[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.

[Pharmacological therapy of obesity]

Obesity is reaching epidemic proportions worldwide and it is correlated with various comorbidities, among which the most relevant are diabetes mellitus, arterial hypertension, and cardiovascular diseases. Obesity management is a modern challenge because of the rapid evolution of unfavorable lifestyles and unfortunately there are no effective treatments applicable to the large majority of obese/overweight people. The current medical attitude is to treat the complications of obesity (e.g. dyslipidemia, hypertension, diabetes, and cardiovascular diseases). However, the potential of treating obesity is enormous, bearing in mind that a volitional weight loss of 10 kg is associated with important risk factor improvement: blood pressure -10 mmHg, total cholesterol -10%, LDL cholesterol -15%, triglycerides -30%, fasting glucose -50%, HDL cholesterol +8%. Drug treatment for obesity is an evolving branch of pharmacology, burdened by severe side effects and consequences of the early drugs, withdrawn from the market, and challenged by the lack of long-term data on the effect of medications on obesity-related morbidity and mortality, first of all cardiovascular diseases. In Europe three antiobesity drugs are currently licensed: sibutramine, orlistat, and rimonabant; important trials with clinical endpoints are ongoing for sibutramine and rimonabant. While waiting for their results, it is convenient to evaluate these drugs for their effects on body weight and cardiometabolic risk factors. Sibutramine is a centrally acting serotonin/noradrenaline reuptake inhibitor that mainly increases satiety. At the level of brown adipose tissue, sibutramine can also facilitate energy expenditure by increasing thermogenesis. The long-term studies (five) documented a mean differential weight reduction of 4.45 kg for sibutramine vs placebo. Considering the principal studies, attrition rate was 43%. This drug not only reduces body weight and waist circumference, but it decreases triglycerides and uric acid as well and it increases HDL cholesterol; in diabetics it improves glycated hemoglobin. Sibutramine has conflicting effects on blood pressure: in some studies there was a minimal decrease, in some others a modest increase. In all the studies this drug increased pulse rate. Sibutramine is not recommended in patients with uncontrolled hypertension, or in case of history of cardio- and cerebrovascular disease. Orlistat is a pancreatic lipase inhibitor that reduces fat absorption by partially blocking the hydrolysis of dietary triglycerides. A recent meta-analysis evaluated 22 studies lasting for at least 12 months, in obese patients with a mean body mass index of 36.7 kg/m2, where orlistat was associated with hypocaloric diet or behavioral interventions: the net average weight loss was 2.89 kg (confidence interval 2.27-3.51 kg). Considering the principal studies, attrition rate ranged from 33 to 57%. Orlistat significantly decreases waist circumference, blood pressure, total and LDL cholesterol, but has no effect on HDL and triglycerides. This drug significantly reduced the incidence of diabetes only in subjects with impaired glucose tolerance. The major adverse effects with orlistat are mainly gastrointestinal (fatty and oily stool, fecal urgency, oily spotting, fecal incontinence) and attenuate over time. Orlistat should be avoided in patients with chronic malabsorption and cholestasis. Rimonabant is a selective antagonist of cannabinoid type 1 receptor. This drug, by inhibiting the overactivation of the endocannabinoid system, produces anorectic stimuli at the central nervous level, but also has effects on the peripheral systems involved in metabolism control, such as liver, adipose tissue, skeletal muscles, endocrine pancreas, and gastrointestinal apparatus, influencing many processes partially unknown. An ample experimental program named RIO (Rimonabant In Obesity) involved about 6600 obese or overweight patients to identify the effects of rimonabant in weight loss and associated cardiometabolic abnormalities, over and beyond a caloric restriction of 600 kcal in the treatment and placebo arms. In the four double-blind RIO trials published (Rio-North America, RIO-Europe, RIO-Lipids, RIO-Diabetes), rimonabant 20 mg significantly (p <0.001) reduced weight by 6.3-6.9 kg in the non-diabetic groups vs placebo (-1.5-1.8 kg), whereas in the diabetic subjects enrolled in RIO-Diabetes, weight loss was 5.3 vs 1.4 kg in the placebo group. Attrition rate at 1 year ranged between 40 and 50%, similar to the studies with sibutramine or orlistat. Similarly to weight loss, also waist circumference was significantly reduced by rimonabant. As for cardiometabolic parameters, rimonabant induced a significant increase in HDL cholesterol and a significant decrease in triglycerides. Even if no significant LDL reduction was achieved, the RIO-Lipids study showed a significant decrease in small dense LDL particles, more atherogenic, in rimonabant-treated subjects. Non-diabetic treated patients improved basal insulin and indirect indexes of insulin resistance, while in the RIO-Diabetes study, the only one including diabetics, glycated hemoglobin improved by 0.7% in the active treatment arm vs placebo. The effects on HDL cholesterol and glycated hemoglobin seem in a large percentage unrelated to weight loss. These effects have been confirmed by another trial, named SERENADE, evaluating the treatment in naive diabetic patients. Rimonabant is not recommended in patients with a history of depressive disorders or suicidal ideation and with uncontrolled psychiatric illness, and is contraindicated in patients with ongoing major depression or ongoing antidepressive treatment. In conclusion, despite an enormous advancement in basic research to understand the pathogenetic mechanisms at the base of obesity, the pharmacological research did not reach the therapeutic opportunities available for other chronic conditions, like hypertension and dyslipidemia. However, the few molecules available for clinical practice (sibutramine, orlistat, rimonabant) have shown, when properly used, to contribute to reduce body weight and undoubtedly improve cardiometabolic risk factors. With this preamble, according to current guidelines and pharmacoeconomic studies, patients who might benefit from antiobesity treatment are those with a body mass index > or =30 or 27-29.9 kg/m2 with major obesity-related comorbidities such as hypertension, diabetes, dyslipidemia, obstructive sleep apnea, and metabolic syndrome.

