TOPLINE:
In healthy young adults, a single 30-minute bout of outdoor aerobic exercise significantly reduces fasting and 1-hour glucose levels during an oral glucose tolerance test (OGTT) the next day and improves insulin sensitivity.
METHODOLOGY:
- Recent studies have identified 1-hour post-load glucose concentration during an OGTT as a specific and early predictor of diabetes, and exercise has long been known for its metabolic benefits in people with and without diabetes.
- The researchers investigated the effect of a single bout of aerobic exercise on 1-hour post-load glucose levels during an OGTT in 32 young, healthy, normal-weight or marginally overweight individuals (mean age, 35 years; 14 women and 18 men) with a sedentary or moderately active lifestyle.
- The participants underwent an initial OGTT after at least 4 days of physical inactivity, followed by a second OGTT the day after a single 30-minute bout of aerobic exercise.
- The exercise session consisted of a light jog for 30 minutes, monitored using a metabolic holter to quantify energy expenditure and exercise intensity. The participants did not undertake any exercise outside the lab sessions.
- Blood glucose levels were measured, and insulin sensitivity and secretion were estimated using surrogate indices derived from OGTT glucose and insulin assays, including the Matsuda index, oral glucose insulin sensitivity (OGIS) index, and quantitative insulin sensitivity check index, as well as the homeostasis model assessment (HOMA) of insulin resistance and of beta-cell function (HOMA-B).
TAKEAWAY:
- Postexercise insulin levels also were significantly lower 1 hour after glucose load, decreasing from 57.4 IU/mL at baseline to 43.5 IU/mL the day after exercise (P = .01).
- Insulin sensitivity improved significantly after exercise, as indicated by increases in the Matsuda index (P = .02) and OGIS index (P = .04), along with a reduction in insulin resistance (P = .04).
- The study found a trend toward increased beta-cell function the day after an exercise bout, as indicated by a nonsignificant increase in HOMA-B from 144.7 at baseline to 167.1 after exercise.
IN PRACTICE:
“Improvement in 1-hour post-load plasma glucose following a single session of aerobic physical activity suggests that exercise could have a direct effect on T2D [type 2 diabetes] risk and cardiovascular risk,” the authors wrote.
SOURCE:
The study was led by Simona Moffa, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, and Gian Pio Sorice, Università Degli Studi di Bari “Aldo Moro,” Bari, Italy. It was published online in the Journal of Endocrinological Investigation.
LIMITATIONS:
The study had a limited sample size, which may affect the generalizability of the findings. C-peptide levels, which could have provided additional insights into insulin secretion, were not assessed in the study.
DISCLOSURES:
The study was supported by grants from Università Cattolica del Sacro Cuore. The authors declared no conflicts of interest.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.