Steroid biomarkers for identifying non-classic adrenal hyperplasia due to 21-hydroxylase deficiency in a population of PCOS with suspicious levels of 17OH-progesterone

OBJECTIVE

We aimed at defining the most effective routine immunoassay- or liquid chromatography-tandem mass spectrometry (LC-MS/MS)-determined steroid biomarkers for identifying non-classic adrenal hyperplasia due to 21-hydroxylase deficiency (21-NCAH) in a PCOS-like population before genotyping.

METHODS

Seventy PCOS-like patients in reproductive age with immunoassay-determined follicular 17OH-progesterone (17OHP) ≥ 2.00 ng/mL underwent CYP21A2 gene analysis and _1-24ACTH test. Serum steroids were measured by immunoassays at baseline and 60 min after ACTH stimulation; basal steroid profile was measured by LC-MS/MS.

RESULTS

Genotyping revealed 23 21-NCAH, 15 single allele heterozygous CYP21A2 mutations (21-HTZ) and 32 PCOS patients displaying similar clinical and metabolic features. Immunoassays revealed higher baseline 17OHP and testosterone, and after ACTH stimulation, higher 17OHP (17OHP₆₀) and lower cortisol, whereas LC-MS/MS revealed higher 17OHP (17OHP_LC-MS/MS), progesterone and 21-deoxycortisol and lower corticosterone in 21-NCAH compared with both 21-HTZ and PCOS patients. Steroid thresholds best discriminating 21-NCAH from 21-HTZ and PCOS were estimated, and their diagnostic accuracy in identifying 21-NCAH from PCOS was established by ROC analysis. The highest accuracy was observed for 21-deoxycortisol ≥ 0.087 ng/mL, showing 100% sensitivity, while the combination of 17OHP_LC-MS/MS ≥ 1.79 ng/mL and corticosterone ≤ 8.76 ng/mL, as well as the combination of ACTH-stimulated 17OHP ≥ 6.77 ng/mL and cortisol ≤ 240 ng/mL by immunoassay, showed 100% specificity.

CONCLUSIONS

LC-MS/MS measurement of basal follicular 21-deoxycortisol, 17OHP and corticosterone seems the most convenient method for diagnosing 21-NCAH in a population of PCOS with a positive first level screening, providing high accuracy and reducing the need for ACTH stimulation test.

Prevalence of endocrine disorders in obese patients: systematic review and meta-analysis

OBJECTIVE

The increasing prevalence of obesity is expected to promote the demand for endocrine testing. To facilitate evidence guided testing, we aimed to assess the prevalence of endocrine disorders in patients with obesity. The review was carried out as part of the Endocrine Work-up for the Obesity Guideline of the European Society of Endocrinology.

DESIGN

Systematic review and meta-analysis of the literature.

METHODS

A search was performed in MEDLINE, EMBASE, Web of Science and COCHRANE Library for original articles assessing the prevalence of hypothyroidism, hypercortisolism, hypogonadism (males) or hyperandrogenism (females) in patients with obesity. Data were pooled in a random-effects logistic regression model and reported with 95% confidence intervals (95% CI).

RESULTS

Sixty-eight studies were included, concerning a total of 19.996 patients with obesity. The pooled prevalence of overt (newly diagnosed or already treated) and subclinical hypothyroidism was 14.0% (95% CI: 9.7-18.9) and 14.6% (95% CI: 9.2-20.9), respectively. Pooled prevalence of hypercortisolism was 0.9% (95% CI: 0.3-1.6). Pooled prevalence of hypogonadism when measuring total testosterone or free testosterone was 42.8% (95% CI: 37.6-48.0) and 32.7% (95% CI: 23.1-43.0), respectively. Heterogeneity was high for all analyses.

CONCLUSIONS

The prevalence of endocrine disorders in patients with obesity is considerable, although the underlying mechanisms are complex. Given the cross-sectional design of the studies included, no formal distinction between endocrine causes and consequences of obesity could be made.

European Society of Endocrinology Clinical Practice Guideline: Endocrine work-up in obesity

Obesity is an emerging condition, with a prevalence of ~20%. Although the simple measurement of BMI is likely a simplistic approach to obesity, BMI is easily calculated, and there are currently no data showing that more sophisticated methods are more useful to guide the endocrine work-up in obesity. An increased BMI leads to a number of hormonal changes. Additionally, concomitant hormonal diseases can be present in obesity and have to be properly diagnosed - which in turn might be more difficult due to alterations caused by body fatness itself. The present European Society of Endocrinology Clinical Guideline on the Endocrine Work-up in Obesity acknowledges the increased prevalence of many endocrine conditions in obesity. It is recommended to test all patients with obesity for thyroid function, given the high prevalence of hypothyroidism in obesity. For hypercortisolism, male hypogonadism and female gonadal dysfunction, hormonal testing is only recommended if case of clinical suspicion of an underlying endocrine disorder. The guideline underlines that weight loss in obesity should be emphasized as key to restoration of hormonal imbalances and that treatment and that the effect of treating endocrine disorders on weight loss is only modest.

Behavioral, socio-environmental, educational and demographic correlates of excess body weight in Italian adolescents and young adults

BACKGROUND AND AIMS

Excess body weight (EBW) is the most prevalent nutritional disorder among adolescents worldwide. Identifying determinants of EBW may help find new intervention strategies. Behavioral, socio-economic, educational and demographic correlates of EBW were examined in a population of Italian adolescents, separately for males and females.

METHODS AND RESULTS

As many as 1039 male and 2052 female students (aged 16-19 ys) attending the last three years of different types of high-school of the Emilia-Romagna region in Italy were offered participation, with 552 males and 841 females being finally evaluated. The prevalence of EBW was 21.0% in males and 14.1% in females. Step-wise multivariate logistic regression analyses were performed showing that EBW was negatively related to energy intake in males (odds ratio for 100 kcal/day (OR) = 0.94, 95% confidence interval (CI): 0.89 to 0.98; P = 0.008), and to father's educational attainment (OR = 0.70, 95% CI: 0.52 to 0.95; P = 0.020), but positively related to parental obesity (OR = 2.80, 95% CI: 1.65 to 4.76; P < 0.001). In females, EBW was positively related to parental obesity (OR = 1.94, 95% CI: 1.15 to 3.29; P = 0.013), but negatively to mother's educational attainment (OR = 0.66, 95% CI: 0.45 to 0.97; P = 0.034) and type of attended school (OR = 0.66, 95% CI: 0.49 to 0.89; P = 0.007). Mother's occupation was also an independent determinant of EBW status in females (OR = 0.39, 95% CI: 0.18 to 0.85; P = 0.018 for being unemployed vs blue-collar).

CONCLUSION

Parental obesity is associated with EBW in male and female adolescents. Importantly, we found sex differences in socio-economic and educational factors impacting on EBW, supporting possible distinct area of investigation.

