Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT00049881 |
| Other study ID # |
1202 |
| Secondary ID |
R01HL071027 |
| Status |
Completed |
| Phase |
N/A
|
| First received |
November 14, 2002 |
| Last updated |
February 17, 2016 |
| Start date |
April 2002 |
| Est. completion date |
March 2004 |
Study information
| Verified date |
January 2005 |
| Source |
National Heart, Lung, and Blood Institute (NHLBI) |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
United States: Federal Government |
| Study type |
Observational
|
Clinical Trial Summary
To conduct genetic studies of the metabolic syndrome characterized by very low levels of
high density lipoprotein cholesterol (HDL-C), hypertriglyceridemia, and obesity.
Description:
BACKGROUND:
Over the past 10 years, extensive studies have been conducted in Turkey to determine the
risk factors for heart disease. Studies involving approximately 10,000 Turkish men and women
from six different regions of Turkey have established that this population is unique in
several ways. The Turks have the lowest plasma levels of high density lipoprotein
cholesterol (HDL-C) of almost any population in the world (75 percent of the men and 50
percent of the women have HDL-C levels <40 mg/dl). The mean HDL-C levels are 10-15 mg/dl
lower than those in Western European or American populations. In addition, Turks, especially
Turkish women, have a tendency toward obesity [38.8 percent of the women have body mass
index (BMI) >30 kg/M2], and both men and women have a tendency toward hypertriglyceridemia.
The low HDL-C, however, is independent of obesity or hypertriglyceridemia. Samples from this
well-characterized population provide a unique opportunity to explore the genetic
determinants associated with the high prevalence of low HDL-C, hypertriglyceridemia, and
obesity (characteristics of the metabolic syndrome).
The study was in response to a Request for Applications entitled "NHLBI Innovative Research
Grant Program" released in July, 2001. The purpose of the initiative was to support new
approaches to heart, lung, and blood diseases and sleep disorders that used existing data
sets or existing biological specimen collections whether obtained through National Heart,
Lung, and Blood Institute support or not.
DESIGN NARRATIVE:
The study analyzed DNA from frozen blood samples to investigate new candidate gene targets
that provided insights into the abnormalities characterizing this population of Turks. The
samples and extensive biodata were available on all 10,000 participants. In Specific Aim 1,
the investigators identified polymorphisms in acyl CoA:diacylglycerol acyltranferase (DGAT)-
I and -2 and in ATP-binding cassette A I (ABCA I) genes that were associated with
differences in BMI, HDL-C, and triglyceride concentration, and other parameters such as
blood pressure. These studies focussed significantly on promoter and coding sequence
polymorphisms in DGAT-I and -2 and ABCAL In Specific Aim 2, the investigators determined
whether the polymorphisms had functional significance by using a luciferase reporter system
to determine expression of polymorphic forms of DGAT and ABCAI, a cholesterol efflux
measurement to determine the functional significance of ABCAI coding sequence polymorphic
sites, and a triglyceride synthesis assay to determine the functional significance of DGAT-I
and -2 polymorphic sites. The polymorphic site association studies were performed on DNA
samples from three subgroups of Turks: (a) individuals likely to have the metabolic
syndrome, (b) individuals with isolated low HDL-C (normal triglycerides), and (c)
normolipidemic unaffected controls.
The study completion date listed in this record was obtained from the "End Date" entered in
the Protocol Registration and Results System (PRS) record.
