Improved blood pressure and flow-mediated dilatation via increased plasma adropin and nitrate/nitrite induced by high-intensity interval training in patients with type 2 diabetes.

NEW FINDINGS: What is the central question of this study? Exercise training increases adropin and nitrite/nitrate (NOx) plasma levels in middle-aged and older healthy people. We hypothesized that high-intensity interval training may improve blood pressure and flow-mediated dilatation through the effects of adropin and NOx in patients of this age with type 2 diabetes. What is the main finding and its importance? High-intensity interval training may be more effective than moderate-intensity continuous training in improving endothelial function, blood pressure and flow-mediated dilatation through its effects on adropin and NOx in patients with type 2 diabetes. ABSTRACT: Adropin is a newly identified bioactive protein that is important in energy hemostasis and vascular endothelial function. Lower levels of adropin in patients with type 2 diabetes are related to coronary atherosclerosis, characterized by impaired flow-mediated dilatation (FMD). The purpose of the present study was to investigate FMD and plasma levels of adropin and nitrite/nitrate (NOx) in patients with type 2 diabetes at baseline and follow-up after 12 weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT). Sixty-six persons with type 2 diabetes were divided into HIIT, MICT, and control groups. The HIIT group intervention was 12 intervals (1.5 min) at 85-90% maximal heart rate (HRmax ) separated by 2 min at 55-60% HRmax in three sessions per week for 12 weeks. MICT training consisted of 42 min of cycling at 70% HRmax . Before and after the intervention, FMD was recorded with high-resolution Doppler ultrasound. Plasma levels of adropin and NOx were measured by enzyme-linked immunosorbent assay. After training FMD was significantly higher in the MICT and HIIT groups compared to the control group (P < 0.05). Plasma levels of adropin and NOx were higher in both exercise groups, but the increase was greater in the HIIT group (P < 0.01). Peak oxygen consumption was increased after exercise training in both groups compared to the control group (P < 0.01). Percentage FMD showed a positive correlation with plasma levels of adropin and NOx (both P < 0.01), and a negative correlation with diastolic blood pressure (r = -0.530, P = 0.035) and systolic blood pressure (r = -0.606, P = 0.013) in the HIIT group. The results indicate that HIIT improved FMD whilst increasing adropin, NOx and peak oxygen consumption. Increased plasma levels of adropin may contribute, in part, to blood pressure reduction by increasing nitric oxide production.

Effect of Cardiac Resynchronisation Therapy on Electrical Remodelling.

BACKGROUND: Cardiac resynchronisation therapy (CRT) is an accepted device therapy in patients with low ejection fraction. Beneficial effects of CRT result from mechanical remodelling. Some controversial reports suggest that CRT may also induce electrical remodelling with intrinsic QRS narrowing but still the effect of CRT on electrical remodelling is an issue for debate. The aim of our study was to evaluate the effects of CRT on intrinsic QRS duration. For clarity, our analysis was performed by the signal averaged electrocardiogram (SAECG) which is a high resolution electrocardiographic signal suitable for accurate measurement of QRS duration. Signal averaged electrocardiogram provides a better value of QRS duration compared to 12-lead ECG by the ability to detect ventricular late potentials. METHODS: A total of 48 consecutive patients with severe systolic dysfunction and typical left bundle branch block (LBBB) were enrolled in the study prospectively. Patients were scheduled for CRT-D implantation according to the current guidelines. Intrinsic QRS duration was accurately measured by SAECG before and at least 14 months after CRT implantation. RESULTS: The mean intrinsic QRS duration remained unchanged during follow-up (from 149.9±13.8ms to 149.6±18.4ms; P= 0.3). Among 32 CRT responder patients, the mean intrinsic QRS duration remained unchanged during follow-up. Also, the mean intrinsic QRS duration showed no significant changes in 16 CRT non-responders. CONCLUSION: Structural remodelling induced by CRT does not necessarily translate into decrease of intrinsic ventricular activation. Despite significant left ventricular recovery, electrical characteristics of the left ventricular conduction system cannot generally be expected to recuperate.

Aortopathic effect of androgenic anabolic steroids.

