National Heart, Lung, and Blood Institute Twin Study

2014-08-27 03:58:01 | BioPortfolio


To assess genetic effects on the variation of cardiovascular and pulmonary risk factors in a cohort of 514 pairs of white male veteran twins.



In 1966, the National Academy of Sciences-National Research Council (NAS-NRC) began the development of a twin registry. Through state birth records, a group of twins born in 1917-1927 was ascertained and matched to veteran records to obtain a roster of 16,000 twins where both members of the pair were in military service. Veterans formed the basis of the registry because Veterans Administration files provided access to current addresses as well as potential for mortality follow-up. From this roster, a group of twins living within 200 miles of the examining centers and agreeing to cooperate was examined. This procedure yielded a set of 514 pairs of twins where both members of the pair were examined. At the time of initial examination, the World War II veteran twins were 42-56 years old. Since the initial examination, the twins have been followed by the NAS-NRC to maintain current addresses and mortality information.

The World War II veteran cohort was originally examined during the 1969-1973 period at five examination centers located in Framingham, Massachusetts; Davis, San Francisco, Los Angeles, California; and Indianapolis, Indiana. The objective of the initial examination was to estimate the heritability of cardiovascular risk factors. Results of the first examination showed significant heritability for height, weight, relative weight, systolic and diastolic blood pressure, glucose tolerance, uric acid, hematocrit, plasma triglycerides, and forced expiratory volume but not for total plasma cholesterol or any of the lipoprotein cholesterol fractions

.A second exam of the cohort was completed during 1981-1982. Of the original cohort of 1028 subjects, 792 or 77 percent were reexamined and approximately 5.5% had died. The objective of the second examination was to assess the change in cardiovascular risk factors over the ten year interval, assess the disease experience of the cohort and gather additional data on new cardiovascular risk factors as well as pulmonary function measurements and covariates. Examination two differed from examination one in that there was greater opportunity to standardize data collection for methods, laboratories, equipment, and time of examination. Greater emphasis was placed on pulmonary function testing. One objective of examination two that was not achieved was the determination of a sufficient number of cardiovascular events to do analyses of concordance of disease and analyses of disease occurrence in relation to risk factors. Analysis of data on 167 monozygotic pairs of twins and 176 dizygotic pairs of twins showed results similar to those of the first examination for systolic and diastolic blood pressure but, unlike the first examination, also showed significant genetic variance for total cholesterol and LDL cholesterol. HDL cholesterol continued to show no genetic variance.

The third examination of the original cohort was conducted in 1986-1987. The primary objective of the third examination was to assess the incidence of cardiovascular and pulmonary diseases for analyses relative to risk factor data and determine if the heritability of cardiovascular disease exceeded what was expected based on the known cardiovascular risk factors. Extensive pulmonary function testing was part of examination three as it was for examination two and provided longitudinal data for analyses of change in pulmonary function in relation to genetic and environmental factors. The exercise electrocardiogram was expanded to the entire cohort for examination three to provide additional data on sub-clinical disease.


The study was longitudinal in design and consisted of three examinations of the cohort over a period of eighteen years. Data collected in examination one in 1969-1973 included: a twin history questionnaire; personal, family and medical histories; a diet history; a physical examination; numerical data on anthropometry, hematology, and pulmonary function; supplemental lab data; an X-ray; clinical diagnostic impression; electrocardiogram; and blood analysis-fasting lipids. Data collected in examination two in 1981-1982 included: a personal and family history; deceased twin information; residence and occupational history; Thurstone Activity Scale; leisure time physical activity; social support; medical history; physical examination; clinical diagnostic impression; job mobility and stress; retirement information; Jenkins Activity Survey; blood lipid measurements. Data collected in examination three in 1986-1987 included the same data as collected in examination two plus an assessment of the prevalence for all twins and the incidence for a subgroup of twins of preclinical cardiovascular disease detected through noninvasive techniques.

The follow-up exam in 1986-87 collected baseline data on cognitive performance in 622 individuals, including 132 monozygotic and 134 dizygotic twin pairs. Beginning in December, 1994, a research grant was used to conduct a fourth exam in the surviving subjects of this cohort that used this rich resource of available data to determine the relationship between cardiovascular risk factors collected over 23 years of follow-up, changes in cognitive function since the last exam, and brain morphology assessed by magnetic resonance imaging (MRI). Given the mean age of this cohort (72 years) in 1995, the next several years represented a critical time to monitor age related changes in brain morphology and cognition. The addition of a fourth exam made the NHLBI Twin Study the longest longitudinal study of cardiovascular disease epidemiology in twin subjects (23 to 25 years of follow-up) and the first to investigate the contribution of genes and the environment to associations between CVD risk factors, cognitive performance, and brain morphology. There were five specific objectives of this study. The first was to evaluate the prospective and cross-sectional relationships of cardiovascular risk factors collected over 23 years of follow-up (e.g., blood pressure, lipids, obesity, smoking) and indices of brain morphology assessed at the fourth exam. The second objective was to determine the extent that twins discordant for essential hypertension or non-insulin-dependent diabetes mellitus (NIDDM) or cardiovascular disease (CHD) showed different MRI profiles. The third was to characterize the neuropsychological changes in performance from Exam 3 to Exam 4 and determine the contribution of genes and the environment to stability or change. The fourth objective was to use the data from exams 1 to 3 to investigate prospective relationships between CVD risk factors and decline in cognitive performance from Exam 3 to Exam 4. The fifth was to determine the heritability of the new measurements obtained for the first time at the fourth examination cycle (e.g., MRI measures of infarct area and localization, white matter hyperintensities (WMHI), and ventricular volumes).

