Aerobic exercise training reduces blood pressure, angiotensin II and oxidative stress of patients with resistant hypertension: the EnRiCH trial

Introduction

Resistant hypertension is a major challenge of modern cardiovascular medicine, as it is a puzzling problem without a clear solution. Exercise training clearly reduces blood pressure (BP) and oxidative stress in patients with hypertension, however evidence is limited regarding resistant hypertension.

Purpose

To determine the effect of an aerobic exercise training program in BP, angiotensin II and oxidative stress in patients with resistant hypertension.

Methods

EnRicH is a prospective, two-center, single-blinded, randomized controlled trial with a parallel two-arm group. Sixty patients with resistant hypertension were randomly assigned in a 1:1 ratio to undergo a 12-week aerobic exercise training program (exercise) or usual care (control). The powered primary efficacy measure was 24-hour ambulatory systolic BP change from baseline. Secondary outcome measures included daytime and nighttime ambulatory BP, office BP, cardiorespiratory fitness, and oxidative stress and inflammatory biomarkers: Interferon-gamma (IFN-y), Angiotensin II, vascular endothelial growth factor (VEGF), and superoxide dismutase (SOD).

Results

Fifty-three patients (exercise n=26, control n=27) completed the study. Patients were mainly women (54.7%), with an office BP of 140.7±15.9/84.2±9.4 mm Hg and taking an average of 4.6 antihypertensive medications (median, 5; range, 3 to 7). At baseline, no differences were found between groups for the study outcomes and patient characteristics. Ambulatory systolic BP was reduced −7.1 mm Hg (95% CI, −12.8 to −1.4; P=0.015) in the exercise group (127.4±12.2 to 121.2±12.2, p=0.007) compared to control group (126.1±17.2 to 126.9±15.2, p=514) over 24-hour. In addition, 24-hour ambulatory diastolic BP (−5.1 mm Hg, −7.9 to −2.3, P=0.001), daytime ambulatory systolic (−8.4 mm Hg, −14.3 to −2.5, P=0.006), and diastolic BP (−5.7 mm Hg, −9.0 to −2.4, P=0.001) were also reduced in the exercise group compared to the control group. There were no differences in the change of nighttime ambulatory BP between groups. Cardiorespiratory fitness improved in the exercise group by 14% (4.7 ml.kg-1.min-1, P<0.001), while it remained unchanged in the control group (−0.37 ml.kg-1.min-1, P=0.442). A significant between-group difference in favor of exercise group was found for IFN-y (−4.3 pg/mL, 95% CI: −7.1 to −1.5; P=0.003), Angiotensin II (−157.0 pg/mL, 95% CI: −288.1 to −25.9; P=0.020), VEGF (10.53 pg/mL, 95% CI: 0.60 to 22.54; P=0.035), and SOD (0.35 pg/mL, 95% CI: 0.10 to 0.58; P=0.009).

Conclusions

A 12-week moderate intensity aerobic exercise program reduced ambulatory BP, angiotensin II and oxidative stress in patients with resistant hypertension. The antihypertensive effects of exercise in patients with resistant hypertension may be mediated by positive changes in oxidative stress and inflammatory biomarkers.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): European Union through European Regional Development Fund – Operational Competitiveness Factors Program (COMPETE)Portuguese Government through FCT - Foundation for Science and Technology

May the brief physical activity assessment tool accurately measure physical activity in patients with resistant hypertension?

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): FEDER Funds through the Operational Competitiveness Factors Program—COMPETE National Funds through the Portuguese Foundation for Science and Technology (FCT) “PTDC/DTP-DES/1725/2014”. SL is a PhD fellow supported by the FCT (Grant Ref: SFRH/BD/129454/2017).

Introduction

Resistant hypertension is a major health problem due to the increased risk of cardiovascular events and mortality. Physical activity and exercise reduces blood pressure in resistant hypertension and is associated with lower cardiovascular risk and mortality. It is presently recommended that physical activity assessment should be a priority in all visits to health settings

Purpose

This study aims to determine if the Brief Physical Activity Assessment Tool (BPAAT), a 2-question tool to assess physical activity, is a valid instrument to detect inactive patients with resistant hypertension. 

