Panagiotis Georgoulias

Abnormal heart rate recovery immediately after treadmill testing: Correlation with clinical, exercise testing, and myocardial perfusion parameters

BackgroundThe increase in heart rate during exercise is considered to be attributed to sympathetic system activation combined with parasympathetic withdrawal. The prognostic importance of the chronotropic response to exercise and heart rate recovery 1 minute after exercise has already been established. The purpose of this study was to evaluate heart rate recovery as an index of myocardial ischemia, by correlating heart rate recovery with known parameters of myocardial ischemia.>/<Methods and ResultsIncluded in the study were 304 consecutive patients (73% men), aged 34 to 82 years. Patients whose heart rate recovery value or myocardial perfusion imaging could have been influenced by factors other than ischemic disease were excluded from the study. The patients underwent single photon emission computed tomography myocardial perfusion imaging combined with symptom-limited exercise testing with thallium 201 or technetium 99m tetrofosmin. The value for heart rate recovery was defined as the decrease in heart rate from peak exercise to 1 minute after termination of exercise. For semiquantitation of the scintigram, the uptake of the radiotracer was graded on a scale from 0 to 4. Twenty-one beats per minute was defined as the lowest normal value for heart rate recovery. We found 74 patients (24%) with an abnormal value. We also found a significant correlation between heart rate recovery 1 minute after exercise and stress myocardial perfusion score. In addition, there was a statistically significant relationship between heart rate recovery and chronotropic variables. Patients with an abnormal value of heart rate recovery were generally of an older age, were more likely men, had a higher frequency of risk factors for coronary artery disease, were mostly taking cardioactive medications, had lower efficiency during treadmill testing, and had more pathologic findings on the scintigram.>/<ConclusionsMyocardial ischemia, as assessed by myocardial perfusion imaging, is an important correlate of heart rate recovery. There is a significant correlation between chronotropic variables during exercise testing and heart rate recovery 1 minute after exercise. It seems that the heart rate recovery value 1 minute after peak exercise may be considered a reliable index of the severity of myocardial ischemia.>/<

Systemic and airway inflammation and the presence of emphysema in patients with COPD

The aim of this study was to determine the impact of HRCT-confirmed emphysema on biomarkers evaluating airway and systemic inflammation in COPD patients. Forty-nine consecutive male COPD outpatients with stable COPD were divided in two groups according to the presence or absence of emphysema on HRCT. Patients underwent pulmonary function tests, plus assessment of exercise capacity, body composition and quality of life. Biomarkers were measured in serum (CRP, interleukin-6, TNF-alpha, leptin, adiponectin, osteocalcin, insulin growth factor-1, and systemic oxidative stress), in plasma (fibrinogen and VEGF) and in whole blood (B-type natriuretic peptide). TNF-alpha, 8-isoprostane and pH were additionally measured in exhaled breath condensate. Patients with emphysema had more severe lung function impairment, lower body-mass index and fat-free mass index, and poorer quality of life. Additionally, they presented increased systemic oxidative stress and plasma fibrinogen and lower BNP compared to patients without emphysema. After proper adjustment for disease severity, all differences remained with the exceptions of body-mass index, fat-free mass index and BNP. COPD patients with HRCT-confirmed emphysema present increased systemic oxidative stress and fibrinogen, suggesting that they may be more prone to the systemic consequences of COPD compared to patients without emphysema.

