Postexercise insulin action in African-American women

J Natl Med Assoc. 2006 Nov;98(11):1832-9.

Abstract

African Americans are more insulin resistant than Caucasians. A single bout of moderate-intensity exercise reduces insulin resistance in sedentary Caucasian individuals. The impact of a single bout of exercise on insulin resistance has never been studied in African Americans. The purpose of this experiment was to evaluate the impact of a single bout of exercise on insulin resistance in African-American women.

Design: Insulin resistance was assessed in 10 sedentary, over-weight or obese African-American women during a sedentary and exercise condition over a two-day period. During the sedentary condition, participants fasted overnight and sat quietly in the laboratory for 75 minutes. During the exercise condition, participants completed 75 minutes of brisk walking on a treadmill. Ninety minutes following each condition, participants completed an oral glucose tolerance test (OGTT). Three-and-a-half hours later, subjects consumed a standardized meal [meal tolerance test (MTT)].

Results: The insulin response to the OGTT was 18% lower (p=0.046), and insulin sensitivity was 18% higher (p=0.042) in the exercise condition compared to the sedentary condition. There were no differences between conditions following the MTT.

Conclusions: These results indicate that overweight/obese, sedentary, insulin resistant African-American women had a significant improvement in insulin sensitivity from 75 minutes of brisk walking.

MeSH terms

  • Adult
  • Black or African American*
  • Energy Metabolism
  • Exercise / physiology*
  • Female
  • Glucose Tolerance Test
  • Humans
  • Insulin Resistance / physiology*
  • Middle Aged
  • Oxygen Consumption / physiology