Background: Exercise performance is dependent on glucose supply as fuel to working muscles.
Objective and hypotheses: We hypothesised that postprandial insulin secretion impacts exercise induced glucose and insulin response.
Method: 27 sedentary obese adolescent males aged 15.31+1.33 were examined. Standard 2 h oral glucose tolerance test (OGTT) with further calculation AUC for glucose and insulin for increments: 030 min (AUCgl.0-30; AUCins.0-30), 3060 min (AUCgl.30-60; AUCins.30-60), 60120 min (AUCgl.60-120; AUCins.60-120). Multi stage treadmill test (Bruce protocol) followed by measurement of insulin and glucose level at the moment test termination with calculation the relevant curves (AUCgl.ex, AUCins.ex).
Results: Mean BMI z-score was 2.72+0.54. Impaired fasting glucose was established in 73%, impaired glucose tolerance in 26.6% participants. None of them was diabetic. Mean fasting glucose 5.29+0.79 mmol/l, mean fasting insulin 38.06+11.19 mIU/ml, mean Homa-IR 8.04+4.09. It was established progressive increasing of glycemic area AUCgl.0-30 <AUCgl.30-60 (P=0.002) <AUCgl.60-120 (P=0.004) as well as insulin one AUCins.0-30 <AUCins.30-60 (P=0.003) <AUCgl.60-120 (P=0.03). Glucose (4.49+0.55 mmol/l) and insulin levels (47.40+26.33 mIU/ml) were statistically decreased after the exercise test. AUCgl.60-120 >AUCgl.ex (P<0.0001); AUCins.60-120 >AUCins.ex (P<0.0001). We found two variants of insulin response at the exercise tolerance after the glucose load with increased (29.6%) and decreased (70.4%) glucose and insulin secretion. AUCins. at all stages of OGTT lower at the first group (P<0.002) as well as Ins.120 (P<0.001).
Conclusion: Metabolic response at the exercise is dependent on insulin secretion at the glucose load. Low postprandial AUCins. followed by Ins.120 <30 mIU/ml are associated with plasma insulin levels rise to correct the glucose immediately after exercise exhaustion.
01 - 03 Oct 2015
European Society for Paediatric Endocrinology