Effects of mild hyperinsulinemia on the metabolic response to exercise

Martin, Michael; Horwitz, David L.; Nattrass, M.; Granger, Jeffrey F.; Rochman, H.; Ash, Sarah

doi:10.1016/0026-0495(81)90084-6

Cited by 17 publications

(3 citation statements)

References 30 publications

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“…Zinman et al [34] showed that high insulin levels in exercising diabetics decrease hepatic glucose production and peripheral release of energy substances. Mild hyperinsulinaemia prevents the normal rise of free fatty acids and 13-hydroxy-butyrate levels and augments the rise in lactate levels during exercise in normal adults [17]. Parizkova et al [23] reported a decrease of free fatty acids in obese children during running on a treadmill [for review see 9].…”

Section: Discussionmentioning

confidence: 99%

The effect of fasting hyperinsulinaemia on physical fitness in obese children

Molnár

Pórszász

1990

Eur J Pediatr

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Treadmill stress testing was carried out according to the Bruce protocol on 14 non-hyperinsulinaemic and 11 hyperinsulinaemic obese children and on 43 age-matched controls. The obese groups were matched for body weight, body composition, physical activity and plasma lipid values. Body composition was calculated on the basis of four skinfold measurements. Exercise duration and physical working capacity corrected for body weight and lean body mass were decreased in the obese children (P less than 0.01). The hyperinsulinaemic obese children had lower physical working capacities (in absolute values and when corrected for body weight and lean body mass) than the non-hyperinsulinaemic obese children (P less than 0.05). The exercise period was not significantly different in the two obese subgroups. While fasting plasma insulin levels showed a significant negative correlation with exercise duration and relative physical working capacity in the obese children, the anthropometric parameters did not. It is suggested that the decreased physical fitness in obese children is further aggravated in those with hyperinsulinaemia.

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Section: Discussionmentioning

confidence: 99%

The effect of fasting hyperinsulinaemia on physical fitness in obese children

Molnár

Pórszász

1990

Eur J Pediatr

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“…When insulin is reduced below normal exercise levels by somatostatin (5), fasting (6), or diabetes (7), the exercise-induced increment in FFA levels is exaggerated. Conversely, hyperinsulinemia leads to a reduction in FFA levels during exercise (8), presumably because of a decrease in lipolytic rate. Nevertheless, the role of insulin in fat metabolism under normal exercise conditions remains to be established.…”

Section: The Role Of the Exercise-induced Fall In Insulin In Fat Metamentioning

confidence: 94%

Exercise-Induced Fall in Insulin and Increase in Fat Metabolism During Prolonged Muscular Work

