Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study, we examined the potential impact of a T-to-C substitution at nucleotide 1519 of the GABA(A)alpha6 receptor subunit gene (GABRA6) on obesity and obesity-related phenotypes as well as circulating hormones, including salivary cortisol, in 284 unrelated Swedish men born in 1944. The subjects were genotyped by using PCR amplification followed by digestion with the restriction enzyme AlwNI. The frequency of allele T was 0.54 and that of allele C was 0.46. Carriers for the T allele (n = 211) had higher waist-to-hip ratio (p = 0.094) and abdominal sagittal diameter (p = 0.084) compared to homozygotes for the C allele (n = 56). The homozygotes for the T allele had, in comparison to heterozygotes, significantly (p = 0.004-0.024) higher mean cortisol levels at 11:45 am; at 30, 45, and 60 min after a standardized lunch; and finally at 5:00 pm. In addition, T/T subjects had significantly (p = 0.031) higher diurnal cortisol secretion compared to T/C subjects. Leptin, insulin, and glucose were not different across the genotype groups. In conclusion, these findings suggest a role of the point substitution (T-to-C) at nucleotide 1519 of GABRA6 in the predisposition to hypercortisolism and perhaps abdominal obesity. The pathophysiology may involve various environmental factors, particularly stress, that destabilize the GABA-hypothalamic-pituitary-adrenal systems in those with genetic vulnerability.
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PMID:Association between a variant at the GABA(A)alpha6 receptor subunit gene, abdominal obesity, and cortisol secretion. 1207 90

The diagnosis of Cushing's syndrome rests on the demonstration of clinical features and biochemical abnormalities that reflect hypercortisolism. If a patient presents with typical clinical features such as weight gain with truncal obesity and supraclavicular fat deposition, wide purple striae, and proximal muscle weakness, the diagnosis is clear-cut and is nearly always substantiated by a 24-hour urine free cortisol excretion value more than four times the normal level. However, many patients present with signs and symptoms that are common in the general population, such as hypertension, generalized weight gain, reproductive abnormalities, and depression. Many of these patients have normal cortisol excretion and do not have Cushing's syndrome. Others have mild hypercortisolism caused by psychiatric disorders, obligate exercise, morbid obesity, sleep apnea, or uncontrolled diabetes mellitus. These patients may be confused with those with the true Cushing's syndrome, and thus are considered to have a "pseudo-Cushing" state. Additional observation over time, and testing with midnight cortisol measurements, the 2-day-2-mg dexamethasone suppression test, or the dexamethasone suppression-CRH stimulation test may be useful to identify true Cushing's syndrome in these patients.
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PMID:Diagnostic tests for Cushing's syndrome. 1238 46

