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

May 25, 2000
June 23, 2005
January 1994
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Complete list of historical versions of study NCT00005374 on ClinicalTrials.gov Archive Site
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Genetics of the Metabolic Syndrome in Japanese Americans
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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.

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.

Observational
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  • Cardiovascular Diseases
  • Coronary Disease
  • Heart Diseases
  • Insulin Resistance
  • Diabetes Mellitus, Non-insulin Dependent
  • Diabetes Mellitus
  • Metabolic Syndrome X
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*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
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May 2004
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No eligibility criteria

Both
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No
Contact information is only displayed when the study is recruiting subjects
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NCT00005374
4268
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National Heart, Lung, and Blood Institute (NHLBI)
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Investigator: Melissa Austin University of Washington
National Heart, Lung, and Blood Institute (NHLBI)
March 2005

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP