Cerebrospinal fluid and blood neurofilament light chain levels in amyotrophic lateral sclerosis and frontotemporal degeneration: A meta-analysis.

BACKGROUND AND PURPOSE: Neurofilament light chain (NFL) has been shown to be increased in amyotrophic lateral sclerosis (ALS) and, to a lesser extent, in frontotemporal dementia (FTD). A meta-analysis of NFL in ALS and FTD was performed. METHODS: Available studies comparing cerebrospinal fluid and blood NFL levels in ALS versus neurologically healthy controls (NHCs), other neurological diseases (ONDs) and ALS mimics, as well as in FTD and related entities (behavioural variant of FTD and frontotemporal lobar degeneration syndromes) versus NHCs, ONDs and other dementias were evaluated. RESULTS: In ALS, both cerebrospinal fluid and blood levels of NFL were higher compared to other categories. In FTD, behavioural variant of FTD and frontotemporal lobar degeneration syndromes, NFL levels were consistently higher compared to NHCs; however, several comparisons with ONDs and other dementias did not demonstrate significant differences. DISCUSSION: Amyotrophic lateral sclerosis is characterized by higher NFL levels compared to most other conditions. In contrast, NFL is not as good at discriminating FTD from other dementias.

Interventions aimed to increase average 24-h systolic blood pressure reduce blood pressure drops in patients with reflex syncope and orthostatic intolerance.

AIMS: Systolic blood pressure (SBP) drops recorded by 24-h ambulatory blood pressure (BP) monitoring (ABPM) identify patients with susceptibility to reflex syncope and orthostatic intolerance. We tested the hypothesis that treatments aimed to increase BP (reassurance, education, and lifestyle measures plus pharmacological strategies) can reduce SBP drops. METHODS AND RESULTS: This was a multicentre, observational proof-of-concept study performed in patients with reflex syncope and/or orthostatic intolerance and with SBP drops on a screening ABPM. Among 144 eligible patients, 111 underwent a second ABPM on average 2.5 months after start of treatment. Overall, mean 24-h SBP increased from 114.1 ± 12.1 to 121.4 ± 14.5 mmHg (P < 0.0001). The number of SBP drops <90 and <100 mmHg decreased by 61%, 46% during daytime, and by 48% and 37% during 24-h period, respectively (P < 0.0001 for all). The dose-response relationship between difference in 24-h average SBP increase and reduction in number of SBP drops reached a plateau around ∼15 mmHg increase of 24-h SBP. The reduction in SBP drop rate was consistent and significant in patients who underwent deprescription of hypotensive medications (n = 44) and in patients who received BP-rising drugs (n = 67). CONCLUSION: In patients with reflex syncope and/or orthostatic intolerance, an increase in average 24-h SBP, regardless of the implemented strategy, significantly reduced the number of SBP drops and symptom burden. A 13 mmHg increase in 24-h SBP appears to represent the optimal goal for aborting the maximal number of SBP drops, representing a possible target for future interventions. ClincalTrials.gov identifier: NCT05729724.

Phase angle (PhA) in overweight and obesity: evidence of applicability from diagnosis to weight changes in obesity treatment.

Phase angle (PhA) is a recently proposed marker of nutritional status in many clinical conditions. Its use in patients with obesity presents different critical concerns due to the higher variability of the two measured parameters (resistance, R, and reactance, Xc) that contribute to the determination of PhA. Controversial is the relation between PhA and BMI that might vary with graded levels of obesity due to the variation in fat and free fat mass. Obesity is frequently associated with metabolic, hepatic, cardiovascular and kidney diseases that introduce variations in PhA values, in relation to multimorbidity and severity degree of these diseases. It is reported that the improvement of clinical condition is associated with a positive change in PhA. Also, the treatment of obesity with weight loss might confirm this effect, but with different responses in relation to the type and duration of the intervention applied. In fact, the effect appears not only related to the percentage of weight loss but also the possible loss of free fat mass and the nutritional, metabolic and structural modifications that might follow each therapeutic approach to decrease body weight. We can conclude that the PhA could be used as marker of health status in patients with obesity supporting an appropriate weight loss intervention to monitor efficacy and fat free mass preservation.

Association between hypotension during 24†h ambulatory blood pressure monitoring and reflex syncope: the SynABPM 1 study.

