Location: Children's Nutrition Research CenterTitle: Lifestyle intervention improves heart rate recovery from exercise in adults with type 2 diabetes: Results from the Look AHEAD study) Author
Submitted to: Journal of Obesity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/14/2012
Publication Date: 11/22/2012
Citation: Ribisl, P.M., Gaussoin, S.A., Lang, W., Bahnson, J., Connelly, S.A., Horton, E.S., Jakicic, J.M., Killean, T., Kitzman, D.W., Knowler, W.C., Stewart, K.J., Foreyt, J.P., Look Ahead Research Group. 2012. Lifestyle intervention improves heart rate recovery from exercise in adults with type 2 diabetes: Results from the Look AHEAD study. Journal of Obesity. Article ID 309196. Interpretive Summary: Type 2 diabetes (T2D) is a serious medical condition and a serious, growing global epidemic. One of the long-term health consequences of T2D is an increased chance of heart diseases and death. One of the contributing factors to this increased heart disease is autonomic nervous system dysfunction (ANSD), which may be associated with T2D. It is possible to detect ANSD with a variety of tests, including heart rate variability (HRV) at rest and the heart rate recovery (HRR) following exercise. The Look AHEAD study had individuals with T2D randomized to either an intensive lifestyle intervention (ILI) or a diabetes support and education (DSE) group. The ILI group received a behavioral weight loss program that included group and individual meetings, a clearly defined weight loss goal, calorie restriction, and increased levels of physical activity. The DSE group received a less intense educational intervention. From this data we evaluated the health, weight loss, and fitness effects of intensive weight loss from ILI compared to DSE upon HRR from walking at various speeds. After one year, participants in the ILI group lost an average of 8.6% of their initial weight compared to 0.7% in the DSE group. Mean fitness increased by 20.9% in the ILI group versus 5.8% in the DSE group in this same time period. Exercise and HRR variables indicating heart health were also found to have improved in the ILI group versus the DSE group. The benefits of weight loss and improved fitness have been shown to produce significant and improved heart health and HRR in individuals. Further studies are needed to investigate any other heart and health benefits that ILI programs may have on overweight and obese individuals with and without T2D.
Technical Abstract: The primary aims of this paper were (1) to evaluate the influence of intensive lifestyle weight loss and exercise intervention (ILI) compared with diabetes support and education (DSE) upon Heart Rate Recovery (HRR) from graded exercise testing (GXT), and (2) to determine the independent and combined effects of weight loss and fitness changes upon HRR. In 4503 participants (45–76 years) who completed one year of intervention, HRR was measured after a submaximal GXT to compare the influence of (ILI) with (DSE) upon HRR. Participants assigned to ILI lost an average 8.6% of their initial weight versus 0.7% in DSE group (P < 0.001), while mean fitness increased in ILI by 20.9% versus 5.8% in DSE (P < 0.001). At Year 1, all exercise and HRR variables in ILI improved (P < 0.0001) versus DSE: heart rate (HR) at rest was lower (72.8+/-11.4 versus 77.7+/-11.7 b/min), HR range was greater (57.7+/-12.1 versus 53.1+/-12.4b/min), HR at 2 minutes was lower (89.3+/-21.8 versus 93.0+/-12.1 b/min), and HRR was greater (41.25+/-22.0 versus 37.8+/-12.5 b/min). Weight loss and fitness gain produced significant separate and independent improvements in HRR.