Methods

Sixty patients with a diagnosis of resistant hypertension were recruited. Outcome measures included clinical data, blood pressure and daily physical activity. Physical activity was objectively measured over a 7-day period with an accelerometer and subjectively assessed (self-assessment) by the BPAAT. The association between the BPAAT and accelerometry, according to the BPAAT scoring categories, was assessed bythe percentage of agreement, Cohen’s Kappa and sensitivity and specificity.

Results

Patients (33 were male) had a mean age of 59.4 ± 9.1years, were on average overweight (BMI 29.5 ± 4.5 kg/m2) and on an average of 4.5 ± 0.7 antihypertensive medications. Forty-two patients (70%) were classified as insufficiently active by the BPAAT compared to the 38 (63.3%) insufficiently active patients identified by the accelerometry data. Regarding the questionnaire’s specificity and sensitivity, the BPAAT correctly identified 32 [84.2 (73.1 – 95.3) %] of the 38 ‘insufficiently active’ patients and 12 [54.5 (34.3 – 74.7) %] of the 22 ‘sufficiently active’ patients identified by accelerometry. The agreement between BPAAT and accelerometry to identify sufficiently/insufficiently active patients, according to the BPAAT’s cut-off values was fair to moderate (Kappa = 0.403 (0.162 – 0.674), with a percentage of agreement of 73.3%.

Conclusion

The BPAAT, a 2-question tool to assess physical activity, seems to be a valid and fast solution to identify insufficiently active adults with resistant hypertension during routine clinical visits.

Higher levels of physical activity is associated with lower arterial stiffness in patients with resistant hypertension

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Portuguese Foundation for Science and Technology (FCT) European Regional Development Fund – Operational Competitiveness Factors Program (COMPETE)

Background

 Physical activity has been associated with reduced arterial stiffness in patients with hypertension. However, in resistant hypertension, a specific population with an increased risk for target organ damage, cardiovascular morbidity, and mortality, the evidence is sparse. 

Purpose

 The present study aimed to determine the association between daily physical activity and arterial stiffness in patients with resistant hypertension.

Methods

 Fifty-seven patients with resistant hypertension were recruited. Physical activity was objectively assessed during 7 consecutive days with accelerometers. Arterial stiffness was evaluated using carotid-femoral pulse wave velocity (cf-PWV) . 

Results

 Participants (50.9% men), aged 58.8 ± 9.4 years, were mainly overweight and were taking in average 4.5 antihypertensive medications. The cf-PWV showed an inverse correlation with light-intensity physical activity (r = -0.290, p = 0.029) and total daily physical activity (r = -0.287, p = 0.030). Additionally, cf-PWV tended to be inversely associated with the number of steps per day (r = -0.242, p = 0.069). Patients with higher risk of cardiovascular events (cf-PWV ≥ 10 m/s) tended to spend less time in light-intensity physical activity (324.0 ± 129.4 vs. 380.5 ± 103.1 min/day, p = 0.090) and to perform less total daily physical activity (351.5 ± 141.7 vs. 411.7 ± 109.1 min/day, p = 0.091) than participants with cf-PWV below the risk threshold value.

Conclusions

 Higher levels of total physical activity and daily levels of light-intensity were associated to lower arterial stiffness. These results emphasize the importance of physical activity as a nonpharmacological tool for patients with resistant hypertension.

Exercise-based cardiac rehabilitation increases daily physical activity of patients following myocardial infarction: subanalysis of two randomised controlled trials

OBJECTIVE

To assess the effects of an exercise-based cardiac rehabilitation programme on daily physical activity levels of patients following myocardial infarction.

DESIGN

Subanalysis of two randomised, prospective controlled trials.

SETTING

Outpatient clinic of a secondary hospital.

PARTICIPANTS

Fifty consecutive patients randomised to the exercise group {n=25; 23 males; mean age 54 [standard deviation (SD) 9] years} or the control group [n=25; 20 males; mean age 58 (SD 9) years].

INTERVENTIONS

The exercise group participated in an 8-week aerobic exercise programme plus usual medical care and follow-up. The control group received usual medical care and follow-up.