Stress activates the central and peripheral components of the stress system, i.e., the hypothalamic-pituitary-adrenal (HPA) axis and the arousal/sympathetic system. The principal effectors of the stress system are corticotropin-releasing hormone (CRH), arginine vasopressin, the proopiomelanocortin-derived peptides alpha-melanocyte-stimulating hormone and beta-endorphin, the glucocorticoids, and the catecholamines norepinephrine and epinephrine. Appropriate responsiveness of the stress system to stressors is a crucial prerequisite for a sense of well-being, adequate performance of tasks and positive social interactions. By contrast, inappropriate responsiveness of the stress system may impair growth and development, and may account for a number of endocrine, metabolic, autoimmune and psychiatric disorders. The development and severity of these conditions primarily depend on the genetic vulnerability of the individual, the exposure to adverse environmental factors and the timing of the stressful event(s), given that prenatal life, infancy, childhood and adolescence are critical periods characterized by increased vulnerability to stressors. The developing brain undergoes rapid growth and is characterized by high turnover of neuronal connections during the prenatal and early postnatal life. These processes and, hence, brain plasticity, slow down during childhood and puberty, and plateau in young adulthood. Hormonal actions in early life, and to a much lesser extent later, can be organizational, i.e., can have effects that last for long periods of time, often for the entire life of the individual. Hormones of the stress system and sex steroids have such effects, which influence the behavior and certain physiologic functions of individuals for life. Exposure of the developing brain to severe and/or prolonged stress may result in hyperactivity/hyperreactivity of the stress system, with resultant amygdala hyperfunction (fear reaction), decreased activity of the hippocampus (defective glucocorticoid-negative feedback, cognition), and the mesocorticolimbic dopaminergic system (dysthymia, novelty-seeking, addictive behaviors), hyperactivation of the HPA axis (hypercortisolism), suppression of reproductive, growth, thyroid and immune functions, and changes in pain perception. These changes may be accompanied by abnormal childhood, adolescent and adult behaviors, including excessive fear ('inhibited child syndrome') and addictive behaviors, dysthymia and/or depression, and gradual development of components of the metabolic syndrome X, including visceral obesity and essential hypertension. Prenatal stress exerted during the period of sexual differentiation may be accompanied by impairment of this process with behavioral and/or somatic sequelae. The vulnerability of individuals to develop varying degrees and/or components of the above life-long syndrome is defined by as yet unidentified genetic factors, which account for up to 60% of the variance. CRH has marked kindling and glucocorticoids have strong consolidating properties, hence both of these hormones are crucial in development and can alone produce the above syndrome. CRH and glucocorticoids may act in synergy, as in acoustic startle, while glucocorticoids may suppress or stimulate CRH, as in the hypothalamus and amygdala, respectively. A CRH type 1 receptor antagonist, antalarmin, inhibits both the development and expression of conditioned fear in rats, and has anxiolytic properties in monkeys. Profound stressors, such as those from sexual abuse, may elicit the syndrome in older children, adolescents and adults. Most frequently, chronic dysthymia and/or depression may develop in association with gastrointestinal complaints and/or the premenstrual tension syndrome. A lesser proportion of individuals may develop the classic posttraumatic stress disorder, which is characterized by hypocortisolism and intrusive and avoidance symptoms; in younger individuals it may present as dissociative personality disorder.
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PMID:Pediatric stress: hormonal mediators and human development. 1264 70

The pathogenesis of nephrolithiasis in Cushing's syndrome is still not completely clarified. The current study aimed at investigating prevalence of nephrolithiasis and role of different lithogenic factors in Cushing's disease (CD). Forty-six CD patients (24 with active and 22 with cured disease) and 46 sex- and age-matched controls entered the study. Body mass index, blood pressure, fasting glucose and insulin, serum and urinary creatinine, urea, uric acid, electrolytes, and cystine, urinary volume, pH, oxalate, and citrate levels, and renal ultrasonography (US) were performed in all patients and controls. Nephrolithiasis was found in 50% of active patients, 27.3% of cured patients, and 6.5% of controls (P < 0.001). Compared with controls, patients with active disease had a significantly increased prevalence of obesity, arterial hypertension, diabetes mellitus, hypercalciuria, hypocitraturia, and hyperuricosuria, significantly higher levels of serum and urinary cystine, urinary creatinine, urea, uric acid, potassium, calcium, phosphorus, and oxalate, significantly lower levels of urinary citrate levels. Compared with controls, patients cured from CD had a significantly increased prevalence of obesity, systemic arterial hypertension, and diabetes mellitus, whereas urinary citrate was significantly decreased. At multivariate analysis, a significantly increased risk to develop kidney stones was independently associated with urinary excretion of uric acid (odds ratio = 1.6, confidence interval = 1.0-2.5) and systemic arterial blood pressure (odds ratio = 2.6, confidence interval = 1.1-6.6). In conclusion, patients with active CD have an increased prevalence of nephrolithiasis compared with general population, which decreases but not disappears in patients successfully cured from the disease. This complication is likely caused by the synergic effect of different hypercortisolism-dependent metabolic and hemodynamic abnormalities, among which systemic arterial hypertension and excessive urinary uric acid excretion seem to play a pivotal role.
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PMID:Nephrolithiasis in Cushing's disease: prevalence, etiopathogenesis, and modification after disease cure. 1272 57

