Genome-wide DNA Methylation Differences in Nonfunctioning Pituitary Adenomas With and Without Postsurgical Progression.

CONTEXT: Tumor progression in surgically treated patients with nonfunctioning pituitary adenomas (NFPAs) is associated with excess mortality. Reliable biomarkers allowing early identification of tumor progression are missing. OBJECTIVE: To explore DNA methylation patterns associated with tumor progression in NFPA patients. METHODS: This case-controlled exploratory trial at a university hospital studied patients who underwent surgery for NFPA that had immunohistochemical characteristics of a gonadotropinoma. Cases included patients requiring reintervention due to tumor progression (reintervention group, n = 26) and controls who had a postoperative residual tumor without tumor progression for at least 5 years (radiologically stable group, n = 17). Genome-wide methylation data from each tumor sample were analyzed using the Infinium MethylationEPIC BeadChip platform. RESULTS: The analysis showed that 605 CpG positions were significantly differently methylated (differently methylated positions, DMPs) between the patient groups (false discovery rate adjusted P value < 0.05, beta value > 0.2), mapping to 389 genes. The largest number of DMPs were detected in the genes NUP93 and LGALS1. The 3 hypomethylated DMPs and the 3 hypermethylated DMPs with the lowest P values were all significantly (P < 0.05) and individually associated with reintervention-free survival. One of the hypermethylated DMPs with the lowest P value was located in the gene GABRA1. CONCLUSION: In this exploratory study, DNA methylation patterns in NFPA patients were associated with postoperative tumor progression requiring reintervention. The DMPs included genes that have been previously associated with tumor development. Our study is a step toward finding epigenetic signatures to predict tumor progression in patients with NFPA.

Expression of GHR and Downstream Signaling Genes in Human Adipose Tissue-Relation to Obesity and Weight Change.

CONTEXT: GH is a strong regulator of metabolism. In obesity, both GH secretion and adipose tissue GHR gene expression are decreased. More detailed information on the regulation of GHR, STAT3/5, and downstream-regulated genes in human adipose tissue during diet-induced weight loss and weight gain is lacking. OBJECTIVE: The aim of the present study was to investigate the gene expression patterns of GHR and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway (JAK2, STAT3, STAT5A, and STAT5B) in human subcutaneous adipose tissue in relation to energy restriction and overfeeding. DESIGN, PATIENTS, AND INTERVENTIONS: Tissue distribution was analyzed in a data set generated by RNA sequencing containing information on global expression in human tissues. Subcutaneous adipose tissue or adipocyte gene expression (measured by DNA microarrays) was investigated in the following settings: (i) individuals with obesity vs individuals with normal weight; (ii) energy restriction; and (iii) overfeeding. RESULTS: GHR expression was decreased in subjects with obesity compared with subjects with normal weight (P < 0.001). It was increased in response to energy restriction and decreased in response to overfeeding (P = 0.015 and P = 0.030, respectively). STAT3 expression was increased in subjects with obesity (P < 0.001). It was decreased during energy restriction and increased during overfeeding (P = 0.004 and P = 0.006, respectively). STAT3-regulated genes showed an overall view of overexpression in obesity. CONCLUSIONS: The results of the present study have shown that GHR, STAT3, and STAT3-regulated genes are dynamically, and reciprocally, regulated at the tissue level in response to energy restriction and overfeeding, suggesting that GH signaling is perturbed in obesity.

Pseudoacromegaly: A Differential Diagnostic Problem for Acromegaly With a Genetic Solution.

