Testosterone supplementation and bone parameters: a systematic review and meta-analysis study.

BACKGROUND: The role of testosterone (T) replacement therapy (TRT) in subjects with late onset hypogonadism is still the object of an intense debate. METHODS: All observational studies and placebo-controlled or -uncontrolled randomized trials (RCTs) comparing the effect of TRT on different bone parameters were considered. RESULTS: Out of 349 articles, 36 were considered, including 3103 individuals with a mean trial duration of 66.6 weeks. TRT improves areal bone mineral density (aBMD) at the spine and femoral neck levels in observational studies, whereas placebo-controlled RTCs showed a positive effect of TRT only at lumber spine and when trials included only hypogonadal patients at baseline (total testosterone < 12 nM). The effects on aBMD were more evident in subjects with lower T levels at baseline and increased as a function of trial duration and a higher prevalence of diabetic subjects. Either T or estradiol increase at endpoint contributed to aBMD improvement. TRT was associated with a significant reduction of bone resorption markers in observational but not in controlled studies. CONCLUSION: TRT is able to inhibit bone resorption and increase bone mass, particularly at the lumbar spine level and when the duration is long enough to allow the anabolic effect of T and estrogens on bone metabolism to take place.

Changes in left ventricular repolarization after short-term testosterone replacement therapy in hypogonadal males.

BACKGROUND AND AIM: Evidences suggest that androgen deficiency is associated with sudden cardiac death (SCD). Our purpose was to analyse some electrocardiographic (ECG) markers of repolarization phase in hypogonadal patients either at baseline or after testosterone replacement therapy (TRT). PATIENTS AND METHODS: Baseline and after 6 months of testosterone replacement therapy, 14 hypogonadal patients and 10 age-matched controls underwent a short-term ECG recordings at rest and immediately after a maximal exercise test. The following ECG parameters have been collected: QTe (the interval between the q wave the end of T wave), QTp (the interval between the q wave and the peak of T wave), and Te (the interval between the peak and the end of T wave). RESULTS: At baseline, in the hypogonadal patients, corrected QTe and QTp values were longer at rest than in the controls at rest (p < 0.05), whereas, during the recovery phase, only the QTp remained significantly longer (p < 0.05). After TRT, hypogonadal patients showed an improvement only in Te (p < 0.05). Conversely, any difference between hypogonadal patients and control subjects was found with respect to the markers of temporal dispersion of repolarization phases, except for a worse QTp → Te coherence (p = 0.001) obtained during the recovery phase. CONCLUSIONS: In conclusion, at rest, hypogonadal patients suffer from a stable increase in the myocardial repolarization phase without an increase in its temporal dispersion and, hence, the SCD risk seems to be low.

Effects of daily tadalafil on lower urinary tract symptoms in young men with multiple sclerosis and erectile dysfunction: a pilot study.

PURPOSE: Men affected by multiple sclerosis often experience neurogenic overactive bladder (OAB), lower urinary tract symptoms and erectile dysfunction (ED). The aim of the study was to investigate modifications of urinary and sexual functions after administration of daily tadalafil (TAD) 5 mg. METHODS: Twenty men were enrolled in a single-blind, 4-week prospective study while 10 men without treatment served as controls. Primary outcomes were changes from baseline of International Prostate Symptom (IPSS), OAB questionnaire (OAB-q-short form) and International Index of Erectile Function (IIEF-5) scores. To evaluate the influence of bladder filling on somatic reflexes, we studied variations of the H-reflex evoked by electrical stimuli applied to the tibial nerve at the popliteal fossa and recorded from the soleus muscle. Also testosterone/estradiol (T/E) ratio was measured before and after treatment. RESULTS: In TAD group, an improvement in IPSS (p < 0.001), OAB-q (p < 0.001) and IIEF-5 (p < 0.001) scores was found. Also, an increase in Q max (p < 0.01) and T/E ratio (p < 0.01) was found with a concomitant reduction in post-void residual volume (p < 0.001) without any changes in the H-reflex. CONCLUSIONS: The study demonstrates for the first time that daily TAD in patients with multiple sclerosis improves storage symptoms, post-void residual volume, steroid hormone pattern and ED without urodynamic changes.

Persistence with denosumab therapy in women affected by osteoporosis with fragility fractures: a multicenter observational real practice study in Italy.

