Biomedical subjects

J D Kark

Publications and source records attributed to J D Kark.

At least 73 records · Page 4Linked to original sources

PubMed1988

Family resemblance for serum uric acid in a Jerusalem sample of families.

Familial aggregation of serum uric acid was studied in a sample of families examined in the Jerusalem Lipid Research Clinic. We first examined homogeneity of familial correlations across the major origin groups in the Israeli population sample. In general correlations were homogeneous across origin groups, except for spouse pairs. Pooled correlations among biological relatives across the origin groups were all statistically significant. Spouse correlation upon adjustment for concomitant variables was moderately positive (r = 0.115), yet significantly different from zero. Genetic and cultural determinants of uric acid were estimated utilizing a path model with 10 parameters to be estimated from a total of 16 correlations. Under a reduced model, genetic heritability (h2) was estimated to be 0.47 +/- 0.05 and cultural heritability (c2) was 0.11 +/- 0.03. However, our data gave suggestive evidence that cultural heritability was higher in parents (c2 = 0.28) than in children (c2 = 0.10). Commingling analysis and segregation analysis were also performed, and our findings imply that in the Israeli population there is no evidence for a major gene for high uric acid levels segregating in families.

Adult↗

PubMed1988

Familial aggregation of coronary heart disease: partial mediation by high density lipoproteins?

The potential explanation of coronary heart disease inheritance by the major coronary risk factors was explored in a random sample of 1044 males, aged 40-70 years, who formed part of the Jerusalem Lipid Research Clinic Prevalence Study. Standardised data were available on personal and family history, coronary risk factors, resting and exercise electrocardiography. Twelve percent of subjects had coronary heart disease (previous myocardial infarction or electrocardiographic changes) and 20% had a family history of heart attack before 60 years in first degree relatives. In the presence of a family history of heart attack, the mean level of high density lipoprotein-cholesterol (HDL-C) was 5 mg/dl lower in cases of coronary heart disease than in controls. No such difference existed in the absence of a family history of heart attack. In multiple logistic regression, HDL-C was a significant negative predictor of coronary heart disease presence, but only in subjects having a positive family history. A 1 standard deviation (10 mg/dl) increment in HDL-C was associated with a two-thirds reduction in heart disease risk. Other risk factors did not predict the occurrence of coronary heart disease to any significant extent in subjects with a positive family history of heart attack. In an overall logistic model combining family history with other risk factors, the significant predictors of heart disease were: age, total plasma cholesterol, hypertension, family history and HDL-C. The interaction term, family history X HDL-C, was also a significant negative predictor of heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1988

Biological and environmental sources of familial aggregation of blood pressure: the Jerusalem Lipid Research Clinic.

Genetic and cultural determinants of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were estimated using a path model on a sample of families examined in the Jerusalem Lipid Research Clinic. This model involves 10 parameters to be estimated from a total of 16 correlations (leaving ample degrees of freedom to test the goodness-of-fit). The general model fitted SBP (X2(6) = 6.95, p = 0.33) and DBP (X2(6) = 5.44, p = 0.49) very well. Both genetic (h2) and cultural (c2) components of inheritance were statistically significant for both blood pressure variables. Under the most parsimonious model, genetic heritabilities (h2) were estimated to be 0.20 and 0.28 for SBP and DBP respectively. Cultural heritability (c2) was 0.12 for SBP and 0.08 for DBP. A significant fraction of the estimate for cultural inheritance was due to a sibling environmental effect not mediated through their parents. Within this population genetic factors, common environmental factors and concomitant variables such as sex, age and origin explained about 40% of blood pressure variability. Most of the variance appears to be due to unmeasured environmental factors and errors of measurement.

Adolescent↗

PubMed1988

Familial aggregation of body mass index in ethnically diverse families in Jerusalem. The Jerusalem Lipid Research Clinic.

Familial aggregation of body mass index in different ethnic populations was studied in a sample of nearly 4000 families resident in Jerusalem. Covariate adjustments were applied to body mass index (BMI) to adjust for variation in means and variances with sex, age and origin and for the effect of education, socioeconomic status and seasonality. The analyses were done separately in each of the origin groups categorized according to the parents' country of birth (Europe, Asia, North Africa, Israel/mixed origin), in order to account for the heterogeneity among the groups. Parent-child correlations were generally homogeneous across the origin groups. Sibling correlations for BMI differed to a greater extent among the groups. The highest correlation was observed in the Asian group (r = 0.49) and the lowest in the North African group (r = 0.16). Pooled correlations among biological relatives across the origin groups were highly significant. Spouse correlation, although significant was smaller, suggesting a stronger influence of genes than shared environment in the determination of the trait. Father-child correlation was significantly higher (r = 0.25) than mother-child value (r = 0.19), suggesting a possible paternal influence on BMI. There was also asymmetry in parent-offspring correlations by the sex of the offspring. Sibling correlation was higher (r = 0.33) than parent-offspring correlation (r = 0.22), suggesting that shared environment within generations tended to have some importance.

Adolescent↗

PubMed1987

Serum immunoglobulin A levels and ethnicity in an Israeli population sample.

Serum IgA concentrations were measured in 1799 healthy Israeli military recruits (698 women and 1101 men) using an automated nephelometric system. The overall prevalence of IgA deficiency defined at a level of less than 50 mg/liter was 1.0 +/- 0.46% (95% confidence limits). No significant difference was found between the sexes in the mean values of serum IgA. Statistically significant ethnic differences were evident. Recruits of European origin had lower serum IgA concentrations than the North African, Israeli, or Asian origin groups. Whether the apparently high prevalence of IgA deficiency in this young population in Israel has clinical significance is at present unknown.

Africa, Northern↗

PubMed1987

Religious observance and plasma lipids and lipoproteins among 17-year-old Jewish residents of Jerusalem.

The association of religious observance and plasma lipids and lipoproteins was studied in a sample of 673 Jewish residents of Jerusalem ages 17-18 years. Religious observance was classified according to the parents' ranking of their perceived degree of religiosity. The study group included children whose parents were orthodox Jews who pedantically observed religious commandments, children of traditional parents who observed some of the rules, and children of nonobservant secular parents. Plasma levels of cholesterol, triglyceride, and low-density lipoprotein were higher in secular children than in the orthodox group. These associations were independent of sex, origin, social class, body mass, and season. High-density lipoprotein cholesterol was somewhat higher in the orthodox group than in the secular children although this difference was not statistically significant. Regression analysis showed that offspring's environment and parental phenotype were the most important predictors of lipid concentrations in adolescents. The association of religious observance with plasma lipids and lipoproteins, however, was independent of parental phenotype lipid values and the contribution of offspring and parents' environment. These findings are consistent with similar differences in plasma lipids described previously among the parents, as well as the lower incidence of myocardial infarction in the orthodox religious group, which has been shown in the Israeli adult population.

Adolescent↗

PubMed1987

Parent-offspring aggregation of plasma lipids in selected populations in North America and Israel. The Lipid Research Clinics Prevalence Study.

Parent-offspring associations of total cholesterol and triglycerides were compared between family dyads in six North American populations examined between 1972 and 1976 as part of the North American Lipid Research Clinics Prevalence Study and those from families examined between 1976 and 1979 at the Lipid Research Clinic located in Jerusalem. Common study design, protocol, and laboratory techniques were used by all Lipid Research Clinics. The authors first examined homogeneity of familial correlations across clinics in the North American population and across origin groups in the Israeli sample. In general, correlations were homogeneous across clinics and origin groups, except for parent-daughter pairs for triglycerides in North America. The pooled familial correlations were similar in the two study populations. There was no asymmetry in parent-offspring correlations by the sex of the offspring. The pooled mother-child correlations were significantly higher than father-child values in the North American sample only. The strength of parent-offspring similarity showed no consistent pattern of change with level of education of parents in either study group. Patterns of familial similarity are discussed in relation to genetic, cultural, and environmental differences between the two study populations.

Adolescent↗

PubMed1987

Family resemblance for fasting blood glucose: the Jerusalem Lipid Research Clinic.

Familial aggregation of fasting plasma glucose was studied in a sample of families examined at the Jerusalem Lipid Research Clinic. We first examined homogeneity of familial correlations across major origin groups in the Israeli sample. Correlations were generally homogeneous across origin groups, except for mother-son pairs. The pooled familial correlations were relatively low for unadjusted blood glucose values, and somewhat higher upon adjustment for sex, age, ethnicity, education, seasonality, body mass, cigarette smoking, alcohol consumption and dietary intake. Genetic and cultural determinants of blood glucose were estimated utilizing a path model with 10 parameters to be estimated from a total of 16 correlations. Under a reduced model genetic heritability (h2) was estimated to be 0.18 +/- 0.08 and cultural heritability (c2) was 0.10 +/- 0.02. However, within this population the additive variation could be explained by a cultural model of inheritance without introducing genetic parameters, and most of the variance is due to "random" unmeasured environmental factors. Commingling analysis was also performed, and our findings imply that there is no evidence for admixture in the distribution of fasting blood glucose in this Israeli population sample.

