Biomedical subjects

J Coresh

Publications and source records attributed to J Coresh.

45 records · Page 3Linked to original sources

PubMed1993

Two-locus and bivariate segregation analysis of HDL-C and apo AI.

Two-locus and bivariate segregation analyses of HDL-C and apo AI were carried out using the GAW8 Berkeley data set. For HDL-C, results are ambiguous. Both the mixed environmental model and the mixed Mendelian model fit the data equally well. For apo AI, however, univariate one-locus segregation analysis suggests a Mendelian major gene controlling its levels. Moreover, two-locus analysis suggests a second major gene is involved. Bivariate segregation analysis indicates these data cannot resolve the question as to whether a single Mendelian major gene with pleiotropic effects controls levels of both HDL-C and apo AI in humans.

Apolipoprotein A-I↗

PubMed1993

Association of plasma triglyceride concentration and LDL particle diameter, density, and chemical composition with premature coronary artery disease in men and women.

Low density lipoprotein (LDL) physical-chemical characteristics were studied as nontraditional risk factors of coronary artery disease (CAD) in a well-characterized population of 98 men aged < or = 50 and 100 women aged < or = 60 who underwent elective diagnostic coronary arteriography. The average LDL diameter was determined by gradient gel electrophoresis, chemical composition (%w/w) was measured, and the density of the major LDL peak was determined by equilibrium density gradient ultracentrifugation. Logistic regression was used to examine the association of various LDL characteristics with CAD before and after adjustment for other covariates. Smaller, cholesterol-poor LDL particles were associated with CAD independently of traditional risk factors (age, sex, smoking, diabetes, LDL and HDL cholesterol concentrations), other than the plasma triglyceride concentration. These characteristics were generally more strongly associated with CAD when measured on the major LDL subfraction (defined as the density gradient ultracentrifugation fraction with the highest LDL concentration) than the average characteristics of the more heterogeneous parent LDL (d 1.019-1.063 g/ml). The associations with CAD among men and women were generally similar. These data show that a broad range of LDL characteristics are associated with CAD before, but not after, adjustment for the plasma triglyceride concentration. These data further indicate the importance of hypertriglyceridemia and LDL heterogeneity in premature CAD.

Apolipoproteins B↗

PubMed1992

Comparison of the plasma levels of apolipoproteins B and A-1, and other risk factors in men and women with premature coronary artery disease.

The predictors of premature coronary atherosclerosis were examined in 203 patients (99 men aged less than or equal to 50 years, and 104 women aged less than or equal to 60 years) undergoing elective diagnostic coronary arteriography. Age, cigarette smoking, hypertension, obesity, diabetes, positive family history of premature coronary artery disease (CAD), and plasma levels of total cholesterol, triglyceride, lipoproteins (i.e., very low, intermediate-, low-, and high-density [HDL] lipoproteins and their subfractions [HDL2 and HDL3], and lipoprotein [a]) and apolipoproteins (apoA-1, apoA-2 and apoB, respectively) were examined using univariate analyses and multivariate logistic regression. In men, age (p less than 0.05), smoking (p less than 0.05), and plasma triglyceride (p less than 0.02) and apoA-1 (p less than 0.05) levels were independently associated with CAD. In women, smoking (p less than 0.001) and plasma apoB levels (p less than 0.04) were the strongest variables independently associated with CAD. It is concluded that the "nontraditional" risk factors (plasma apoA-1 and apoB levels) are better predictors of premature CAD than are plasma lipoproteins and that smoking is the strongest of the traditional nonlipid risk factors.

Adult↗

PubMed1992

Vascular reactivity in young adults and cardiovascular disease. A prospective study.

Cardiovascular reactivity in response to the cold pressor test has been associated with an increased risk of coronary heart disease in middle-aged men. We studied 905 white male medical students, median age 22 years, in the Johns Hopkins Precursors Study. Systolic blood pressure, systolic blood pressure change during the cold pressor test, smoking, cholesterol, Quetelet index, and family history of coronary heart disease were measured on enrollment during 1948-1964. Incidence of cardiovascular morbidity and mortality was ascertained by annual questionnaires and death certificates. There was no association between change in systolic blood pressure during the cold pressor test, whether examined as a continuous variable or a 20 mm Hg or more rise, and the risk of subsequent cardiovascular disease or coronary heart disease. These findings did not change after adjustment for cardiovascular disease risk factors. Previously reported associations may have been due to preexisting arteriosclerosis, which increases the rise in systolic blood pressure during the cold pressor test. We conclude that cardiovascular reactivity to the cold pressor test in young adulthood is not a strong predictor of future cardiovascular disease.

Adult↗

PubMed1992

Pedigree and sib-pair linkage analysis suggest the apolipoprotein B gene is not the major gene influencing plasma apolipoprotein B levels.

Previous studies suggest that plasma apolipoprotein B-100 (apoB) level is strongly influenced by genetic factors. Characterizing alleles that influence plasma apoB level would help define genetic risk factors for coronary artery disease. This study examined the role of variability in the apolipoprotein B gene (APOB) in determining plasma apoB level. Twenty-three informative families from the Johns Hopkins Coronary Artery Disease Family Study were studied. Linkage analysis between three polymorphisms in the APOB gene (XbaI at codon 2488, MspI at codon 3611, and EcoRI at codon 4154) and a putative major gene with a codominant allele for elevated apoB levels gave evidence against linkage (LOD score of -7.9 at a recombination fraction of .001). None of the families had a LOD score greater than 0.5, while five families had a LOD score less than -0.5. Sib-pair analysis also showed no relationship between the proportion of genes identical by descent at the APOB locus and either crude or adjusted plasma apoB levels. Thus, in 23 informative families, there was no evidence for the presence, in APOB, of common alleles that influence plasma apoB levels. These results suggest that APOB is not the major locus influencing plasma apoB levels.