Acromegaly is usually not a difficult condition to diagnose once the possibility of this disease has been raised. However, a few conditions present with some aspects of acromegaly or gigantism but without growth hormone (GH) excess. Such cases are described as "pseudoacromegaly" or "acromegaloidism". Here we describe a female patient investigated for GH excess at 10 years of age for tall stature since infancy (height and weight > +3 standard deviations) and typical acromegalic features, including large hands/feet, large jaw, tongue, hoarse deep voice, and headache. Results of radiography of the sella turcica and GH response at an oral glucose tolerance test and insulin-arginine- thyrotrophin-luteinizing hormone-releasing hormone test were normal. Ethinylestradiol and medroxyprogesterone were given for 2 years; this successfully stopped further height increase. Although the patient's growth rate plateaued, coarsening of the facial features and acral enlargement also led to investigations for suspicion of acromegaly at 23 and 36 years of age, both with negative results. On referral at the age of 49 years, she had weight gain, sweating, sleep apnea, headaches, joint pain, and enlarged tongue. Endocrine assessment again showing normal GH axis was followed by genetic testing with a macrocephaly/overgrowth syndrome panel. A denovo mutation in the NSD1 gene (c.6605G>C; p.Cys2202Ser) was demonstrated. Mutations affecting the same cysteine residue have been identified in patients with Sotos syndrome. In summary, Sotos syndrome and other overgrowth syndromes can mimic the clinical manifestations of acromegaly or gigantism. Genetic assessment could be helpful in these cases.

MECHANISMS IN ENDOCRINOLOGY: Clinical and pharmacogenetic aspects of the growth hormone receptor polymorphism.

Pharmacogenetics aims to maximize the beneficial effects of a medical therapy by identifying genetic finger prints from responders and non-responders and, thereby improving safety and efficacy profile of the drug. Most subjects who are deficient in growth hormone (GHD) are candidates for recombinant human GH (rhGH) therapy. To date, it is well established that even after adjustments for several clinical variables, such as age, gender, body composition and the age at onset of the GHD, response to rhGH treatment is highly variable among individuals, part of which is believed to be due to genetic factors within the GH system. As the first genetic variant to potentially influence the individual response to rhGH therapy in children with growth disorders, polymorphism in the GH receptor (GHR) has attracted a great interest as a target for pharmacogenetics. Studies have been conducted to compare the functional and molecular effects of the full-length GHR (fl-GHR) isoform with the exon 3 deleted (d3-GHR) isoform in children and adults treated with rhGH therapy. Additionally, the impact of the GHR polymorphism has been investigated in relation to the clinical status and response to medical treatment in acromegaly, especially to the GHR antagonist drug pegvisomant. We have performed a narrative review of the studies performed to date on the association of GHR polymorphism with rhGH response in children and adults, and its potential influence in the medical management of acromegaly. In addition, data from studies on the general population and in other chronic diseases examining a role of this genetic variant in the regulation of growth and metabolism are summarized.

Visceral Fat and Novel Biomarkers of Cardiovascular Disease in Patients With Addison's Disease: A Case-Control Study.

Context: Patients with Addison's disease (AD) have increased cardiovascular mortality. Objective: To study visceral fat and conventional and exploratory cardiovascular risk factors in patients with AD. Design: A cross-sectional, single-center, case-control study. Subjects: Patients (n = 76; n = 51 women) with AD and 76 healthy control subjects were matched for sex, age, body mass index (BMI), and smoking habits. Main outcome measures: The primary outcome variable was visceral abdominal adipose tissue (VAT) measured using computed tomography. Secondary outcome variables were prevalence of metabolic syndrome (MetS) and 92 biomarkers of cardiovascular disease. Results: The mean ± standard deviation age of all subjects was 53 ± 14 years; mean BMI, 25 ± 4 kg/m2; and mean duration of AD, 17 ± 12 years. The median (range) daily hydrocortisone dose was 30 mg (10 to 50 mg). Median (interquartile range) 24-hour urinary free cortisol excretion was increased in patients vs controls [359 nmol (193 to 601 nmol) vs 175 nmol (140 to 244 nmol); P < 0.001]. VAT did not differ between groups. After correction for multiple testing, 17 of the 92 studied biomarkers differed significantly between patients and control subjects. Inflammatory, proinflammatory, and proatherogenic risk biomarkers were increased in patients [fold change (FC), >1] and vasodilatory protective marker was decreased (FC, <1). Twenty-six patients (34%) vs 12 control subjects (16%) fulfilled the criteria for MetS (P = 0.01). Conclusion: Despite higher cortisol exposure, VAT was not increased in patients with AD. The prevalence of MetS was increased and several biomarkers of cardiovascular disease were adversely affected in patients with AD.