Adolescent↗

PubMed1987

Complex segregation analysis of plasma lipid and lipoprotein variables in a Jerusalem sample of nuclear families.

Plasma lipid and lipoprotein concentrations from 3,074 nuclear families in the multiethnic Jerusalem Lipid Research Clinic study population were analyzed for possible involvement of major genes in determination of high levels of these traits. Complex segregation analysis under a mixed model including major gene and multifactorial transmissible components was performed on transformed-plasma lipids and lipoproteins after covariance adjustment for age, sex and environmental measures. Likelihood analysis provided evidence for recessive major genes influencing plasma triglyceride, and low-density lipoprotein cholesterol (LDL-C). The estimated gene frequencies for triglyceride and for hyperbetalipoproteinemia in our study population were about 0.1. Our positive results for total cholesterol and high-density lipoprotein cholesterol (HDL-C) were nonconclusive and the major effects could result from causes other than major genes. The mixed-model parameters were homogeneous across origin groups for LDL-C and HDL-C and heterogeneous for total plasma cholesterol and triglyceride. The multifactorial-transmission heritability index was similar in all origin groups for all the traits. The origin heterogeneity in the major gene parameters appeared to be mainly due to the North African group which favored a multifactorial transmission for all traits except for LDL-C.

Cholesterol↗

PubMed1987

Peripheral vascular disease in a middle-aged population sample. The Jerusalem Lipid Research Clinic Prevalence Study.

Peripheral artery status and prevalence of peripheral vascular disease were studied in a sample of 1,036 men and 556 women, residents of Jerusalem. Ankle blood pressures determined by the Doppler ultrasound technique (Parks Electronic Lab, USA), were higher in men than in women and increased with age. In a multivariable regression analysis, systolic blood pressure and plasma cholesterol levels were significantly and inversely related to the ankle/arm blood pressure in men, and alcohol intake was inversely associated in women. The prevalence of peripheral vascular disease, as determined by symptoms of intermittent claudication, was 1.3% in men and 1.8% in women; absent pedal pulses were found in 1.1% of the men and in 2.0% of the women; leg pain on the treadmill was a reason for termination of exercise in 3.7% of the men and in 5.4% of the women and an ankle/arm blood pressure ratio of less than 0.90 in 4.2% of the men and in 5.4% of the women. The overlapping of the diagnostic criteria was low. No consistent determinants of the various measures of peripheral vascular status were found. In multivariable logistic models, cigarette smoking was significantly associated with intermittent claudication [Odd ratio (OR) = 3.03, 95% confidence interval (CI) 1.27 to 7.26], age was associated with leg pain on the treadmill (OR = 1.91, 95% CI 1.08 to 3.40 in men and OR 3.52, 95% CI 1.52 to 8.16 in women), body mass index was associated with absent and diminished pulses in women (OR = 1.61, 95% CI 1.07 to 2.42, systolic blood pressure was associated with an ankle/arm ratio of less than 0.90 in men (OR = 1.35, 95% CI 1.01 to 1.81), and glucose was associated with absent and diminished pulses in women (OR = 1.20, 95% CI 1.00 to 1.44).

Adult↗

PubMed1986

Heterogeneity in multifactorial inheritance of plasma lipids and lipoproteins in ethnically diverse families in Jerusalem.

Genetic and cultural determinants of total cholesterol (TC), triglyceride (TG), low- and high-density lipoprotein cholesterol (LDL-C, HDL-C), and HDL-C/TC were estimated utilizing a path model in a random sample of nearly 4,000 families examined in the Jerusalem Lipid Research Clinic. The analyses were done separately in each of the ethnic groups categorized according to the parents' country of birth (Europe, Asia, North Africa, and Israel/mixed origin) in order to identify the nature and sources of any heterogeneity among the groups. Both genetic (h2) and cultural (c2) components of inheritance were significant for all lipid variables in each of the ethnic groups. Under the most parsimonious model, estimates of h2 in the ethnic groups were .40-.55, .40-.51, .45-.50, .41-.48, and .42-.78 for TC, LDL-C, HDL-C, HDL-C/TC, and TG, respectively. The c2 ranged from 3% to 5% for TC and LDL-C and from 4% to 10% for HDL-C, HDL-C/TC, and TG. The major parameters of the path model were generally homogeneous across the origin groups. The h2 appeared to be higher in the Asian and c2 was slightly greater in the European group. The stronger sibling environmental effect in the Asia group, the somewhat lower transmission of environment in the North African group, and the lower correlation between spouse environments in the North African group were the major sources of the origin heterogeneity. Within this population, genetic factors appear to be the major determinants of lipid variations, suggesting relative homogeneity of the distribution of environmental determinants of plasma lipids.

