Reanalysis of CVD Risk Factors Via Likelihood Methods

This study has been completed.
Sponsor:
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
ClinicalTrials.gov Identifier:
NCT00005408
First received: May 25, 2000
Last updated: June 23, 2005
Last verified: May 2000
  Purpose

To reanalyze data on risk factors for cardiovascular disease (CVD) including total cholesterol and high density lipoprotein (HDL) cholesterol for the subjects in the first, second, and third exams of the NHLBI Twin Study.


Condition
Cardiovascular Diseases
Heart Diseases
Atherosclerosis

Study Type: Observational

Resource links provided by NLM:


Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: July 1992
Estimated Study Completion Date: April 1994
Detailed Description:

BACKGROUND:

The results of these longitudinal analyses yielded new insights on genetic effects affecting CVD risk factors during the aging process.

DESIGN NARRATIVE:

The analyses utilized maximum likelihood estimators of genetic variance which were asymptotically more efficient than the method-of-moments estimators used in previous analyses. The models used incorporated terms to partition the variance in a trait from twin data into either i) additive genetic variance and unshared environmental variance (the AE model), ii) additive genetic variance, dominance genetic variance, and unshared environmental variance (the ADE model), or iii) additive genetic variance, shared environmental variance, and unshared environmental variance (the ACE model). The AE, ADE, and ACE models were fitted separately to data from each of the three exams to obtain a cross-sectional analysis. The investigators also extended these models for use with longitudinal data by incorporating terms to represent the covariance of variance components from different exams.

Two important additional objectives of this study were i) to introduce resistant estimation techniques in twin modeling, which trimmed the effect of outlier data points smoothly, and ii) to carefully study the performance of maximum likelihood and method-of-moments estimators when assumptions of the twin model were violated. The results of these parts of the study should yield a more complete understanding of the relative merits and limitations of twin modeling procedures.

  Eligibility

Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   No
Criteria

No eligibility criteria

  Contacts and Locations
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No Contacts or Locations Provided
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00005408     History of Changes
Other Study ID Numbers: 4326
Study First Received: May 25, 2000
Last Updated: June 23, 2005
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Atherosclerosis
Cardiovascular Diseases
Heart Diseases
Arteriosclerosis
Arterial Occlusive Diseases
Vascular Diseases

ClinicalTrials.gov processed this record on July 29, 2014