New perspectives on the definition and management of polycystic ovary syndrome

BACKGROUND

There is a growing debate on the opportunity of improving the understanding in the diagnosis and management of polycystic ovary syndrome (PCOS).

OBJECTIVE

This review article summarizes recent research related to the definition of polycystic ovary syndrome (PCOS).

METHODS

Review of the recent literature on the topic.

RESULTS

New ideas on the definition of hyperandrogenism, based on new scientific data and clinical perspectives are presented. (i) In fact, recent studies have pointed out the need to improve the concept of androgen excess by using a larger androgen profile, rather than simply measuring the testosterone blood levels. (ii) Due to the poor correlation between androgen blood levels and the degree of hirsutism, it is proposed that the definition of hyperandrogenism should be based on the presence of blood androgen excess and hirsutism, considered separately, because their pathophysiological mechanisms may differ according to the different phenotypes of PCOS. (iii) The potential role of obesity in favoring the development of PCOS during adolescence is also discussed and the concept of "PCOS secondary to obesity" is developed. (iv) Finally, the need for greater appropriateness in the evaluation of possible coexistence is highlighted, in patients with PCOS who have fasting or glucose-stimulated very high insulin levels, or severe insulin-resistant states.

CONCLUSIONS

Based on what was discussed in this review, we believe that there are margins for modifying some of the current criteria that define the various PCOS phenotypes.

The steroid response to human chorionic gonadotropin (hCG) stimulation in men with Klinefelter syndrome does not change using immunoassay or mass spectrometry

PURPOSE

Liquid-chromatography tandem mass-spectrometry (LC-MS/MS) was developed in parallel to Immunoassays (IAs) and today is proposed as the "gold standard" for steroid assays. Leydig cells of men with Klinefelter syndrome (KS) are able to respond to human chorionic gonadotropin (hCG) stimulation, even if testosterone (T) production was impaired. The aim was to evaluate how results obtained by IAs and LC-MS/MS can differently impact on the outcome of a clinical research on gonadal steroidogenesis after hCG stimulation.

METHODS

A longitudinal, prospective, case-control clinical trial. (clinicaltrial.gov NCT02788136) was carried out, enrolling KS men and healthy age-matched controls, stimulated by hCG administration. Serum steroids were evaluated at baseline and for 5 days after intramuscular injection of 5000 IU hCG using both IAs and LC-MS/MS.

RESULTS

13 KS patients (36 ± 9 years) not receiving T replacement therapy and 14 controls (32 ± 8 years) were enrolled. T, progesterone, cortisol, 17-hydroxy-progesterone (17OHP) and androstenedione, were significantly higher using IAs than LC-MS/MS. IAs and LC-MS/MS showed direct correlation for all five steroids, although the constant overestimation detected by IAs. Either methodology found the same 17OHP and T increasing profile after hCG stimulation, with equal areas under the curves (AUCs).

CONCLUSIONS

Although a linearity between IA and LC-MS/MS is demonstrated, LC-MS/MS is more sensitive and accurate, whereas IA shows a constant overestimation of sex steroid levels. This result suggests the need of reference intervals built on the specific assay. This fundamental difference between these two methodologies opens a deep reconsideration of what is needed to improve the accuracy of steroid hormone assays.

Endocrine dysfunction in hereditary hemochromatosis

Hereditary hemochromatosis (HH) is a genetic disorder of iron overload and subsequent organ damage. Five types of HH are known, classified by age of onset, genetic cause, clinical manifestations and mode of inheritance. Except for the rare form of juvenile haemochromatosis, symptoms do not usually appear until after decades of progressive iron loading and may be triggered by environmental and lifestyle factors. Despite the last decades discovery of genetic and phenotype diversity of HH, early studies showed a frequent involvement of the endocrine glands where diabetes and hypogonadism are the most common encountered endocrinopathies. The pathogenesis of diabetes is still relatively unclear, but the main mechanisms include the loss of insulin secretory capacity and insulin resistance secondary to liver damage. The presence of obesity and/or genetic predisposition may represent addictive risk factor for the development of this metabolic disease. Although old cases of primary gonad involvement are described, hypogonadism is mainly secondary to selective deposition of iron on the gonadotropin-producing cells of the pituitary gland, leading to hormonal impaired secretion. Cases of hypopituitarism or selected tropin defects, and abnormalities of adrenal, thyroid and parathyroid glands, even if rare, are reported. The prevalence of individual gland dysfunction varies enormously within studies for several bias due to small numbers of and selected cases analyzed, mixed genotypes and missing data on medical history. Moreover, in the last few years early screening and awareness of the disease among physicians have allowed hemochromatosis to be diagnosed in most cases at early stages when patients have no symptoms. Therefore, the clinical presentation of this disease has changed significantly and the recognized common complications are encountered less frequently. This review summarizes the current knowledge on HH-associated endocrinopathies.

Human chorionic gonadotropin stimulation gives evidence of differences in testicular steroidogenesis in Klinefelter syndrome, as assessed by liquid chromatography-tandem mass spectrometry

BACKGROUND

Men with Klinefelter syndrome (KS) show hypergonadotropic hypogonadism, but the pathogenesis of hypotestosteronemia remains unclear. Testicular steroidogenesis in KS men was evaluated over three decades ago after human chorionic gonadotropin (hCG) stimulation, but inconclusive results were obtained. Intriguingly, some recent studies show increased intratesticular testosterone concentrations in men with KS.

OBJECTIVE

To analyze serum steroid profile, as a proxy of testicular steroidogenesis, after hCG stimulation in KS compared with control men.

DESIGN

A prospective, longitudinal, case-control, clinical trial.

METHODS

Thirteen KS patients (36±9 years) not receiving testosterone (TS) replacement therapy and 12 eugonadic controls (32±8 years) were enrolled. Serum steroids were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) at baseline and for five consecutive days after intramuscular injection of 5000IU hCG.

RESULTS

Progesterone (P), 17-hydroxyprogesterone (17OHP), TS, and estradiol (E2) showed a significant increase (P<0.001) after hCG stimulation in both groups. On the contrary, androstenedione (AS) and dehydroepiandrosterone did not increase after hCG stimulation. The 17OHP/P ratio increased in both groups (P<0.001), the TS/AS ratio (17β-hydroxysteroid dehydrogenase type 3 (17βHSD3) activity) did not increase after hCG in any group, and the E2/TS ratio (aromatase activity) increased significantly in both groups (P=0.009 in KS and P<0.001 in controls). Luteinizing hormone decreased after hCG in both groups (P=0.014 in KS and P<0.001 in controls), whereas follicle-stimulating hormone decreased only in control men (P<0.001).

