Genetic Epidemiology of Coronary Heart Disease Risk in Women Twins

February 17, 2016 updated by: National Heart, Lung, and Blood Institute (NHLBI)
To examine genetic and environmental influences on several recently identified coronary heart disease risk factors in identical and fraternal adult women twins. The risk factors included low density lipoprotein (LDL) subclass patterns, plasma apolipoprotein levels, body fat distribution, and serum insulin levels.

Study Overview

Status

Completed

Conditions

Detailed Description

BACKGROUND:

In 1974, a twin registry was established from members of the Kaiser Permanente Medical Care Program's Northern California region. In all, 9,821 twin pairs were enrolled. In 1978-1979, 434 pairs of female twins were recruited from the registry for a clinical examination of coronary heart disease risk factors. The clinical examination included an extensive health questionnaire, measurements of plasma lipids and serum chemistries, analyses of genetic markers for determination of zygosity, measurement of expired air carbon monoxide and serum thiocyanate levels, and a complete physical examination. During the ten years since the first examination, several new or more specific coronary heart disease risk factors have been recognized, including low density lipoprotein and insulin levels, and the anatomic distribution of body fat.

DESIGN NARRATIVE:

All women who participated in the first examination were invited to participate in the second examination. Medical records and/or death certificates were obtained to document coronary heart disease events. Questionnaires were used to collect information on health history, nutrition, and physical activity. A clinical examination assessed blood pressure, a variety of anthropometric measures and cardiovascular fitness. Blood specimens were collected for clinical chemistry and lipid/lipoprotein profiles. To assess genetic influence, the heritability of each of the risk factors was estimated. Blood was frozen for future studies of polymorphic DNA markers. Using the monozygotic co-twin control method, the effects of environmental or behavioral factors on these risk factors were assessed after controlling for genetic factors that could explain their association. Two hypotheses were examined that could be uniquely addressed using twin data. First, the association of body fat distribution with other coronary heart disease risk factors was mediated by serum insulin levels. Secondly, cardiovascular fitness explained in part the association of physical activity with coronary heart disease risk factors such as HDL-cholesterol and insulin levels. Lipoprotein analyses were conducted at Donner Laboratory at Berkeley.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

Study Type

Observational

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

No older than 100 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

No eligibility criteria

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Heart, Lung, and Blood Institute (NHLBI)

Investigators

  • Joseph Selby, Kaiser Foundation Research Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 1989

Primary Completion

December 7, 2022

Study Completion (Actual)

December 1, 1991

Study Registration Dates

First Submitted

May 25, 2000

First Submitted That Met QC Criteria

May 25, 2000

First Posted (Estimate)

May 26, 2000

Study Record Updates

Last Update Posted (Estimate)

February 18, 2016

Last Update Submitted That Met QC Criteria

February 17, 2016

Last Verified

June 1, 2004

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1120 (Ain Shams University)
  • R01HL041830 (U.S. NIH Grant/Contract)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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