Resistive training improves insulin sensitivity after stroke

Abstract

Background: Insulin resistance is highly prevalent after stroke, contributing to comorbid cardiovascular conditions that are the leading cause of death in the stroke population. This study determined the effects of unilateral resistive training (RT) of both the paretic and nonparetic legs on insulin sensitivity in stroke survivors.

Methods: We studied 10 participants (mean age 65 ± 2 years; mean body mass index 27 ± 4 kg/m2) with hemiparetic gait after remote (>6 months) ischemic stroke. All subjects underwent 1-repetition maximum (1-RM) strength testing, 9 had an oral glucose tolerance test (OGTT), and 7 completed a 2-hour hyperglycemic clamp (with glucose elevation targeted at 98 mg/dL above baseline fasting level) before and after 12 weeks (3×/week) of progressive, high repetition, high-intensity RT. Body composition was assessed by dual-energy x-ray absorbtiometry in all participants.

Results: Leg press and leg extension 1-RM increased in the paretic leg by 22% (P < .05) and 45% (P < .01), respectively. Fasting insulin decreased 23% (P < .05), with no change in fasting glucose. The 16% reduction in OGTT insulin area under the curve (AUC) across training was not statistically significant (P = .18). There was also no change in glucose AUC. First-phase insulin response during the hyperglycemic clamp (0-10 minutes) decreased 24% (P < .05), and second-phase insulin response (10-120 minutes) decreased 26% (P < .01). Insulin sensitivity increased by 31% after RT according to clamp calculations (P < .05).

Conclusions: These findings provide the first preliminary evidence that RT may reduce hyperinsulinemia and improve insulin sensitivity after disabling stroke.

Keywords: Diabetes; energy metabolism; exercise; rehabilitation; stroke recovery.

Figure 1

Mean plasma insulin at each of 3 phases (baseline, 0–10 minutes, and 10–120 minutes) during the 2-hour hyperglycemic clamp (n = 7). There was a significant insulin reduction for each phase after 12 weeks of resistive training (RT). Values are mean ± standard error. *P < .05; **P < .01.