Effect of personalized moderate exercise training on Wistar rats fed with a fructose enriched water

Abstract

Background: Metabolic Syndrom has become a public health problem. It mainly results from the increased consumption of fat and sugar. In this context, the benefits of personalized moderate exercise training were investigated on a metabolic syndrome male wistar rat model food with fructose drinking water (20-25% w/v). Different markers including body weight, metabolic measurements, blood biochemistry related to metabolic syndrome complications have been evaluated.

Methods: Male Wistar rats were randomly allocated to 4 groups: control (sedentary (C, n = 8) and exercise trained (Ex, n = 8)), fructose fed (sedentary (FF, n = 8) and exercise trained fructose fed rats (ExFF, n = 10)). ExFF and Ex rats were trained at moderate intensity during the last 6 weeks of the 12 weeks-long protocol of fructose enriched water. Metabolic control was determined by measuring body weight, fasting blood glucose, HOMA 2-IR, HIRI, MISI, leptin, adiponectin, triglyceridemia and hepatic dysfunction.

Results: After 12 weeks of fructose enriched diet, rats displayed on elevated fasting glycaemia and insulin resistance. A reduced food intake, as well as increased body weight, total calorie intake and heart weight were also observed in FF group. Concerning biochemical markers, theoretical creatinine clearance, TG levels and ASAT/ALAT ratio were also affected, without hepatic steatosis. Six weeks of 300 min/week of moderate exercise training have significantly improved overweight, fasting glycaemia, HOMA 2-IR, MISI without modify HIRI. Exercise also decreased the plasma levels of leptin, adiponectin and the ratio leptin/adiponectin. Regarding liver function and dyslipidemia, the results were less clear as the effects of exercise and fructose-enriched water interact together, and, sometimes counteract each other.

Conclusion: Our results indicated that positive health effects were achieved through a personalized moderate training of 300 min per week (1 h/day and 5 days/week) for 6 weeks. Therefore, regular practice of aerobic physical exercise is an essential triggering factor to attenuate MetS disorders induced by excessive fructose consumption.

Keywords: Aerobic training; Fructose enriched water rat model; Metabolic syndrome.

Fig. 1

Weight, glucose and insulin tolerance measured during the study. a – Body weight evolution for the whole experiment. c control (n = 24 for 3 to 9 weeks, and n = 8 for 9 to 15 weeks). Ex: Exercise standard diet (n = 8). FF: fructose supplemented (n = 26 for 3 to 9 weeks and n = 8 for 9 to 15 weeks). ExFF: Exercise fructose supplemented (n = 10). b - Effect of training and fructose supplementation on blood glucose levels during OGTT, 15, 30, 45, 60, 90, 120 min after glucose charge in all groups, after subtracting baseline concentrations at 13 weeks old. c - Evolution of net glucose AUC in the four rat groups at 13 weeks old. d - Effect of training and fructose supplementation on plasma insulin levels during OGTT after subtracting baseline concentrations at 13 weeks old.*C compared to FF (***p < 0.001). e - Evolution of net insulin AUC in the four rat groups at 13 weeks old. For a, b, c, d, e figures: groups C: control (n = 7). Ex: Exercise standard diet (n = 8). FF: fructose supplemented (n = 7). ExFF: Exercise fructose supplemented (n = 10). Values are means ± SEM. For C and E figures, statistical differences with post-hoc test are observed when lowercase letters (a, b) are different with p < 0.05

Fig. 2

Evolution of hepatic complications. a – Quantification of ASAT/ALAT Ratio. C: control (n = 7). Ex: Exercise standard diet (n = 7). FF: fructose supplemented (n = 8). ExFF: Exercise fructose supplemented (n = 8). Values are means ± SEM. Statistical differences are observed when lowercase letters (a, b) are different. b - Hematoxylin and Eosin staining of liver (× 40 and × 100) for one rat of C group and one rat of FF group. Bar scale =50 μm. Arrow = lipid droplet. Small lipid droplets can be found only on FF group. c – Classification of steatosis evolution. The scale was determined as: Score 0: no lipid droplet. Score 1: less than 10 microvesicles of lipid droplets. Score 2: more than 10 microvesicles lipid droplets. Score 3: macro and micro vesicles lipid droplets > 30. Score 4: steatosis. The observation was performed on slides of each rat of C (n = 8), Ex (n = 8), FF (n = 8), ExFF (n = 10). The results displayed the percentage of rat for each score