MAIN OUTCOME MEASURES

The primary outcome measure was change in time spent undertaking moderate-to-vigorous physical activity per day, assessed by accelerometer over 7 consecutive days. Secondary outcome measures were cardiorespiratory fitness, body mass, and resting blood pressure and heart rate.

RESULTS

Moderate-to-vigorous physical activity levels increased significantly in the exercise group [43.2 (SD 36.3) to 53.5 (SD 31.9) minutes/day, P=0.030], and remained unchanged in the control group [40.8 (SD 26.2) to 36.8 (SD 26.5) minutes/day, P=0.241] from baseline to the end of the programme. Cardiorespiratory fitness increased significantly in the exercise group (mean difference 2.8; 95% of the difference 1.3 to 4.4ml/kg/minute, P=0.001) after the 8-week programme.

CONCLUSIONS

In patients under optimal medication following myocardial infarction, participation in an 8-week exercise-based cardiac rehabilitation programme was found to improve physical activity levels consistent with health-related benefits. Future studies are needed to determine whether the increase in physical activity is maintained in the long term.

GNAS A-1121G variant is associated with improved diastolic dysfunction in response to exercise training in heart failure patients

β1-adrenergic receptors (ADRB1) and Gαs proteins (GNAS) play important roles in the regulation of cardiac function. The present study sought to investigate whether ADRB1 Arg389Gly (rs1801253), GNAS -1211 G/A (rs6123837) and GNAS 2291 C/T (rs6026584) variants are associated with left ventricular function and exercise tolerance in heart failure patients. 61 heart failure patients completed a 6-month exercise-training programme. Left ventricular ejection fraction (LVEF), mitral inflow velocities (deceleration time, and E/A ratio) and exercise tolerance (METs) were assessed at baseline and following exercise training. There were no associations between the studied variants and LVEF or E/A ratio measured at baseline and after exercise training. Deceleration time of early mitral flow was higher at baseline in GNAS -1211G allele carriers compared with -1211A allele homozygotes (P<0.05). Exercise training attenuated deceleration time in -1211G allele carriers (P<0.05) but not in -1211A allele homozygotes. Moreover, ADRB1 389Gly homozygotes had a greater training-induced increase in exercise tolerance than 389Arg homozygotes (P=0.04). This study shows that the functional GNAS -1121 G/A polymorphism is associated with diastolic function at baseline and in response to exercise training in heart failure patients. Furthermore, our data suggest that ADRB1 Arg389Gly polymorphism may influence exercise tolerance.

Exercise training increases interleukin-10 after an acute myocardial infarction: a randomised clinical trial

The present study assessed the effects of exercise training on biomarkers of inflammation in postinfarction patients. This single-centre prospective randomized controlled trial encompassed 42 patients after the first myocardial infarction divided into exercise-training (n=22) or usual care (n=20) groups. Complete randomization was performed by choosing one of 2 sealed envelopes. The exercise-training group participated in an 8-week programme comprising 3 aerobic exercise sessions per week. The control group received usual care. The main measures were changes in circulating levels of C-reactive protein, interleukin (IL)-6 and -10, soluble vascular cell adhesion molecule-1 (VCAM-1), soluble intercellular adhesion molecule-1 (ICAM-1), anthropometrics, dietary intake, daily physical activity, and cardiorespiratory fitness. 4 patients terminated the study prematurely, leaving 38 for the statistical analysis (exercise-training, n=20; control group, n=18). In comparison to control group, exercise-training group improved IL-10 levels [1.7(7.0) vs.  - 0.3(2.4) pg/mL, P<0.05], daily moderate-intensity physical activity (12.9±21.3 vs.  - 0.7±13.4 min, P<0.05), and cardiorespiratory fitness (3.0±3.5 vs. 0.3±4.1 ml/min/kg, P<0.05). Additionally, the change in VCAM-1 and ICAM-1 levels was significantly higher in the control group (respectively, 26.6±112.1 vs. 94.1±90.0 ng/mL and 7.3±41.0 vs. 35.0±39 ng/mL, P<0.05). In conclusion, exercise training improved the inflammatory profile in post myocardial infarction patients by enhancing the anti-inflammatory cytokine IL-10.