BACKGROUND: Anabolic androgens have been reported to be associated with cardiovascular complications. One study revealed that increase in vascular stiffness in bodybuilders is associated with anabolic androgens and improvement in vascular function may occur following anabolic androgens discontinuation. The aim of this study was to investigate any possible relation between aortic elastic properties and anabolic androgens. METHODS: Study population was divided into 3 groups: Group-1 [n = 35] consisted of bodybuilders who denied any current or previous use of anabolic androgens. Group-2 [n = 18] was bodybuilders with regular using of anabolic androgens for at least 2 year prior to the start of our study. Group-3 was 13 healthy age-matched sedentary men as a control group. Cardiac echocardiography was performed in the bodybuilders and controls and indexes of aortic function were calculated. RESULTS: Aortic stiffness was approximately twofold higher in anabolic androgens user bodybuilders compared with drug-free bodybuilders [P < 0.001]. CONCLUSION: The present study demonstrates that chronic anabolic androgens use clearly produces significant decrease in the elastic properties of aorta.

Improved carotid intima-media thickness-induced high-intensity interval training associated with decreased serum levels of Dkk-1 and sclerostin in type 2 diabetes.

AIMS: Carotid intima-media thickness (cIMT) is a validated surrogate marker of atherosclerosis. Dickkopf-1 (Dkk-1) and sclerostin modulate wingless signaling, which is involved in atherosclerosis. The purpose of this study was to investigate whether 12 weeks of high-intensity interval training (HIIT) would improve cIMT and serum Dkk-1 and sclerostin levels in patients with type 2 diabetes. METHODS: Seventy-four sedentary patients with type 2 diabetes were randomly divided into HIIT and control groups. The HIIT group intervention was 6 intervals (4 min) at 85%-90% HRmax separated by 3 min at 45%-50% HRmax in 3 sessions/week for 12 weeks. Before and after the intervention, cIMT, artery diameter and wall/lm ratio were recorded with high-resolution ultrasound. Serum sclerostin and Dkk-1 were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: cIMT decreased significantly in the HIIT group (0.83 ±â€¯0.17 baseline, 0.71 ±â€¯0.14 follow-up) compared to the control group (0.84 ±â€¯0.20 baseline, 0.85 ±â€¯0.19 follow-up) (P < .05). Dkk-1 and sclerostin decreased significantly after 12 weeks of HIIT (P < .01). In addition, VO2peak was increased in the HIIT group than the control group (by 6.2 mL/kg/min) (P < .05). There was a positive correlation between percent changes in cIMT and percent changes in Dkk-1 and sclerostin (both P < .01). Additionally, there were a negative correlation between percent changes VO2peak and cIMT (r = - 0.740, P = .003), Dkk-1 (r = - 0.844, P < .001) and sclerostin (r = - 0.575, P = .001) in HIIT group. CONCLUSION: Our results indicate that HIIT decreases cIMT, serum levels of Dkk-1 and sclerostin and improves VO2peak in patients with type 2 diabetes.

Short QT interval: A novel predictor of androgen abuse in strength trained athletes.

OBJECTIVES: To find the relationship between anabolic androgenic steroids (AAS) using and QT interval in athletes. METHODS: Between January 1, 2005 and May 31, 2007, we examined QTc interval duration in 165 consecutive male professional bodybuilders [age: 32.1 +/- 4.6 years]. Of these, 79 were AAS users. The control group included 90 sedentary age and gender matched subjects [none of them were AAS users]. RESULTS: The QTc interval of AAS abusing bodybuilders was significantly shorter compared with QTc interval in AAS-free bodybuilders and control group. Short QTc interval (< or =380 ms) was an independent predictor of AAS abusing in the multivariate analysis. CONCLUSIONS: To the best of our knowledge, there is no published report regarding electrocardiographic diagnosis and screening of AAS abusing athletes. In the present study, we present an easy and applicable method to screen and diagnose AAS abusing among professional bodybuilders. In the presence of QTc interval < or = 380 ms in a bodybuilder, one would predict AAS abusing with 83% sensitivity and 88% specificity.

Effect of endurance and strength exercise on release of brain natriuretic peptide.