Reduced DNA methylation and psychopathology following endogenous hypercortisolism - a genome-wide study.

Patients with Cushing's Syndrome (CS) in remission were used as a model to test the hypothesis that long-standing excessive cortisol exposure induces changes in DNA methylation that are associated with persisting neuropsychological consequences. Genome-wide DNA methylation was assessed in 48 women with CS in long-term remission (cases) and 16 controls matched for age, gender and education. The Fatigue impact scale and the comprehensive psychopathological rating scale were used to evaluate fatigue, depression and anxiety. Cases had lower average global DNA methylation than controls (81.2% vs 82.7%; p = 0.002). Four hundred and sixty-one differentially methylated regions, containing 3,246 probes mapping to 337 genes were identified. After adjustment for age and smoking, 731 probes in 236 genes were associated with psychopathology (fatigue, depression and/or anxiety). Twenty-four gene ontology terms were associated with psychopathology; terms related to retinoic acid receptor signalling were the most common (adjusted p = 0.0007). One gene in particular, COL11A2, was associated with fatigue following a false discovery rate correction. Our findings indicate that hypomethylation of FKBP5 and retinoic acid receptor related genes serve a potential mechanistic explanation for long-lasting GC-induced psychopathology.

The GH receptor exon 3 deleted/full-length polymorphism is associated with central adiposity in the general population.

OBJECTIVE: To test the hypothesis that the GH receptor (GHR) exon 3 deleted (d3)/full-length (fl) polymorphism influences anthropometry and body composition in the general population. DESIGN AND SETTING: The Swedish Obese Subjects (SOS) reference study is a cross-sectional population-based study, randomly selected from a population registry. A subgroup of the population-based Malmö Diet and Cancer study (MDC-CC) was used as a replication cohort. METHODS: The SOS reference study comprises 1135 subjects (46.2% men), with an average age of 49.5 years. The MDC-CC includes 5451 successfully genotyped subjects (41.5% men), with an average age of 57.5 years. GHR d3/fl genotypes were determined using TagSNP rs6873545. Linear regression analyses were used to test for genotype-phenotype associations. RESULTS: In the SOS reference study, subjects homozygous for the d3-GHR weighed ∼4 kg more (P=0.011), and had larger waist-to-hip ratio (WHR, P=0.036), larger waist circumference (P=0.016), and more fat-free mass estimated from total body potassium (P=0.026) than grouped fl/d3 and fl/fl subjects (d3-recessive genetic model). The association with WHR was replicated in the MDC-CC (P=0.002), but not those with other anthropometric traits. CONCLUSIONS: In this population-based study, the GHR d3/fl polymorphism was found to be of functional relevance and associated with central adiposity, such that subjects homozygous for the d3-GHR showed an increased abdominal obesity.

Body composition and bone mineral density in women with Cushing's syndrome in remission and the association with common genetic variants influencing glucocorticoid sensitivity.

OBJECTIVE: Adverse body compositional features and low bone mineral density (BMD) are the characteristic of patients with active Cushing's syndrome (CS). The aim of this study was to evaluate body composition and BMD in women with CS in long-term remission and the influence of polymorphisms in genes affecting glucocorticoid (GC) sensitivity on these end-points. DESIGN, PATIENTS AND METHODS: This was a cross-sectional, case-controlled study, including 50 women previously treated for CS and 50 age and gender-matched controls. Median (interquartile range) remission time was 13 (5-19) years. Body composition and BMD were measured with dual-energy X-ray absorptiometry. Five polymorphisms in four genes associated with GC sensitivity were analysed using TaqMan or Sequenom single-nucleotide polymorphism genotyping. RESULTS: Patients with CS in remission had increased abdominal fat mass (P<0.01), whereas BMD was not significantly different at any site between patients and controls. In patients, the NR3C1 Bcl1 polymorphism was associated with reduced total (P<0.05) and femur neck BMD (P<0.05). The polymorphism rs1045642 in the ABCB1 gene was associated with increased abdominal fat mass (P<0.05) and decreased appendicular skeletal muscle mass (P<0.05). GC replacement was associated with reduced total BMD (P<0.01), BMD at lumbar spine (P<0.05) and increased abdominal fat (P<0.01). CONCLUSION: Ongoing GC replacement therapy together with polymorphisms in two genes related with GC sensitivity is associated with abdominal obesity and adverse skeletal health in patients with CS in long-term remission.

