Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT00031213 |
| Other study ID # |
992 |
| Secondary ID |
R01HL070299 |
| Status |
Completed |
| Phase |
N/A
|
| First received |
February 27, 2002 |
| Last updated |
July 28, 2016 |
| Start date |
September 2001 |
| Est. completion date |
August 2007 |
Study information
| Verified date |
January 2008 |
| Source |
National Heart, Lung, and Blood Institute (NHLBI) |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
United States: Federal Government |
| Study type |
Observational
|
Clinical Trial Summary
To evaluate the relationship of baseline toenail chromium concentrations to weight loss, as
well as the interaction between heavy metals and the beneficial effects of weight loss.
Description:
BACKGROUND:
Heavy metals are a heterogeneous group of highly reactive substances, which may act as
essential cofactors for physiologic processes and/or as toxic elements. Chromium, in
particular, has been associated with obesity, diabetes, and weight loss. Other heavy metals
have been associated with some of the consequences of obesity, including hypertension,
hyperlipidemia, and cardiovascular disease. The Look AHEAD Study, a large randomized
controlled trial of intensive lifestyle intervention for weight loss in obese patients with
Type 2 diabetes mellitus, provides an excellent opportunity to address the impact of
chromium on weight loss and diabetes control, as well as to assess the impact of other heavy
metals on the physiologic consequences of weight loss.
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.
DESIGN NARRATIVE:
This is an ancillary prospective observational study within the Look AHEAD trial. The
ancillary study will collect toenail clippings from all participants (n = 5,000) at baseline
and at the 1-year visit, and analyze a random subset of the toenails for their heavy metal
content using instrumental neutron activation analysis. Toenails provide a time-integrated
measure of heavy metal exposure, while instrumental neutron activation analysis provides the
concentrations of about 50 heavy metals in the toenail samples, including chromium. This
information will allow an evaluation of the relationship of baseline toenail chromium
concentrations to weight loss, as well as the interaction between heavy metals and the
beneficial effects of weight loss. The proposed study may provide, valuable insight into the
determinants of the efficacy of weight loss interventions. In fact, the Look AHEAD trial,
because of its size, may be one of the few studies in which these relationships can be
measured reliably. In addition, the ancillary study will permit the setup of a specimen bank
of toenails to be used in future case-cohort or nested case-control studies of the
association of heavy metals with Look AHEAD endpoints, especially myocardial infarction and
cardiovascular death.