CONCLUSION

This study demonstrates for the first time using LC-MS/MS that Leydig cells of KS men are able to respond to hCG stimulation and that the first steps of steroidogenesis are fully functional. However, the TS production in KS men is impaired, possibly related to reduced hydroxysteroid deydrogenase activity due to an unfavorable intratesticular metabolic state.

Improving the diagnosis of 11β-hydroxylase deficiency using home-made MLPA probes: identification of a novel chimeric CYP11B2/CYP11B1 gene in a Sicilian patient

PURPOSE

11β-Hydroxylase deficiency (11OHD) represents the second most common cause of congenital adrenal hyperplasia. It is caused by mutations in the CYP11B1 gene localized about 40 kb from the CYP11B2 gene with which it shares a homology of 95 %. The asymmetric recombination of these two genes is involved both in 11OHD and in glucocorticoid-remediable aldosteronism (GRA). Our objective was to set up an easy and rapid method to detect these hybrid genes and other kinds of deletions, to improve the molecular diagnosis of 11OHD.

METHODS

A set of 8 specific probes for both the CYP11B1 and the CYP11B2 genes to be used for multiplex ligation-dependent probe amplification (MLPA) analysis was designed to detect rearrangements of these genes.

RESULTS

The method developed was tested on 15 healthy controls and was proved to be specific and reliable; it led us to identify a novel chimeric CYP11B2/CYP11B1 gene in one patient that carried the known A306V mutation on the other allele. Specific amplification and sequencing of the hybrid gene confirmed the breakpoint localization in the second intron.

CONCLUSIONS

The MLPA kit developed enables the detection of deletions, duplications or chimeric genes and represents an optimal supplement to DNA sequence analysis in patients with 11OHD. In addition, it can also be used to show the presence of the opposite chimaera associated with GRA.

Relationships between total and regional adiposity and epicardial fat in obese women: how can dual-energy X-ray absorptiometry be associated with echocardiographic epicardial fat measurements?

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Obesity is an increasingly prevalent metabolic disorder and it is associated with a large number of comorbidities, including cardiovascular diseases. Adipose tissue is an active endocrine organ and its ectopic depots and distribution have different metabolic meanings on risks for health; as a matter of fact, epicardial fat seems to play a specific role in cardiovascular diseases. The use of dual-energy X-ray absorptiometry (DXA) to evaluate and follow-up patients affected by obesity is becoming a very important point in the management of the disease.

WHAT THIS STUDY ADDS

An investigation of the association between epicardial fat and regional adiposity by DXA in female obese patients. The total amount of central (trunk) fat mass is more strongly correlated than android visceral fat mass to epicardial thickness in obese women. In the interpretation of whole-body DXA data, physician should consider trunk fat mass for good and independent predictivity on epicardial fat depots. Our aim was to analyse in a population of obese women the relationship between the amount of epicardial fat as measured by transthoracic echocardiography (US) and the parameters of regional adiposity by dual-energy X-ray absorptiometry (DXA), with particular reference to a new software for visceral fat assessment and to a new 'heart-suited' regions of interests (ROIs). Sixty patients who satisfied technical inclusion criteria underwent whole-body DXA scan and US on the same day. Total and android fat mass (FM) and FM percentage (FM%) were considered as well as visceral fat (VAT) subcompartment in the android region; moreover, six new ROIs were designed on whole-body DXA images for the investigation of adiposity parameters at heart level. US provided epicardial fat thickness (EPI-thickness) and area (EPI-area), as measured following previously validated methods. Body mass index (BMI), gynoid and lower limbs (FM and FM%) were found not statistically correlated with EPI-thickness. The highest correlation was achieved by trunk FM (and FM%, with r = 0.544 and 0.480 respectively, P < 0.001), followed by ROI-1 FM (ROI-1 was drawn following thoroughly the cardiac profile), and android FM. Multivariate analysis including age, weight, BMI, trunk FM and the new ROIs (added one by one), retained in the final model trunk FM. Correlations of DXA with EPI-area were superimposable. In obese women, VAT or other new-designed ROIs are not better correlated than traditional ROIs (i.e. trunk) with epicardial fat amount.

Glucose intolerance states in women with the polycystic ovary syndrome

The polycystic ovary syndrome (PCOS), the most common hyperandrogenic disorder affecting 4-7% of women, is often associated with metabolic alterations, chiefly insulin resistance and obesity. Based on available scientific evidence, PCOS should be regarded as an independent risk for the development of glucose intolerance states. This short review summarizes the available literature on the prevalence and incidence of impaired glucose tolerance and Type 2 diabetes in this disorder. In addition, some insights on potential factors responsible for individual susceptibility are discussed. Targeted intervention studies focused on prevention and treatment of glucose intolerance states in PCOS are warranted.

[Value of MRI in detection of extracapsular extension in prostate cancer: a prospective study comparing imaging and histology]

OBJECTIVE

To establish MRI's performances for the detection of extracapsular progression of prostate carcinoma, in a single center, analyzing the correlation between MRI imaging and histological analysis of prostate specimen.

METHODS

From February 2008 to June 2012, all the patients selected for prostatectomy had a pre-operative MRI. Diffusion, T2 and dynamic T1 with gadolinium injection sequences were realized on a 1.5T-MRI with external antenna. All imaging data was analyzed by a specialized radiologist. Prostate specimens were histologically analyzed throughout large blades for utmost topographic comparison. The histological TNM was compared to the MRI data. MRI's capacity in determining the existence and the size of extracapsular progression was studied.

RESULTS

One hundred and fifty-eight patients (median age 62 years old, mean PSA 8.6 ng/mL) were included, among which 45% of d'Amico low risk and 55% of intermediate and high risk. Histological results were 63% of pT2 and 37% of pT3. MRI's sensibility and specificity for detecting extracapsular progression were 0.30 and 0.85 respectively (PPV 0.54; NPV 0.67), with a 65% accuracy. In the low risk group, sensibility equaled to 0.16.

CONCLUSION

In our experience, MRI results were not reliable to influence the choice of treatment. It should be executed by expert radiologists, who are still very few.

Is there a dose-response relationship of metformin treatment in patients with polycystic ovary syndrome? Results from a multicentric study

STUDY QUESTION

Do different dosages of metformin account for different clinical and biochemical outcomes in women with polycystic ovary syndrome (PCOS) and do basal anthropometric and metabolic characteristics of the patients provide any indications regarding the dose required to reach the target effect?

SUMMARY ANSWER

Different doses of metformin exerted the same effects on clinical, biochemical and metabolic parameters in patients affected by PCOS.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

Since the insulin-sensitizing agents came into use in the management of PCOS, metformin has shown a positive benefits-risks ratio. Nonetheless, therapeutic schedules are not well standardized. This is the first study which systematically analyses the effect of different doses of metformin on clinical, hormonal and metabolic features of PCOS. On the basis of our results, higher doses are no more effective than lower doses.

