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Biomedical subjects

D Carmelli

Publications and source records attributed to D Carmelli.

At least 91 records · Page 5Linked to original sources
PubMed1990

Genetic and behavioral influences on body fat distribution.

Genetic and environmental influences on four measures of body fat distribution - subscapular/triceps ratio (STR), waist/hip ratio (WHR), and regression-adjusted subscapular skinfold and waist circumference indices - were examined in 265 pairs of white male twins, ages 59 to 70 years, who participated in the third examination of the National Heart, Lung, and Blood Institute's Twin Study. Skinfold indices of fat distribution were not highly correlated with indices based on body circumferences (r = 0.26-0.37 for the four possible correlations). After adjustment for overall obesity, the heritability of the adjusted subscapular skinfold index was substantial (h2 = 0.60, P less than 0.001), as were estimates for both subscapular and tricep skinfolds individually. By contrast, heritability of the STR was low and of borderline statistical significance (h2 = 0.24, P = 0.06). Heritability for the WHR (h2 = 0.31, P = 0.07) was also low. Although higher estimates were observed for the adjusted waist circumference index (h2 = 0.46, P = 0.02) and for the component circumferences, these were not clearly due to genetic influences. Among behavioral influences, cigarette smoking was strongly related to the WHR and adjusted waist circumference index (P less than 0.0001). A crude measure of total physical activity was weakly, inversely related to WHR (P = 0.06), and slightly more strongly related to the adjusted waist circumference index (P = 0.01). Skinfold indices were unrelated to either behavior. We conclude that: (1) skinfold indices measure a different dimension of fat distribution than circumference indices; (2) there is evidence for a genetic influence on subcutaneous fat distribution, but less evidence for such an influence on the WHR; (3) behavioral factors appear to be more important in determining the WHR than subcutaneous fat patterning.

Adipose Tissue↗
PubMed1989

Cross-spouse correlates of blood pressure in hypertension-prone families in Utah.

This study used a subsample of 543 married couples from a large group of families in Utah, who were originally studied to assess the genetic and environmental determinants of hypertension. Excluding individuals on medication and controlling for the major risk factors for hypertension, evidence was obtained for cross-spouse blood pressure associations equal in magnitude to self-psychosocial and demographic measures. Observed spouse-spouse similarity for blood pressures remained significant after adjustment for shared psychological factors. It is speculated that different aspects of each spouse's nonmarital environments (e.g. work, social support) have differential impacts on the marital environment and on physiologic indicators of health.

Adult↗
PubMed1989

Psychological correlates of two measures of coronary-prone hostility.

The psychological correlates of the Cook and Medley Hostility (Ho) Scale and independent behavioral ratings of hostility were compared in a sample of adult, middle-aged male participants from the National Heart, Lung and Blood Institute Twin Study. Although the Ho Scale and behavioral ratings of hostility purport to measure the same construct, the underlying correlational pattern for each was quite different. Scores on the Ho Scale were associated positively with anxiety, neuroticism, and the tendency to "fake good"; behavioral hostility was related to measures of dominance, vigor, and self-confidence. Some correlates, such as the hard-driving and speed and impatience subscales from the Jenkins Activity Survey, represent a core set of correlates common to both. The meaning of hostility must be clarified before this construct's link to coronary heart disease can be defined.

Adult↗
PubMed1988

Psychological characteristics in twins discordant for smoking behavior: a matched-twin-pair analysis.

The matched-twin-pair methodology was used to investigate the pattern of interactions between twinning and personality in 127 monozygotic and 140 dizygotic adult male twin pairs. Eighteen standard and three research scales from the California Psychological Inventory were used to identify differences in personality between twins discordant for smoking and in nonsmoking and ever-smoking twins treated as individuals. Although no evidence was obtained for a significant heritability component in the smoking habit, numerous interactions between the twinning condition (e.g., monozygotic or dizygotic) and personality were identified. As expected, monozygotic twins discordant for smoking show fewer personality differences than do individuals discordant for smoking. Discordant dizygotic twins show more disparity than unrelated individuals. The only personality scale showing a consistent discriminating effect regardless of the twinning condition was that measuring socialization. Results are discussed in terms of the environmental conditions that may contribute differentially to the smoking behavior in related and unrelated individuals.

Adult↗
PubMed1988

Risk factors for late relapse in male and female ex-smokers.

Three hundred twenty-nine ex-smokers (149 males and 180 females) who had maintained abstinence for at least 3 months prior to intake were followed for a period of 1 year to ascertain individual characteristics from cognitive, behavioral, environmental, and health domains that were predictive of later relapse. Multiple logistic regression analysis revealed significant associations between relapse, family history, and stress variables in males and between relapse, family history, stress, pre- and postcessation smoking characteristics, work-related variables, and physical activity in females. Within the predictor sets, both risk and protective factors were identified. The male and female models are discussed separately, compared, and related to previous research. Implications for further model development are specified; most notably, the utility of conceptualizing relapse independent of gender is questioned. Future research efforts could focus on the role played by family smoking history in adult relapse behavior. Smoking cessation interventions may need to tailor their efforts specifically to men and to women. Along with techniques to manage stress both during and after cessation, women may benefit especially from interventions that provide nicotine replacement and counseling for work-related difficulties.