Is there an interaction between BDKRB2 -9/+9 and GNB3 C825T polymorphisms and elite athletic performance?

The -9 deletion allele in the BDKRB2 -9/+9 polymorphism was associated previously with improved endurance performance. We compared the frequency distribution of the BDKRB2 -9/+9 (rs5810761) polymorphism between athletes (n=155) of sports with different demands (endurance runners; n=74 vs sprinters; n=81) as well as between athletes of different competitive levels (elite level; n=46 vs national level; n=109). These results were compared with those of 240 non-athletic healthy individuals. We also tested the influence of the interaction between the BDKRB2 -9/+9 and the GNB3 C825T (rs5443) genotypes in relation to endurance performance. Genotype distribution and allele frequencies were found to be similar in the endurance athlete, sprinter, and control groups (P=0.83 for genotype distribution and P=0.9 for allele frequencies). Similarly, no statistical differences were found between the subgroups of elite-level endurance athletes and national-level endurance athletes, or between elite-level and national-level sprinters (P>0.09 for all comparisons). There was no interaction between BDKRB2 -9/+9 and GNB3 C825T polymorphisms in relation to endurance performance (P=0.16 for interaction effect). In conclusion, the BDKRB2 +9/-9 polymorphism is not associated with endurance performance, at least among Israeli athletes, and the GNB3TT+BDKRB2 -9/-9 "optimal genotype" is not associated with endurance performance.

Is there an ACE ID - ACTN3 R577X polymorphisms interaction that influences sprint performance?

Functional R577X (rs.1815739) and ID (rs.5186) polymorphisms in the alpha-actinin-3 ( ACTN3) and the angiotensin converting enzyme (ACE) genes, respectively, have been associated with sprint performance. The aim of this study was to determine their effect on sprint performance among 81 Israeli sprinters and 240 healthy controls. Results revealed that the ACE II genotype+ ACTN3 R allele (P=0.003 for sprinters vs. controls), and the ACTN3 RR genotype +ACE I allele (P=0.001 for sprinters vs. controls) might be the genotype for sprinters. In the whole cohort the probability of ACTN3 RR genotype+ ACE I allele being a sprinter (odds ratio 2.67, 95% confidence interval 1.45-4.93) and of ACE II genotype+ ACTN3 R allele being a sprinter (odds ratio 3.57, 95% confidence interval 1.78-7.15) was significantly higher than that in the controls. In conclusion, the above data suggest that ACE ID/ ACTN3 R577X genotype combination is associated with sprint ability. However, ACE ID/ ACTN3 R577X genotype combination is not related to the level of performance.

CK-MM gene polymorphism does not influence the blood CK activity levels after exhaustive eccentric exercise

Gene variants, such as creatine kinase (CK) polymorphisms, have been suggested to explain the inter-individual blood CK response to eccentric exercise. However, since this association is still doubtful, the purpose of this study was to analyse the relationship between the magnitudes of the CK response to exercise with the occurrence of muscle CK-MM NcoI polymorphism in young healthy subjects. Blood CK activity was assessed in 70 subjects immediately before and 3, 24, 48, 72, 96, 120, 168 h after strenuous eccentric exercise. Based on the amount of CK release by each subject, the sample was distributed in quartiles and the genotype and allele frequency distribution was compared among quartiles. Despite the inter-individual variability of CK response observed between subjects, there were no differences in genotype and allele frequencies among quartiles. The results allowed us to conclude that CK response after exhaustive eccentric exercise is not associated with CK-MM Ncol polymorphism.