BACKGROUND: Persistence is commonly considered a key factor for the successful management of osteoporosis and fragility fractures. Denosumab is the first biologic agent developed for the treatment of osteoporosis with satisfying data regarding the persistence with this therapy. AIM: The purpose of this multicenter observational real practice study was to evaluate the persistence with denosumab treatment in post-menopausal women affected by osteoporosis. MATERIAL/SUBJECTS AND METHODS: Women were recruited in four specialized centers for the management of osteoporosis in North, Center and South of Italy. We included women with a diagnosis of post-menopausal osteoporosis, aged >50 years, able to obtain a prescription according to the Italian reimbursement criteria in force during the study period for anti-osteoporotic pharmacological treatment. They initiated a treatment with subcutaneous denosumab (Prolia®) 60 mg/every 6 months between November 2011 and May 2016. Women who had received aromatase inhibitors were excluded. Patients were assessed at baseline and every 6 months for all treatment length. Persistence data were evaluated for a total of 36 months. RESULTS: Eight hundred seventy women were enrolled; mean aged 70 years, with a mean body mass index of 24.8 ± 4.1 kg/m2. At the Dual-energy X-ray absorptiometry assessment, the mean lumbar spine T-score was -2.76 ± 1.14 standard deviations (SD) and the mean femoral neck T-score was -2.49 ± 0.80 SD. During the study, the total persistence was 91.4%. Total dropouts were 75 (8.6%), higher within the initial 6-month period of treatment. CONCLUSIONS: Persistence to denosumab treatment in our observational real practice study was very high. These results suggest that factors such as frequency of visits, pharmacological schedule, and opportunity to call the doctor might play an important role in the persistence and adherence to treatment to obtain maximum therapeutic effect and avoid further fragility fractures.

Acute endothelial response to testosterone gel administration in men with severe hypogonadism and its relationship to androgen receptor polymorphism: a pilot study.

PURPOSE: Testosterone (T) exerts different effects on the cardiovascular system. Despite this knowledge, the acute vascular effect of androgen remains still poorly understood. METHODS: We investigated the acute effects of T on vascular function in ten men (18-40 years age) with hypogonadism and severe hypotestosteronemia [serum total testosterone (TT) = 0.6 ± 0.3 ng/mL]. In a 4-day double-blind, randomized, placebo-controlled crossover study, we administered 80 mg daily dose of transdermal-T gel (TG) and evaluated endothelial variations with Endopat2000 (reactive hyperemia index, RHI and the augmentation index, AI); also, CAG repeat polymorphism in exon 1 of the androgen receptor gene was investigated. RESULTS: After TG administration, RHI significantly improved at 4 h (p < 0.05), while AI improvement was recorded at 4 and 96 h, also when adjusted for heart rate (AI@75; p < 0.01 and p < 0.001, respectively). Direct relationships between ΔT, ΔDHT and ΔRHI variations (r = 0.37, p < 0.01; r = 0.17, p < 0.05, respectively) as well as between "CAG repeats" length and ΔLnRHI at 96 h (p < 0.03, r (2) = 0.47) were found. An inverse relationship between ΔT and ΔAI (p < 0.01, r = -0.35) and ΔAI@75 (p < 0.01, r = -0.38) were found. CONCLUSION: Administration of TG causes an acute vasodilation and improves arterial stiffness probably due to non-genomic actions of T. Endothelial vasodilatory response was more pronounced depending on higher plasma TT and DHT levels attained. Clinical implications in elderly frail populations are discussed.

Tadalafil modulates aromatase activity and androgen receptor expression in a human osteoblastic cell in vitro model.

PURPOSE: Phosphodiesterase type-5 inhibitor (PDE5i) tadalafil administration in men with erectile dysfunction is associated with increased testosterone/estradiol ratio, leading to hypothesize a potential increased effect of androgen action on target tissues. We aimed to characterize, in a cellular model system in vitro, the potential modulation of aromatase and sex steroid hormone receptors upon exposure to tadalafil (TAD). METHODS: Human osteoblast-like cells SAOS-2 were chosen as an in vitro model system since osteoblasts are target of steroid hormones. Cells were tested for viability upon TAD exposure, which increased cell proliferation. Then, cells were treated with/without TAD for several times to evaluate potential modulation in PDE5, aromatase (ARO), androgen (AR) and estrogen (ER) receptor expression. RESULTS: Osteoblasts express significant levels of both PDE5 mRNA and protein. Exposure of cells to increasing concentrations of TAD (10(-8)-10(-7) M) decreased PDE5 mRNA and protein expression. Also, TAD inhibited ARO mRNA and protein expression leading to an increase in testosterone levels in the supernatants. Interestingly, TAD increased total AR mRNA and protein expression and decreased ERα, with an increased ratio of AR/ER, suggesting preferential androgenic vs estrogenic pathway activation. CONCLUSIONS: Our results demonstrate for the first time that TAD decreases ARO expression and increases AR protein expression in human SAOS-2, strongly suggesting a new control of steroid hormones pathway by PDE5i. These findings might represent the first evidence of translational actions of PDE5i on AR, which leads to hypothesize a growing relevance of this molecule in men with prostate cancer long-term treated with TAD for sexual rehabilitation.