Adolescent↗

PubMed1986

Complex segregation analysis of low levels of plasma high-density lipoprotein cholesterol in a sample of nuclear families in Jerusalem.

Low levels of high-density lipoprotein cholesterol (HDL-C) are associated with increased risk of coronary heart disease (CHD). Therefore, assessment of the mode of inheritance of HDL-C is of importance. HDL-C concentrations in 3,074 nuclear families in the multiethnic Jerusalem Lipid Research Center study population were analyzed for possible involvement of major genes in determination of low levels of this trait. Complex segregation analysis under the mixed model of inheritance (major gene and multifactorial components) was performed on transformed HDL-C concentrations after adjustment for age, sex, and environmental measures. Evidence for segregation of a recessive major gene for depressed HDL-C, with an allele frequency of q = 0.06, in addition to multifactorial transmission (H = 0.45) was found in these families. Estimates from the mixed model were homogeneous across the different ethnic groups. When the substantial multifactorial background was excluded from the model, we found evidence for an additive (codominant) Mendelian gene (d = 0.48), which demonstrates the necessity of using the mixed model. Our previous results were inconclusive with respect to the involvement of a major gene in determination of high levels of HDL-C. However, we tentatively postulate an uncommon recessive gene for low levels of HDL-C in the Israeli population in addition to polygenic and environmental determinants.

Adolescent↗

PubMed1986

Religious orthodoxy and myocardial infarction in Jerusalem--a case control study.

We examined the hypothesis that the degree of religious orthodoxy is an independent risk factor for coronary heart disease incidence in a study of 454 men and 85 women who experienced a first myocardial infarction. They were compared with a control group of 295 men and 391 women. All were Jewish residents of Jerusalem. The degree of religious orthodoxy was ascertained by interview of participants. Among the cases, 51% of the men and 50% of the women defined themselves as secular compared with 21% and 16%, respectively, among the controls. In a multivariate logistic model (including terms for age, ethnicity, education, smoking, physical exercise, body mass index and religious orthodoxy), the coefficients for age and smoking were positive and statistically significant, and those for education negative and significant. The risk for European born subjects was greater than for the other ethnic origin groups (statistically significant only in men). Secular subjects had a significantly higher risk of myocardial infarction compared to orthodox subject (odds ratio of 4.2 (95% confidence interval 2.6-6.6) for men and 7.3 (95% confidence interval 2.3-23.0 for women). This relationship was independent of the other variables in the model. The relation persisted in a subsample of cases who were examined 2-3 months after the acute phase of the infarction upon controlling for plasma cholesterol, high density lipoprotein cholesterol and hypertension. This finding should be substantiated. It would appear important to identify the components of religiosity associated with reduced risk.

Adolescent↗

PubMed1986

Comparison of nutrient intakes of selected populations in the United States and Israel: the Lipid Research Clinics prevalence study.

Nutrient intakes of 2,772 US and 2,680 Jerusalem participants of the Lipid Research Clinics Program were assessed by 24-h dietary recall in men aged 15-19 and 40-59 yr and women aged 15-19 and 35-59 yr. Energy intake was higher in the US than in Jerusalem. In Jerusalem intake of total fat ranged between 32.2-33.7% of kcal, of saturated fatty acids (SFA) between 9.8-10.9%, of polyunsaturated fatty acids (PFA) between 7.9-8.6%, of carbohydrates between 50.5-53.9%, and of starch between 24.0-30.5%. The P:S ratio ranged between 0.80 and 1.01. The corresponding ranges for the US were 38.8-40.8% for fat, 14.3-15.9% for SFA, 5.9-6.8% for PFA, 38.9-46.2% for carbohydrates, 17.0-17.9% for starch, and 0.40-0.53 for the P:S ratio. Intake of cholesterol (mg/1000 kcal) was higher in Jerusalem than in the US. These data address the feasibility of reducing fat in diets of free-living, Western populations.

Adolescent↗

PubMed1986

Biological and environmental sources of variation in plasma lipids and lipoproteins: the Jerusalem Lipid Research Clinic.