In vitro and in vivo properties of usnic acid encapsulated into PLGA-microspheres

Microparticles will probably play a promising role in the future of chemotherapy. These polymeric delivery systems are capable of maximizing the therapeutic activity while reducing side effects of anti-cancer agents. Usnic acid (UA) is a secondary metabolite produced by lichens, which exhibits an anti-tumour activity. In this study, PLGA-microspheres containing usnic acid from Cladonia substellata were prepared by the double emulsion method, with or without PEG as stabilizer. The morphology of the microspheres was examined by optical and scanning electron microscopy. The in vitro kinetic profile of usnic acid loaded-microspheres was carried out by dissolution testing. The usnic acid content was analysed by HPLC. The cytotoxicity of free and encapsulated usnic acid was evaluated against HEp-2 cells using the MTT method. The anti-tumour assay was performed in mice against Sarcoma-180 tumour (UA 15 mg kg(-1) weight body/day) during 7 days. Animals were then sacrificed and tumour and organs were excised for histopathological analysis. Microspheres presented a smooth spherical surface with a mean diameter of 7.02 +/- 2.72 microm. The usnic acid encapsulation efficiency was approximately 100% (UA 10 mg 460 mg(-1) microspheres). A maximum release of 92% was achieved at the fifth day. The IC50 values for free and encapsulated usnic acid were 12 and 14 microg ml(-1), respectively. The encapsulation of usnic acid into microspheres promoted an increase of 21% in the tumour inhibition as compared with the free usnic acid treatment. In summary, usnic acid was efficiently encapsulated into PLGA-microspheres and the microencapsulation improved its anti-tumour activity.

Bioequivalence of two lamivudine tablet formulations

The present study describes the determination of the bioavailability of a new commercial tablet formulation of lamivudine (CAS 134678-17-4) compared with a reference formulation. The comparative bioequivalence of the test and a reference formulation (each 3 x 150 mg) was assessed in 24 healthy volunteers by means of a randomized two-way crossover design. Prior to the study both the test and reference formulations were examined for conformation to chromatographic purity and drug content. Each volunteer received the test (T) and the reference formulation (R) with a one-week drug-free interval between administrations. The plasma concentrations of T were monitored over a period of 12 h after drug administration using a sensitive HPLC method. Pharmacokinetic parameters for T were determined from plasma concentration-time data. Statistical tests were carried out at 90% confidence intervals using a parametric method (three-way ANOVA) for AUC and Cmax, and non-parametric method for Tmax. The present study showed that both formulations were bioequivalent for the geometric mean of AUC(0-12), AUC0-infinity), Cmax, and Tmax at the 90% confidence interval. The bioavailability of the test (%) was 96.7, 93.3, 99.7, 100.3, respectively. The T:R ratio was, in each case, well within the acceptable range of 100 +/- 20%.

Synthesis and cytotoxic activity of N-substituted thiosemicarbazones of 3-(3,4-methylenedioxy)phenylpropanal

Five new N-substituted thiosemicarbazones of 3-(3,4-methylenedioxy)phenylpropanal were synthesized. Safrole, a natural product obtained from sassafras oil (Ocotea pretiosa), was oxidized to alcohol using BH3-THF and H2O2, followed by oxidation to aldehyde using pyridinium dichromate (PDC) and condensation with five N-substituted derivatives of thiosemicarbazide. Tests were performed to evaluate the cytotoxic activity with continuous chain KB cells (epidermoide carcinoma of the floor of the mouth). Compounds 5 and 6 showed IC50 values of 1.5 and 4.6 micrograms/ml, respectively.

Synthesis of some 4-oxo-delta 2-thiazolin-2-ylhydrazones as potential antiprotozoal agents

Several 4-oxo-delta 2-thiazolin-2-ylhydrazone derivatives 6 (6-1 - 6-19) derived from the cyclization reaction between the thiosemicarbazones 5 and homologous alpha-chloroacids were prepared. Only compound 6-2 was found to be active against Entamoeba histolytica and Trichomonas vaginalis.