Extracellular water and blood pressure in adults with growth hormone (GH) deficiency: a genotype-phenotype association study.

OBJECTIVES: Growth hormone deficiency (GHD) in adults is associated with decreased extracellular water volume (ECW). In response to GH replacement therapy (GHRT), ECW increases and blood pressure (BP) reduces or remains unchanged. Our primary aim was to study the association between polymorphisms in genes related to renal tubular function with ECW and BP before and 1 year after GHRT. The ECW measures using bioimpedance analysis (BIA) and bioimpedance spectroscopy (BIS) were validated against a reference method, the sodium bromide dilution method (Br(-)). DESIGN AND METHODS: Using a candidate gene approach, fifteen single-nucleotide polymorphisms (SNPs) in nine genes with known impact on renal tubular function (AGT, SCNN1A, SCNN1G, SLC12A1, SLC12A3, KCNJ1, STK39, WNK1 and CASR) were genotyped and analyzed for associations with ECW and BP at baseline and with their changes after 1 year of GHRT in 311 adult GHD patients. ECW was measured with the Br(-), BIA, and BIS. RESULTS: Both BIA and BIS measurements demonstrated similar ECW results as the reference method. At baseline, after adjustment for sex and BMI, SNP rs2291340 in the SLC12A1 gene was associated with ECW volume in GHD patients (p = 0.039). None of the SNPs influenced the ECW response to GHRT. One SNP in the SLC12A3 gene (rs11643718; p = 0.024) and three SNPs in the SCNN1G gene [rs5723 (p = 0.02), rs5729 (p = 0.016) and rs13331086 (p = 0.035)] were associated with the inter-individual differences in BP levels at baseline. A polymorphism in the calcium-sensing receptor (CASR) gene (rs1965357) was associated with changes in systolic BP after GHRT (p = 0.036). None of these associations remained statistically significant when corrected for multiple testing. CONCLUSION: The BIA and BIS are as accurate as Br(-) to measure ECW in GHD adults before and during GHRT. Our study provides the first evidence that individual polymorphisms may have clinically relevant effects on ECW and BP in GHD adults.

Common genetic variants in the glucocorticoid receptor and the 11ß-hydroxysteroid dehydrogenase type 1 genes influence long-term cognitive impairments in patients with Cushing's syndrome in remission.

CONTEXT: Cognitive function is impaired in patients with Cushing's syndrome (CS) in remission. OBJECTIVE: The objective of the investigation was to study the effects of polymorphisms in genes associated with glucocorticoid (GC) sensitivity on cognitive function in patients with CS in long-term remission. DESIGN: This was a cross-sectional, case-controlled, single-center study. PATIENTS: Fifty-three patients with CS in remission and 53 controls matched for age, gender, and educational level participated in the study. MAIN OUTCOME MEASURES: Cognitive function, studied using standardized neuropsychological testing, and polymorphisms in the GC receptor (NR3C1; Bcl1 and A3669G), mineralocorticoid receptor (NR3C2; I180V), 11ß-hydroxysteroid dehydrogenase type 1 (11ßHSD1; rs11119328), and ATP binding cassette B1 (ABCB1; rs1045642) genes were measured. The association between cognitive function and polymorphisms were analyzed using linear regression with adjustments for age and educational level. RESULTS: The mean age in patients and controls was 53 ± 14 years. The median (interquartile range) duration of remission was 13 (5-18) years. In patients, the single-nucleotide polymorphism rs11119328 was associated with impairments in processing speed, auditory attention, auditory working memory, and reading speed. This association was not seen in matched controls. The Bcl1 polymorphism was associated with fatigue and worse visual attention and working memory. The remaining single-nucleotide polymorphisms were not associated with cognitive performance. CONCLUSION: In this study, polymorphisms in the 11ßHSD1 and NR3C1 genes were associated with impaired cognitive function, indicating that GC sensitivity and prereceptor regulation of GC action may play a role in the long-term consequences of CS. The study provides a novel insight into the etiology of cognitive dysfunction in patients with CS in remission.