[Endocannabinoid system and energy metabolism: physiology and pathophysiology]

The ability of the endocannabinoid system to control appetite, food intake and energy balance has recently received great 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 receptor and endocannabinoids are integrated components of the networks controlling appetite and food intake. Interestingly, the endocannabinoid system has recently been shown to control several metabolic functions by acting on peripheral tissues, such as adipocytes, hepatocytes, 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, therefore drugs interfering with this overactivation by blocking CB1 receptor are considered as valuable candidates for the treatment of obesity and related cardiometabolic risk factors.

The endocannabinoid system in the regulation of cardiometabolic risk factors

Obesity has increased at a striking rate over the last 3 decades in the Western world. This negative trend dramatically affects physical health and, ultimately, cardiovascular risks. In fact, particularly at the visceral level, obesity is strongly associated with an increased risk for life-threatening conditions, such as type 2 diabetes mellitus, hypertension, dyslipidemia, and cardiovascular disease. Although nutritional changes and physical activity are commonly thought of as the core treatments for obesity, it is necessary to further support obese patients with a pharmacologic approach for 2 reasons: to reduce the metabolic risk profile, and to avoid the regaining of weight. Among the various pharmacologic targets explored in recent years, the endocannabinoid (EC) system now constitutes the most promising proposal so far. In this review, after focusing on the central and peripheral signaling pathways that preserve energy homeostasis, we review the role of the EC system in regulating food's rewarding properties, controlling caloric intake by acting in hypothalamic pathways, and in modulating metabolic functions of several peripheral organs. In addition, we provide evidence that supports the recently proposed hypothesis that a close association exists between obesity and overactivation of the EC system.

Obesity and infertility

PURPOSE OF REVIEW

To summarize major factors affecting fertility in obesity.

RECENT FINDINGS

Fertility can be negatively affected by obesity. In women, early onset of obesity favours the development of menses irregularities, chronic oligo-anovulation and infertility in the adult age. Obesity in women can also increase risk of miscarriages and impair the outcomes of assisted reproductive technologies and pregnancy, when the body mass index exceeds 30 kg/m. The main factors implicated in the association may be insulin excess and insulin resistance. These adverse effects of obesity are specifically evident in polycystic ovary syndrome. In men, obesity is associated with low testosterone levels. In massively obese individuals, reduced spermatogenesis associated with severe hypotestosteronemia may favour infertility. Moreover, the frequency of erectile dysfunction increases with increasing body mass index.