Glucocorticoids are implicated as a pathophysiological mediator of obesity and its accompanying metabolic and cardiovascular complications. Obese patients exhibit normal circulating cortisol levels, related to increased glucocorticoid production and degradation. However, it has been demonstrated that local production of active cortisol from inactive cortisone driven by 11 beta-hydroxysteroid dehydrogenase type 1 is exaggerated in adipose tissue of obese subjects. Such local hypercortisolism may be responsible for increased adipocyte differentiation and enhanced secretion of free fatty acids and other substances involved in the metabolic and cardiovascular complications observed in obesity.
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PMID:[Glucocorticoids, 11 beta-hydroxysteroid dehydrogenase type 1, and visceral obesity]. 1283 21

Obesity and insulin resistance, menstrual abnormalities and clinical and biochemical signs of hyperandrogenism are common features in women with polycystic ovary syndrome (PCOS) and Cushing's syndrome (CS). Further, an overdrive of the pituitary-adrenal axis has been documented in PCOS and this condition is often present in women with CS. For this reason, screening for hypercortisolism is often needed in obese women with polycystic ovaries. The aim of this study was to compare the diagnostic value of different screening tests for CS in a population of obese premenopausal women with PCOS and without PCOS (OB) and in a group of patients with CS. We reviewed retrospectively the case records of 117 obese women of reproductive age (60 PCOS and 57 OB, BMI 25.1-70.1, 13-45 yr) who were screened for CS at our Institution in the years 1995-2001 and turned out to be free of the disease. Data were compared with those of 58 premenopausal obese women with active CS (BMI 25.1-50.2 kg/m2, 18-45 yr). Screening for CS was performed by urinary free cortisol (UFC) (three consecutive 24-h urine collections), cortisol circadian rhythm (blood samples taken at 08:00-17:00-24:00 h), and 1 mg overnight dexamethasone suppression test (DST). A 24:00 h plasma cortisol (MNC) of 207 nmol/l, a UFC of 221 nmol/day and plasma cortisol after DST of 50 nmol/l and 138 nmol/l were taken as cut-off values for the diagnosis of CS. As expected, patients with CS showed elevated basal and post-dexamethasone plasma cortisol and UFC levels (p < 0.001 vs OB and PCOS). PCOS had higher UFC (p < 0.005) but not MNC and post-DST plasma cortisol levels compared to OB. DST showed the greatest specificity and diagnostic accuracy in differentiating CS from PCOS and OB (both p < 0.05 vs MNC and UFC, according to the 138 nmol/l criterion) while MNC and UFC displayed a similar discriminatory value. However, by using a lower threshold (50 nmol/l) as response criterion, there were no diagnostic differences between DST and the other tests. Specificity and diagnostic accuracy of UFC measurement was lower in PCOS than in OB (both p < 0.05) whilst there were no differences between groups for DST and MNC. Similarly, the area under the ROC curve relative to DST, giving an estimate of the inherent diagnostic accuracy of the test, was slightly greater than those of MNC and UFC (z = 0.694 and z = 0.833 for DST vs MNC and UFC, respectively, both p = NS). These results indicate that the 1-mg DST and MNC are unaffected by the presence of PCOS and can be safely used to screen for CS premenopausal obese women with PCOS, while caution should be exercised in interpreting mildly elevated UFC levels in these patients.
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PMID:Screening for Cushing's syndrome in obese women with and without polycystic ovary syndrome. 1295 68