SNPs within the GH-signaling pathway are associated with the early IGF1 response to GH replacement therapy in GHD adults.

OBJECTIVE: GH-deficient (GHD) adults have reduced serum concentrations of IGF1. GH replacement therapy increases serum IGF1 concentrations, but the interindividual variation in treatment response is large and likely influenced by genetic factors. This study was designed to test the hypothesis that single-nucleotide polymorphisms (SNPs) in genes within the GH signaling pathway influence the serum IGF1 response to GH replacement. DESIGN AND METHODS: A total of 313 consecutive GHD adults (58.1% men; mean age 49.7 years) were studied before and after 1 week, 6 months, and 1 year of GH treatment. GH dose was individually titrated to normalize serum IGF1 levels. Six SNPs in the GH receptor (GHR) and the GH signaling pathway (JAK2, STAT5B, SOCS2, and PIK3CB) genes were selected for genotyping. The GHR exon 3-deleted/full-length (d3/fl) polymorphism was analyzed using tagSNP rs6873545. RESULTS: After 1 week of GH replacement, homozygotes of the fl-GHR showed a better IGF1 response to GH than carriers of the d3-GHR (P=0.016). Conversely, homozygotes of the minor allele of PIK3CB SNP rs361072 responded better than carriers of the major allele (P=0.025). Compared with baseline, both SNPs were associated with the IGF1 response at 6 months (P=0.041 and P=0.047 respectively), and SNP rs6873545 was further associated with the IGF1 response at 1 year (P=0.041). CONCLUSIONS: Our results indicate that common genetic variants in the GH signaling pathway may be of functional relevance to the response to GH replacement in GHD adults.

The GH/IGF-1 axis in obesity: pathophysiology and therapeutic considerations.

Obesity has become one of the most common medical problems in developed countries, and this disorder is associated with high incidences of hypertension, dyslipidaemia, cardiovascular disease, type 2 diabetes mellitus and specific cancers. Growth hormone (GH) stimulates the production of insulin-like growth factor 1 in most tissues, and together GH and insulin-like growth factor 1 exert powerful collective actions on fat, protein and glucose metabolism. Clinical trials assessing the effects of GH treatment in patients with obesity have shown consistent reductions in total adipose tissue mass, in particular abdominal and visceral adipose tissue depots. Moreover, studies in patients with abdominal obesity demonstrate a marked effect of GH therapy on body composition and on lipid and glucose homeostasis. Therefore, administration of recombinant human GH or activation of endogenous GH production has great potential to influence the onset and metabolic consequences of obesity. However, the clinical use of GH is not without controversy, given conflicting results regarding its effects on glucose metabolism. This Review provides an introduction to the role of GH in obesity and summarizes clinical and preclinical data that describe how GH can influence the obese state.

Genotypes associated with lipid metabolism contribute to differences in serum lipid profile of GH-deficient adults before and after GH replacement therapy.

OBJECTIVE: GH deficiency (GHD) in adults is associated with an altered serum lipid profile that responds to GH replacement therapy (GHRT). This study evaluated the influence of polymorphisms in genes related to lipid metabolism on serum lipid profile before and after 1 year of GHRT in adults. DESIGN AND METHODS: In 318 GHD patients, total cholesterol (TC) serum concentrations, LDL-C, HDL-C, and triglycerides (TG) were assessed. Using a candidate gene approach, 20 single nucleotide polymorphisms (SNPs) were genotyped. GH dose was individually titrated to obtain normal serum IGF1 concentrations. RESULTS: At baseline, the minor alleles of cholesteryl ester transfer protein (CETP) gene SNPs rs708272 and rs1800775 were associated with higher serum TC and apolipoprotein E (APOE) gene SNP rs7412 with lower TC concentrations; CETP SNPs rs708272, rs1800775, and rs3764261 and apolipoprotein B (APOB) gene SNP rs693 with higher serum HDL-C; APOE SNP rs7412, peroxisome proliferator-activated receptor gamma (PPARG) gene SNP rs10865710 with lower LDL-C, and CETP SNP rs1800775 with higher LDL-C; and APOE/C1/C4/C2 cluster SNP rs35136575 with lower serum TG. After treatment, APOB SNP rs676210 GG genotype was associated with larger reductions in TC and LDL-C and PPARG SNP rs10865710 CC genotype with greater TC reduction. All associations remained significant when adjusted for age, sex, and BMI. CONCLUSIONS: In GHD adults, multiple SNPs in genes related to lipid metabolism contributed to individual differences in baseline serum lipid profile. The GH treatment response in TC and LDL-C was influenced by polymorphisms in the APOB and PPARG genes.