AIMS: Diagnostic criteria for ambulatory blood pressure monitoring (ABPM) in patients with suspected reflex syncope are lacking. The study hypothesis was that patients with reflex syncope have a higher prevalence of systolic blood pressure (SBP) drops on ABPM. METHODS AND RESULTS: ABPM data from reflex syncope patients and controls, matched by average 24 h SBP, age, sex, and hypertension were compared. Patients with constitutional hypotension, orthostatic hypotension, and predominant cardioinhibition during carotid sinus massage or prolonged electrocardiogram monitoring or competing causes of syncope were excluded. Daytime and nighttime SBP drops (<110, 100, 90, 80 mmHg) were assessed. Findings were validated in an independent sample. In the derivation sample, daytime SBP drops were significantly more common in 158 syncope patients than 329 controls. One or more daytime drops <90 mmHg achieved 91% specificity and 32% sensitivity [odds ratio (OR) 4.6, P < 0.001]. Two or more daytime drops <100 mmHg achieved 84% specificity and 40% sensitivity (OR 3.5, P = 0.001). Results were confirmed in the validation sample of 164 syncope patients and 164 controls: one or more daytime SBP drops <90 mmHg achieved 94% specificity and 29% sensitivity (OR 6.2, P < 0.001), while two or more daytime SBP drops <100 mmHg achieved 83% specificity and 35% sensitivity (OR 2.6, P < 0.001). CONCLUSION: SBP drops during ABPM are more common in reflex syncope patients than in controls. Cut-off values that may be applied in clinical practice are defined. This study expands the current indications for ABPM to patients with reflex syncope.

Algorithm of the major and minor diagnostic criteria for active myopic choroidal neovascularization.

PURPOSE: To propose an algorithm of the major and minor diagnostic criteria for macular myopic choroidal neovascularization (mCNV). METHODS: This single-center, retrospective, cross-sectional study was based in Istituto Auxologico Italiano, Milan, Italy. Two authors evaluated the clinical and imaging parameters of eyes with high myopia (spherical equivalent of -6D or less) and suspected to have naïve, recurrent, or inactive mCNV. Recordings of the eyes that met the inclusion criteria were then independently evaluated by two other senior retinal specialists. Fluorescein angiography (FA), spectral domain optical coherence tomography (SD-OCT), and OCT angiography were used for multimodal imaging. RESULTS: One-hundred and twenty-two eyes (n = 107; 39 men, 68 women) were included in the study. The mean patient age was 66 years (range, 22-89 years). There were 83 and 39 eyes in the active mCNV and control groups, respectively. The best diagnostic algorithm had positive- and negative-predictive values of 89% and 85%, respectively, and was based on four criteria: leakage/staining on FA, retinal thickening, fuzzy area on SD-OCT, and recent metamorphopsia. When excluding FA-derived findings, retinal pigment epithelium (RPE) features played a diagnostic role in 33 eyes (27%). Twenty-seven eyes with active mCNV (32%) did not have the fuzzy area. Taken singularly, no clinical or imaging parameter had both sensitivity and specificity greater than 78%. Matching of 2 or 3 biomarkers did not yield a sensitivity or specificity greater than 79%. Sensitivities and specificities ≥ 90% were found in ten criteria combinations that included four to five biomarkers. The most frequent were metamorphopsia, fuzzy area, retinal thickening, and leakage. Less frequently, they included hemorrhage, staining, and RPE features such as elevation, flattening, and focal interruption. For all the parameters, the agreement between the investigators was good (Cohen k ≥ 0.66), being the lowest when detecting the ELM interruption within the lesion. CONCLUSIONS: A combination of at least four clinical and biological markers yielded the highest positive- and negative-predictive values. More ("major") and less ("minor") frequent diagnostic criteria are proposed.

AV junction ablation and cardiac resynchronization for patients with permanent atrial fibrillation and narrow QRS: the APAF-CRT mortality trial.

