Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT00031226 |
| Other study ID # |
993 |
| Secondary ID |
R01HL070300 |
| Status |
Completed |
| Phase |
N/A
|
| First received |
February 27, 2002 |
| Last updated |
March 12, 2014 |
| Start date |
September 2004 |
| Est. completion date |
August 2007 |
Study information
| Verified date |
March 2014 |
| Source |
Arizona State University |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
United States: Federal Government |
| Study type |
Observational
|
Clinical Trial Summary
To determine how weight loss achieved by intensive lifestyle intervention including diet and
exercise alters lipoprotein oxidation/oxidative stress and antioxidant status in overweight
diabetic individuals.
Description:
BACKGROUND:
Overweight and diabetes increase risk of cardiovascular disease but the mechanism(s) that
account for this effect remain to be clarified. Oxidation of low-density lipoprotein (LDL)
is thought to contribute to atherosclerosis. Diabetes may increase oxidative stress, and
this may contribute to increased risk of cardiovascular disease in diabetics. Caloric
restriction and the initiation of exercise may increase oxidative stress in the short term
and may thus adversely affect cardiovascular disease. Over the long term, metabolic
adaptation may reduce oxidative stress. Such adaptation, together with beneficial changes in
lipoprotein concentration, composition, and character, may allow expression of beneficial
effects of weight loss on cardiovascular endpoints. However, the influence of weight loss on
measures of lipoprotein oxidation/oxidative stress and antioxidant status in overweight
diabetics has never been investigated.
The study is ancillary to the Look AHEAD clinical trial which is sponsored primarily by the
National Institute of Diabetes and Digestive and Kidney Diseases and secondarily by the
National Heart, Lung, and Blood Institute, the National Institute of Nursing Research, the
Office of Research on Women's Health, the National Center on Minority Health and Health
Disparities, and the Centers for Disease Control and Prevention. The Look AHEAD study is a
multicenter, randomized clinical trial to examine the long-term effects of a lifestyle
intervention designed to achieve and maintain weight loss in overweight diabetics. The study
is in response to an initiative on Ancillary Studies in Heart, Lung, and Blood Disease
Trials released in June, 2000.
DESIGN NARRATIVE:
The primary aim of this project is to determine the influence of intensive lifestyle
intervention on lipoprotein oxidation as assessed by autoantibodies to oxidized low-density
lipoprotein. Other complementary indices of oxidative stress, and antioxidant status as
assessed by circulating concentrations of lipophilic antioxidants, will be compared between
lifestyle intervention and community care (control) arms of the Look AHEAD study. Such
comparisons will be performed both early after intervention and later when metabolic
adaptation is expected. By contrasting subgroups defined by differential compliance to diet
or exercise, by gender, menopausal status, ethnicity, and age, secondary aims will consider
whether changes in lipoprotein oxidation/oxidative stress and antioxidant status differ
between such subgroups. Other aims will consider whether differences in lipoprotein
oxidation/oxidative stress among the above subgroups can be accounted for by differences in
lipoprotein concentration, composition, or character, carbohydrate metabolism, or
antioxidant status. The results of this study will provide a potential mechanistic
explanation for differences in cardiovascular endpoints between intervention and community
care groups.
