Solomon H. Katz

Can cardiovascular risk be predicted by newborn, childhood, and adolescent body size? An examination of longitudinal data in urban African Americans

OBJECTIVE Recent retrospective studies of older adults have demonstrated a correlation between lower birth weight and hypertension and insulin resistance. We tested this finding in our sample of urban African Americans with prospective data on growth and blood pressure and also tested other variables (in addition to birth weight) for their relationship to adult cardiovascular risk. STUDY DESIGN A prospective study of birth weight, growth, and blood pressure (Philadelphia Perinatal Collaborative Project) followed a sample of 137 African Americans, with nine examinations from birth through 28.0 +/- 2.7 years. Metabolic measurements (oral glucose tolerance testing, euglycemic hyperinsulinemic clamp, and plasma lipid concentration) were performed on the subjects as adults. Bivariate correlations among parameters were computed using the Pearson r. The chi-squared statistic was used to determine associations of outcomes with birth weight. Stepwise multiple linear regressions were computed using newborn, early childhood, adolescent, and young adult parameters to predict adult outcomes. RESULTS Birth weight and blood pressure at age 28 years are not correlated (Pearson r = 0.06). Birth weight is also unrelated to adult obesity. However, weight at 0.3 years and after and body mass index at 7 years and after are correlated with adult weight. Furthermore, weight at age 14 years is significantly negatively correlated with measures of insulin-stimulated glucose use, indicating that obese adolescents may be at greater risk than nonobese adolescents for development of non-insulin dependent diabetes in adulthood. CONCLUSIONS We found no relationship between birth weight and adult outcomes pertaining to cardiovascular risk in this sample of adult African Americans. However, we did find evidence that somatic growth (body weight and body mass index) is significantly related to obesity and attenuated insulin-stimulated glucose utilization in adulthood. These findings indicate that the origins of adult cardiovascular disease are related to somatic growth, but not intrauterine growth, and are evident during childhood.

Genetic analysis of anthropometric measures in 11-year-old twins: the Medical College of Virginia Twin Study.

ABSTRACT: We have conducted a cross-sectional analysis of the genetic and environmental contributions to the variance of anthropometric measurements in children during early adolescence. Univariate path analysis was used to estimate the relative contributions of genes, individual environment, and family environment to measures of childhood obesity in 259 11-y-old Caucasian twin pairs. Triceps, subscapular, and suprailiac skinfold thicknesses, as well as waist circumferences, ht, and wt were measured in a standardized protocol. In this sample, a parsimonious model that included only additive genetic effects and environmental factors unique to the individual provided an adequate explanation for the variation in ht, wt, quetelet index, and subscapular and triceps skinfolds. In this largely preadolescent population, different magnitudes of genetic effects were seen in males and females for waist circumference, biiliac diameter, and suprailiac skinfold.

Absence of a relationship between degree of white ancestry and intellectual skills within a black population.

Genetic differences have been offered as an hypothesis to explain the average IQ difference usually found between US black and white populations (Jensen, 1973; Shockley, 1972). While most behavioral scientists would choose to ignore the hypothesis as distasteful, there is little direct evidence against it (Scarr and Weinberg, 1976). Those who prefer an environmental hypothesis to account for the average difference between black and white groups on intellectual tests have not succeeded in accounting for the magnitude of the effect, nor have those who hold a genetic hypothesis been able to refute an environmental stance. No direct comparisons of black and white samples will settle the issue of possible genetic differences, because obvious environmental differences are confounded with any genetic differences between the populations that are socially classified as black and white (Scarr-Salapatek, 1971a, 1971b, 1972, 1973, 1974; Scarr and Weinberg, 1976). The fact that US blacks are a hybrid population 1 makes the study of admixture a potential method to evaluate the effects of racial genetic differences. Those environmental differences between the races that affect al l blacks equally, but no whites, will not contaminate the possible relationship between genetic racial differences and intellectual performance within the hybrid group. Thus, if genetic, racial differences do contribute to average intellectual differences between blacks and whites, then those blacks with higher degrees of white ancestry should perform better on intellectual tests than those with lesser degrees of admixture (Jensen, 1973; Shuey, 1966). Even within the hybrid group, the effects of environmental differences cannot be ignored. The amount of racial discrimination may be related to the degree of

Prenatal DDT Exposure in Relation to Anthropometric and Pubertal Measures in Adolescent Males

DDT (dichlorodiphenyltrichloroethane), a pesticide once used widely in agriculture and now limited to public health use, remains a controversial chemical because of a combination of benefits and risks. DDT or its breakdown products are ubiquitous in the environment and in humans. Compounds in the DDT family have endocrine actions and have been associated with reproductive toxicity. A previous study reported associations between prenatal exposure to p,p′-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene] and increased height and weight in adolescent boys. We examined a group with higher exposures to see whether similar associations would occur. Our study group was 304 males born in Philadelphia in the early 1960s who had participated in a previous study. Anthropometric and pubertal measures from one to six visits during their adolescent years were available, as were stored maternal serum samples from pregnancy. We measured p,p′-DDE, p,p′-DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)-ethane], and o,p′-DDT [1,1,1-trichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl)-ethane] in the maternal serum. Outcomes examined in the boys were height, ratio of sitting height to height, body mass index, triceps skinfold thickness, ratio of subscapular to the sum of triceps and subscapular skinfold thicknesses, skeletal age, serum testosterone, and serum dehydroepiandrosterone sulfate. No associations between prenatal exposure to any of the DDT compounds and any outcome measure were seen.