Apolipoproteins B↗

PubMed1991

Left ventricular hypertrophy and skin color among American blacks.

The association between skin color, a measure of black-white genetic admixture, and left ventricular hypertrophy was examined in 551 black men and women, from three US cities, who underwent electrocardiography and skin reflectance measurements during 1972-1974. The overall prevalence of left ventricular hypertrophy (Minnesota Code 3-1 or 3-3) was 14% (18% in men; 11% in women). Left ventricular hypertrophy was strongly associated with systolic (p less than 0.001) and diastolic (p = 0.001) blood pressure, but less so with skin color (p = 0.09) [corrected]. The prevalence of left ventricular hypertrophy was 16% in the darkest versus 12% in the lightest quartile of skin color. In a multiple logistic regression model, adjusting for systolic blood pressure and blood pressure medication use, the relation between left ventricular hypertrophy and skin color was insignificant (p = 0.18); the odds ratio of having left ventricular hypertrophy in dark (75th percentile of skin color) versus light (25th percentile) skinned blacks after adjustment for systolic blood pressure, systolic blood pressure medications, age, and sex was 1.2 (95 percent confidence interval 0.8-1.8). Overall, the association between left ventricular hypertrophy and skin color was weak and not statistically significant, suggesting that black individuals do not have a genetic susceptibility to the effects of blood pressure on the myocardium. We did not postulate any significant effect modification of this association by sex. However, the data suggest that the association between skin color and left ventricular hypertrophy may be different between men and women.

Adult↗

PubMed1991

The association of skin color with blood pressure in US blacks with low socioeconomic status.

To determine the association of skin color, measured by a reflectometer, with blood pressure in US blacks, we studied a community sample of 457 blacks from three US cities. Persons taking antihypertensive medications were excluded. Both systolic and diastolic blood pressure were higher in darker persons and increased by 2 mm Hg for every 1-SD increase in skin darkness. However, the association was dependent on socioeconomic status, whether measured by education or an index consisting of education, occupation, and ethnicity, being present only in person with lower levels of either indicator. Using multiple linear regression, both systolic and diastolic blood pressure remained significantly associated with darker skin color in the lower levels of socioeconomic status, independent of age, body mass index, and concentrations of blood glucose, serum urea nitrogen, serum uric acid, and urinary sodium and potassium. The association of skin color with blood pressure only in low socioeconomic strata may be due to the lesser ability of such groups to deal with the psychosocial stress associated with darker skin color. However, these findings also are consistent with an interaction between an environmental factor associated with low socioeconomic status and a susceptible gene that has a higher prevalence in persons with darker skin color.

Black or African American↗

PubMed1988

The effect of variability in the fertility schedule on numbers of kin.

"The kinship formulas developed by Goodman, Keyfitz, and Pullum (1974) are extended to encompass populations in which fertility varies among women. An expression is derived to determine the amount by which the number of sisters in a heterogeneous population exceeds that in a population with homogeneous fertility. This expression, which is a function of the variance in the gross reproduction rate of the population, can readily be applied to numbers of other kin, such as aunts and cousins. Several trial calculations indicate that calculations of average numbers of sisters based on an assumption of uniform fertility could result in a underestimate of about 13 percent." (SUMMARY IN FRE)

Demography↗

PubMedDate not supplied

A community-based study of explanatory factors for the excess risk for early renal function decline in blacks vs whites with diabetes: the Atherosclerosis Risk in Communities study.

CONTEXT: The explanation for the excess risk for diabetic renal disease in blacks is uncertain. OBJECTIVES: To compare the incidence of early renal function decline in black and white adults with diabetes and to examine possible explanatory factors for racial differences. DESIGN: Prospective cohort study. SETTING: Four US communities participating in the Atherosclerosis Risk in Communities study. PARTICIPANTS: Community-based sample of 1434 diabetic adults aged 45 to 64 years. MEASUREMENTS: Detailed baseline assessment using structured interview, results of physical examination, and laboratory measurements. MAIN OUTCOME: Development of early renal function decline defined by an increase in serum creatinine of at least 35.4 micromol/L (0.4 mg/dL) during 3 years of follow-up. RESULTS: During 3 years of follow-up, early renal function decline developed in 45 blacks (28.4 per 1000 person-years [PY]) and 25 whites (9.6 per 1000 PY). After adjustment for age, sex, and baseline serum creatinine level, early renal function decline was more than 3 times as likely to develop in blacks than whites (odds ratio, 3.15; 95% confidence interval, 1.86-5.33). Additional adjustment for education, household income, health insurance, fasting glucose level, mean systolic blood pressure, smoking history, and physical activity level reduced the relative odds in blacks to 1.38 (95% confidence interval, 0.71-2.69), corresponding to a 82% reduction in excess risk. CONCLUSIONS: These data suggest that early renal function decline is 3 times more likely to develop in blacks than whites and that potentially modifiable factors, including lower socioeconomic status, suboptimal health behaviors, and suboptimal control of glucose level and blood pressure, account for more than 80% of this disparity.

Black People↗