DESIGN

A multicentric cohort prospective study. A total of 250 PCOS women were enrolled, 49 lost to follow-up. Menstrual cyclicity, hormonal assays, oral glucose tolerance test, lipid profile and ultrasonographic pelvic examination were evaluated at the baseline and after 6 months of metformin treatment at different doses (1000, 1500 and 1700 mg).

PARTICIPANTS AND SETTING

A total of 201 PCOS patients completed the study without protocol violations in three university hospitals: seventy-three patients from Centre A (treated with metformin 500 mg twice a day), 60 patients from Centre B (treated with metformin 500 mg three times a day) and 68 patients from Centre C (treated with metformin 850 mg twice a day).

MAIN RESULTS AND THE ROLE OF CHANCE

Metformin exerted an overall positive effect on the clinical and endocrine-metabolic features of PCOS. The degree of these effects was independent of the administered dosage in every range of basal body mass index (BMI). When patients were stratified according to their insulinaemic status, scattered inter-doses differences were found in some of the outcome measures. Patients who exhibited an increase of >2 menstrual cycles/year were considered as responders to treatment. Responders had a higher basal BMI than non-responders and showed a greater reduction in plasma testosterone levels after metformin treatment, but other outcome measures did not differ significantly. Total insulin secretion in the 180 min following the glucose tolerance test before metformin treatment (basal AUC-I) was significantly correlated with the decrease in insulin secretion induced by metformin in both the whole group and in responders, but only correlated with the variation in the number of cycles in responders.

BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION

The different doses were administered in different centres, and between-centre variation is a potential confounding factor.

GENERALIZABILITY TO OTHER POPULATIONS

The paradigm of using the minimum effective dose of metformin could be pursued in other pathological conditions characterized by insulin resistance.

STUDY FUNDING/COMPETING INTEREST(S)

No funding or competing interests to declare.

Basal insulin-like factor 3 levels predict functional ovarian hyperandrogenism in the polycystic ovary syndrome

AIM

The aims of the study were to understand the association between insulin-like factor 3 (INSL3) and functional ovarian hyperandrogenism (FOH) in PCOS and the regulatory role played by LH.

SUBJECTS AND METHODS

Fifteen PCOS women were classified as FOH (FOH-PCOS, no.=8) and non-FOH (NFOH-PCOS, no.=7) according to the response of 17OH-progesterone to buserelin (a GnRH analogue) with respect to 15 controls. FOH-PCOS and NFOH-PCOS were compared for basal INSL3 levels. In addition, the effect of buserelin on INSL3 concentrations and the relationship between basal and buserelin-stimulated LH and 17OH-progesterone and INSL3 were evaluated.

RESULTS

Basal INSL3 levels were higher in FOH-PCOS than NFOH-PCOS (p=0.001) and controls (p=0.001), whereas they did not differ between NFOHPCOS and controls. In addition, FOH-PCOS had a higher response of LH to buserelin with respect to NFOH-PCOS. Within all PCOS women the levels of INSL3 positively correlated with free testosterone (p=0.022) and negatively with SHBG (r= p=0.031). Moreover, positive correlations with the absolute increase of 17OH-progesterone (p<0.001) and with the LH area under the curve (p=0.001) after buserelin administration were found. In the multiple regression analysis INSL3 persisted significantly correlated only with 17OH-progesterone response to buserelin. Finally, INSL3 was not significantly modified after buserelin administration either in FOHPCOS or in NFOH-PCOS.

CONCLUSIONS

These data suggest that INSL3 is related to FOH in PCOS women, but this association seems not to be mediated by LH, further reinforcing the concept that a pathophysiological heterogeneity for ovarian hyperandrogenism in PCOS exists.

Peripheral endocannabinoid system-mediated actions of rimonabant on growth hormone secretion are ghrelin-dependent

The somatotroph axis is a crucial pathway regulating metabolism. Despite the fact that the endocannabinoid system has been also revealed as a potent modulator of energy homeostasis, little information is available concerning a putative interaction between these two systems. The aim of the present study was to determine the in vivo effects of the blockade of the cannabinoid receptor type 1 (CB1) over growth hormone (GH) secretion using the CB1 antagonist rimonabant. The results obtained show that the blockade of the CB1 peripheral receptor by i.p. injection of rimonabant significantly inhibited pulsatile GH secretion. Similarly, it was found that this injection significantly decreased ghrelin-induced GH secretion without any effect on growth hormone-releasing hormone (GHRH)-induced GH discharge. In situ hybridisation showed that the peripheral blockade of CB1 did not affect hypothalamic somatostatin mRNA levels; however, GHRH mRNA expression was significantly decreased. The blockade of the vagus nerve signal by surgical vagotomy eliminated the inhibitory action of rimonabant on GHRH mRNA and consequently on GH. On the other hand, the central CB1 blockade by i.c.v. rimonabant treatment was unable to reproduce the effect of peripheral blockade on GHRH mRNA, nor the GH response to ghrelin. In conclusion, the data reported in the present study establish, from a physiological point of view, the existence of a novel mechanism of GH regulation implicating the action of the cannabinoid receptor on the somatotroph axis.

Prominent role of low HDL-cholesterol in explaining the high prevalence of the metabolic syndrome in polycystic ovary syndrome

BACKGROUND AND AIMS

The main objective was to evaluate the prevalence of the metabolic syndrome in Caucasian women with PCOS, using either of the currently proposed definitions (NCEP/ATPIII, IDF and AHA/NHLBI) and, therefore, to estimate the concordance between these three classifications. Secondary objectives were to evaluate: i) which individual criterion of the metabolic syndrome is most strongly associated with PCOS; and ii) whether the severity of hyperandrogenemia, hyperinsulinemia and insulin resistance may influence the presence of the metabolic syndrome in PCOS women.

METHODS AND RESULTS

The metabolic syndrome was assessed in 200 Caucasian women with PCOS and in 200 Caucasian controls, matched for age and BMI, considering the NCEP/ATPIII, IDF and AHA/NHLBI definitions. PCOS women had an increased prevalence of the metabolic syndrome compared with controls: 32 versus 23% with the NCEP/ATPIII, 39 versus 25% with the IDF and 37 versus 24% with the AHA/NHLBI, respectively (Cohen's Kappa index between the three classifications, P < 0.001). Multivariate logistic regressions revealed that among the individual criteria of the metabolic syndrome, only low HDL-cholesterol levels were significantly associated with PCOS (P < 0.001) which, in turn, are related to insulin(AUC) (P = 0.029) but not to androgens.

CONCLUSION

This case-control study indicates a high prevalence of the metabolic syndrome in Caucasian PCOS women that is independent of the diagnostic classification used. Furthermore, it shows that low HDL-cholesterol is the criterion which best explains the high prevalence of the metabolic syndrome in PCOS subjects which, in turn, is influenced by hyperinsulinemia, rather than by hyperandrogenemia.