OBJECTIVES: The aim of this study was to investigate the effects of 8-week endurance and resistance exercise training on release of brain natriuretic peptide. MATERIALS AND METHODS: Study population was categorized into 4 groups: Group-1 (n = 6) consisted of sedentary individuals who volunteered to complete 8-weeks of endurance exercise; Group-2 (n=6) consisted of sedentary individuals who volunteered to complete 8-weaks of resistance exercise. Three blood samples [for Terminal pro BNP (NT-Pro-BNP)] were taken before, immediately after exercise and after 8 weeks of exercise training. RESULTS: NT-Pro BNP was significantly increased immediately after endurance exercise [from 37.9 ± 1.4 pg/ml to 52.1 ±1.5 pg/ml; P = 0.002] and was decreased to 23.2 ± 9.3 pg/ml after 8 weeks of endurance exercise [P = 0.013]. On the other hand, NT-Pro BNP showed no significant changes immediately after resistance exercise [from 26.6 ± 4.9 pg/ml to 24.1 ±4.5 pg/ml; P = 0.553]. In contrast, NT-Pro BNP was significantly increased to 39.5 ±1.6 pg/ml after 8 weeks of resistance exercise [P = 0.012]. CONCLUSION: Endurance exercise training reduces circulating NT-Pro BNP concentration, which is likely a marker of reduced ventricular wall tension and improved myocardial function. In contrast, strength exercise induces significant increase in NT-Pro BNP, which could be partially attributed to myocardial damage.

Effect of chronic cocaine abuse on the elastic properties of aorta.

BACKGROUND: Any unfavorable effect of cocaine on aortic elastic properties will contribute to the adverse effects of cocaine on the cardiovascular system. OBJECTIVES: The aim of this study was to evaluate the aortic elastic properties in long-term crack cocaine abusers. METHODS: Twenty-eight consecutive chronic cocaine abusers and 36 control subjects with similar age, gender, cholesterol, and triglyceride plasma levels, as well as incidence of cigarette smoking, hypertension, and diabetes mellitus were enrolled in the study. RESULTS: The average duration of cocaine abuse was 10 +/- 3.2 years. Diastolic thoracic aortic diameter was increased in cocaine users compared with control subjects (P < 0.05). Aortic strain and distensibility were approximately twofold lower and aortic stiffness index approximately threefold higher in patients compared with control subjects (P < 0.01). The duration of cocaine abuse was related to low aortic strain and distensibility as well as increased aortic stiffness index (R =-0.32, R =-0.38, and R = 0.28, respectively, weighted for age; P < 0.01). When the cocaine abusers were divided into quartiles of duration of cocaine using (first quartile: <5 years; second quartile: >5 and <8 years; third quartile: >8 and <11 years; and fourth quartile: >11 years), progressive increase was found in aortic stiffness index. CONCLUSION: The present study demonstrates that chronic cocaine abuse clearly produces significant decrease in the elastic properties of aorta. This effect of cocaine is related to the duration of cocaine abuse.

Prevalence of Brugada sign in patients presenting with palpitation in southern Iran.

AIMS: Brugada syndrome is a cardiac channel abnormality that is associated with a high risk of ventricular fibrillation and sudden cardiac death and characterized by an electrocardiographic pattern of right bundle branch block and transient or persistent ST-segment elevation in leads V1-V3. No data regarding the frequency of Brugada syndrome exist in an Iranian population. The aim of this study was to determine the frequency of Brugada-type ECG pattern in southern Iran. METHODS AND RESULTS: All patients presenting with palpitation were enrolled in the study. A Brugada-type ECG pattern was determined according to the criteria recommended by European Heart Association Molecular Basis of Arrhythmias Study Group. A total of 3895 patients (mean age 38.2 +/- 11.9 years, 54% women) met all study criteria. One hundred patients (2.56%) had Brugada-type ECG pattern. Of these, 21 patients (0.54%) had definite Brugada sign (Type 1 or Types 2 and 3 with conversion to Type 1 following procainamide test). Of 21 patients with definite Brugada sign, eight had Brugada syndrome, four had history of syncope, two had coved-type ECG in the family, one had polymorphic ventricular tachycardia, and one had history of sudden cardiac death in the family. Five patients underwent ICD implantation. The incidence of a Brugada-type ECG pattern was 2.43% in subjects between 17 and 30 years and 0.13% in subjects >30 years (P = 0.01). CONCLUSION: Frequency of Brugada sign in an Iranian population presenting with palpitation is greater than some European countries and lower than a Japanese urban population.