Effect of ghrelin on gonadotrophin secretion in women during the menstrual cycle

BACKGROUND It has been suggested that ghrelin may affect reproduction in animals by decreasing pituitary LH secretion. The role of ghrelin on LH secretion in women has not been investigated. Our aim was to assess the effect of ghrelin administration on basal and GnRH-induced LH secretion during the menstrual cycle. METHODS Normally cycling women (n = 10) received on Day 3 of three consecutive cycles a single bolus i.v. of either ghrelin (1 microg/kg, cycle 1) or GnRH (100 microg, cycle 2) or GnRH plus ghrelin (cycle 3). In cycle 1, ghrelin was also injected in late follicular and mid-luteal phase of the cycle. Saline was injected in a preceding cycle (cycle 1, control). Blood samples were taken before drugs or saline injection (time 0) as well as at -15, 15, 30, 45, 60, 75, 90 and 120 min. RESULTS Plasma ghrelin levels increased rapidly, peaking at 15 or 30 min (P < 0.001), then decreased steadily, approaching pre-injection levels at 120 min. Serum FSH, LH, estradiol and progesterone levels remained unchanged. The stimulating effect of GnRH on LH and FSH secretion was unaffected by ghrelin injection. In contrast to saline, ghrelin stimulated a significant increase in growth hormone levels. CONCLUSIONS Under these experimental conditions, our results demonstrate for the first time the inability of a bolus of ghrelin to affect basal and GnRH-induced LH and FSH secretion. It is suggested that ghrelin does not play a major physiological role in gonadotrophin secretion in women.

Leptin, adiponectin, and ghrelin levels in female patients with asthma during stable and exacerbation periods.

Objective. The mechanisms underlying the relationship between obesity and asthma have not been fully established. Data in the literature suggest that adipose tissue-derived hormones may be implicated. However, no definite conclusions regarding the role of leptin and adiponectin with asthma are available. No studies have examined the role of ghrelin in asthma. Methods. We assessed the circulating concentrations of leptin, adiponectin, and ghrelin in 32 postmenopausal stable asthma patients, 37 female asthmatics during exacerbations and 8 weeks later, and 22 controls. We examined the relationship between the three peptides and indexes of pulmonary function, airway inflammation, and atopy. Results. Stable asthma patients exhibited higher leptin and lower ghrelin concentrations compared with controls. Patients with severe asthma had higher leptin and lower adiponectin levels versus patients with mild to moderate asthma. Both leptin concentrations and leptin/adiponectin ratio served as markers for discriminating asthma patients from controls on the one hand, and severe from mild to moderate asthmatics on the other. Leptin levels were inversely correlated with both FEV1/FVC and FEF25–75 in patients with mild to moderate asthma. Atopic asthma patients had higher leptin concentrations than nonatopic asthma patients. There was a positive correlation between serum leptin and total IgE levels in atopic asthmatics. Finally, serum leptin levels and leptin/adiponectin ratio were significantly increased during asthma exacerbations, while adiponectin and ghrelin levels were significantly decreased. Conclusion. Our findings suggest that leptin, adiponectin, and ghrelin may play a significant role in the pathogenesis of asthma during both stable state and asthma exacerbation, independent of obesity.

Association between habitual physical activity and brown adipose tissue activity in individuals undergoing PET-CT scan

Augmented brown adipose tissue (BAT) mass and activity lead to higher basic metabolic rate which is beneficial against obesity. Our aim was to investigate whether habitual (i.e. usual weekly participation) physical activity is linked with BAT activity and mass in humans, in a group of patients undergoing 18F‐fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) scanning.

Depression in Patients with Cardiovascular Disease

It has been widely suggested that depression negatively affects patients with cardiovascular disease. There are several pathophysiological mechanisms as well as behavioral processes linking depression and cardiac events. Improvements in nursing and medical care have prolonged survival of this patient population; however, this beneficial outcome has led to increased prevalence of depression. Since mortality rates in chronic heart failure patients remain extremely high, it might be as equally important to screen for depression and there are several valid and reliable screening tools that healthcare personnel could easily employ to identify patients at greater risk. Consultation should be provided by a multidisciplinary team, consisting of cardiologists, psychiatrists, and hospital or community nurses so as to carefully plan, execute, and evaluate medical intervention and implement lifestyle changes. We aim to systematically review the existing knowledge regarding current definitions, prognostic implications, pathophysiological mechanisms, and current and future treatment options in patients with depression and cardiovascular disease, specifically those with heart failure.