Increased clearance of cortisol by 5beta-reductase in a subgroup of women with adrenal hyperandrogenism in polycystic ovary syndrome

OBJECTIVE

Increased peripheral metabolism of cortisol may explain compensatory ACTH-dependent adrenal steroidogenesis and hence hyperandrogenism in polycystic ovary syndrome (PCOS). Previous studies have described an increased 5alpha-reduction of cortisol or impaired regeneration of cortisol by 11beta-HSD1 in PCOS. However, these observations may be confounded by obesity. Moreover, the relationship between alterations in cortisol metabolism and the extent of adrenal androgen hyper-secretion in response to ACTH has not been established. This study aimed to examine the association between cortisol metabolism and ACTH-dependent adrenal hyperandrogenism in PCOS, independently of obesity.

DESIGN

We compared 90 PCOS women (age 18-45 yr) stratified by adrenal androgen responses to ACTH1-24 and 45 controls matched for age and body weight.

METHODS

PCOS women were stratified as normal responders (NR), intermediate responders (IR), and high responders (HR) to 250 microg ACTH1-24: NR (no.=27) had androstenedione and DHEA responses within 2 SD of the mean in controls; IR (no.=43) had DHEA responses >2 SD above controls; HR (no.=20) had both androstenedione and DHEA responses >2 SD above controls.

RESULTS

All groups were similar for age, body weight, and body fat distribution. Basal testosterone, androstenedione, and 5alpha-dihydrotestosterone plasma levels were similarly elevated among the 3 groups of PCOS compared with controls, whereas basal DHEA-S was higher in HR (2.8+/-1.2 microg/ml) and IR (2.4+/-1.1 microg/ml) than in NR (1.8+/-0.8 microg/ml) and controls (1.7+/-0.6 microg/ml). The HR group had the lowest basal plasma cortisol levels (101+/-36 ng/ml vs IR 135+/-42 ng/ml, NR 144+/-48 ng/ml, and controls 165+/-48 ng/ml; all p<0.01), but the greatest cortisol response to ACTH1-24 (Delta(60-0)cortisol 173+/-60 ng/ml vs IR 136+/-51 ng/ml, NR 114+/-50 ng/ml, and controls 127+/-50 ng/ml; all p<0.01), and the highest urinary excretion of total and 5beta-reduced cortisol metabolites (eg 5beta-tetrahydrocortisol/ cortisol ratio 25.2+/-15.3 vs IR 18.8+/-10.7, NR 19.7+/-11.4, and controls 17.2+/-13.7; all p<0.05). There were no differences in urinary excretion of 5alpha-reduced cortisol metabolites or in 5alpha-dihydrotestosterone/testosterone ratio between groups.

CONCLUSIONS

Adrenal androgen excess in PCOS is associated with increased inactivation of cortisol by 5beta-reductase that may lower cortisol blood levels and stimulate ACTH-dependent steroidogenesis.

Monogenic polycystic ovary syndrome due to a mutation in the lamin A/C gene is sensitive to thiazolidinediones but not to metformin

CONTEXT

Despite the very high prevalence of the polycystic ovary syndrome (PCOS), the underlying pathogenetic mechanism has remained obscure.

OBJECTIVE

To determine the cause of two sisters' PCOS associated with severe insulin resistance.

DESIGN

Clinical case report. Methods Two sisters who presented with hyperandrogenism and menstrual disorders in the context of PCOS, and were subsequently found to be severely insulin resistant. Physical examination revealed muscular hypertrophy with a paucity of fat in the extremities, trunk and gluteal regions, in spite of excess fat deposits in the face, neck and dorsocervical region. Known genes involved in familial partial lipodystrophy were screened. At the same time, metformin (1700 mg/day) was commenced. After 2-3 years of uninterrupted therapy, lack of clinical improvement led to the introduction of pioglitazone (30 mg/day).

RESULTS

Both sisters were found to be heterozygous for the R482Q mutation in the lamin A/C gene (LMNA) gene, establishing the definitive diagnosis as Dunnigan-type familial partial lipodystrophy complicated by severe insulin resistance and secondary PCOS. Treatment with pioglitazone resulted in progressive amelioration of insulin resistance, hyperinsulinaemia and hyperandrogenaemia. Menses also improved, with restoration of a eumenorrhoeic pattern, and the framework of ultrasound PCO was in complete remission.

CONCLUSIONS

Assessment of insulin sensitivity and adipose tissue topography should be a key part of the initial evaluation of patients with PCOS. Identifying such forms of PCOS with monogenic insulin resistance as the primary pathogenic abnormality may have practical implications for therapy, since they respond to thiazolidinediones, but not to metformin.

The endocannabinoid system and energy metabolism

Many different regulatory actions have been attributed to endocannabinoids, and their involvement in several pathophysiological conditions is under intense scrutiny. Cannabinoid receptors [cannabinoid receptor type 1 (CB1) and CB2] participate in the physiological modulation of many central and peripheral functions. The ability of the endocannabinoid system to control appetite, food intake and energy balance has recently received considerable attention, particularly in the light of the different modes of action underlying these functions. The endocannabinoid system modulates rewarding properties of food by acting at specific mesolimbic areas in the brain. In the hypothalamus, CB1 receptors and endocannabinoids are integrated components of the networks controlling appetite and food intake. Interestingly, the endocannabinoid system was recently shown to control several metabolic functions by acting on peripheral tissues such as adipocytes, hepatocytes, the gastrointestinal tract, the skeletal muscles and the endocrine pancreas. The relevance of the system is further strengthened by the notion that visceral obesity seems to be a condition in which an overactivation of the endocannabinoid system occurs, and therefore drugs interfering with this overactivation by blocking CB1 receptors are considered as potentially valuable candidates for the treatment of obesity and related cardiometabolic risk factors.

[Fetal lung imaging]

Exponential improvements in imaging techniques over the last ten years, through patients' and physicians' wishes for less invasive fetal work-up, now allow us to better explore and understand fetal lung physiology during pregnancy. Diagnostic and prognostic consequences at stake are huge, especially for fetuses at risk of pulmonary hypoplasia. We will decline in three parts (normal lung, malformative lung and pulmonary hypoplasia), through a review of the literature and at the light of our experience, the potentialities and limitations of all imaging modalities (Ultrasound, Doppler, 3D, MRI). Then, we will dwell on future leads and the need for large-scale collaborative studies.

Cannabinoid type 1 receptor: another arrow in the adipocytes' bow

The endocannabinoid system has recently emerged as an important modulator of several functions of adipose tissue, including cell proliferation, differentiation and secretion. Here, we will review the effects of cannabinoid type 1 (CB(1)) receptor activation/blockade in adipocytes by summarising the data in the literature since the discovery of the presence of this receptor in adipose tissue. We will also discuss our original data obtained in mouse 3T3-L1 adipocyte cells using WIN55 212, a CB(1)/CB(2) receptor agonist and SR141716 (rimonabant), a specific CB(1) receptor antagonist, respectively, in different experimental settings.