Study Design

Observational Model: Natural History


Cardiovascular Diseases




National Heart, Lung, and Blood Institute (NHLBI)

Results (where available)

View Results


Published on BioPortfolio: 2014-08-27T03:58:01-0400

Clinical Trials [1262 Associated Clinical Trials listed on BioPortfolio]

Cardiovascular Diseases in HIV-infected Subjects (HIV-HEART Study)

Human immunodeficiency virus (HIV) infection has been associated with a variety of cardiovascular diseases. Even most industrialised countries exhibit a growing and aging population of HIV...

The Effects of Aerobic Exercise in Microvascular Endothelium Function in Patients With Cardiovascular Diseases

This study evaluates the effects of different volumes of aerobic exercise training in cardiovascular parameters of patients with cardiovascular diseases enrolled in a cardiac rehabilitatio...

ARROW:identificAtion of postpRandial biomaRkers tOWards Cardiovascular Prevention

The purpose of this study is to better understand the association between the postprandial biomarker responses after a food challenge with the development of cardiovascular diseases in hea...

Development, Testing, and Validation of A Protocol To Assess Cardiovascular Reactivity in Human Populations

To develop a comprehensive protocol for assessing cardiovascular reactivity to stressors, for use in epidemiological and clinical investigations of cardiovascular diseases in healthy popul...

Cardiovascular Diseases in the Silesian Region in Poland.

The Silesian Cardiovascular Database is an observational study of all patients hospitalized due to cardiovascular diseases. The date include information on the clinical characteristics, tr...

PubMed Articles [11517 Associated PubMed Articles listed on BioPortfolio]

12-year trends in cardiovascular risk factors (2002-2005 through 2011-2014) in patients with cardiovascular diseases: Tehran lipid and glucose study.

To examine the trend of cardiovascular diseases (CVD) risk factors among a Middle Eastern population with prevalent CVD during a median follow up of 12 years.

Introduction and Update on Obesity and Cardiovascular Diseases 2018.

Pharmacological Modulation of Vagal Nerve Activity in Cardiovascular Diseases.

Cardiovascular diseases are life-threatening illnesses with high morbidity and mortality. Suppressed vagal (parasympathetic) activity and increased sympathetic activity are involved in these diseases....

Human Emotions on the Onset of Cardiovascular and Small Vessel Related Diseases.

The aim of the present study was to examine the relation between understanding of emotions and cardiovascular related diseases, namely coronary heart disease, diabetes mellitus and obesity. The unique...

Epicardial fat and osteoprotegerin - does a mutual relation exist? Pilot study.

Epicardial fat (EPI) plays important role in development of metabolic and cardiovascular diseases. According to population studies EPI represents independent risk factor of cardiovascular diseases (CV...

Medical and Biotech [MESH] Definitions

Pathological conditions involving the CARDIOVASCULAR SYSTEM including the HEART; the BLOOD VESSELS; or the PERICARDIUM.

Methods and procedures for the diagnosis of diseases or dysfunction of the cardiovascular system or its organs or demonstration of their physiological processes.

Diseases of long duration and generally slow progression. The four main types of noncommunicable diseases are CARDIOVASCULAR DISEASES (e.g., heart attacks and stroke), CANCER, chronic respiratory diseases (e.g., CHRONIC OBSTRUCTIVE PULMONARY DISEASE and ASTHMA) and DIABETES MELLITUS.

Unexpected rapid natural death due to cardiovascular collapse within one hour of initial symptoms. It is usually caused by the worsening of existing heart diseases. The sudden onset of symptoms, such as CHEST PAIN and CARDIAC ARRHYTHMIAS, particularly VENTRICULAR TACHYCARDIA, can lead to the loss of consciousness and cardiac arrest followed by biological death. (from Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 7th ed., 2005)

Dental care for patients with chronic diseases. These diseases include chronic cardiovascular, endocrinologic, hematologic, immunologic, neoplastic, and renal diseases. The concept does not include dental care for the mentally or physically disabled which is DENTAL CARE FOR DISABLED.

More From BioPortfolio on "National Heart, Lung, and Blood Institute Twin Study"

Quick Search


Relevant Topics

Cardiology is a specialty of internal medicine.  Cardiac electrophysiology : Study of the electrical properties and conduction diseases of the heart. Echocardiography : The use of ultrasound to study the mechanical function/physics of the h...

Pulmonary relating to or associated with the lungs eg Asthma, chronic bronchitis, emphysema, COPD, Cystic Fibrosis, Influenza,  Lung Cancer, Pneumonia, Pulmonary Arterial Hypertension, Sleep Disorders etc Follow and track Lung Cancer News ...

Cardiovascular disease (CVD)
Acute Coronary Syndromes (ACS) Blood Cardiovascular Dialysis Hypertension Stent Stroke Vascular Cardiovascular disease (CVD) includes all the diseases of the heart and circulation including coronary heart disease (angina...

Searches Linking to this Trial