The discovery of leptin (LEP) shed new light on mechanisms regulating body fat mass (BFM). In this aspect, interactions between LEP and glucocorticoids at hypothalamic level may be of great importance. Factors that influence plasma LEP levels have not been fully recognized and available data on LEP levels are often inconsistent. The aim of this study was to evaluate absolute and BFM-corrected plasma LEP levels and their diurnal variation, as well as to assess the relationship between LEP levels, body fat distribution, and hormones influencing body fat in subjects with various levels of endogenous cortisol and different nutritional status. Group I was composed of 14 women aged 14-58 yrs, BMI of 23.9-37.1 kg/m2, with hypercortisolism due to ACTH-dependent and ACTH-independent Cushing's syndrome (CUS). 17 women with visceral obesity (OTY) and normal or disturbed carbohydrate metabolism, i.e. impaired glucose tolerance (IGT) and diabetes mellitus (DM), aged 24 do 50 yrs, BMI 30.0-46.1 kg/m2, were included in group II. Group III consisted of 14 women with Addison's disease (AD), aged 18 do 63 yrs, BMI 15.4-31.6 kg/m2. The control group IV (KON) included 17 healthy women with normal BMI. BMI, WHR, body composition, and body fat distribution (DEXA method) were assessed in all subjects. Basal plasma levels of LEP, beta-endorphin (B-EP), cortisol (F), insulin-like growth factor-1 (IGF-1) were measured with RIA test kits. Plasma adrenocorticotrophin (ACTH) levels, serum levels of insulin (IRI) and growth hormone (GH) were measured with IRMA test kits. Blood glucose (G) concentration was determined with an enzymatic method. Adiposity-corrected LEP levels were expressed as LEP/BFM and LEP/%BF indices. Fasting insulin resistance index (FIRI) was also calculated. Higher BFM and %BF values were found in the OTY group as compared with CUS KON and AD groups. BFM distribution did not differ in KON and AD groups whereas CUS subjects exhibited a higher accumulation of fat in the trunk when compared to OTY subjects. Absolute LEP levels were correlated with trunk BF in CUS patients whereas in KON and AD groups these levels were correlated only with limb fat. Absolute LEP levels in CUS and OTY groups were comparable, whereas LEP/BFM and LEP/%BF indices were higher in the CUS group (Table 1) reflecting upregulation of LEP levels (Figs. 1, 2). BFM-corrected LEP levels were comparable in groups with normal cortisolemia, i.e. in OTY and KON groups, whereas in the AD group both absolute and BFM-corrected LEP levels were lower than in controls. No correlation was found between plasma levels of F and LEP in CUS and AD groups. This correlation was negative in KON (Fig. 3) and positive in OTY groups (Fig. 4). Moreover, KON and AD groups demonstrated a negative correlation between plasma ACTH and LEP levels. CUS patients showed positive, BFM-independent correlations between LEP levels, FIRI and G values, and a positive, BFM-dependent correlation between IRI and LEP levels. OTY patients exhibited a BFM-dependent positive correlation between FIRI and LEP levels. In these and in AD patients, a positive, BFM-independent correlation between IRI and LEP levels was found. Moreover, a negative, BFM-dependent correlation between GH and LEP levels was found in OTY patients. In this group, B-EP levels were positively correlated with LEP/BFM and LEP/%BF indices (Fig. 5). A negative correlation between LEP levels, LEP/BFM and LEP/%BF indices was ascertained in the AD group. In CUS, OTY, and KON groups, but not in the AD group, a midnight increase in leptin levels was observed. In conclusion, upregulation of leptin levels in relation to body fat in Cushing's syndrome is independent of the source of hypercortisolism. Apparently, it results from insulin resistance and hyperglycaemia and contributes to coexisting metabolic abnormalities. In Addison's disease, downregulation of leptin may reflect an adaptation mechanism to cortisol deficiency and result from low insulin and extremely high adrenocorticotrophin levels. In women with normal cortisol levels, irrespectively of nutritional status; leptin levels reflect body fat content. In obese subjects, leptin levels may be influenced by cortisol levels, high levels of insulin, IGF-1, and beta-endorphin as well as low levels of growth hormone. Disturbed function of hypothalamic-pituitary-adrenal axis (CUS, AD) does not directly influence diurnal variation in plasma leptin levels. In Cushing's syndrome, visceral fat may be a predominant source of leptin, whereas in women with normal or low cortisol levels peripherally accumulated fat may determine leptin secretion.
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PMID:[Evaluation of leptin levels in plasma and their reliance on other hormonal factors affecting tissue fat levels in people with various levels of endogenous cotisol]. 1460 84

