TY - JOUR
T1 - A ∼60-min brisk walk increases insulin-stimulated glucose disposal but has no effect on hepatic and adipose tissue insulin sensitivity in older women
AU - Wang, Xuewen
AU - Patterson, Bruce W.
AU - Smith, Gordon I.
AU - Kampelman, Janine
AU - Reeds, Dominic N.
AU - Sullivan, Shelby A.
AU - Mittendorfer, Bettina
PY - 2013/6/1
Y1 - 2013/6/1
N2 - The purpose of this study was to determine whether brisk walking improves multiorgan (liver, muscle, adipose tissue) insulin sensitivity in older women. Ten nonobese older women (age: 66.7 ± 1.5 yr, mean ± SE) completed two 2-stage hyperinsulinemic-euglycemic clamp procedures [insulin infusion rate stage 1:10 mU/m2 body surface area (BSA) per min; stage 2:50 mU/m2 BSA per min] in conjunction with stable isotope-labeled glucose and palmitate tracer infusions: one in the morning after a single, ∼1-h bout of brisk treadmill walking, the other after an equivalent period of rest in the late afternoon of the preceding day. We found that basal glucose rate of appearance (Ra) into plasma was not different after rest and after exercise (17.3 ± 0.8 and 17.1 ± 0.4 μmol/kg fat-free mass per min, respectively). The insulin-mediated decrease in glucose Ra during stage 1 of the clamp was also not different after rest and exercise (82.2% ± 3.4% and 77.7% ± 2.1%, respectively), but glucose rate of disappearance (Rd) during stage 2 of the clamp was significantly greater (P<0.05) after exercise than rest (88.0 ± 5.9 and 78.4 ± 6.5 μmol/kg fat-free mass per min, respectively). There were no differences in palmitate Ra during basal conditions or insulin infusion after exercise and after rest. Therefore, we conclude that a single bout of brisk walking for ∼ 1 h improves muscle insulin sensitivity but has no effect on liver and adipose tissue insulin sensitivity in older women.
AB - The purpose of this study was to determine whether brisk walking improves multiorgan (liver, muscle, adipose tissue) insulin sensitivity in older women. Ten nonobese older women (age: 66.7 ± 1.5 yr, mean ± SE) completed two 2-stage hyperinsulinemic-euglycemic clamp procedures [insulin infusion rate stage 1:10 mU/m2 body surface area (BSA) per min; stage 2:50 mU/m2 BSA per min] in conjunction with stable isotope-labeled glucose and palmitate tracer infusions: one in the morning after a single, ∼1-h bout of brisk treadmill walking, the other after an equivalent period of rest in the late afternoon of the preceding day. We found that basal glucose rate of appearance (Ra) into plasma was not different after rest and after exercise (17.3 ± 0.8 and 17.1 ± 0.4 μmol/kg fat-free mass per min, respectively). The insulin-mediated decrease in glucose Ra during stage 1 of the clamp was also not different after rest and exercise (82.2% ± 3.4% and 77.7% ± 2.1%, respectively), but glucose rate of disappearance (Rd) during stage 2 of the clamp was significantly greater (P<0.05) after exercise than rest (88.0 ± 5.9 and 78.4 ± 6.5 μmol/kg fat-free mass per min, respectively). There were no differences in palmitate Ra during basal conditions or insulin infusion after exercise and after rest. Therefore, we conclude that a single bout of brisk walking for ∼ 1 h improves muscle insulin sensitivity but has no effect on liver and adipose tissue insulin sensitivity in older women.
KW - Exercise
KW - Insulin sensitivity
KW - Older adults
UR - http://www.scopus.com/inward/record.url?scp=84878592132&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.01364.2012
DO - 10.1152/japplphysiol.01364.2012
M3 - Article
C2 - 23493357
AN - SCOPUS:84878592132
SN - 8750-7587
VL - 114
SP - 1563
EP - 1568
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 11
ER -