SUMMARY

Much more attention should be paid to the impact of obesity on fertility in both women and men. This appears to be particularly important for women before assisted reproductive technologies are used. Treatment of obesity may improve androgen imbalance and erectile dysfunction, the major causes of infertility in obese men.

17-hydroxyprogesterone responses to gonadotropin-releasing hormone disclose distinct phenotypes of functional ovarian hyperandrogenism and polycystic ovary syndrome

CONTEXT

The exaggerated 17-hydroxyprogesterone response to GnRH agonists, which reflects functional ovarian hyperandrogenism (FOH), is believed to be the prominent abnormality in women with polycystic ovary syndrome (PCOS).

OBJECTIVE

Our objectives were to quantify the prevalence of PCOS with FOH and to evaluate whether the presence of FOH may distinguish different clinical and biochemical phenotypes.

DESIGN, SETTING, AND PARTICIPANTS

We conducted an observational study at an academic hospital that included 148 PCOS women and 22 healthy age-matched normal-weight control women.

MAIN OUTCOME MEASURES

A hormone profile was taken at baseline and in response to (1-24)ACTH and to a GnRH agonist, buserelin, administered during dexamethasone suppression.

RESULTS

Based on the data obtained in the control subjects, the PCOS patients were divided into two groups, one with a normal (NR-PCOS, n = 78) and one with a high 17-hydroxyprogesterone response (HR-PCOS, n = 70) to buserelin. The two groups of PCOS subjects had similar anthropometric parameters and clinical signs of hyperandrogenism. Age and body weight at menarche were significantly lower and higher, respectively, in the HR-PCOS group than the NR-PCOS group. Moreover, the HR-PCOS group had higher basal testosterone (P < 0.001), free androgen index (P < 0.01), 17-hydroxyprogesterone (P < 0.05), estrogens (P < 0.05), area under the curve for insulin (insulin(AUC)) (P < 0.05), and C-peptide(AUC) (P < 0.01) and lower insulin sensitivity (as composite insulin sensitivity index) (P < 0.05) than the NR-PCOS group. The response of 17-hydroxyprogesterone to (1-24)ACTH (as percent variation) was lower in the HR-PCOS group with respect to the NR-PCOS group (P < 0.05), whereas the response of cortisol, androstenedione, and dehydroepiandrosterone was similar. Finally, the HR-PCOS group had lower percent suppression of androstenedione (P < 0.001) and 17-hydoxyprogesterone (P < 0.05) to dexamethasone. In a multiple regression model applied in all PCOS women, insulin(AUC) but not androgens or markers of insulin resistance predicted the 17-hydroxyprogesterone response to buserelin to a highly significant extent (t = 3.269; P < 0.01).

CONCLUSIONS

This study indicates that the paradigm that FOH is a specific feature of the PCOS status can no longer be sustained. We have shown that women with an exaggerated 17-hydroxyprogesterone response to a GnRH agonist, buserelin, are characterized by more severe hyperandrogenemia, glucose-stimulated beta-cell insulin secretion, and worse insulin resistance than those without evidence of FOH. Our data may be consistent with the hypothesis that excess insulin may represent a candidate factor responsible for FOH in these women, through the overactivation of the cytochrome P450 17alpha-hydroxylase/17,20-lyase (CYP17) enzyme pathway.

Plasma acylated ghrelin levels are higher in patients with chronic atrophic gastritis

OBJECTIVES

Ghrelin is mainly produced by the endocrine cells of the gastric oxyntic mucosa. For this reason we decided to investigate the modification of the circulating levels not only of total but also of acylated ghrelin in a series of patients with chronic atrophic gastritis.

DESIGN

Twenty-five patients with chronic atrophic gastritis and 25 healthy subjects were studied. In all 50 subjects gastrin and total and acylated ghrelin levels were evaluated. All patients underwent endoscopy with multiple biopsies, and the possibility of Helicobacter pylori infection was investigated.

RESULTS

Significantly higher acylated ghrelin levels (82.8 +/- 61.3 vs. 35.1 +/- 17.1 pmol/l), acylated/total ghrelin ratio (0.422 +/- 0.202 vs. 0.152 +/- 0.085) and gastrin levels (1071 +/- 816 vs. 66 +/- 22 ng/l) were observed in the 25 patients with chronic atrophy than in the healthy subjects. Otherwise, no significant relationships were found when total ghrelin was correlated with the presence of atrophy, or with gastrin levels. In the healthy subjects, but not in the patients, acylated and total ghrelin levels were significantly higher in female than in male patients.

CONCLUSIONS

The increase in acylated ghrelin levels and in the acylated/total ghrelin ratio in patients with atrophy of the body and fundus can be explained by hypothesizing an increase in the acylating process in the presence of gastric atrophy. It suggests that there may be a compensatory increase in plasma active ghrelin concentration in response to gastric atrophy, a condition which causes a loss of ghrelin-producing cells and an increase in gastric pH.

Circulating obestatin levels and the ghrelin/obestatin ratio in obese women

OBJECTIVE

We measured blood levels of obestatin, total ghrelin, and the ghrelin/obestatin ratio and their relationship with anthropometric and metabolic parameters, adiponectin and insulin resistance, in overweight/obese and normal-weight women.

DESIGN

Outpatients Unit of Endocrinology of the S Orsola-Malpighi Hospital of Bologna, Italy.

METHODS

Fasting obestatin, ghrelin, adiponectin and lipid levels, fasting and glucose-stimulated oral glucose tolerance test insulin, and glucose levels were measured in 20 overweight/obese and 12 controls. The fasting ghrelin/obestatin ratio was calculated; the homeostasis model assessment-IR (HOMA-IR) and insulin sensitivity index (ISI(composite)) were calculated as indices of insulin resistance.

RESULTS

Obese women had higher obestatin and lower ghrelin blood levels, and a lower ghrelin/obestatin ratio compared with controls. In all subjects, obestatin was significantly and positively correlated with total cholesterol and triglycerides, but not with ghrelin, anthropometric, and metabolic parameters. In the obese women, however, obestatin and ghrelin concentrations were positively correlated. By contrast, the ghrelin/obestatin ratio was significantly and negatively correlated with body mass index, waist, waist-to-hip ratio, fasting insulin, and HOMA-IR, and positively with ISI(composite) but not with adiponectin. None of these parameters were correlated with the ghrelin/obestatin ratio in the obese.

CONCLUSIONS

Increased obestatin, decreased ghrelin levels, and a decreased ghrelin/obestatin ratio characterize obesity in women. This supports the hypothesis that the imbalance of ghrelin and obestatin may have a role in the pathophysiology of obesity. On the other hand, some relevant differences between our data on circulating levels of obestatin and the ghrelin/obestatin ratio in obese subjects and those reported in the few studies published so far imply that further research is needed.

Insulin-like factor 3: a new circulating hormone related to luteinizing hormone-dependent ovarian hyperandrogenism in the polycystic ovary syndrome

CONTEXT

Insulin-like factor 3 (INSL3), a member of the relaxin-insulin family, is produced in the Leydig cells and at reduced levels in ovarian theca interna cells of antra follicles as well as in the corpora lutea and ovarian stroma. Among the factors potentially involved in the stimulation of gonadal expression of INSL3, recent data obtained in rats show an important role of LH. Ovaries from most women affected by polycystic ovary syndrome (PCOS) are characterized by hyperplasia of the theca interna and of cortical stroma and by an increased number of small antral follicles, and the majority of women with PCOS, particularly normal-weight subjects, have LH levels that are above the normal range.

OBJECTIVE

The objective of this study was to investigate INSL3 circulating levels in both normal-weight and overweight-obese PCOS women and the association of INSL3 with gonadotropin and androgenic pattern and with ovarian morphology.

DESIGN

This was a controlled study.

SETTING

The study took place at an academic hospital.

PARTICIPANTS

The participants included 44 PCOS patients (22 normal-weight and 22 overweight-obese) and 44 controls comparable for age and body weight.

MAIN OUTCOME MEASURES

The main outcome measures included INSL3 serum concentrations, measured by RIA, in PCOS patients and controls and their correlation with clinical and biochemical phenotype and with ovarian morphology.

RESULTS

INSL3 serum concentrations were significantly higher in PCOS patients with respect to controls (P = 0.003), particularly in normal-weight (P = 0.001) but not in overweight-obese (P = 0.312) PCOS patients. INSL3 serum concentrations were positively correlated with total and free testosterone and with LH levels in all women (total testosterone, P < 0.001; free testosterone, P = 0.001; LH, P = 0.002) as well as in PCOS patients (total testosterone, P = 0.024; free testosterone, P = 0.045; LH, P = 0.049). Moreover, in the PCOS group, INSL3 levels were related to a greater 17OH-progesterone response to buserelin (P = 0.015), an index of ovarian hyperandrogenism. Finally, in PCOS women, INSL3 levels were positively correlated with ovarian follicle number (P = 0.028).

CONCLUSIONS

INSL3 could be considered a new circulating hormone related to LH-dependent ovarian hyperandrogenism, particularly in normal-weight PCOS women.

Polycystic ovary syndrome: a multifaceted disease from adolescence to adult age

Polycystic ovary syndrome (PCOS), one of the most common causes of ovulatory infertility, affects 4-7% of women. Although it was considered that PCOS may have some genetic component and that clinical features of this disorder may change throughout a life span, starting from adolescence to postmenopausal age, no effort has been made to define differences in the phenotype and clinical presentation according to age. Indeed, it has been widely recognized in the last decade that several features of metabolic syndrome (MS), particularly insulin resistance and hyperinsulinemia, are inconsistently present in the majority of women with PCOS. This represents an important factor in the evaluation of PCOS throughout life, which implies that PCOS by itself may not be a hyperandrogenic disorder exclusively related to young and fertile-aged women, but may also have some health implications later in life. In young women with PCOS, hyperandrogenism, menses irregularities, and insulin resistance may occur together, emphasizing the pathophysiological role of excess androgen and insulin on PCOS. Hyperandrogenism and infertility represent the major complaints of PCOS in adult fertile age. In addition, obesity and MS may affect more than half these women. Later in life, it becomes clear that the association of obesity (particularly the abdominal phenotype) and PCOS renders affected women more susceptible to develop type 2 diabetes mellitus (T2DM), with some difference in the prevalence rates among countries, suggesting that environmental factors are important in determining individual susceptibility. Little is known about ovarian morphology and androgen production in women with PCOS after menopause. Some studies found that morphological ultrasonographic features consistent with polycystic ovaries are very common in postmenopausal women, and that these features are associated with higher than normal testosterone levels and metabolic alterations. There is an obvious need for further research in this area. Identification of major complaints and features of PCOS during the different ages of an affected woman may help, in fact, to plan individual therapeutic strategies, and, possibly, prevent long-term chronic metabolic diseases.

Requirement of cannabinoid receptor type 1 for the basal modulation of hypothalamic-pituitary-adrenal axis function

The endocannabinoid system affects the neuroendocrine regulation of hormone secretion, including the activity of the hypothalamus-pituitary-adrenal (HPA) axis. However, the mechanisms by which endocannabinoids regulate HPA axis function have remained unclear. Here we demonstrate that mice lacking cannabinoid receptor type 1 (CB1-/-) display a significant dysregulation of the HPA axis. Although circadian HPA axis responsiveness is preserved, CB1-/- mice are characterized by an enhanced circadian drive on the HPA axis, resulting in elevated plasma corticosterone concentrations at the onset of the dark as compared with wild-type (CB1+/+) littermates. Moreover, CB1-/--derived pituitary cells respond with a significantly higher ACTH secretion to CRH and forskolin challenges as compared with pituitary cells derived from CB1+/+ mice. Both CBL-/- and CB1+/+ mice properly respond to a high-dose dexamethasone test, but response to low-dose dexamethasone is influenced by genotype. In addition, CB1-/- mice show increased CRH mRNA levels in the paraventricular nucleus of the hypothalamus but not in other extrahypothalamic areas, such as the amygdala and piriform cortex, in which CB1 and CRH mRNA have been colocalized. Finally, CB1-/- mice have selective glucocorticoid receptor mRNA down-regulation in the CA1 region of the hippocampus but not in the dentate gyrus or paraventricular nucleus. Conversely, mineralocorticoid receptor mRNA expression levels were found unchanged in these brain areas. In conclusion, our findings indicate that CB1 deficiency enhances the circadian HPA axis activity peak and leads to central impairment of glucocorticoid feedback, thus further outlining the essential role of the endocannabinoid system in the modulation of neuroendocrine functions.

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.

The Hypothalamic-Pituitary-Adrenal Axis Activity in Obesity and the Metabolic Syndrome

A hypothetical role of glucocorticoids in human obesity has been suggested since the abdominal obesity phenotype and syndromes of endogenous or exogenous hypercortisolism share several clinical, metabolic, and cardiovascular similarities. An emerging body of evidence indicates that both neuroendocrine dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis as well as peripheral alterations of cortisol metabolism may play a role in the pathophysiology of abdominal obesity. Major alterations of the HPA axis in vivo may be identified in different ways. They include evaluation of hormone concentrations: (a) in basal conditions, in blood, urine, or saliva samples; (b) during dynamic studies following stimulation with different neuropeptides or psychological stress challenges, or suppression with inhibiting agents of the HPA axis at different levels; and (c) after mixed meals or meals containing different nutrient compositions. In addition, alteration of peripheral cortisol metabolism can be detected by direct measurement of cortisol metabolites in urine, although this is a matter of more complex investigation. Alterations of the HPA axis in abdominal obesity are associated with insulin resistance, which suggests a direct responsibility of these hormonal alterations in the susceptibility of affected patients to develop both metabolic and cardiovascular diseases. According to available data, no single marker probably has the power to detect subtle alterations of the HPA axis in conditions, such as the abdominal obesity and the metabolic syndrome. On the contrary, they indicate the need for multiple parameters. At present, evaluation of urinary free cortisol, particularly during the night-time, and salivary-free cortisol appear to be promising for these purposes, whereas dynamic tests should be reserved for specific clinical settings, involving well-characterized patients.

Cannabinoid receptors as therapeutic targets for obesity and metabolic diseases

One of the most interesting pharmacological targets proposed in the past ten years for fighting obesity and related metabolic disorders is the endocannabinoid system. The role of the endocannabinoid system is crucial in regulating the rewarding properties of food, in controlling energy balance by acting at the hypothalamic circuitries involved in food intake, and in peripheral metabolism by influencing adipocytes, hepatocytes, myocytes and pancreatic endocrine cells. Obesity seems to be a condition associated with a pathological overactivation of the endocannabinoid system; therefore, restoring a normal endocannabinoid tone by antagonizing the cannabinoid receptor type 1 (CB(1)) could help arrest both the development and the maintenance of obesity.

Treatment with flutamide, metformin, and their combination added to a hypocaloric diet in overweight-obese women with polycystic ovary syndrome: a randomized, 12-month, placebo-controlled study

CONTEXT

The few controlled trials performed so far indicate that the addition of metformin and/or flutamide to a hypocaloric diet in obese women with polycystic ovary syndrome (PCOS) effectively influences different phenotypic aspects of the syndrome. All these studies are, however, characterized by a short to medium period of treatment.

OBJECTIVE

Our objective was to investigate the long-term effects of these therapies.

DESIGN AND SETTING

We conducted a prospective, randomized, placebo-controlled trial at a medical center.

PATIENTS

Of 80 overweight-obese women with PCOS, 76 completed the study.

INTERVENTIONS

Patients were placed on a hypocaloric diet for the first month and then on a hypocaloric diet plus placebo, metformin (850 mg, orally, twice a day), flutamide (250 mg, orally, twice a day), or metformin plus flutamide for the subsequent 12 months (20 subjects in each group).

MAIN OUTCOME MEASURES

We assessed clinical features, computerized tomography measurement of fat distribution, androgens, lipids, and fasting and glucose-stimulated glucose and insulin levels at baseline and after 6 and 12 months of treatment.