Acyl Ghrelin and Metabolic Hormones in Pregnant and Lactating Sows

Ghrelin, the endogenous ligand of the growth hormone (GH) secretagogue receptor, is considered a pleiotropic regulator involved in a large array of functions, including control of energy balance, regulation of food intake and, more recently, modulation of the reproductive axis. The present study was aimed at determining the changes in plasma concentrations of acyl-ghrelin in pregnant and lactating sows, with special emphasis on the relationship with the levels of GH, leptin, non-esterified fatty acids (NEFA) and insulin-like growth factor (IGF-1). Blood samples were collected via jugular venipuncture from 22 multiparous sow 30, 60 and 90 days after artificial insemination, 7 and 21 days after farrowing and at first oestrus post-weaning. Plasma concentrations of acyl-ghrelin, leptin, GH and IGF-1 were quantified by validated radioimmunoassay; NEFA were determined using a colorimetric procedure. Plasma acyl ghrelin levels were highest at 30 days of pregnancy and decreased thereafter and during lactation. At the beginning of lactation, GH, IGF-1 and NEFA concentrations significantly increased, while a significant reduction occurred in leptin. In conclusion, ghrelin concentrations in sow maternal circulation does not seem to play an important role in maintaining circulating GH levels during lactation; moreover, ghrelin is not associated with leptin, NEFA and IGF-1 levels.

Cannabinoid Receptor Antagonists and the Metabolic Syndrome: Novel Promising Therapeutical Approaches

Recent findings in animals and in humans have shown that cannabinoid type 1 receptor antagonists are suitable to become the most promising validated class of drugs to tackle obesity and related disorders. This mini-review will provide a concise and updated revision of the state of art on this topic.

How many sites of action for endocannabinoids to control energy metabolism?

The promising results obtained by clinical trials using Rimonabant to tackle visceral obesity and related disorders recently promoted a remarkable impulse to carry out detailed investigations into the mechanisms of action of endocannabinoids in regulating food intake and energy metabolism. The endocannabinoid system has been known for many years to play an important role in the modulation of the neuronal pathways mediating the rewarding properties of food. However, in the last few years, with the advanced understanding of the crucial role of the hypothalamic neuronal network in the regulation of appetite, several studies have also directed attention to the orexigenic role of the endocannabinoid system, substantiating the well known appetite stimulating properties of derivatives of Cannabis sativa. Furthermore, the last 2 years have seen a number of relevant publications emphasizing the role of endocannabinoids as significant players in various peripheral metabolic processes. To date, the roles of the endocannabinoid system in influencing energy metabolism have proved to be more complex than was formerly believed. However, the diverse ability to modulate both central and peripheral processes highlights the pivotal involvement of the endocannabinoid system in the control of metabolic processes. This review describes the roles of endocannabinoids and the cannabinoid type 1 receptor (CB1) in the control of energy balance.

Review article: The impact of obesity on reproduction in women with polycystic ovary syndrome

The polycystic ovary syndrome (PCOS) is one of the most common causes of infertility due to anovulation in women. The clinical features of PCOS are heterogeneous and may change throughout the lifespan, starting from adolescence to postmenopausal age. This is largely dependent on the influence of obesity and metabolic alterations, including an insulin-resistant state and the metabolic syndrome, which consistently affect most women with PCOS. Obesity does in fact have profound effects on both the pathophysiology and the clinical manifestation of PCOS, by different mechanisms leading to androgen excess and increased free androgen availability and to alterations of granulosa cell function and follicle development. Notably, simple obesity per se represents a functional hyperandrogenic state. These mechanisms involve early hormonal and metabolic factors during intrauterine life, leptin, insulin and the insulin growth factor system and, potentially, the endocannabinoid system. Compared with normal weight women with PCOS, those with obesity are characterised by a worsened hyperandrogenic and metabolic state, poorer menses and ovulatory performance and, ultimately, poorer pregnancy rates. The importance of obesity in the pathogenesis of PCOS is emphasised by the efficacy of lifestyle intervention and weight loss, not only on metabolic alterations but also on hyperandrogenism, ovulation and fertility. The increasing prevalence of obesity among adolescent and young women with PCOS may partly depend on the increasing worldwide epidemic of obesity, although this hypothesis should be supported by long-term prospective epidemiological trials. This may have great relevance in preventive medicine and offer the opportunity to expand our still limited knowledge of the genetic and environmental background favouring the development of the PCOS.

The potential role of increased adrenal volume in the pathophysiology of obesity-related type 2 diabetes

The hypothalamic-pituitary-adrenal (HPA) axis seems to play an important role in obesity and Type 2 diabetes (DM). The aim of the present study was to determine the adrenal volume in obese patients with DM in comparison to obese non-diabetic patients. Eleven diabetic obese and 19 non-diabetic obese women were sequentially invited to take part in the study. Computed tomography (CT) scan of the abdomen was performed to determine adrenal volume, visceral (VF) and sc fat (SCF). Daily urinary free cortisol (UFC) was used as a measure of integrated cortisol production. In the diabetic patients, hemoglobin A1c was measured as an index of metabolic control. Compared to nondiabetic controls, patients with diabetes had a significantly higher total adrenal volume (4.29+/-1.50 vs 2.95+/-1.64; p=0.03). A highly significant correlation was detected between VF and VF/SCF ratio and total adrenal volume in the whole group (r=0.36, p=0.04 and r=0.48, p=0.008, respectively). This study, therefore, suggests an association between abdominal obesity, enlarged adrenals and Type 2 diabetes. These findings support the hypothesis that an increased activity of the HPA axis in obese subjects may be involved in the pathogenesis of Type 2 diabetes.

Endocannabinoids and energy metabolism

Although adjustments to nutritional lifestyle and increased physical activity remain the milestones of weight loss therapy, it is evident from the exponential increase of the number of obese subjects in Western countries that these two approaches alone are no longer able to limit this progression. This alarming phenomenon occurs in spite of a great effort exerted in the last 10 yr to shed light on the pathogenetic mechanisms inducing obesity, although many inconclusive hopes have been generated in the field of pharmacotherapeutics to tackle obesity. Among the several targets exploited in recent years, the endocannabinoid system nowadays constitutes the most promising and the most intriguing proposed so far. On one hand, our aim is to provide an overview on the role of the endocannabinoid system in the physiology of energy metabolism, on the other hand a further aim is to summarize how the system also controls food intake and energy balance by acting at both cerebral and peripheral level.