We have previously described a general pattern of homogeneity in genetic and cultural determinants of blood lipids and lipoproteins among the major origin groups in the Israeli population. This paper reports on these determinants of total plasma cholesterol (TC), triglyceride (TG), low- and high-density lipoprotein cholesterol (LDL-C, HDL-C), and of the HDL-C/TC ratio, estimated from the total sample of 4,000 families whose members were examined in the Jerusalem Lipid Research Clinic. Both genetic (h2) and cultural (c2) components of inheritance were significant for all lipid variables. Under the most parsimonious model genetic heritability (h2) ranges from 0.45 for LDL-C, 0.47 for HDL-C to 0.64 for HDL-C/TC ratio. Cultural heritability (c2) was 0.03 for LDL-C, 0.04 for TC, 0.05 for TG and 0.07 for HDL-C and HDL-C/TC ratio. Within this population, as in others, genetic factors appear to be the major determinants of lipid variation, suggesting relative homogeneity of environmental correlates of plasma lipids.

Adolescent↗

PubMed1986

Blood group and height in a multiethnic population.

In a sample of 4,472 boys, aged 17-18 years, resident in Jerusalem, those with blood groups B or AB tended to be slightly shorter than groups O and A (p = 0.011). Participants were classified into 8 groups according to father's country of origin: Israel, Southern Europe/Balkans, rest of Europe, North Africa, Iraq, Iran, Yemen and the rest of Asia. The association of ABO blood group, classified according to the presence of the B antigen (groups B and AB) or its absence (O and A), with height differed in the 8 origin groups (p = 0.026 for interaction). In 7 of the 8 groups, subjects with the B allele were either shorter or of equal height to groups O and A and in only one instance were they taller. These findings do not support the generalizability of a positive association of the presence of the B antigen with height suggested by Borecki et al. [1985].

ABO Blood-Group System↗

PubMed1985

Coffee, tea, and plasma cholesterol: the Jerusalem Lipid Research Clinic prevalence study.

The association of intake of coffee and tea, assessed by 24 hour dietary recall, with plasma cholesterol and its lipoprotein fractions was studied in a sample of 1007 men and 589 women aged 35-64 resident in Jerusalem. These cross sectional data showed a significant linear association (p less than 0.001) between consumption of coffee in men and plasma cholesterol and low density lipoprotein cholesterol concentrations. Men who drank five cups of coffee or more had plasma cholesterol concentrations about 0.5 mmol/l (20 mg/100 ml) higher than non-drinkers after controlling for age, ethnicity, body mass, education, season of year, smoking, tea drinking, and dietary intake of fat and carbohydrates. In women adjusted mean plasma cholesterol concentration was 0.34 mmol/l (13 mg/100 ml) higher in coffee drinkers grouped together (p less than 0.01). The test for a linear trend was not significant. The association in both sexes was largely with the low density lipoprotein cholesterol fraction. High density lipoprotein cholesterol concentrations were somewhat increased in women who drank coffee (p less than 0.01 for a linear trend) but not in men. Tea drinking was not associated with unadjusted plasma cholesterol concentrations in either sex. Male tea drinkers, but not female, had slightly higher adjusted plasma cholesterol concentrations than non-drinkers (0.15 mmol/l (6 mg/100 ml), p = 0.04). No dose response relation was evident. In this population, characterised by a low intake of saturated fatty acids and relatively low mean plasma cholesterol concentrations, coffee drinking may be a determinant of low density lipoprotein cholesterol concentrations.

Adult↗

PubMed1985

Aggregation of plasma lipids and lipoproteins in families with and without coronary heart disease.

Familial aggregation of total plasma cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) was analyzed in 37 families with incidence cases of first myocardial infarction (MI), in 154 families of coronary heart disease (CHD) prevalence cases and in control families. Fasting plasma lipid levels were adjusted for age, sex, country of origin and season of year. Mean TC, LDL-C and TG levels were higher among cases, their spouses and among 17-year-old children of incidence cases than among control families. HDL-C was lower among cases and among wives of incidence cases than in their controls. No differences in HDL-C were noted among children. Mid parent-child correlations for TC and LDL-C were higher in 32 families of men who had a MI (r = 0.43 and r = 0.49) than for control families (r = 0.32 and r = 0.29, respectively). When the 5 families of mothers who had a first MI were included in the analysis, the case-child correlations for TC and LDL-C were 0.60 and 0.68, respectively. Father-child correlation for HDL-C was significantly lower (r = -0.17) among the MI incidence case families than among the control families (r = 0.22; P less than 0.05). No substantial differences in familial correlations for lipid variables were noted in the CHD prevalence families and their controls. These findings suggest that total cholesterol and LDL-C levels, but not HDL-C levels, may be a risk marker in adolescents. The associations evident in adolescent children of families with MI incidence cases were not apparent in children whose parents had CHD on entering the study. This could be due to the probably greater misclassification of CHD prevalence cases than MI incidence cases, the awareness in patients with CHD and subsequent behavioural changes, to possible differences in patterns of survival in the two categories, or may reflect a chance finding.

Adolescent↗