AIMS: In patients with atrial fibrillation (AF) and heart failure (HF), strict and regular rate control with atrioventricular junction ablation and biventricular pacemaker (Ablation + CRT) has been shown to be superior to pharmacological rate control in reducing HF hospitalizations. However, whether it also improves survival is unknown. METHODS AND RESULTS: In this international, open-label, blinded outcome trial, we randomly assigned patients with severely symptomatic permanent AF >6 months, narrow QRS (≤110 ms) and at least one HF hospitalization in the previous year to Ablation + CRT or to pharmacological rate control. We hypothesized that Ablation + CRT is superior in reducing the primary endpoint of all-cause mortality. A total of 133 patients were randomized. The mean age was 73 ± 10 years, and 62 (47%) were females. The trial was stopped for efficacy at interim analysis after a median of 29 months of follow-up per patient. The primary endpoint occurred in 7 patients (11%) in the Ablation + CRT arm and in 20 patients (29%) in the Drug arm [hazard ratio (HR) 0.26, 95% confidence interval (CI) 0.10-0.65; P = 0.004]. The estimated death rates at 2 years were 5% and 21%, respectively; at 4 years, 14% and 41%. The benefit of Ablation + CRT of all-cause mortality was similar in patients with ejection fraction (EF) ≤35% and in those with >35%. The secondary endpoint combining all-cause mortality or HF hospitalization was significantly lower in the Ablation + CRT arm [18 (29%) vs. 36 (51%); HR 0.40, 95% CI 0.22-0.73; P = 0.002]. CONCLUSIONS: Ablation + CRT was superior to pharmacological therapy in reducing mortality in patients with permanent AF and narrow QRS who were hospitalized for HF, irrespective of their baseline EF. STUDY REGISTRATION: ClinicalTrials.gov Identifier: NCT02137187.

Clinical benefits of sex steroids given as a priming prior to GH provocative test or as a growth-promoting therapy in peripubertal growth delays: Results of a retrospective study among ENDO-ERN centres.

OBJECTIVES: Sex steroids, administered as a priming before GH stimulation tests (GHST) to differentiate between growth hormone deficiency (GHD) and constitutional delay of growth and puberty (CDGP) or as growth-promoting therapy using low-dose sex steroids (LDSS) in CDGP, are much debated. We aimed to compare auxological outcomes of CDGP or GHD children undergoing primed or unprimed GHST and to evaluate LDSS treatment in CDGP. DESIGN: Retrospective study among three paediatric University Hospitals in Italy and UK. METHODS: 184 children (72 females) aged 12.4 ± 2.08 years underwent primed (/P+ ) or unprimed (/P- ) GHST and were followed up until final height (FH). CDGP patients were untreated (CDG P- ) or received LDSS (CDGP+ ). The cohort included 34 CDG P- /P+ , 12 CDGP+ /P+ , 51 GHD/P+ , 29 CDG P- /P- , 2 CDGP+ /P- and 56 GHD/P- . FH standard deviation score (SDS), Δ SDS FH-target height (TH) and degree of success (-1 ≤ Δ SDS FH-SDS TH ≤ +1) were outcomes of interest. RESULTS: GHD/P+ had better FH-SDS (-0.87 vs -1.49; P = .023) and ΔSDS FH-TH (-0.35 vs -0.77; P = .002) than CDGP- /P+ . Overall, GHD/P+ showed the highest degree of success (90%, P = .006). Regardless of priming, both rhGH and LDSS improved degree of success compared to no treatment (89% and 86% vs 63%, P = .0009). GHD/P+ showed a trend towards a higher proportion of permanent GHD compared to GHD/P- (30.43% vs 15.09%; P = .067). CONCLUSION: In peripubertal children, priming before GHST improves diagnostic accuracy of GHST for idiopathic GHD. LDSS treatment improves auxological outcomes in CDGP.

Association between renin-angiotensin-aldosterone system inhibitors and risk of dementia: A meta-analysis.

OBJECTIVE: To evaluate the association of all RAAS inhibitors, ACE inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) on dementia onset (any dementia, Alzheimer's disease and vascular dementia) using a meta-analytic approach. METHODS: A systematic MEDLINE search was carried out to identify all observational studies published up to the 30th September 2020 evaluating the association between RAAS inhibitors and risk of dementia. Studies were included if original investigations considering incident dementia cases, with ACEIs and/or ARBs as exposure and other antihypertensives (AHs) use as reference, and if reporting association estimates and relative variability measures. Random effect pooled relative risks (pRR) and the corresponding 95% confidence intervals (95%CI) were calculated according to DerSimonian and Laird's (DL) or to Hartung Knapp Sidik Jonkman (HKSJ) method depending on the number of studies and between-studies heterogeneity. A linear mixed meta-regression model (MM) was applied to take into account correlation among association estimates from the same study. RESULTS: 15 studies were included in the meta-analysis. ARBs but not ACEIs' use led to a significant reduction of the risk of any dementia (pRR 0.78, 95%CIMM 0.70-0.87) and Alzheimer's disease (pRR 0.73, 95%CIMM 0.60-0.90). Moreover, when compared to ACEIs, ARBs reduced of 14% the risk of any dementia (pRR 0.86, 95%CIDL 0.79-0.94). CONCLUSIONS: ARBs but not ACEIs led to a reduction in the risk of any dementia. The difference between ARBs and ACEIs in terms of preventive effectiveness could be due to distinct profiles of antagonism towards independent receptor pathways or to differential influences on amyloid metabolism.