Gastric immunolocalization and plasma profiles of acyl-ghrelin in fasted and fasted-refed prepuberal gilts

Ghrelin is a peripheral circulating hormone, mainly released from the stomach, which can stimulate food intake. We studied fed, fasted and fasted-refed prepuberal gilts in order to outline possible changes in gastric mucosal ghrelin cells and in plasma ghrelin profiles in response to food deprivation. Acyl-ghrelin-immunoreactive cells were numerous in oxyntic glands, less abundant in cardiac glands and least frequent in pyloric glands, with the addition of a minor population of labelled cells in the gastric pit mucosa. When fed and fasted animals were compared (72-h fast versus fed; n = 4 each), no clear-cut differences were revealed in labelled cell numbers, nor in their staining intensity. An RIA for plasma porcine acyl-ghrelin (n-octanoylated at Ser-3), not recognizing des-acyl-ghrelin, was validated. Plasma acyl-ghrelin progressively increased upon fasting (over 6, 12, 24 and 48 h); ghrelin levels significantly (P<0.05) higher than those prefast were reached at 72 h. After refeeding, plasma ghrelin was rapidly restored to basal values by 6 h. In the same animals, plasma insulin was significantly reduced throughout the fasting period (6-72 h), while rapidly increasing after refeeding. Non-esterified fatty acid levels increased during fasting (12-72 h) and rapidly returned to low values after refeeding. In conclusion, the present study demonstrates that starvation and refeeding influence ghrelin plasma level in prepuberal gilts. The absence of detectable changes in ghrelin cells, as seen in immunohistochemistry, could be due to a large intracellular storage of potentially releasable acylghrelin.

Short-term modification of sex hormones is associated with changes in ghrelin circulating levels in healthy normal-weight men

The aim of this study was to evaluate the effect of selective and short-term sex hormone modifications on ghrelin levels in normal-weight eugonadal men undergoing hormonal contraceptive treatments. Seven men received an oral progestin [cyproterone acetate (CPA) or dienogest (DNG)] 10 mg/day for 3 weeks (CPA-DNG group), 7 CPA orally 5 mg/day in association with testosterone enanthate (TE) im 200 mg/week for 8 weeks (CPA-TE group), and 7 placebo (PLAC) for 8 weeks (PLAC group). Anthropometry and blood levels of LH, FSH, testosterone, estradiol, glucose, insulin and total ghrelin were evaluated. At baseline, no parameters differed among the three groups. After treatment, LH and FSH decreased in both CPA-DNG and CPA-TE groups, whereas they did not change in the PLAC group. Testosterone and estradiol decreased in the CPA-DNG group to the hypogonadal range, increased in the CPA-TE group to supraphysiological concentrations and, as expected, remained unchanged in the PLAC group. Total ghrelin levels increased in the CPA-DNG, decreased in the CPA-TE and did not change in the PLAC group. Ns modifications in the other parameters were observed in any group, demonstrating that the short-term changes of circulating sex hormones are able to modify ghrelin levels. These data, therefore, suggest that sex steroids are important regulators of ghrelin in normal-weight healthy men too.

Metabolic alterations and cardiovascular risk factors in the polycystic ovary syndrome

Available literature indicates that polycystic ovary syndrome (PCOS) represents a condition with a high prevalence of the metabolic syndrome, a greater and precocious appearance of glucose intolerance states, including type 2 diabetes mellitus, and a potentially greater risk for cardiovascular diseases. With respect to metabolic disorders, however, there is also emerging evidence that they are more prevalent in PCOS rather than in the general population, and that there are regional differences in the world, depending on lifestyle and other environmental factors. This evidence should be taken into consideration in future strategies focusing on prevention of metabolic and cardiovascular disorders in PCOS, not only on treatment of infertility and signs of androgen excess.

Response of the hypothalamic-pituitary-adrenal axis to small dose arginine-vasopressin and daily urinary free cortisol before and after alprazolam pre-treatment differs in obesity

OBJECTIVE

Arginine vasopressin (AVP) has a central role in the response of the hypothalamic-pituitary-adrenal (HPA) axis to stress conditions. A low dose of AVP has been shown to have a modest, but significant effect on ACTH response in normal weight subjects. The aim of this study was to test the response of the HPA axis in obese subjects in order to assess eventual primary neuroendocrine alterations, previously demonstrated by using AVP combined with corticotropin releasing hormone (CRH). In addition, given its central inhibitory action on the HPA axis, we investigated whether the suppressive capacity of alprazolam (APZ) pretreatment on the hormone response to low-dose AVP challenge and daily urinary free cortisol (UFC) excretion rate may be altered in the presence of obesity.

DESIGN

Fifteen overweight or obese women and eight normal-weight controls randomly underwent two low-dose AVP tests (0.3 UI iv bolus), one without (AVP test) and the other preceded by APZ administration (0.5 mg at midnight and 0.5 mg 90 min before the test in the morning at 08:30 h) (APZ/AVP test). Blood samples for ACTH and cortisol assay were obtained at baseline and throughout each test. The day before each test, 24h-UFC/ creatinine was also mea-sured.

RESULTS

Basal ACTH levels were similar in the two groups, whereas cortisol concentrations were significantly lower in the overweight/obese group. Overweight/obese women had higher ACTH and cortisol responses to the AVP tests and significantly greater hormone inhibition after APZ than controls. In both groups, AVP-induced delta-peak cortisol values before and after APZ pre-treatment were significantly correlated. Body fat distribution had no effect on the HPA axis response to AVP either before or after APZ. Moreover, APZ decreased 24h-UFC/creatinine values unsignificantly in controls and by approximately 50% in the overweight/obese subjects. These changes were unrelated to the cortisol response to the AVP test before and after APZ pretreatment. On the other hand, percent changes of 24h-UFC/creatinine after APZ were negatively related to the body mass index (BMI) but positively with waist circumference values, which indicates that the abdominal obesity phenotype may counteract the 24 h-UFC/creatinine that would be expected on the basis of BMI values.

CONCLUSIONS

Our data further support the concept that in women obesity may represent a condition of hyperresponsiveness or hypersensitivity of the HPA axis to neuroendocrine stimuli, which appear to be independent of feedback control. In addition, the data on the inhibiting capacity of APZ on UFC excretion confirm that the alterations of the HPA axis in obesity is particularly evident in the abdominal phenotype.