Left-handedness in twins: Incidence and patterns of performance in an adolescent sample

Data on handedness and cognitive performance in an adolescent sample of same-sex twins were collected, and questions about incidence of left-handedness in twins and the relation between handedness and cognitive performance were considered. Same-sex twins have been found to have a higher incidence of left-handedness than that usually reported in the general population. There is a high incidence of handedness discordance (one twin right-handed and his cotwin left-handed) in both monozygotic and dizygotic twin pairs. In this sample, males and Blacks had particularly high rates of left-handedness. Among the monozygotic and dizygotic discordant pairs, quite different patterns of cognitive performance were found. On the Raven Progressive Matrices, the Columbia Test of Mental Maturity, and the Peabody Picture Vocabulary Test, the left-handers did better than their right-handed cotwins in the monozygotic pairs and the right-handers did better than their left-handed cotwins in the dizygotic pairs. Within subjects, no significant differences were found for superiority of spatial or verbal abilities for either right-handers or left-handers. No general statements can be made about the performance of left-handed twins, since performance differs according to zygosity and handedness of cotwin configurations.

The Impact of a Pediatric Medical Home on Immunization Coverage

This study assessed whether having access to provisions in the American Academy of Pediatrics “medical home” concept was associated with being age-appropriately immunized at 3, 12, and 24 months. Cross-sectional data on 495 Delaware children were collected fromJune 1994 to June 1995. Immunization status was determined with the Delaware immunization registry. The medical home was not significantly associated with immunization coverage. This study confirms that race, insurance status, maternal education, and family incomes are predictive of having poor immunization outcomes. Simply providing medical homes may not be an effective strategy to improve use of preventive services.

Maternal Cigarette Smoking During Pregnancy and Life-Course-Persistent Offending

Evidence exists documenting the relationship between maternal cigarette smoking and offspring criminal behavior. Although efforts to understand this relationship in a theoretical framework have only recently emerged, attempts made have been grounded in Moffitt’s developmental taxonomy of antisocial behavior. Specifically, maternal cigarette smoking is generally viewed as a potential disruption in the offspring’s neuropsychological development, which is subsequently associated with life-course-persistent offending. Using a birth cohort of 987 African Americans, the authors extend previous research by empirically assessing, prospectively, the link between maternal cigarette smoking and life-course-persistent offending while using different operationalizations of Moffitt’s offending categorization. The authors’ findings offer some support for the relationship between maternal cigarette smoking and life-course-persistentoffending, which is dependenton how this conceptis operationalized.

Blood pressure, body fat, and dehydroepiandrosterone sulfate variation in adolescence.

Several significant interrelations among variation in blood pressure, body fat, and adrenal androgen levels, as assessed by serum dehydroepiandrosterone sulfate concentrations, were found in black male and female adolescents, aged 12 to 16 years. In girls, high levels of dehydroepiandrosterone sulfate were associated with significantly higher levels of blood pressure (alpha = 0.05), even after adjusting for the significant association between increased levels of dehydroepiandrosterone sulfate and body fat. The increased body fat (i.e., body mass index) found with higher levels of dehydroepiandrosterone sulfate in girls was related to significantly greater (alpha = 0.05) accumulations of fat in the upper trunk, as opposed to the limb. In boys, high levels of serum dehydroepiandrosterone sulfate, low body mass index, and significantly higher blood pressure were interrelated (alpha = 0.05). In addition to the interaction of increased body mass index or body fat and increased levels of dehydroepiandrosterone sulfate in association with higher blood pressure, high levels of the adrenal androgen, even in boys with low body mass index, were associated independently with relatively higher blood pressure. Body proportion analyses for these boys indicated that they were tall and thin, in contrast to the other boys with low body mass index, who were generally short and thin.

Concurrent validity studies of blood pressure instrumentation. The Philadelphia Blood Pressure Project.

There is increasing evidence that blood pressure (BP) screening during adolescence may detect early evidence of hypertensive disease. Choice of instrumentation becomes important to maximize the accuracy and interpretive value of several serial readings. We therefore conducted two studies of adolescents, comparing auscultatory (Baumanometer and Random-zero), ultrasonic (Arteriosonde 1216), and infrasonic (Physiometrics SR-2) devices. These instruments were compared serially (Study 1) for older adolescents (n = 48). The Baumanometer, Arteriosonde 1216, and Physiometrics SR-2 were compared both serially and simultaneously (Study 2) for younger and older adolescents (n = 24). In both studies, the order of device presentation was completely counterbalanced. In Study 1, reliability estimates were high (r greater than 0.65), with the exception of the Arteriosonde 1216 diastolic readings, and the Physiometrics SR-2 yielded significantly lower mean diastolic BP readings than the other devices. Diastolic Phase V readings taken with the Random-zero were significantly higher when the Random-zero was presented at the end of the sequence of instrument presentation. This order of presentation effect is probably attributable to the need for overinflation when using the Random-zero device and may cause an overestimation of diastolic BP in the young. In Study 2, again the Arteriosonde 1216 did not perform reliably in recording diastolic BP. Further, the Physiometrics SR-2 device, although reliable, yielded diastolic readings significantly lower (p less than 0.001) than diastolic Phase IV readings taken both serially and simultaneously.(ABSTRACT TRUNCATED AT 250 WORDS)

Early Childhood and Maternal Antecedents to Drug Use

In a longitudinal study, the substance use/abuse histories were obtained on a community sample of 640, (mean age of 24.9 years) randomly selected from the 8,000 Philadelphia black subjects who had been studied comprehensively from birth to seven years of age in the National Collaborative Perinatal Project (NCPP). Among other conclusions, it is postulated from some of the many significant associations found between early life variables and substance use/abuse in early adulthood, that an infant is at risk who has the following combination of characteristics and family situation: outgoing, responsive, assertive or impulsive, or willful, and who is in an unfavorable family environment, with a mother who is generally negative toward the infant, has a larger number of small children and has had more fetal deaths, in a generally poor social environment.