, p-value < 0.01). Effect estimates of the individual dimensions ranged from 0.97 (95%CI 0.21;1.73, p-value = 0.01) for interpersonal sensitivity to 1.67 (95%CI 0.86;2.47, p-value < 0.01) for paranoid ideation. In addition, children exposed to intrauterine stress, as measured by the principal component, had higher hair cortisone levels (adjusted B = 0.54, 95%CI 0.21;0.88, p-value < 0.01). Exposure to maternal psychopathology and stress was not associated with offspring hair cortisol. Stratification by child sex resulted in associations between maternal symptoms of psychopathology during pregnancy and child hair cortisone levels in boys and associations between maternal symptoms of stress during pregnancy and child hair cortisone levels in girls. CONCLUSION Our results suggest that maternal psychopathology and stress during pregnancy are associated with long-term HPA axis activity of the offspring. The association of maternal psychopathology and stress during pregnancy with offspring hair cortisone levels is a novel finding. Future studies should examine whether these psychophysiological differences between exposed and non-exposed children underlie offspring morbidity associated with maternal psychopathology and stress during pregnancy.

Changes in thyroid hormone concentrations during neonatal extracorporeal membrane oxygenation

Objective:Thyroid hormone concentrations can be disturbed during critical illness. Our aim was to determine changes in thyroid hormone concentrations during neonatal extracorporeal membrane oxygenation (ECMO).Study Design:We included 21 ECMO-treated neonates. Age-specific s.d. scores (SDS) of free and total thyroxine (FT4; TT4), reverse and total triiodothyronine (rT3; TT3), thyroid-stimulating hormone (TSH) and thyroxine-binding globulin (TBG) were determined at six fixed time-points. Data were analyzed using general linear models.Results:At baseline, mean SDS FT4 (−0.78, 95% CI: −1.37 to −0.19), TT4 (−1.97, 95% CI: −2.76 to −1.18), TT3 (−0.88, 95% CI: −1.13 to −0.63), TSH (−2.14, 95% CI: −2.93 to −1.35) and TBG (−3.52, 95% CI: −4.55 to −2.50) were low with high mean SDS rT3 (0.53, 95% CI: 0.28 to 0.78). One hour after start ECMO, TT4, TSH and TBG had further declined; 12 h after start ECMO TT3 had declined (all P<0.05). After this decline, mean SDS TSH increased to the baseline level 12 h after start ECMO (−2.50, 95% CI: −3.22 to −1.79), and was higher than baseline 48 h after start ECMO (−0.56, 95% CI: −1.29 to 0.17). This TSH increase was followed by increases in TT4 and TT3. FT4 remained constant within the normal range during ECMO.Conclusions:Thyroid hormone concentrations before ECMO were suggestive of non-thyroidal illness syndrome (NTIS). During ECMO, increases in TSH, TT4 and TT3 after an initial decline possibly reflect spontaneous restoration of the hypothalamic–pituitary–thyroid axis. FT4 remained constant within the normal range. This suggests that thyroxine therapy is not required during ECMO.