Eight participants with complication-free Type 1 diabetes, whose mean ± sem age was 38 (6) years, mean ± sem HbA_1c concentration was 71 ±11 mmol/mol (8.7 ±1.0%) and mean ± sem Type 1 diabetes duration was 15 ±13 years, attended the research facility after an overnight fast on four separate occasions, having administered their basal insulin the night before (glargine 27.5±3.1U, n=8), but omitted morning rapid-acting insulin. Participants completed either a one-set (14-min), two-set (28-min), or three-set (42-min) resistance exercise trial (eight exercises x 10 repetitions) at 67±3% one-repetition maximum followed by a 60-min recovery, or a resting control trial. Venous blood samples were taken before and after exercise. Data were analysed using repeated-measures anova (P≤0.05).

Whereas IL-6 levels remained similar to baseline levels after one set of resistance exercises (30 min, P=0.287; 60 min, P=0.318), IL-6 levels were > baseline levels at 60 min post-exercise after a two-set exercise trial (2.94 ± 0.94 pg/ml, P=0.002) and doubled at both 30 min (4.01 ± 1.00 pg/ml, P=0.048) and 60 min (4.28 ± 1.25 pg/ml, P=0.084) post-exercise after the three-set resistance exercise trial. Post-exercise blood glucose area under the curve (mmol/l/60 min) was greater after both the one-set (P=0.025) and two-set trials (P=0.008), than after the control trial, but similar between the three-set trial and the control trial (P=0.240). The rise in IL-6 from baseline to peak concentration significantly correlated inversely with blood glucose area under the curve (r=-0.65, P=0.041).

Circulating IL-6 is increased by resistance exercise in a volume-dependent manner, and resistance exercise-induced increases in IL-6 correlated with reductions in post-exercise hyperglycaemia in Type 1 diabetes, suggesting a role for IL-6 in improving post-resistance exercise glycaemic disturbances in Type 1 diabetes.