Lean mass in obese adult subjects correlates with higher levels of vitamin D, insulin sensitivity and lower inflammation.

AIM: Several chronic metabolic alterations are present in obese subjects. While it is well known about the detrimental effect of abdominal adipose tissue on chronic metabolic clinical condition, less is known on the role of lean mass in obese subjects. Thus, the aim of our study was to evaluate the potential correlation of muscle mass, metabolic condition and inflammation status in obese individuals. METHODS: The study included 426 obese subjects (86 men and 340 female; mean age 44.8 ± 14 years; BMI: 34.9 ± 6.1 kg/m(2)). Exclusion criteria were chronic medical conditions or use of medications affecting bone metabolism, alterations of hormonal and nutritional status, vitamin D supplementation, recent weight loss and prior bariatric surgery. Patients underwent measurements of bone mineral density (lumbar and hip) and body composition (lean mass, total and trunk fat mass) by dual X-ray absorptiometry and were evaluated for hormonal and metabolic profile and inflammatory markers. RESULTS: Higher lean body mass (LM%) was inversely correlated with homeostasis model assessment of insulin resistance (p < 0.0091; r(2) 0.03938) and associated with lower fibrinogen levels (p < 0.0001; r(2) 0.1263). Interestingly, in obese subjects, LM% was associated with higher levels of vitamin D (p < 0.0001, r(2) 0.1140), osteocalcin (p < 0.0001, r(2) 0.2401) and insulin-like growth factor-1 (IGF-1) (p < 0.0002, r(2) 0.1367). CONCLUSION: Our results show for the first time that in obese patients, higher amounts of lean mass are directly linked to a lower inflammatory profile and to better insulin sensitivity, but also to the presence of higher level of vitamin D and IGF-1. Moreover, these data suggest that higher levels of lean mass in obese people correlate with a better metabolic profile and, thus, strongly suggest the need to develop programs to facilitate an increase in physical activity in obese people.

Effects of testosterone undecanoate replacement and withdrawal on cardio-metabolic, hormonal and body composition outcomes in severely obese hypogonadal men: a pilot study.

PURPOSE: Modifications of cardiovascular and metabolic parameters during testosterone (T) replacement and withdrawal have never been investigated in severely obese hypogonadal men. METHODS: Twenty-four severely obese (mean BMI 42; mean age 54.5) hypogonadal men (mean T = 245 ± 52 ng/dL) were enrolled in an observational, parallel-arm, open-label, 54-week study of hypocaloric diet plus physical activity (DPE; n = 12) or DPE plus T injections (DPE + T; n = 12), followed by 24 weeks of DPE alone. Primary endpoints were variations from baseline of cardiovascular (cardiac performance, blood pressure, endothelial function, carotid intima-media thickness, CIMT; epicardial fat thickness, EF) and body composition (fat/lean mass) parameters. Secondary endpoints were variations from baseline of hormonal (T and GH) and metabolic (oral glucose tolerance test, lipids, fibrinogen) parameters. RESULTS: At 54 weeks, DPE + T showed improvements in EF, ejection fraction, diastolic function, CIMT and endothelial function (p < 0.01 vs. controls). Also, hormonal (T, p < 0.0001; GH, p < 0.01), metabolic (HOMA, p < 0.01; microalbuminuria, p < 0.01), lipid (total cholesterol, p < 0.05) and inflammatory (fibrinogen, p < 0.05) parameters improved. After 24 weeks from T withdrawal, all cardiac and hormonal parameters returned to baseline, while fat but not lean mass and blood pressure ameliorations were maintained. An inverse relationship either between EF vs. endothelial function and EF vs. T levels was found (r (2) = -0.46, p < 0.001 and r (2) = -0.56, p < 0.0005, respectively) while direct relationship between T vs. endothelial function occurred (r (2) = 0.43, p < 0.005) in DPE + T. A 33 % dropout rate was reported in DPE without serious adverse events. CONCLUSIONS: In middle-aged hypogonadal obese men, 1-year T treatment was safe and improved cardio-metabolic and hormonal parameters. We firstly demonstrated that T withdrawal determines a return back to hypogonadism within 6 months, with loss of cardiovascular and some body composition improvements attained.

The application of digital pulse amplitude tonometry to the diagnostic investigation of endothelial dysfunction in men with erectile dysfunction.

The application of digital pulse amplitude by fingertip peripheral arterial tonometry (PAT) device in patients with erectile dysfunction (ED) has never been performed. We investigated the diagnostic value of reactive hyperaemia (RH) and augmentation index (AI) as evaluated using PAT in men with ED of any origin. A total of 40 patients underwent diagnostic investigation for ED, including dynamic penile duplex ultrasound (PDU) and PAT device. Moreover, 30 patients without ED served as controls. According to PDU cutoff at 35 cm/sec, patients were divided into vascular (n = 30) and nonvascular (n = 10) ED aetiology. Moreover, controls with (n = 10) or without (n = 20) vascular risk factors (VRFs) were studied in a separate analysis. Average RH-PAT was not different in men with or without ED (P = 0.56) independently of VRFs. The AI was higher in men with ED compared with the controls (P < 0.0001) as well as when controlled for the presence or absence of VRFs (P < 0.0001). An inverse relationship between AI and PSV was also found (r² = -0.72, P < 0.0001). In conclusion, an increased AI but not an impaired RH-PAT is present in men with vascular ED independently of VRFs and may represent an early detection of vascular impairment that may precede endothelial dysfunction in populations at low risk for developing vascular ED.

Efficacy and safety of two different testosterone undecanoate formulations in hypogonadal men with metabolic syndrome.

AIM: To investigate efficacy and safety of two different preparations of testosterone undecanoate (TU) in 52 hypogonadal men [mean age 57 yr and mean testosterone (T) < 320 ng/dl] with metabolic syndrome (MS). SUBJECTS AND METHODS: Randomized, double-blind, double-dummy study with three parallel treatment arms [oral TU; transdermal placebo gel (P); im TU] administration for 12 months (mo). Each subject was randomized (1:1:3) to receive either oral TU (2 capsules of 40 mg/twice per day at breakfast and dinner, equalling a total dose of 160 mg/day; no.=10) for 6 mo and continued with im TU for further 6 mo, or P (3-4 g/day; no.=10) and im TU (1000 mg/12 weeks from week 6; no.=32) for 12 mo. RESULTS: After 6 mo, im TU increased T and free- T levels (p<0.0001), and improved metabolic parameters [reduction in Homeostasis Model Assessment (HOMA) index, p<0.0001; waist circumference and fat mass, p<0.001, respectively], in International Index of Erectile Function-5 and Aging Males' Symptoms scores (p<0.01, respectively). After 12 months, im TU produced further increases in T and free- T levels (p<0.0001) and metabolic parameters (reduction in HOMA-index, p<0.0001; waist circumference p<0.0001; fat mass, p<0.001). No major adverse event due to T treatment occurred. CONCLUSIONS: Clinical efficacy of T replacement therapy in hypogonadal men with MS is reached when its plasmatic levels approach into the medium-high range of normality (>5 ng/ml), although subjective threshold values may be different. Administration of im TU was more effective than oral TU to reach the target for T levels and to improve MS parameters. TU was safe over 12 months and discontinuation rates were similar to placebo.

Safety and Efficacy of a New Swallowable Intragastric Balloon Not Needing Endoscopy: Early Italian Experience.

PURPOSE: The aim of this study was to evaluate the safety and efficacy of a new intragastric balloon (Elipse™ Balloon, Allurion Technologies, Natick, MA USA) not needing endoscopy. MATERIALS AND METHODS: The balloon was swallowed under fluoroscopy in 38 consecutive patients (F/M 28/10, mean age 46.4 ± 10.6 years, mean weight 109.7 ± 21.9 kg, and mean body mass index (BMI) 38.6 ± 6.7 kg/m2). After 4 months, the balloon spontaneously emptied and it was excreted through the digestive tract without upper endoscopy. RESULTS: There were no complications during balloon passage. After 16 weeks, the mean weight loss was 12.7 kg, mean percent excess weight loss was 26%, and mean BMI reduction was 4.2 kg/m2. Total body weight loss was 11.6%. There was a significant reduction in major co-morbidities related to metabolic syndrome: blood pressure (p < 0.02), waist circumference (p < 0.002), triglycerides (p < 0.0001), blood glucose (p < 0.001), and HOMA-IR index (p < 0.001). At the end of the treatment, 37 balloons were naturally excreted in the stool, and one balloon was endoscopically removed. CONCLUSIONS: The results of this study on 38 consecutive patients demonstrate that the Elipse™ Balloon is safe, effective, and very well accepted by patients.

The effect on clinical results of adding recombinant LH in late phase of ovarian stimulation of patients with repeated implantation failure: a pilot study.

OBJECTIVE: To evaluate the efficacy of recombinant LH (r-LH) addition in the late phase of ovarian stimulation in patients with repeated implantation failure (RIF). PATIENTS AND METHODS: 66 infertile couples undergoing ICSI treatment due to male factor were allocated to group A (33) and to group B (33). Group A (29 subjects) received recombinant FSH (r-FSH) supplemented by r-LH in the late follicular phase starting the same day of GnRH-antagonist (GnRH-ant) administration, and group B (32 subjects) received r-FSH alone. All patients were stimulated with a GnRH-ant flexible protocol starting r-FSH on day 2 of a spontaneous or induced cycle. hCG (10000 IU) was administered by intramuscular route when at least 2 follicles reached 18 mm in diameter. RESULTS: Metaphase II (MII) oocytes with cytoplasmic maturation showed a significant difference in the r-LH group (89.02%) compared to the one with FSH alone (81.15%) (p < 0.01). The number of positive pregnancy test, 14 (48.3%) and 8 (25%), was significantly greater in the r-LH group compared to the group treated with r-FSH alone (p < 0.03). The number of gestational sacs was 20 in the r-LH group vs. 9 in the r-FSH group (p < 0.001). The implantation rate was significantly higher in the r-LH group compared to the r-FSH only group (19% vs. 7% respectively; p < 0.01). Also, a lower abortion rate was found in the r-LH group (21% vs. 37.5% respectively - p < 0.01). CONCLUSIONS: Ovarian stimulation should be personalized because it seems that some subgroups of patients, like those with RIF, reach a better clinical outcome with the addition of r-LH in the advanced follicular phase stimulation.

A pilot study to evaluate the effects of vardenafil on sexual distress in men with obesity.

There are no interventional studies on the impact of sexual distress (SD) in men with obesity. We investigated the effects of vardenafil (VAR) on SD in middle-aged (mean age 49 ± 8), healthy, obese men in the absence of premature ejaculation, ED or hypogonadism. After a 4-week run-in period, 20 men with high body mass index (BMI=40 ± 8) and SD at the Sexual Distress Esteem Questionnaire-Male (mean score 65 ± 20 AU) were randomized to receive either VAR 10 mg on demand (N=10) or matched-placebo (PLB, N=10). Primary endpoints were variations from baseline in the intravaginal ejaculatory latency time (IELT) measured by the stopwatch technique; secondary endpoints were variations from baseline in Self-Esteem and Relationship (SEAR) and Male Sexual Health Questionnaire-Ejaculatory domain (MSHQ-EjD) scores. VAR significantly improved IELT (P<0.0001), as well as SEAR (P<0.001) and MSHQ-EjD (P<0.005) scores, whereas no changes were observed after PLB. Interestingly, an inverse relationship between BMI and IELT was found in all the men studied (r(2)=0.37, P<0.001). SD in healthy obese men seems to be correlated mainly with inadequate ejaculatory control, especially in men with higher BMI. Our preliminary results suggest that treatment with VAR may improve ejaculatory control, thus ameliorating self-esteem and sexual performance in men with obesity.

Is there a role for phosphodiesterase type-5 inhibitors in the treatment of premature ejaculation?

Premature ejaculation (PE) is considered to be the most common male sexual dysfunction. The realization that PE may co-exist with ED prompted the use of PDE5-i's alone or in combination with selective serotonin reuptake inhibitors (SSRIs) for treating ejaculatory disorders. Until recently, there was little evidence that PDE5-i's alone may have a role in the treatment of PE in the absence of ED, and current available treatments include only on-demand dapoxetine. However, available data indicate that there is clinical, anatomical, physiological, pharmacological and genetic evidence to explain the efficacy of PDE5-i's. Nine manuscripts that examined the efficacy of PDE5-i's in the treatment of PE, alone or in combination with SSRIs, were retrieved. All studies reported some significant changes in the intravaginal ejaculatory latency time and sexual satisfaction scores, although not all were clinically meaningful. Well-designed multicenter studies are urgently required to further elucidate the efficacy and safety, as well as the mechanisms of action of PDE5-i's in the treatment of PE. The aim of this review is to discuss basic rationale and to show clinical evidence sustaining the possibility to use off-label PDE5-i's to treat PE.