Vitamin D and COVID-19 severity and related mortality: a prospective study in Italy.

BACKGROUND: Vitamin D deficiency has been suggested to favor a poorer outcome of Coronavirus disease-19 (COVID-19). We aimed to assess if 25-hydroxyvitamin-D (25OHD) levels are associated with interleukin 6 (IL-6) levels and with disease severity and mortality in COVID-19. METHODS: We prospectively studied 103 in-patients admitted to a Northern-Italian hospital (age 66.1 ± 14.1 years, 70 males) for severely-symptomatic COVID-19. Fifty-two subjects with SARS-CoV-2 infection but mild COVID-19 symptoms (mildly-symptomatic COVID-19 patients) and 206 subjects without SARS-CoV-2 infection were controls. We measured 25OHD and IL-6 levels at admission and focused on respiratory outcome during hospitalization. RESULTS: Severely-symptomatic COVID-19 patients had lower 25OHD levels (18.2 ± 11.4 ng/mL) than mildly-symptomatic COVID-19 patients and non-SARS-CoV-2-infected controls (30.3 ± 8.5 ng/mL and 25.4 ± 9.4 ng/mL, respectively, p < 0.0001 for both comparisons). 25OHD and IL-6 levels were respectively lower and higher in severely-symptomatic COVID-19 patients admitted to intensive care Unit [(ICU), 14.4 ± 8.6 ng/mL and 43.0 (19.0-56.0) pg/mL, respectively], than in those not requiring ICU admission [22.4 ± 1.4 ng/mL, p = 0.0001 and 16.0 (8.0-32.0) pg/mL, p = 0.0002, respectively]. Similar differences were found when comparing COVID-19 patients who died in hospital [13.2 ± 6.4 ng/mL and 45.0 (28.0-99.0) pg/mL] with survivors [19.3 ± 12.0 ng/mL, p = 0.035 and 21.0 (10.5-45.9) pg/mL, p = 0.018, respectively). 25OHD levels inversely correlated with: i) IL-6 levels (ρ - 0.284, p = 0.004); ii) the subsequent need of the ICU admission [relative risk, RR 0.99, 95% confidence interval (95%CI) 0.98-1.00, p = 0.011] regardless of age, gender, presence of at least 1 comorbidity among obesity, diabetes, arterial hypertension, creatinine, IL-6 and lactate dehydrogenase levels, neutrophil cells, lymphocytes and platelets count; iii) mortality (RR 0.97, 95%CI, 0.95-0.99, p = 0.011) regardless of age, gender, presence of diabetes, IL-6 and C-reactive protein and lactate dehydrogenase levels, neutrophil cells, lymphocytes and platelets count. CONCLUSION: In our COVID-19 patients, low 25OHD levels were inversely correlated with high IL-6 levels and were independent predictors of COVID-19 severity and mortality.

When to Suspect Hidden Hypercortisolism in Type 2 Diabetes: A Meta-Analysis.

OBJECTIVE: To investigate whether the available literature helps to identify the characteristics of patients with type 2 diabetes (T2D) more frequently associated with hidden hypercortisolism (HidHyCo). METHODS: A meta-analysis was performed using studies that assessed both the prevalence of HidHyCo in patients with T2D and the characteristics of these patients with and without HidHyCo. The DerSimonian and Laird (DSL) and Hartung-Knapp-Sidik-Jonkman (HKSJ) methods were utilized. RESULTS: Among the 18 available studies, 6 provided the necessary data. The association between HidHyCo and advanced T2D (based on the patients' description given in each study in the presence of microvascular/macrovascular complications or insulin treatment plus hypertension or hypertension treated with 2 or more drugs), hypertension, insulin treatment, and dyslipidemia was reported in 5 (2184 patients), 6 (2283 patients), 3 (1440 patients), and 3 (987 patients) studies, respectively. HidHyCo was associated with advanced T2D as assessed by both the DSL (odds ratio [OR], 3.4; 95% confidence interval [95% CI], 2.12-5.67) and HKSJ (OR, 3.60; 95% CI, 2.03-6.41) methods and with the prevalence of hypertension or insulin treatment as assessed by the DSL method (OR, 1.92; 95% CI, 1.05-3.50 and OR, 2.29; 95% CI, 1.07-4.91, respectively) but not as assessed by the HKSJ method. CONCLUSION: Patients with advanced T2D have a higher prevalence of HidHyCo. These data inform about the selection of patients with T2D for HidHyCo screening.