Adult↗
PubMed1988

Characteristics of participants and nonparticipants in the NHLBI Twin Study.

The NHLBI Twin Study is a longitudinal study of cardiovascular disease risk factors in 514 pairs of white, middle aged, male, veteran twins. The initial examination took place between 1969-1973. Ten years later, 81% of the living cohort returned for a second examination. Data collected up to 30 years prior to recruitment for the initial examination were used to characterize participants and nonparticipants; data from the initial examination were used to characterize returnees and nonreturnees to the second examination. Participants had significantly lower diastolic blood pressure and higher socioeconomic status than nonparticipants as measured thirty years earlier. Between the first and second examinations, the mortality of participants was less than 50% of the mortality of nonparticipants. Returnees to the second examination had a better health profile at the initial examination than nonreturnees, with significantly lower levels of cigarette smoking, glucose intolerance, hypertension, and diabetes and higher levels of pulmonary function. However, returnees were more obese than nonreturnees. Thus, this study of cardiovascular disease risk factors in twins appears to be affected by response bias in a way similar to studies of individuals. Additional analyses of biases that may affect the genetic component of the study indicated that factors related to classical twin analyses were relatively unaffected by selection.

Analysis of Variance↗
PubMed1988

Genetic heritability and shared environmental influences of type A measures in the NHLBI Twin Study.

Data from the NHLBI Twin Study were used to investigate the genetic component in a number of Type A measures given to these twins during a second cardiovascular examination. Specifically, the objective of the current study was to determine the extent to which various Type A measures are influenced by genetic effects and by measurable environmental and cultural factors. Analyses of these data for twins yielded a number of results. First, the Type A behavior pattern as assessed by the structured interview was only weakly associated with self-report inventories developed as alternatives to the structured interview. Second, among the self-report measures of Type A, only the Thurstone Temperament Schedule Active scale showed a clear significant genetic component. Most important, a number of demographic and social characteristics known to be associated with the various Type A scales had a differential effect on twin similarities. Specifically, for the job involvement subscale of the Jenkins Activity Survey, twins of both zygosities became equally similar after adjustments for covariates, while no effect on twin similarity was noted for the Thurstone Temperament Schedule Active scale. It is concluded that a complex constellation of genetic predispositions and acquired behaviors underlies the Type A behavior construct.

Aged↗
PubMed1987

Stability of the type A structured interview and related questionnaires in a 10-year follow-up of an adult cohort of twins.

Associations between initial and 10-year follow-up assessment of the Type A behavior pattern (TABP) were examined in a sample of adult male twins using a broad range of instruments. When assessment is made by the Structured Interview and limited to the dichotomous Types A and B rating, 67% of the subjects received the same rating on both occasions. Spearman rank correlations between repeated self-report measures of TABP ranged from .55 to .70. Overall the stability among the self-report measures was greater than between the self-reports and the Structured Interview. Utilizing the twin design the relationship of genetic and environmental factors to tracking of TABP was examined and compared between monozygotic and dizygotic twin pairs. The implication of these results to the TABP construct is discussed.

Adult↗
PubMed1986

Cross-family correlates of blood pressure in the Western Collaborative Group Study.

The present study examined the association between one spouse's characteristics and his/her partner's blood pressure (BP) and the combined effect of parental characteristics on the BP levels of offspring in a subgroup of families recruited from the Western Collaborative Group Study (WCGS). Among the individual personality characteristics examined were pace of activity, reflectiveness, dominance, and emotional stability as assessed by the Thurstone Temperament Schedule (TTS). The confounding effects of age, weight, and father's disease status were controlled for by multiple-regression techniques. The results indicate a differential pattern of cross-spouse and cross-family associations for parents and offspring in these families. Higher scores on the TTS activity scale were associated with increased levels of BP in males and decreased levels of BP in females. The observed associations were of the same magnitude as those of more traditional correlates such as age and weight. The findings from the cross-family association analyses are contrasted with the separate patterns of familial correlation of BP and personality characteristics.

Age Factors↗
PubMed1985

Familial resemblance on the Thurstone Activity Scale, systolic blood pressure, and total cholesterol among first degree relatives of subjects with and without coronary heart disease.

An investigation of the pattern of familial resemblance of three different risk factors assessed in families of coronary heart disease (CHD) patients and controls is presented. The fathers of these families participated in the Western Collaborative Group Study that first established the type A/B behavior pattern as an independent risk factor for CHD. A recently developed methodology, the Structured Exploratory Data Analysis (SEDA), was implemented to examine parental interaction, parent-offspring closeness, asymmetries in transmission, and other differences in the pattern of familial similarities among family members of case and control subjects. The analysis performed revealed pronounced parent-child similarity for total serum cholesterol values in both case and control families; spouse closeness and parent-child resemblance for systolic blood pressure measurements only in control families; and sex asymmetries in the parent-child closeness on pace of activity, which also differed between case and control families. The results of this investigation underscore the value of examining the joint pattern of familial resemblance of a number of risk factors as a means for differentiating between cultural and biological factors affecting familial aggregation of CHD.