Effects of vardenafil administration on intravaginal ejaculatory latency time in men with lifelong premature ejaculation.

Premature ejaculation (PE) is thought to be the most common male sexual dysfunction; however, the prevalence of lifelong (LL)-PE is relatively low. The aim of this study was to investigate the effects of on-demand vardenafil (10 mg) to modify the intravaginal ejaculatory latency time (IELT) in men with LL-PE without erectile dysfunction. Forty-two men (18-35 years) were enrolled in a 16-week, double-blind, placebo-controlled, cross-over study. Primary end point was the modification from baseline of IELT assessed by stopwatch technique; secondary end points were post-ejaculatory refractory time (PERT) and variations of scores at the Index of Premature Ejaculation questionnaire. The changes in geometric mean IELT were superior after taking vardenafil (0.6+/-0.3 vs 4.5+/-1.1 min, P<0.01), compared with placebo (0.7+/-0.3 vs 0.9+/-1.0 min, ns). PERT dropped significantly after vardenafil (16.7+/-2.0 vs 4.3+/-0.9 min, P<0.001), compared with placebo (15.3+/-2.2 vs 15.8+/-2.3 min). Patients who took vardenafil (vs placebo) reported significantly (P<0.01) increased ejaculatory control (6+/-2 vs 16+/-2), improved overall sexual satisfaction (7+/-2 vs 15+/-1) and distress (4+/-1 vs 8+/-1) scores, respectively. Multiple regression analysis (r(2)=0.86) for IELT by the number of attempts at sexual intercourse showed significant differences between the slopes of lines for placebo and vardenafil (P<0.0001). The most common adverse events for vardenafil (vs placebo) were headache (10 vs 3%), flushing (12 vs 0%) and dyspepsia (10 vs 0%), which tended to disappear over the time. In conclusion, in our study, vardenafil increased IELT and reduced PERT in men with LL-PE. Besides, improvements in confidence, perception of ejaculatory control and overall sexual satisfaction were reported.

Early endothelial dysfunction as a marker of vasculogenic erectile dysfunction in young habitual cannabis users.

Aim of the study was to evaluate whether endothelial dysfunction is a marker of erectile dysfunction (ED) in recreational drug abuse. Sixty-four non-consecutive men complaining of ED from at least 3 months were included. All patients underwent detailed history about recreational drug abuse and were then submitted to dynamic penile duplex ultrasound (PDU). According to pharmaco-stimulated peak systolic velocity (PSV) cutoff at 35 cm s(-1), patients were divided into two groups: organic (O; n=30) and non-organic (NO; n=34) ED. All subjects and 7 healthy age-matched subjects as controls, underwent veno-occlusive plethysmography (VOP) for the evaluation of endothelium-dependent dilatation of brachial arteries. Blood pressure, total and free testosterone, prolactin, estradiol, low-density lipoprotein and high-density lipoprotein cholesterol were also evaluated; patients were classified with regard to insulin resistance through the HOMA-IR index. Cannabis smoking was more frequent in O-ED vs NO-ED (78% vs 3%, P<0.001) in the absence of any concomitant risk factor or comorbidity for ED. VOP studies revealed impaired endothelium-dependent vasodilatation in O-ED but not in NO-ED and controls (12+/-6 vs 32+/-4 and 34+/-5 ml min(-1), respectively; P=0.003). Overall patients showed a direct relationship between HOMA-IR and PSV (r(2)=0.47, P<0.0001), which was maintained in men with organic ED (r(2)=0.62, P<0.0001). In cannabis consumers, a direct relationship between HOMA-IR and VOP was also found (r(2)=0.74, P<0.0001). Receiver-operating characteristic (ROC) curve analysis revealed that VOP values below 17.22 ml min(-1) were suggestive for vasculogenic ED. We conclude that early endothelial damage may be induced by chronic cannabis use (and endocannabinoid system activation); insulin resistance may be the hallmark of early endothelial dysfunction and may concur to determine vascular ED in the absence of obesity. Further studies are warranted to establish a direct relationship between cannabis abuse, onset of insulin resistance and development of vascular ED.