Obstructive sleep apnoea treatment and blood pressure: which phenotypes predict a response? A systematic review and meta-analysis.

The treatment for obstructive sleep apnoea (OSA) with continuous positive airway pressure (CPAP) or mandibular advancement devices (MADs) is associated with blood pressure (BP) reduction; however, the overall effect is modest. The aim of this systematic review and meta-analysis of randomised controlled trials (RCTs) comparing the effect of such treatments on BP was to identify subgroups of patients who respond best to treatment.The article search was performed in three different databases with specific search terms and selection criteria. From 2289 articles, we included 68 RCTs that compared CPAP or MADs with either passive or active treatment. When all the studies were pooled together, CPAP and MADs were associated with a mean BP reduction of -2.09 (95% CI -2.78- -1.40) mmHg for systolic BP and -1.92 (95% CI -2.40- -1.43) mmHg for diastolic BP and -1.27 (95% CI -2.34- -0.20) mmHg for systolic BP and -1.11 (95% CI -1.82- -0.41) mmHg for diastolic BP, respectively. The subgroups of patients who showed a greater response were those aged <60 years (systolic BP -2.93 mmHg), with uncontrolled BP at baseline (systolic BP -4.14 mmHg) and with severe oxygen desaturations (minimum arterial oxygen saturation measured by pulse oximetry <77%) at baseline (24-h systolic BP -7.57 mmHg).Although this meta-analysis shows that the expected reduction of BP by CPAP/MADs is modest, it identifies specific characteristics that may predict a pronounced benefit from CPAP in terms of BP control. These findings should be interpreted with caution; however, they are particularly important in identifying potential phenotypes associated with BP reduction in patients treated for OSA.

Periodic limb movements during sleep and blood pressure changes in sleep apnoea: Data from the European Sleep Apnoea Database.

BACKGROUND AND OBJECTIVE: OSA and PLMS are known to induce acute BP swings during sleep. Our current study aimed to address the independent effect of PLMS on BP in an unselected OSA patient cohort. METHODS: This cross-sectional analysis included 1487 patients (1110 males, no previous hypertension diagnosis or treatment, mean age: 52.5 years, mean BMI: 30.5 kg/m2 ) with significant OSA (defined as AHI ≥ 10) recruited from the European Sleep Apnoea Cohort. Patients underwent overnight PSG. Patients were stratified into two groups: patients with significant PLMS (PLMSI > 25 events/hour of sleep) and patients without significant PLMS (PLMSI < 25 events/hour of sleep). SBP, DBP and PP were the variables of interest. For each of these, a multivariate regression linear model was fitted to evaluate the relationship between PLMS and outcome adjusting for sociodemographic and clinical covariates (gender, age, BMI, AHI, ESS, diabetes, smoking and sleep efficiency). RESULTS: The univariate analysis of SBP showed an increment of BP equal to 4.70 mm Hg (P < 0.001) in patients with significant PLMS compared to patients without significant PLMS. This increment remained significant after implementing a multivariate regression model (2.64 mm Hg, P = 0.044). No significant increment of BP was observed for DBP and PP. CONCLUSION: PLMS is associated with a rise in SBP regardless of AHI, independent of clinical and sociodemographic confounders. A PLMS phenotype may carry an increased risk for cardiovascular disease in OSA patients.

Predictors of the transition from metabolically healthy obesity to unhealthy obesity.

