Abstract 616: Aging, Menopause And Metabolic Syndrome As Related To The Beneficial Effects Of Exercise Training

Menopause and aging are associated with increased blood pressure. High fructose may modify the development of the pathologies associated with these conditions. The objective was to investigate the effects of exercise training (ET) in aged, oophorectomy mimic of menopause fructose-fed rats. Female Wistar rats (24 months old) were ovariectomized, fed with fructose (100g/L) in drinking water and divided in 5 groups (n=8/group): control (C), ovariectomized (O), ovariectomized trained (OT, n= 8), ovariectomized fructose (OF, n= 8) and ovariectomized fructose trained (OFT, n= 8). The ET was performed on a treadmill (1 h/day; 5 days/wk for 8 wk). The metabolic results showed that ET decreased adipose tissue in both trained groups (OT: 4.3±0.5, OFT: 5.3±0.7), compared with sedentary rats (C: 6.2± 0.6, O: 9.6±1.3, OF: 10.1±0.6, g). The same findings were observed for insulin resistance (OT: 4.6±0.2, OFT: 5.5±0.6 vs C: 3.2± 0.6, O: 3.2±0.3, OF: 4.0±0.5, mg/dl/min). ET increased physical capacity (OT: 20±0.9, OFT: 17.5±0.9 vs C: 11.5± 0.5, O: 10±0.5, OF: 10.3±0.5 Min/h). The hemodynamic results showed that ET attenuated the increase in MBP (C: 109.4± 1.9, OT: 103±1.1, OFT: 107±1.1 vs O: 119.1±1.9, OF: 119.1±2.7, mmHg) and HR (C: 341.4± 8, OT: 302±1, OFT: 306.4±8 vs O: 398.17±19, OF: 378.9±17 Bpm). The sympathetic tonus was decreased in C, OT and OTF (C: 63.6± 4, OT: 62.2±3, OFT: 51.2± 7 beats/ min) when compared with O and OF (O: 102.6±12, OF: 91.9±7 beats/min) while vagal tonus was increased just in OT (OT: 44.8±5) vs (C: 24.9± 6, OFT: 22±3, O: 13±6, OF: 9±2 beats/min). The OT and OTF groups showed an increased bradycardic response to BP changes (C: -1.50±0.06 OT: -1.74±0.12, OFT: -1.77±0.15 vs O: -0.93±0.07, OF: -1.21±0.12 bpm/mmHg). ET increased the Standard deviation of the pulse interval (C: 6.7±1.1 OT: 11.6±0.8, OFT: 13.0±1.5 vs O: 7.05±0.6, OF: 9.57±0.7 ms) and decreased VARR PAS (C: 6.7±1.09 OT: 23.6±0.8, OFT: 30.7±2.6 vs O: 56.4±8.1, OF: 40.5±3.7 mmHg2) as well as representative sympathetic modulation (LF PAS) (C: 6.7±1.1 OT: 3.6±0.5, OFT: 3.7±0.4 vs O: 9.8±1.2, OF: 8.3±0.8 mmHg. In conclusion, ET effectively improved metabolic and cardiovascular parameters altered by aged or excessive fructose consumption in rats submitted to ovarian hormone deprivation.

Abstract 345: Effects of Physical Exercise on Blood Pressure of Patients With Chronic Kidney Disease on Hemodialysis: Meta-analysis of Randomized Clinical Trials

Background: The incidence of End Stage Renal Disease (ESRD) has increased in recent years. Hypertension is a well described complication of chronic kidney disease. Its incidence in hemodialysis patients is approximately 80% and there is substantial evidence of the relationship between high blood pressure and cardiovascular risk in this population.

Objective: To systematically review the effects of physical exercise on blood pressure of patients with ESRD undergoing hemodialysis (HD).

METHODS: MEDLINE, EMBASE, COCHRANE CENTRAL and LILACS databases were searched for trials published between January 1980 and August 2011. Only randomized clinical trials (RCTs) with adult patients diagnosed with ESRD on HD comparing aerobic exercise, resistance training or combined resistance and aerobic training with the control group were eligible. The selection of studies, data extraction and assessment of methodological quality were performed by two independent reviewers. The meta-analysis was conducted using the random effects model.

Results: Our search found 1.034 articles, from which 12 RCTs (389 participants) met the eligibility criteria and were included. We observed that combined resistance and aerobic training (six RCTs) reduces the systolic (-5.84 mmHg; 95% CI: -9.8, -1.88) and the diastolic blood pressure (-3.90 mmHg; 95% CI: -6.20, -1.60); however, the same was not observed with aerobic exercise (six RCTs) (SBP: -0.84 mmHg, 95% CI: -7.18, 5.51 and DBP: 0.68 mmHg, 95% CI: -3.38, 4.74). Probably, the absence of blood pressure decrease with aerobic exercise was due to the small sample size of those studies, the inclusion of both hypertensive and non hypertensive patients and the lack of information whether there was a control of the dosage of antihypertensive medication during follow-up.

Conclusions: Combined resistance and aerobic training reduces the blood pressure of ESRD patients on HD and, therefore, can be recommended as an adjuvant non-pharmacological intervention in the treatment of ESRD patients on HD. Sources of Funding: Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Renin angiotensin system and cardiac hypertrophy after sinoaortic denervation in rats

OBJECTIVE

The aim of this study was to evaluate the role of angiotensin I, II and 1-7 on left ventricular hypertrophy of Wistar and spontaneously hypertensive rats submitted to sinoaortic denervation.

METHODS

Ten weeks after sinoaortic denervation, hemodynamic and morphofunctional parameters were analyzed, and the left ventricle was dissected for biochemical analyses.

RESULTS

Hypertensive groups (controls and denervated) showed an increase on mean blood pressure compared with normotensive ones (controls and denervated). Blood pressure variability was higher in denervated groups than in their respective controls. Left ventricular mass and collagen content were increased in the normotensive denervated and in both spontaneously hypertensive groups compared with Wistar controls. Both hypertensive groups presented a higher concentration of angiotensin II than Wistar controls, whereas angiotensin 1-7 concentration was decreased in the hypertensive denervated group in relation to the Wistar groups. There was no difference in angiotensin I concentration among groups.

CONCLUSION

Our results suggest that not only blood pressure variability and reduced baroreflex sensitivity but also elevated levels of angiotensin II and a reduced concentration of angiotensin 1-7 may contribute to the development of left ventricular hypertrophy. These data indicate that baroreflex dysfunction associated with changes in the renin angiotensin system may be predictive factors of left ventricular hypertrophy and cardiac failure.