Reverse feeding suppresses the activity of the GH axis in rats and induces a preobesogenic state.

Reversed feeding (RF) is known to disrupt hormone rhythmicity and metabolism. Although these effects may be mediated in part by phase inversion of glucocorticoid secretion, the precise mechanism is incompletely characterized. In this study, we demonstrate that acute nocturnal food deprivation in male rats suppressed the amplitude of spontaneous GH secretion during the dark phase by 62% (P < 0.001), without affecting baseline secretion. Prolonged RF, which reduced pituitary weight (by 22%; P < 0.05), also suppressed GH pulse height sufficiently to reduce skeletal growth (by 4-5%; P < 0.01) and terminal liver weight (by 11%; P < 0.001). Despite this suppression of the GH axis, proportionate adiposity was not elevated, probably due to the accompanying 16% reduction in cumulative food intake (P < 0.01). We demonstrate that RF also resulted in phase inversion of core clock gene expression in liver, abdominal white adipose tissue (WAT) and skeletal muscle, without affecting their expression patterns in the suprachiasmatic nucleus. In addition, RF resulted in phase inversion of hepatic peroxisome proliferator-activated receptor γ2 mRNA expression, a 3- to 5-fold elevation in fatty acid synthase mRNA in WAT in both light- and dark-phase samples (P < 0.01) and an elevation in muscle uncoupling protein 3 mRNA expression at the beginning of the light phase (P < 0.01). Consumption of a high-fat diet increased inguinal (by 36%; P < 0.05) and retroperitoneal WAT weight (by 72%; P < 0.01) only in RF-maintained rats, doubling the efficiency of lipid accumulation (P < 0.05). Thus, RF not only desynchronizes central and peripheral circadian clocks, and suppresses nocturnal GH secretion, but induces a preobesogenic state.

Rapid and high throughput genotyping of the growth hormone receptor exon 3 deleted/full-length polymorphism using a tagSNP.

OBJECTIVE: The growth hormone (GH) receptor (GHR) exon 3 deleted/full-length (d3/fl) polymorphism has been suggested to affect GH sensitivity. The conventional genotyping method used for this polymorphism (multiplex PCR with fragment detection by gel electrophoresis) is laborious and requires large amount of DNA template. This has restricted analysis of this polymorphism to small cohorts. Our aim was to evaluate the accuracy of using a tagging single nucleotide polymorphism (tagSNP) as a marker for the d3/fl polymorphism. DESIGN: The d3/fl polymorphism was analyzed using TaqMan SNP genotyping of the tagSNP rs6873545 in 183 patients with adult GH deficiency (GHD). The results were compared to d3/fl genotypes determined by the conventional method. RESULTS: Genotyping success rate for the tagSNP was 100%. Frequency of the d3-allele was 24.0% (d3/d3 7.7%, d3/fl 32.2% and fl/fl 60.1%) and the results from the two different methods were identical. Moreover, three samples previously undetermined when genotyped using the conventional method were successfully analyzed using the tagSNP. CONCLUSION: The GHR d3/fl polymorphism can be studied by TaqMan SNP genotyping. Use of the tagSNP facilitates investigations of the effects of the d3/fl polymorphism in large cohorts.

Influence of the exon 3-deleted/full-length growth hormone (GH) receptor polymorphism on the response to GH replacement therapy in adults with severe GH deficiency.