Blood Pressure↗
PubMed1985

Twin similarity in cardiovascular stress response.

Cardiovascular (CV) responses to laboratory stressors were measured in 12 pairs of identical and 21 pairs of fraternal adult male twins. For this study, blood pressure and heart rate were measured during a mental arithmetic task and the Cold Pressor Test. The analyses of cardiovascular responses to these stressors were designed to test for the presence of a genetic component in cardiovascular reactivity in an adult sample of twins aged 54-64 years. The results suggest that certain measures of cardiovascular reactivity to laboratory stressors may be heritable for both physical and psychological stressors. The possible role of this genetic component in the etiology and course of coronary heart disease is discussed.

Blood Pressure↗
PubMed1985

Permutation methods for the structured exploratory data analysis (SEDA) of total cholesterol measured in five Israeli populations.

Three structured exploratory data analysis-functionals are applied to plasma total cholesterol concentrations measured for 2,480 young men and women aged 17-18 years and living in Jerusalem, and for their parents. These triad families are divided into five groups according to whether both parents were born in Asia, North Africa, Europe-America, or Israel or whether they were of mixed "origins." The significances of the functionals were determined by a spectrum of permutation techniques that selectively shuffled the trait values across families in order to systematically alter certain family structure relationships while keeping other familial relationships intact. These analyses suggest that generational differences and various distributional effects influence patterns of spouse and parent-offspring interactions within these families and that the nature and forms of these effects and interactions may differ according to the origin of the parents. Results are discussed in relationship to historical and cultural differences among groups.

Adolescent↗
PubMed1985

The relationship between wives' social and psychologic status and their husbands' coronary heart disease. A case-control family study from the Western Collaborative Group Study.

Analysis of spouse data from the Western Collaborative Group Study indicated that a number of the wives' behavioral characteristics and their social status were associated with the occurrence of coronary heart disease among their husbands. During 1970-1971, a total number of 130 case and control nuclear families were recruited on a voluntary basis to further investigate the familial component of the Type A/B behavior patterns and their behavioral and psycho-social correlates. When stratified by the behavior type of the husband, we found that Type A men married to women with 13 or more years of schooling had an increased odds ratio (OR) of 3.6 for coronary heart disease compared with 0.4 in Type B men with similarly educated wives. The wife's employment status outside the home did not show a significant association with coronary disease in the husband (OR = 1.3). A self-reported measure of perceived accomplishments of the wife showed an association with coronary disease of the husband that was independent of his Type A/B behavior type (OR = 2.7). Further analyses of the psychologic aspects of the marital partners, as assessed by the Thurstone Temperament Schedule, indicated that Type A husbands who had coronary disease were married to wives who were more active and dominant than wives of noncases. On the other hand, Type B men who had stable wives with 13 or more years of education seemed to be protected from coronary disease. The relationship between coronary disease and husbands' characteristics showed case husbands to be more dominant and reflective regardless of their Type A/B behavior.

Adult↗
PubMed1983

The genetics of quantitative plasma Lp(a): analysis of a large pedigree.

Likelihood analysis using the mixed model of quantitative plasma Lp(a) measurements on members of a large pedigree provided evidence that high levels of Lp(a) are inherited as a dominant major gene with polygenic background. The dominant allele frequency was estimated as 0.10. The major gene and polygenic components together accounted for 95% of the variation seen in the measurements. The major gene index and OBP plots, methods that do not allow for the presence of both components, favored the polygenic model over the major gene model as the mode of inheritance. No association was found with any of the lipids, lipoproteins or apolipoproteins considered.

Female↗
PubMed1983

Properties of the major gene index for three-allele and two-locus models.

The expected value of the MGI(2) statistic was evaluated for several three-allele and two-locus models for which we have specified dominance relationships among phenotype classes based on heterozygote and homozygote genotype groupings. In a parallel simulation study we investigated the nature of MGI(alpha) for alpha = 1/2, 1, 2 under more elaborate continuous trait expressions incurred from superposition of a background distribution upon each of the phenotypic mean effects.

Alleles↗
PubMed1983

Prolonged mechanical ventilation for respiratory failure: a cost-benefit analysis.

To define the costs and benefits associated with prolonged mechanical ventilation, we studied retrospectively the records of 137 consecutive patients who required at least 48 h of ventilator support. The patients were physiologically unstable and required intensive care. Causes of respiratory failure included pulmonary diseases, post-operative complications, neuromuscular diseases, cardiac dysfunction, and GI disease. Forty-nine (36%) patients survived the hospitalization, and 38 (28%) patients were alive 3 yr after receiving prolonged mechanical ventilation. The mean total hospital cost was +16,930/patient (U.S. dollars, 1976-1977). The cost-benefit averaged +1826/yr of extended life. These costs varied from +460/yr of extended life for patients with respiratory failure complicating asthma to +8026/yr for patients with cardiac dysfunction. The cost-benefit ratio increased sharply for men older than 56 yr and for women older than 75 yr. These data document the importance of the basic disease process and the patient's age in the cost-benefit relationship.

Age Factors↗