Pancreatic β-cell function increases in a linear dose-response manner following exercise training in adults with prediabetes
Pancreatic β-cell function increases in a linear dose-response manner following exercise training in adults with prediabetes
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DOI:
10.1152/ajpendo.00260.2013
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发表时间:
2013-11-01
影响因子:
5.1
通讯作者:
Kirwan, John P.
中科院分区:
文献类型:
--
作者:
Malin, Steven K.;Solomon, Thomas P. J.;Kirwan, John P.
Although some studies suggest that a linear dose-response relationship exists between exercise and insulin sensitivity, the exercise dose required to enhance pancreatic beta-cell function is unknown. Thirty-five older obese adults with prediabetes underwent a progressive 12-wk supervised exercise intervention (5 days/wk for 60 min at similar to 85% HRmax). Insulin and C-peptide responses to an OGTT were used to define the first- and second-phase disposition index (DI; beta-cell function = glucose-stimulated insulin secretion X clamp-derived insulin sensitivity). Maximum oxygen consumption ((V) over dotO(2max)) and body composition (dual-energy X-ray absorptiometry and computed tomography) were also measured before and after the intervention. Exercise dose was computed using (V) over dotO(2max) heart-rate derived linear regression equations. Subjects expended 474.5 +/- 8.8 kcal/session (2,372.5 +/- 44.1 kcal/wk) during the intervention and lost similar to 8% body weight. Exercise increased first- and second-phase DI (P < 0.05), and these changes in DI were linearly related to exercise dose (DIfirst phase: r =0.54, P < 0.001; DIsecond phase: r = 0.56, P = 0.0005). Enhanced DI was also associated with increased (V) over dotO(2max) (DIfirst phase: r = 0.36, P = 0.04; DIsecond phase: r = 0.41, P < 0.02) but not lower body fat (DIfirst phase: r = -0.21, P = 0.25; DIsecond phase: r = -0.30, P = 0.10) after training. Low baseline DI predicted an increase in DI after the intervention (DIfirst phase: r = -0.37; DIsecond phase: r = -0.41, each P < 0.04). Thus, exercise training plus weight loss increased pancreatic beta-cell function in a linear dose-response manner in adults with prediabetes. Our data suggest that higher exercise doses (i.e., >2,000 kcal/wk) are necessary to enhance beta-cell function in adults with poor insulin secretion capacity.