Resumen de Insulin and Fiber Type in the Offspring of T2DM Subjects with Resistance Training and Detraining.
Hamish R. Osborne, Katherine L. Schofield, Nancy J. Rehrer, Tracy L. Perry, Angus A. Ross, Jesper L. Andersen
AB Purpose: Effects of resistance training and detraining on glucose and insulin responses to an oral glucose load, muscle fiber type, and muscular performance in the offspring of those with type 2 diabetes (familial insulin resistant (FIR)) were investigated. Methods: Six FIR participants and 10 controls (C) completed 9 wk of resistance training and 9 wk of detraining. Measures of strength and power, an oral glucose tolerance test, and a muscle biopsy to determine myosin heavy chain (MHC) fiber composition were taken at baseline (T1), after training (T2), and after detraining (T3). Results: Three-repetition maximum increased (P <= 0.001) similarly in both groups in all strength measures, e.g., leg press (FIR T1, T2: 121 +/- 34 kg, 186 +/- 50 kg; C T1, T2: 137 +/- 42 kg, 206 +/- 64 kg, respectively (means +/- SD)). Wingate peak power increased (FIR T1, T2: 505 +/- 137 W, 523 +/- 143 W; C T1, T2: 636 +/- 211 W, 672 +/- 223 W, respectively; P <= 0.005 (means +/- SD)). Training reduced insulin area under the curve more (P = 0.050) in FIR (T1, T2: 1219 +/- 734 pmol[middle dot]L-1, 837 +/- 284 pmol[middle dot]L-1, respectively (means +/- SD)) than that in C (T1, T2: 647 +/- 268 pmol[middle dot]L-1, 635 +/- 258 pmol[middle dot]L-1, respectively (means +/- SD)). MHC distribution did not change with training. Strength (three-repetition maximum measures) decreased with detraining (P <= 0.001) although Wingate power did not. Detraining increased insulin area under the curve (P = 0.018) in FIR (T2, T3: 837 +/- 285 pmol[middle dot]L-1, 1040 +/- 194 pmol[middle dot]L-1, respectively (means +/- SD)) but not in C (T2, T3: 635 +/- 258 pmol[middle dot]L-1, 625 +/- 213 pmol[middle dot]L-1, respectively (means +/- SD)). MHC IIX fibers increased with detraining (P = 0.026). Conclusion: FIR appears to have exaggerated responses to resistance training and detraining, with a greater reduction in insulin release with glucose ingestion after training and increase when training ceases. Resistance training has a significant effect on insulin responses and may reduce future risk of type 2 diabetes mellitus among FIR.