Asymmetric synthesis and biological evaluation of beta-L-(2R,5S)- and alpha-L-(2R,5R)-1,3-oxathiolane-pyrimidine and -purine nucleosides as potential anti-HIV agents

In order to study the structure-activity relationships of L-oxathiolanyl nucleosides as potential anti-HIV agents, a series of enantiomerically pure L-oxathiolanyl pyrimidine and purine nucleosides were synthesized and evaluated for anti-HIV-1 activity in human peripheral blood mononuclear (PBM) cells. The key intermediate 8 was synthesized starting from L-gulose via 1,6-thioanhydro-L-gulopyranose. The acetate 8 was condensed with thymine, 5-substituted uracils and cytosines, 6-chloropurine, and 6-chloro-2-fluoropurine to give pyrimidine and purine nucleosides. Upon evaluation of these final nucleosides, the 5-fluorocytosine derivative 51 was found to be the most potent compound among those tested. In the case of 5-substituted cytosine analogues, the antiviral potency was found to be in the following decreasing order: cytosine (beta-isomer) > 5-iodocytosine (beta-isomer) > 5-fluorocytosine (alpha-isomer) > 5-methylcytosine (alpha-isomer) > 5-methylcytosine (beta-isomer) > 5-bromocytosine (beta-isomer) > 5-chlorocytosine (beta-isomer). Among the thymine, uracil, and 5-substituted uracil derivatives, thymine (alpha-isomer) and uracil (beta-isomer) derivatives exhibited moderate anti-HIV activity. In the purine series, the antiviral potency is found to be in the following decreasing order: adenine (beta-isomer) > 6-chloropurine (beta-isomer) > 6-chloropurine (alpha-isomer) > 2-NH2-6-Cl-purine (beta-isomer) > guanine (beta-isomer) > N6-methyladenine (alpha-isomer) > N6-methyladenine (beta-isomer). The cytotoxicity was also determined in human PBM cells as well as Vero cells. None of the synthesized nucleosides was toxic up to 100 microM in PBM cells.

1,3-dioxolanylpurine nucleosides (2R,4R) and (2R,4S) with selective anti-HIV-1 activity in human lymphocytes

In order to study the structure-activity relationships of dioxolane nucleosides as potential anti-HIV-1 agents, various enantiomers of pure dioxolanylpurine nucleosides were synthesized and evaluated against HIV-1 in human peripheral blood mononuclear cells. The enantiomerically pure key intermediate 1, which was synthesized in nine steps from 1,6-anhydro-beta-D-mannose, was condensed with 6-chloropurine, 6-chloro-2-fluoropurine, and 2,6-dichloropurine in the presence of TMS triflate. The chloro or fluoro substituents were readily converted into amino, N-methylamino, hydroxy, methoxy, thiol, and methylthio under appropriate reaction conditions. Upon evaluation of these dioxolanes, the guanine derivative 24 exhibited the most potent anti-HIV-1 activity without cytotoxicity up to 100 microM in various cells. The decreasing antiviral activity order of beta-isomers was as follows: guanine > 6-chloro-2-aminopurine > 2-fluoroadenine > or = adenine > or = 2,6-diaminopurine > hypoxanthine > 2-chloroadenine > 6-chloropurine approximately equal to N6-methyladenine approximately equal to 6-mercaptopurine approximately equal to 6-(methylthio)purine.

Asymmetric synthesis of 1,3-dioxolane-pyrimidine nucleosides and their anti-HIV activity

In order to study the structure-activity relationships of dioxolane nucleosides as potential anti-HIV agents, various enantiomerically pure dioxolane-pyrimidine nucleosides have been synthesized and evaluated against HIV-1 in human peripheral blood mononuclear cells. The enantiomerically pure key intermediate 8 has been synthesized in nine steps from 1,6-anhydro-D-mannose (1), which was condensed with 5-substituted pyrimidines to obtain various dioxolane-pyrimidine nucleosides. Upon evaluation of these compounds, cytosine derivative 19 was found to exhibit the most potent anti-HIV agent although it is the most toxic. The order of anti-HIV potency was as follows: cytosine (beta-isomer) greater than thymine greater than cytosine (alpha-isomer) greater than 5-chlorouracil greater than 5-bromouracil greater than 5-fluorouracil derivatives. Uracil, 5-methylcytosine, and 5-iodouracil derivatives were found to be inactive. Interestingly, alpha-isomer 20 showed good anti-HIV activity without cytotoxicity. As expected, other alpha-isomers did not exhibit any significant antiviral activity. (-)-Dioxolane-T was 5-fold less effective against AZT-resistant virus than AZT-sensitive virus.