ESPE Abstracts

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: 0–30 min (AUCgl._0-30; AUCins._0-30), 30–60 min (AUCgl._30-60; AUCins._30-60), 60–120 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.