PURPOSE: Evidence that metabolically healthy obesity (MHO) is a stable benign condition is unclear. The aim of this study was to estimate the transition of MHO subjects to unhealthy obesity (occurrence of cardio-metabolic events and/or risk factors) and its predictors. METHODS: We conducted an explorative follow-up study in a subset of MHO patients > 40 years without any cardio-metabolic risk factors and with normal LDL cholesterol (LDLc) levels, identified among 1530 obese patients. Due to the low sample size, a bootstrap approach was applied to identify the variables to be included in the final multivariate discrete-time logit model. RESULTS: The prevalence of MHO was 3.7%. During the follow-up (mean 6.1 years, SD 2.0), none of the MHO reported cardiovascular events, diabetes or prediabetes; 26 subjects developed risk factors (53% high LDLc and 50% hypertension). At the 6 and 12-year of follow-up, the cumulative incidence of transition to unhealthy obesity was 44% (95% CI 31-59%) and 62% (95% CI 45-79%), the incidence of high LDLc was 23% (95% CI 13-37%) and 40% (95% CI 25-59%) and that of hypertension was 20% (95% CI 11-33%) and 30% (95% CI 17-48%). LDLc and duration of follow-up were independent predictors of the transition from MHO to unhealthy obesity [OR 1.038 (1.005-1.072) and 1.360 (1.115-1.659)]. CONCLUSIONS: Results suggest that (a) MHO individuals do not move over time forward diabetes/prediabetes but develop risk factors, such as hypertension and higher LDL c that worsen the cardiovascular prognosis; (b) LDLc and the flow of time independently predict the transition to unhealthy status. LEVEL OF EVIDENCE: Level III, cohort study.

Is ellipsoid zone integrity essential for visual recovery in myopic neovascularization after anti-VEGF therapy?

PURPOSE: To evaluate functional prognostic factors and neuroretinal changes after anti-vascular endothelial growth factor (VEGF) treatment in patients with naïve, recent myopic neovascularization (mCNV), as assessed by spectral-domain optical coherence tomography (SD-OCT). METHODS: Specific changes in tomographic features between baseline and final follow-up were retrospectively evaluated by two examiners independently. Imaging was obtained by a multi-modal imaging system which combines fluorescein angiography and SD-OCT. RESULTS: Twenty-two eyes (male, six; female, 16; mean age, 65 ± 14 years) were considered. Mean follow-up was 21.5 ± 14 months. Best-corrected visual acuity (BCVA) improved from 0.38 ± 0.26 to 0.16 ± 0.20 logMAR (p < 0.001). The ellipsoid zone and the external limiting membrane (ELM) were disrupted in 21 (95.5%) and 15 (68.2%) eyes at baseline, and in 16 (72.7%) and nine (40.9%) eyes after therapy respectively. The ellipsoid zone and ELM were typically intact at lesion margins in 13 (59.1%) and 19 eyes (86.5%) respectively at baseline. The inner retina was intact in 20 eyes (91%). Six eyes (27.3%) exhibited complete regression without fibrosis. Absence of hemorrhage and integrity of lesion-adjacent ELM and of lesion-adjacent ellipsoid zone at baseline were factors for better final BCVA (p ≤ 0.05) CONCLUSION: Vision gain might occur despite ellipsoid zone or ELM restoration. Hemorrhage could be considered a negative prognostic factor, integrity of lesion-adjacent ELM and of lesion-adjacent ellipsoid zone as positive prognostic factors. Myopic CNV can also resolve completely without fibrosis.

Vascular Dynamics and Peripheral Oxygen Uptake in Obese Individuals during Progressive Physical Exercise.

BACKGROUND: Obese men show higher O2 consumption than lean men during physical exercise, with a trend toward higher peripheral O2 extraction; this is probably due to their larger muscle mass. OBJECTIVES: The aim of this study was to examine this phenomenon by measuring 2 vasoactive substances, endothelin-1 (ET-1) and nitric oxide (NO), during a progressive submaximal exercise. METHODS: Seventeen obese (body mass index [BMI] 38.6) and 15 lean (BMI 22.5) men performed a maximal progressive cycle ergometer exercise to determine peak power output (PPO) and peak O2 consumption (V∙O2peak); thereafter, they performed a submaximal cycle ergometer incremental test (every 6 min) at the same percentage of V∙O2peak until they reached 57.5% PPO. Blood samples were collected at rest and at the end of every step to measure ET-1 and NO concentrations. RESULTS: At rest, the ET-1 and NO concentrations in obese men and lean controls were the same. However, during exercise, the ET-1 concentration at each step was significantly lower (p < 0.05) in the obese group. There was no significant difference in NO concentration between the 2 groups, although the increase at the beginning of the exercise session was faster in obese individuals. During submaximal exercise, end-tidal O2 pressure (PETO2) was lower in the obese group, with a significant difference in the PETO2/fat-free mass ratio at each step. CONCLUSIONS: ET-1 and NO levels during physical exercise are different in obese versus lean men. This may support the notion that increased O2 consumption in obesity is due to different behaviors of the cardiorespiratory and circulatory systems.