NEW YORK (Reuters Health) – People with pre-diabetes who engage in regular aerobic exercise improve their vascular reactivity to nearly normal levels, even if they do not lose weight, researchers said in Philadelphia last weekend at the American Association of Clinical Endocrinologists 21st Annual Meeting and Clinical Congress.
“Doctors should tell their patients with pre-diabetes to do moderate exercise,” lead author Dr. Sabyasachi Sen, from Bay State Medical Center and Tufts University School of Medicine in Boston told Reuters Health.
“The patients in this study did what the American Diabetes Association recommends, 150 minutes of aerobic exercise a week at 70% of their maximum heart rate, and showed improvement in several of their lipid fractions and their vascular reactivity,” he said.
There is a lack of data on endothelial function in pre-diabetes, although there is a fair amount in the literature confirming endothelial cell dysfunction and poor vascular reactivity in diabetics.
In a randomized crossover trial, Dr. Sen and his team studied 20 exercise-naïve subjects with pre-diabetes aged 45 to 65, with body mass index ranging from 25 to 34.9.
Ten subjects did 150 minutes per week of aerobic exercise for six weeks, and 10 did no exercise. After a four-week washout period, the groups switched. The investigators studied endothelial function in both groups with flow mediated dilatation (FMD) of the brachial artery. They also looked at endothelial, bio-inflammatory markers and blood pressure, fasting lipids, insulin, and glucose.
The mean FMD in the no-exercise phase was 5.7%. After exercise, the FMD improved to 11.2%.
No weight loss was noted, but there were statistically significant reductions in leptin, interleukin-6, high sensitivity-C reactive protein (hs-CRP), tumor necrosis factor (TNF), fasting triglyceride, low-density lipoprotein, and ApoB levels with exercise, Dr. Sen said.
In addition, insulin sensitivity as measured by homeostatic model assessment (HOMA) and Apo-A1 improved after exercise. However, fasting glucose levels, HbA1c, and high density lipoprotein (HDL) cholesterol levels did not change.
Without exercising, pre-diabetic patients had vascular reactivity levels as poor as those in patients with overt diabetes, Dr. Sen said.
“Knowing that exercise significantly improves vascular reactivity for pre-diabetic patients is substantial,” he said. “The pre-diabetic stage is a therapeutic window when aerobic exercise can make significant improvement in vascular reactivity and bring it back towards normalcy, before these patients progress to overt diabetes. It may be too late in the overt diabetes stage to make significant impact in vascular reactivity with exercise alone.”