Exercise training prevents increased intraocular pressure and sympathetic vascular modulation in an experimental model of metabolic syndrome.

E.F.S Castro,D.J Feriani,B Rodrigues,M.C Irigoyen,C.T Mostarda,K De Angelis,I.C Moraes-Silva

doi:10.1590/1414-431x20144217

Abstract

The present study aimed to study the effects of exercise training (ET) performed by rats on a 10-week high-fructose diet on metabolic, hemodynamic, and autonomic changes, as well as intraocular pressure (IOP). Male Wistar rats receiving fructose overload in drinking water (100 g/L) were concomitantly trained on a treadmill for 10 weeks (FT group) or kept sedentary (F group), and a control group (C) was kept in normal laboratory conditions. The metabolic evaluation comprised the Lee index, glycemia, and insulin tolerance test (KITT). Arterial pressure (AP) was measured directly, and systolic AP variability was performed to determine peripheral autonomic modulation. ET attenuated impaired metabolic parameters, AP, IOP, and ocular perfusion pressure (OPP) induced by fructose overload (FT vs F). The increase in peripheral sympathetic modulation in F rats, demonstrated by systolic AP variance and low frequency (LF) band (F: 37±2, 6.6±0.3 vs C: 26±3, 3.6±0.5 mmHg2), was prevented by ET (FT: 29±3, 3.4±0.7 mmHg2). Positive correlations were found between the LF band and right IOP (r=0.57, P=0.01) and left IOP (r=0.64, P=0.003). Negative correlations were noted between KITT values and right IOP (r=-0.55, P=0.01) and left IOP (r=-0.62, P=0.005). ET in rats effectively prevented metabolic abnormalities and AP and IOP increases promoted by a high-fructose diet. In addition, ocular benefits triggered by exercise training were associated with peripheral autonomic improvement.

Highlights

Metabolic syndrome (MS) is defined by physiological, biochemical, clinical, and metabolic changes that directly increase the risk of diabetes and cardiovascular mortality [1,2]
The main finding of the present study lies in the fact that metabolic, intraocular pressure (IOP), Arterial pressure (AP), and peripheral autonomic alterations promoted by a high-fructose diet can be BW (g) NA length Lee index Glycemia Kitt (%/min)
BW: body weight; NA length: naso-anal length; Kitt: rate constant for blood glucose disappearance. * P,0.05 vs C

Summary

Introduction

Metabolic syndrome (MS) is defined by physiological, biochemical, clinical, and metabolic changes that directly increase the risk of diabetes and cardiovascular mortality [1,2]. Several studies have shown that the large increase in fructose consumption in the last several decades has paralleled the increase in obesity rates [10,11] In this context, fructose overload in drinking water or chow has been used to promote metabolic, hemodynamic, structural, and functional derangements in animals. Fructose overload in drinking water or chow has been used to promote metabolic, hemodynamic, structural, and functional derangements in animals This MS model has been used by our laboratory [12,13] and others [9,14,15,16] to elucidate the various aspects of obesity, dyslipidemia, and insulin resistance associated with autonomic changes

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