CONTEXT: There is considerable individual variation in the clinical response to GH replacement therapy in GH deficient (GHD) adults. Useful predictors of treatment response are lacking. OBJECTIVE: The aim of the study was to assess the influence of the exon 3-deleted (d3-GHR) and full-length (fl-GHR) GH receptor isoforms on the response to GH replacement therapy in adults with severe GHD. DESIGN AND PATIENTS: A total of 124 adult GHD patients (79 men; median age, 50 yr) were studied before and after 12 months of GH therapy. GHD patients were divided into those bearing fl/fl alleles (group 1) and those bearing at least one d3-GHR allele (group 2), and the genotype was related to the effects of GH therapy on IGF-I levels and total body fat (BF). INTERVENTION: GH dose was individually titrated to obtain normal serum IGF-I levels. MAIN OUTCOME MEASURES: GHR genotype was determined by PCR amplification, IGF-I levels by immunoassay, and BF by a four-compartment model. RESULTS: Seventy-two (58%) patients had fl/fl genotype and were classified as group 1, whereas 52 (42%) had at least one d3-GHR allele and were classified as group 2 (40 were heterozygous and 12 were homozygous). At baseline, there were no significant differences in the study groups. Changes in IGF-I and BF after 12 months of GH treatment did not differ significantly between the two genotype groups. CONCLUSION: The presence of d3-GHR allele did not influence the response to GH replacement therapy in our cohort of adults with severe GHD.

Cell death-inducing DFF45-like effector C is reduced by caloric restriction and regulates adipocyte lipid metabolism.

Members of the cell death-inducing DFF45-like effector (CIDE) gene family have been shown to regulate lipid metabolism. In this article, we report that the third member of the human CIDE family, CIDEC, is down-regulated in response to a reduced caloric intake. The down-regulation was demonstrated by microarray and real-time polymerase chain reaction analysis of subcutaneous adipose tissue in 2 independent studies on obese patients undergoing treatment with a very low calorie diet. By analysis of CIDEC expression in 65 human tissues, we conclude that human CIDEC is predominantly expressed in subcutaneous adipocytes. Together, these observations led us to investigate the effect of decreased CIDEC expression in cultured 3T3-L1 adipocytes. Small interfering RNA-mediated knockdown of CIDEC resulted in an increased basal release of nonesterified fatty acids, decreased responsiveness to adrenergic stimulation of lipolysis, and increased oxidation of endogenous fatty acids. Thus, we suggest that CIDEC is a regulator of adipocyte lipid metabolism and may be important for the adipocyte to adapt to changes in energy availability.

Relations of adipose tissue CIDEA gene expression to basal metabolic rate, energy restriction, and obesity: population-based and dietary intervention studies.

CONTEXT: Cell death-inducing DNA fragmentation factor-alpha-like effector A (CIDEA) could be a potential target for the treatment of obesity via the modulation of metabolic rate, based on the findings that CIDEA inhibits the brown adipose tissue uncoupling process in rodents. OBJECTIVES: Our objects were to investigate the putative link between CIDEA and basal metabolic rate in humans and to elucidate further the role of CIDEA in human obesity. DESIGN: We have explored CIDEA gene expression in adipose tissue in two different human studies: a cross-sectional and population-based study assessing body composition and metabolic rate (Mölndal Metabolic study, n = 92); and a longitudinal intervention study of obese subjects treated with a very low calorie diet (VLCD) (VLCD study, n = 24). RESULTS: The CIDEA gene was predominantly expressed in adipocytes as compared with other human tissues. CIDEA gene expression in adipose tissue was inversely associated with basal metabolic rate independently of body composition, age, and gender (P = 0.014). The VLCD induced an increase in adipose tissue CIDEA expression (P < 0.0001) with a subsequent decrease in response to refeeding (P < 0.0001). Reduced CIDEA gene expression was associated with a high body fat content (P < 0.0001) and high insulin levels (P < 0.01). No dysregulation of CIDEA expression was observed in individuals with the metabolic syndrome when compared with body mass index-matched controls. In a separate sample of VLCD-treated subjects (n = 10), uncoupling protein 1 expression was reduced during diet (P = 0.0026) and inversely associated with CIDEA expression (P = 0.0014). CONCLUSION: The findings are consistent with the concept that CIDEA plays a role in adipose tissue energy expenditure.