Type 2 diabetes and the polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder, affecting women in reproductive age, characterized by chronic anovulation and hyperandrogenism. The etiology of PCOS is still unknown. However, several studies have suggested that insulin resistance plays an important role in the pathogenesis of the syndrome. As a consequence of insulin-resistance, women affected by PCOS often present abnormalities of glucose metabolism and lipid profile, and have an increased risk of type 2 diabetes and cardiovascular disease over-time. Besides insulin-resistance, it has been demonstrated that some of these women also have alterations in beta-cell-function. Both disorders (insulin-resistance and beta-cell-dysfunction) are recognized as major risk factors for the development of type 2 diabetes. Long-term studies, evaluating the glucose-insulin system in women affected by PCOS, have shown a higher incidence of glucose intolerance, including both impaired glucose tolerance and type 2 diabetes, compared to age and weight matched control populations. The risk of glucose intolerance among PCOS subjects seems to be approximately 5 to 10 fold higher than normal and appears not limited to a single ethnic group. Moreover, the onset of glucose intolerance in PCOS women has been reported to occur at an earlier age than in the normal population (approximately by the 3rd-4th decade of life). However, other risk factors such as obesity, a positive family history of type 2 diabetes and hyperandrogenism may contribute to increasing the diabetes risk in PCOS.

Low ghrelin concentrations in nonalcoholic fatty liver disease are related to insulin resistance

Several physiological and pathophysiological conditions, including changes in body fat, food intake, and insulin resistance, are known to be associated with variations in plasma ghrelin concentrations. We tested the hypothesis that insulin resistance exerts a primary role by measuring ghrelin in 86 patients with nonalcoholic fatty liver disease (NAFLD), a condition in which insulin resistance is relatively independent of obesity. Compared with 40 matched healthy subjects, patients with NAFLD had similar glucose levels and higher plasma insulin and insulin resistance [homeostasis model assessment (HOMA)-R index] by over 60%. Ghrelin was reduced (mean +/- SD, 226 +/- 72 pmol/liter in NAFLD vs. 303 +/- 123 in controls; P < 0.0001). In relation to quartiles of body mass index, ghrelin progressively decreased in controls (P = 0.003), but not in patients (P = 0.926). In relation to quartiles of HOMA-R, ghrelin decreased in both groups, and significantly correlated with HOMA-R. After adjustment for age and sex, HOMA-R was the sole factor significantly associated with low ghrelin in the whole group (odds ratio, 5.79; 95% confidence interval, 2.62-12.81; P < 0.0001) and specifically in NAFLD (2.96; 1.12-7.79; P = 0.028). The study suggests that insulin resistance is a major factor controlling ghrelin levels in subjects with and without NAFLD.

Anti-androgen treatment increases circulating ghrelin levels in obese women with polycystic ovary syndrome

In a previous study we were the first to describe a negative correlation between circulating ghrelin concentrations and androgen levels in human plasma, suggesting an interaction between ghrelin and the endocrine regulation of reproductive physiology. We now investigated a potential direct regulatory influence of circulating androgens on plasma ghrelin levels. Fourteen obese women with polycystic ovary syndrome (PCOS) on a hypocaloric diet were randomly assigned to treatment groups (open-labeled design), receiving either placebo (no.=7) or the antiandrogen flutamide (no.=7) for 6 months. Anthropometry, visceral (VAT) and subcutaneous (SAT) adipose tissue (quantified by computerized tomography), plasma hormone levels, insulin sensitivity indexes (Quantitative Insulin-Sensitivity Check Index-QUICKI) and Homeostatic Model Assessment applied to the oral glucose tolerance test (HOMA(OGTT)) were evaluated at baseline and at the end of the study. Body weight decreased and insulin resistance indexes improved in both groups. A tendency toward a greater loss of VAT was observed in the flutamide group. Only in the flutamide group was a significant reduction of androgens levels observed. Plasma ghrelin levels significantly increased following treatment with flutamide, while ghrelin remained unchanged in the placebo group. We observed a negative correlation between changes of ghrelin levels and changes of androgen plasma concentration in the flutamide-treated group. In the same group a positive correlation was found between plasma ghrelin changes and insulin sensitivity as expressed by HOMA(OGTT). Analysis in a multiple regression model, however, showed that plasma ghrelin changes were mainly due to changes of androgen levels rather than improved insulin sensitivity. We, therefore, conclude that androgens are independent modulators of circulating ghrelin concentrations.

Testosterone levels in obese male patients with obstructive sleep apnea syndrome: relation to oxygen desaturation, body weight, fat distribution and the metabolic parameters

To investigate the impact of obstructive sleep apnea syndrome (OSAS) on testosterone levels and on the main parameters of the metabolic syndrome in abdominally obese men, 15 male subjects with abdominal obesity phenotype and polysomnographic diagnosis of OSAS (OB-OSAS) and 15 controls matched for age and anthropometric parameters (OB) were investigated. Anthropometry, SHBG, sex hormones and several parameters of the metabolic syndrome were measured. Only subjects with an Epworth Sleepiness Score greater than 10 underwent a polysomnographic study with calculation of the number of desaturation rates per sleeping hour (ODI), the minimal oxygen saturation during each desaturation episode (minSaO2) and the mean minimal arterial oxygen saturation for the whole night period (MminSaO2). Both total and free testosterone levels were lower in OB-OSAS than in OB patients. A negative correlation between polysomnographic parameters (ODI, minSaO2 and MminSaO2) and testosterone levels was found. The relationship between total and free testosterone and ODI persisted after adjusting for body mass index (BMI) and waist (W) values. Triglyceride and uric acid levels were significantly higher in OB-OSAS than in OB patients. A negative correlation between testosterone and acid uric level and a positive correlation between testosterone and HDL-cholesterol level was found, regardless of BMI and W circumference, particularly in the OB-OSAS group. Our study suggests that, in patients with obesity and OSAS, the severity of hypoxia during sleeping hours may be an additional factor in reducing testosterone levels, regardless of BMI and abdominal fatness. This may contribute in worsening metabolic abnormalities which, in men with OSAS, exceed those expected on the basis of degree of obesity and pattern of fat distribution.

Endogenous cannabinoid system as a modulator of food intake

The ability of Cannabis sativa (marijuana) to increase hunger has been noticed for centuries, although intensive research on its molecular mode of action started only after the characterization of its main psychoactive component Delta(9)-tetrahydrocannabinol in the late 1960s. Despite the public concern related to the abuse of marijuana and its derivatives, scientific studies have pointed to the therapeutic potentials of cannabinoid compounds and have highlighted their ability to stimulate appetite, especially for sweet and palatable food. Later, the discovery of specific receptors and their endogenous ligands (endocannabinoids) suggested the existence of an endogenous cannabinoid system, providing a physiological basis for biological effects induced by marijuana and other cannabinoids. Epidemiological reports describing the appetite-stimulating properties of cannabinoids and the recent insights into the molecular mechanisms underlying cannabinoid action have proposed a central role of the cannabinoid system in obesity. The aim of this review is to provide an extensive overview on the role of this neuromodulatory system in feeding behavior by summarizing the most relevant data obtained from human and animal studies and by elucidating the interactions of the cannabinoid system with the most important neuronal networks and metabolic pathways involved in the control of food intake. Finally, a critical evaluation of future potential therapeutical applications of cannabinoid antagonists in the therapy of obesity and eating disorders will be discussed.