Insulin and fiber type in the offspring of T2DM subjects with resistance training and detraining.
OBJECTIVE
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·L, 837 ± 284 pmol·L, respectively (means ± SD)) than that in C (T1, T2: 647 ± 268 pmol·L, 635 ± 258 pmol·L, 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·L, 1040 ± 194 pmol·L, respectively (means ± SD)) but not in C (T2, T3: 635 ± 258 pmol·L, 625 ± 213 pmol·L, respectively (means ± SD)). MHC IIX fibers increased with detraining (P = 0.026).


CONCLUSIONS
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.
School of Physical Education, University of Otago, Dunedin, New Zealand.
Katherine L
KL
Schofield
Nancy J
NJ
Rehrer
Tracy L
TL
Perry
Angus
A
Ross
Jesper L
JL
Andersen
Hamish
H
Osborne
D000328:Adult; D016022:Case-Control Studies; D016241:Child of Impaired Parents; D003924:Diabetes Mellitus, Type 2; D005080:Exercise Test; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D000078790:Insulin Secretion; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000166:cytology / Q000502:physiology*; D018657:Muscle Fibers, Slow-Twitch / Q000166:cytology / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D009520:New Zealand; D055070:Resistance Training / Q000379:methods; D055815:Young Adult
D007328:Insulin