et al. 1989

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The role of the exercise-induced fall in insulin in fat metabolism was studied in dogs during 150 min of treadmill exercise alone (controls) or with insulin clamped at basal levels by an intraportal infusion to prevent the normal fall in insulin concentration (ICs).To counteract the suppressive effect of insulin on glucagon release, glucagon was supplemented by an intraportal infusion in ICs. In all dogs, catheters were placed in a carotid artery and in the portal and hepatic veins for sampling and in the vena cava and the splenic vein for infusion purposes. Glucose levels were clamped in ICs to recreate the glycemic response evident in controls. In controls, insulin fell by 7 ± 1 ixll/ml but was unchanged from basal levels in ICs (0 ± 2 fxU/ml). Glucagon, norepinephrine, epinephrine, and cortisol rose similarly in controls and ICs. Arterial free-fatty acid (FFA) levels rose by 644 ± 1 2 6 jxeq/L in controls but did not increase in ICs ( -1 2 ± 148 ixeq/L). Arterial glycerol levels rose by 337 ± 43 and 183 ± 19 fxM in controls and ICs. Hepatic FFA delivery and fractional extraction increased by 17 ± 3 and 0.06 ± 0.02 |xmol • k g 1 • min 1 , respectively, in controls. In ICs, hepatic FFA delivery increased by only 1 ± 2 (xmol • kg~1 • min 1 , whereas hepatic fractional extraction fell slightly (-0.03 ± 0.03). Consequently, net hepatic FFA uptake rose by 4.8 ± 1 . 5 fxmol • k g 1 • Cortisol Epinephrine Free fatty acid Glucagon Glucose Glycerol p-Hydroxybutyrate Insulin Lactate Norepinephrine 1 1 1 1 1 1 1 1 1 1 nm pM |JLM ng/L mM mM (JLM pM mM nM = 0.360 ng/dl = 0.183 pg/ml = 1 |xeq/L = 1 pg/ml = 18 mg/dl = 9.21 mg/dl = 0.01 mg/dl = 0.139 ixU/ml = 1 meq/L = 169 pg/mlFrom the m i n 1 in controls but decreased slightly in ICs (-0.5 ± 1.1 jimol • k g 1 • min 1 ). At least partly because of the differences in hepatic FFA uptake, arterial phydroxybutyrate (50 ± 14 vs. 23 ± 8 jiM) and net hepatic p-hydroxybutyrate output (2.2 ± 0.7 vs. 0.4 ± 0.3 ixmol • k g 1 • min 1 ) rose more in controls than in ICs. In summary, the exercise-induced fall in insulin 7) is essential to the increase in FFA levels during prolonged muscular work, 2) facilitates hepatic FFA uptake by enhancing the delivery of FFAs to the liver and their extraction by the liver, and 3) enhances the net p-hydroxybutyrate output by the liver, at least in part through the effects described in 1 and 2. Hence, the exercise-induced fall in insulin is essential for the transition to the increased rate of FFA metabolism that occurs as work duration progresses. Diabetes 38: 1989 T he most important change in substrate utilization that occurs as exercise duration progresses is the transition to an increased rate of free-fatty acid (FFA) metabolism. This increase in FFA utilization delays glycogen depletion and provides the muscle with a virtually inexhaustible supply of substrate for energy production. Despite the importance of FFA usage during prolonged exercise, little is known about the signals that control the mobilization and metabolism of this substrate duri...

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“…The distribution of body fat (upper vs. lower body) can influence RER during exercise via differing hormonal responses [38], potentially helping to explain some of the divergent findings. Other factors that could influence RER include cycling cadence [30,193], hydration status [31], short-term exercise training volume [19], genetic variation [41], hyperinsulinemia [194], insulin resistance [195], daily energy and protein intake, protein supplementation during exercise, and pre-exercise glucose levels, but further investigation is needed in these areas.…”

Section: Other Possible Contributing Factorsmentioning

confidence: 99%

Factors Influencing Substrate Oxidation During Submaximal Cycling: A Modelling Analysis

2022

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Background Multiple factors influence substrate oxidation during exercise including exercise duration and intensity, sex, and dietary intake before and during exercise. However, the relative influence and interaction between these factors is unclear. Objectives Our aim was to investigate factors influencing the respiratory exchange ratio (RER) during continuous exercise and formulate multivariable regression models to determine which factors best explain RER during exercise, as well as their relative influence. Methods Data were extracted from 434 studies reporting RER during continuous cycling exercise. General linear mixed-effect models were used to determine relationships between RER and factors purported to influence RER (e.g., exercise duration and intensity, muscle glycogen, dietary intake, age, and sex), and to examine which factors influenced RER, with standardized coefficients used to assess their relative influence. Results The RER decreases with exercise duration, dietary fat intake, age, VO2max, and percentage of type I muscle fibers, and increases with dietary carbohydrate intake, exercise intensity, male sex, and carbohydrate intake before and during exercise. The modelling could explain up to 59% of the variation in RER, and a model using exclusively easily modified factors (exercise duration and intensity, and dietary intake before and during exercise) could only explain 36% of the variation in RER. Variables with the largest effect on RER were sex, dietary intake, and exercise duration. Among the diet-related factors, daily fat and carbohydrate intake have a larger influence than carbohydrate ingestion during exercise. Conclusion Variability in RER during exercise cannot be fully accounted for by models incorporating a range of participant, diet, exercise, and physiological characteristics. To better understand what influences substrate oxidation during exercise further research is required on older subjects and females, and on other factors that could explain additional variability in RER.

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Effects of mild hyperinsulinemia on the metabolic response to exercise

Cited by 17 publications

References 30 publications

The effect of fasting hyperinsulinaemia on physical fitness in obese children

The effect of fasting hyperinsulinaemia on physical fitness in obese children

Exercise-Induced Fall in Insulin and Increase in Fat Metabolism During Prolonged Muscular Work

Factors Influencing Substrate Oxidation During Submaximal Cycling: A Modelling Analysis

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