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Heavy Metals, Obesity and Cardiovascular Risk - Ancillary to Look AHEAD

Completed
Conditions
Heart Diseases
Diabetes Mellitus, Non-insulin Dependent
Myocardial Infarction
Diabetes Mellitus
Cardiovascular Diseases
Obesity
Registration Number
NCT00031213
Lead Sponsor
National Heart, Lung, and Blood Institute (NHLBI)
Brief 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.

Detailed 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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
Not specified
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Secondary Outcome Measures
NameTimeMethod
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