Genetics of the Metabolic Syndrome in Japanese Americans

This study has been completed.
Sponsor:
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
ClinicalTrials.gov Identifier:
NCT00005374
First received: May 25, 2000
Last updated: June 23, 2005
Last verified: March 2005
  Purpose

To investigate the genetic influence of candidate gene polymorphisms on risk factors for the metabolic insulin resistance syndrome in Japanese American sibships and kindreds. The original grant in 1994 had as its objective to understand the genetic epidemiology of coronary heart disease (CHD) risk factors in Japanese- American families with probands living in Seattle, Washington.


Condition
Cardiovascular Diseases
Coronary Disease
Heart Diseases
Insulin Resistance
Diabetes Mellitus, Non-insulin Dependent
Diabetes Mellitus
Metabolic Syndrome X

Study Type: Observational

Resource links provided by NLM:


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

Study Start Date: January 1994
Estimated Study Completion Date: May 2004
Detailed Description:

BACKGROUND:

Although each of the risk factors have recently been associated with increased risk of CHD and are known to be genetically influenced, none of them have been investigated in a large sample of American families of Japanese ancestry. The project represents a unique and timely opportunity to characterize the genetic epidemiology of CHD risk factors among Japanese Americans. The findings could lead to the development of effective preventive strategies targeted to subgroups of individuals with high risk due to underlying genetic susceptibility.

DESIGN NARRATIVE:

In the original study, several hypotheses were tested, including: 1) that a predominance of small LDL particles (ALP phenotype B), as determined by gradient gel electrophoresis, was inherited as a single gene trait in Japanese-American kindreds and to compare these results with previous studies in Caucasian families; 2) that ALP-B was associated with risk factors characteristic of the insulin resistance syndrome and NIDDM among individual Japanese-American family members. 3) that plasma levels of Lp(a) were inversely associated with apo(a) size phenotypes, as determined by high- resolution SDS-agarose-gel electrophoresis followed by immunoblotting, in individual Japanese-American subjects, and to compare and contrast these associations with those previously reported in Caucasians and other ethnic groups; 4) that in addition to apo(a) gene effects, the segregation of plasma levels of Lp(a) in families was nherited consistent with the presence of another single major gene effect. The study also established a repository of frozen white cells for future genetic studies of candidate genes associated with risk of CHD in Japanese Americans. These hypotheses were all tested based on blood samples, blood pressure and anthropometric measurements, and questionnaire data from 33 Japanese-American kindreds identified through participants in the ongoing Japanese-American Community Diabetes Study in Seattle. The kindreds consist of 126 nuclear families and 443 individual family members, including probands, siblings, spouses, offspring and nieces and nephews of full Japanese descent.

In 1998, the renewal has three specific aims. The first aim was to identify genetic influences on the risk factors that characterize ther metabolic insulin resistance syndrome (including fasting insulin, proinsulin, C-peptide and glucose; body weight and waist circumference; lipoproteins; blood pressure; fibrinogen; factor VII and plasminogen activator inhibitor. Statistical genetic analysis approaches used in the first aim included univariate complex segregation analysis, factor analysis, and quantitative multivariate genetic analysis. The second specific aim was to test for genetic linkage between specific candidate genes involved in lipid metabolism, carbohydrate metabolism, blood pressure, obesity, and hemostasis with genetically influenced risk factors of the metabolic syndrome in Japanese-Americans. The third specific aim was, when the DNA repository had been completed (750 samples by the end of year four), to apply to the NHLBI Mammalian Genotyping Service to perform a whole genome screen to identify new genes involved in susceptibility to the metabolic syndrome.

  Eligibility

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

No eligibility criteria

  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00005374

Sponsors and Collaborators
Investigators
Investigator: Melissa Austin University of Washington
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00005374     History of Changes
Other Study ID Numbers: 4268
Study First Received: May 25, 2000
Last Updated: June 23, 2005
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Metabolic Syndrome X
Insulin Resistance
Coronary Disease
Coronary Artery Disease
Cardiovascular Diseases
Heart Diseases
Diabetes Mellitus
Diabetes Mellitus, Type 2
Syndrome
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases
Myocardial Ischemia
Vascular Diseases
Arteriosclerosis
Arterial Occlusive Diseases
Endocrine System Diseases
Disease
Pathologic Processes

ClinicalTrials.gov processed this record on September 16, 2014