Molecular nanomedicine towards cancer: 111In‐labeled nanoparticles

Nanomedicine is the medical application of materials, devices, or systems in the nanometer scale and is currently undergoing explosive development. Molecular imaging of cancer using nanosized materials comprises an important part in diagnosis, therapy, and drug discovery in medical nanosciences. Radiopharmaceuticals are a key tool of molecular imaging in the field of nuclear medicine. The in vivo administration of radiolabeled nanoparticles (NPs) can provide an accurate biodistribution profile of the nanoformulations, as well as visualization of their route in vivo. Surface modifications of NPs with antibodies, peptides, or other small molecules that bind to tumor cell receptors have resulted in the development of sensitive and specific targeted imaging and diagnostic modalities for in vitro and in vivo applications. Radiometals are the most favorable of all radionuclides for labeling applications and they have the most suitable properties for single-photon emission computed tomography imaging. Indium-111((111)In), specifically, is a readily available gamma-emitting radiometal, which is widely used in clinical practice for diagnosis and/or therapy. Herein, we will overview the latest evolvement on (111)In-labeled nanoparticles for biodistribution assessment and/or imaging evaluation of nanocarriers, as well as therapy in cancer.

The Association of Metabolic Syndrome with Adipose Tissue Hormones and Insulin Resistance in Patients with COPD without Co-morbidities

Chronic obstructive pulmonary disease (COPD) and metabolic syndrome represent common causes of morbidity and mortality in ageing populations. The effect of the co-existence of COPD and metabolic syndrome on adipose tissue hormones and insulin resistance as well as the differences between COPD patients with and without metabolic syndrome have not been adequately studied. The prevalence of metabolic syndrome, based on Adult Treatment Panel III (ATP III) criteria, was evaluated in 114 male patients with COPD without significant co-morbidities. Pulmonary functions tests (PFTs), arterial blood gases, quality of life and BODE index were assessed. Blood samples were obtained for the assessment of adipose tissue hormones and insulin resistance. The overall prevalence of metabolic syndrome was 21%, being more prevalent in earlier stages of COPD. Patients with COPD and metabolic syndrome were younger with higher body-mass index (BMI), had better pulmonary function, less static hyperinflation and air-trapping, better diffusing capacity for carbon monoxide and BODE index. These patients had higher levels of leptin, lower levels of adiponectin and increased insulin resistance, as expressed by HOMA index, compared with patients without metabolic syndrome. Metabolic syndrome was more prevalent in younger patients with less severe COPD. These patients may constitute a specific COPD phenotype with greater leptin to adiponectin imbalance and insulin resistance, despite smaller impairment in PFTs. The prognosis and differences of these patients compared with other COPD phenotypes needs to be determined in prospective studies.

Elimination Half-Life of Anti-Müllerian Hormone

CONTEXT Anti-Müllerian hormone (AMH) is a glycoprotein that is secreted by the granulosa cells in the human ovary. In the postpubertal female, circulating AMH reflects the number of follicles within the ovary. It is mandatory to know the serum elimination half-life (t(1/2)) of AMH to study in vivo short-term changes of the hormone. OBJECTIVE Our objective was to determine the kinetics of decay of AMH in the human female. PATIENTS, DESIGN, AND SETTING Premenopausal women undergoing total abdominal hysterectomy plus bilateral salpingo-oophorectomy participated in this cohort study (n = 21) at an academic tertiary referral center. INTERVENTIONS Serum samples were obtained immediately before surgery and in 12-h intervals thereafter for 8 d. MAIN OUTCOME MEASURE AMH elimination was calculated, applying a one-compartment model with first-order kinetics. RESULTS Mean preoperative AMH levels were 0.67 ng/ml (range, 0.1-1.78 ng/ml) and dropped to 0.08 ng/ml within 84 h after surgery. The AMH decay followed first-order kinetics. The mean terminal t(1/2) of AMH was calculated as 27.6 ± 0.8 h. CONCLUSION AMH elimination reaches approximately 84% after 3 d, approximately 91% after 4 d, approximately 95% after 5 d, and can be considered complete after 8 d.

Failure of the GnRH antagonist ganirelix to block the positive feedback effect of exogenous estrogen in normal women

This study investigated whether the GnRH antagonist ganirelix is able to block the positive-feedback effect of E2 in normal women. Ganirelix was unable to block the positive-feedback effect, suggesting that the clinical efficacy of GnRH antagonists in IVF cycles is determined by the hyperstimulation process.