RESULTS

After 6 months, compared with placebo, flutamide further decreased visceral/sc fat mass (P = 0.044), androstenedione (P < 0.001), dehydroepiandrosterone sulfate (P < 0.001), and hirsutism score (P < 0.001), whereas metformin further increased frequency of menstruation (P = 0.039). After 12 months, flutamide maintained the effects observed after 6 months on visceral/sc fat mass (P = 0.033) and androstenedione (P < 0.001), whereas it produced an additional decrease in dehydroepiandrosterone sulfate (P = 0.020) and hirsutism score (P = 0.019); metformin further improved the menstrual pattern (P = 0.013). Moreover, after 12 months, flutamide improved more than placebo the menstrual pattern (P = 0.008), glucose-stimulated glucose levels (P = 0.041), insulin sensitivity (P < 0.001), and low-density lipoprotein cholesterol levels (P = 0.003), whereas metformin decreased glucose-stimulated insulin levels (P = 0.014). The combination of the two drugs maintained the specific effect of each of the compounds, without any additive or synergistic effect.

CONCLUSIONS

These findings add relevance to the usefulness of metformin and flutamide in the treatment of dieting overweight-obese PCOS women and provide a rationale for targeting different therapeutic options according to the required outcomes in the long term.

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.

Regulation, function, and dysregulation of endocannabinoids in models of adipose and beta-pancreatic cells and in obesity and hyperglycemia

CONTEXT

Cannabinoid CB(1) receptor blockade decreases weight and hyperinsulinemia in obese animals and humans in a way greatly independent from food intake.

OBJECTIVE

The objective of this study was to investigate the regulation and function of the endocannabinoid system in adipocytes and pancreatic beta-cells.

DESIGN, SETTING, AND PATIENTS

Mouse 3T3-F442A adipocytes and rat insulinoma RIN-m5F beta-cells, pancreas and fat from mice with diet-induced obesity, visceral and sc fat from patients with body mass index equal to or greater than 30 kg/m(2), and serum from normoglycemic and type 2 diabetes patients were studied.

MAIN OUTCOME MEASURE

Endocannabinoid enzyme and adipocyte protein expression, and endocannabinoid and insulin levels were measured.

RESULTS

Endocannabinoids are present in adipocytes with levels peaking before differentiation, and in RIN-m5F beta-cells, where they are under the negative control of insulin. Chronic treatment of adipocytes with insulin is accompanied by permanently elevated endocannabinoid signaling, whereas culturing of RIN-m5F beta-cells in high glucose transforms insulin down-regulation of endocannabinoid levels into up-regulation. Epididymal fat and pancreas from mice with diet-induced obesity contain higher endocannabinoid levels than lean mice. Patients with obesity or hyperglycemia caused by type 2 diabetes exhibit higher concentrations of endocannabinoids in visceral fat or serum, respectively, than the corresponding controls. CB(1) receptor stimulation increases lipid droplets and decreases adiponectin expression in adipocytes, and it increases intracellular calcium and insulin release in RIN-m5F beta-cells kept in high glucose.

CONCLUSIONS

Peripheral endocannabinoid overactivity might explain why CB(1) blockers cause weight-loss independent reduction of lipogenesis, of hypoadiponectinemia, and of hyperinsulinemia in obese animals and humans.

Metabolic effects of obesity on reproduction

Obese women are characterized by similar comorbidities to men, particularly type 2 diabetes mellitus and cardiovascular diseases. Moreover, they also develop some specific problems, including fertility-related disorders and some hormone-dependent forms of cancer. The relationship between excess body fat and reproductive disturbances appears to be stronger for early-onset obesity. Early onset of obesity, particularly during adolescence, favours the development of menses irregularities, chronic oligo-anovulation and infertility in adulthood. Moreover, obesity in women can increase the risk of miscarriage and impair the outcome of assisted reproductive technologies. The main factor implicated in the association between obesity and fertility-related disorders is insulin excess, which accompanies insulin resistance. Hyperinsulinaemia may be directly responsible for the development of androgen excess, through its effects in reducing sex hormone-binding globulin synthesis and circulating concentrations, and in stimulating ovarian androgen production rates. Androgen excess, in turn, represents one of the major factors leading to altered ovarian physiology and associated ovulatory disturbances. Obesity-associated hyperleptinaemia may represent an additional factor involved in anovulation, not only through the induction of insulin resistance, but also through a direct impairment of ovarian function.

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.