Congenital adrenal hyperplasia is a general term applied to several disorders caused by inherited recessive defects of cortisol synthesis. The most common form is 21-hydroxylase deficiency, accounting for 95% of cases. The classical forms have an incidence of one in 15,000 and the non-classical forms about one in 1,000. The classical or severe phenotype presents in the newborn period or early infancy with virilization and adrenal insufficiency, with or without salt-losing; the non-classical or mild phenotype presents in late childhood or early adulthood with signs of hyperandrogenism. This wide range of clinical expression is explained by genetic variation. Although there is a certain amount of genotype-phenotype correlation, discrepancies have been described. During the last 30 years there has been a substantial improvement in diagnosis and treatment of this disease, and patients with CAH now reach adulthood. Treatment of this condition is intended to reduce excessive corticotropin secretion and replace glucocorticoids and mineralocorticoids as physiologically as possible. Clinical management is often complicated by periods of inadequately treated hyperandrogenism, iatrogenic hypercortisolism, or both. Long-term consequences in adult life may include short stature, obesity, diminished bone mass, gonadal dysfunction with low fertility rates and psychosexual dysfunction in females. New treatment approaches are under investigation, such as the use of anti-androgens, inhibitors of estrogen production and adrenalectomy for severely resistant cases.
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PMID:Childhood-onset congenital adrenal hyperplasia: long-term outcome and optimization of therapy. 1513 1

We assessed the value of midnight salivary cortisol for the initial diagnosis of Cushing's syndrome. Sixty-three patients with various causes of Cushing's syndrome (37 with Cushing's disease, 17 with adrenal Cushing's syndrome, and nine with ectopic ACTH syndrome) and 54 control subjects with simple obesity were studied. All patients with Cushing's syndrome excreted more than 90 microg urinary free cortisol (UFC)/d (248 nmol/d), and all controls excreted less than 90 microg/d UFC. All patients with Cushing's syndrome had a midnight salivary cortisol concentration above 2.0 ng/ml (5.52 nmol/liter), whereas only three controls did so [2.0 ng/ml (5.52 nmol/liter); 2.05 ng/ml (5.66 nmol/liter); and 3.6 ng/ml (9.96 nmol/liter)]. This cut-off provides a sensitivity of 100% and a specificity of 96%. In patients with Cushing's syndrome, midnight salivary cortisol concentrations were correlated with UFC collected over the same period of time (0800-0800 h). Salivary cortisol measurements taken every 4 h showed a typical lack of circadian variation. The daily measurement of midnight salivary cortisol concentrations for 2 wk or more in five other out-patients (with obvious Cushing's disease, subclinical adrenal Cushing's syndrome, suspected Cushing's syndrome, pituitary incidentaloma, and prolactinoma) demonstrated the clinical utility of this factor. Measuring midnight salivary cortisol is an easy and noninvasive means of diagnosing hypercortisolism. Its diagnostic accuracy is identical to, if not better than, that of previously described gold standards.
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PMID:Midnight salivary cortisol for the initial diagnosis of Cushing's syndrome of various causes. 1524 Jun 13

Alterations of the intrauterine and early postnatal nutritional, metabolic, and hormonal environment may cause predispositions to the development of disorders and diseases in later life. Mechanisms responsible for this perinatally acquired 'malprogramming' still remain unclear. It has long been known, however, that hormones are environment-dependent organizers of the developing 'neuroendocrine-immune network', which regulates all fundamental processes of life. When present in nonphysiological concentrations during critical ontogenetic periods, hormones can therefore also act as 'endogenous functional teratogens'. Fetal and neonatal hyperinsulinism is a pathognomic feature in the offspring of diabetic mothers. Perinatal hyperinsulinism also occurs due to early postnatal overfeeding. Data obtained by our group indicate that elevated insulin concentrations during critical periods of perinatal life may induce a lasting 'malprogramming' of neuroendocrine systems regulating body weight, food intake, and metabolism. Similar characteristics may occur due to perinatal hyperleptinism, hypercortisolism etc. Since mechanisms of early 'programming' of obesity, diabetes, and the metabolic syndrome X are unclear, a complex 'neuroendocrine malprogramming' of the regulation of body weight and metabolism may provide a general etiopathogenetic concept in this context, exemplarily revealing critical new implications for chances and challenges of perinatal preventive medicine in the future.
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PMID:'Fetal programming' and 'functional teratogenesis': on epigenetic mechanisms and prevention of perinatally acquired lasting health risks. 1534 12


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