A prospective study of familial aggregation of blood pressure in young children.

In a prospective study, we evaluated familial aggregation of blood pressure in a sample of 175 normotensive families with children 3 to 6 yr old. Systolic and diastolic blood pressure measurements of parents and children were correlated at 1, 2, and 3 yr intervals. Spearman rank-order correlation coefficients between parents and children were significant for mother-son pairs. In particular, mother-son blood pressure correlation coefficients were significant for systolic blood pressure across all 3 yr and for diastolic blood pressure during yr 2. Further analyses were performed adjusting for body mass index (BMI), age, physical activity, sodium intake, potassium intake, and parental smoking status, and alcohol use. The Spearman correlation coefficients for mother-son pairs remained significant for yr 1 and 3 after adjusting for these blood pressure correlates. These results are consistent with cross-sectional studies and suggest that both genetic and environmental contributions to blood pressure status are important in young children.     

A longitudinal study of blood pressure in a national survey of children.

Blood pressure changes over a three- to four-year period were studies in a cohort of 2,168 children examined during the US Heath Examination Survey. The sample used is a representative subset of a national probability sample. Significant positive correlations between initial and follow-up blood pressures were observed. In addition, relatively obese children tended to demonstrate higher blood pressures within age-race-sex specific subgroups.     

A cross-sectional study of vitamin C intake and blood pressure in the elderly.

Data collected as part of a study designed to examine the nutritional status of non-institutionalized elderly individuals, ages 60-100 years, residing in the Boston area were used to investigate the relationship between blood pressure (BP) and vitamin C intake reported by three-day diet records. Four hundred and ten subjects not taking antihypertensive medications were grouped into 5 categories of vitamin C intake: < 60, 60-119, 120-179, 180-239, > or = 240 mg/day. Relative differences in systolic and diastolic BP between subjects consuming > or = 240 mg/day compared to those consuming < 60 mg/day were -6.9% (p < 0.05) and -6.6% (p < 0.05), respectively. The prevalence of elevated BP (systolic > or = 160 mmHg or diastolic > or = 100 mmHg) was approximately 50% lower (p < 0.05) across this range of vitamin C intake. Adjustment of these associations for age, sex, body mass, smoking, dietary sodium:potassium ratio, and other dietary factors did little to alter the relationship between vitamin C and BP. These results lend support to the hypothesis that vitamin C and BP are related, but further research is required to test whether the relationship is causal.     

A longitudinal evaluation of blood pressure in children.

Blood pressure levels obtained on two occasions, one year apart, were evaluated among 212 children. An overall correlation of .65 was obtained for systolic pressure and .43 for diastolic pressure. The results suggest that adult levels of correlation are not reached in childhood and that screening programs must consider the relative lability of children's measurements in establishing referral criteria.     

Gamma-glutamyltransferase, alcohol, and blood pressure. A four year follow-up study

PURPOSE: We performed this study to see: 1) whether gamma-glutamyltransferase (GGT) was a predictor for hypertension irrespective of amount of alcohol consumption; and 2) whether the relationship between alcohol consumption and blood pressure (BP) was different depending on GGT. METHODS: This study included 8170 healthy male workers in a steel manufacturing company who had undergone health examinations in both 1994 and 1998. RESULTS: The adjusted relative risk (RR) for hypertension over four years among those with GGT >or=30 U/L at baseline was 1.6 (95% confidence interval (CI): 1.1-2.4), compared to those with GGT < 30 U/L. This relationship was shown only in drinkers. Among subjects with GGT < 30U/L, no matter how much the subjects drank, the risk of hypertension in drinkers was similar with that of non-drinkers. However, among those with GGT >or=30 U/L, adjusted RRs for light, moderate, and heavy drinkers compared to non-drinkers were 1.4 (95% CI: 0.5-4.5), 5.2 (95% CI: 1.5-18.0), and 5.3 (95% CI: 1.0-27.6). CONCLUSIONS: This study showed that elevated GGT could be a predictor for hypertension in drinkers and the relationship between alcohol consumption and hypertension was shown only among those with GGT >or= 30 U/L at baseline. These findings suggest that increased serum GGT levels may reflect individual susceptibility to the blood pressure raising effect of alcohol.     

Alcohol consumption and blood pressure. An Italian study

We studied the relationship between alcohol consumption and arterial pressure in 1190 subjects of both sexes aged between 18 and 63 years who were examined during the course of a program of preventive medicine organized by Centro Diagnostico Italiano. In 711 subjects who were not requested to alter their usual alcohol consumption we found a significant relationship between alcohol consumption and systolic arterial pressure, b+SE(b), 4.6 ± 2.1 mmHg/100 g ethanol/day. In particular, males who were heavy drinkers (> 50 g_ethanol/day) presented significantly higher systolic pressure levels than the other men, d±SE(d), 3.7 ± 1.6 mmHg, whereas no significant differences were observed among the various classes of women subdivided according to alcohol intake (only 4.6% of the women consumed > 50 g ethanol/day). On the other hand, in 479 subjects who were requested to abstain from alcohol consumption during the three days preceding the examination, no significant relation was found between alcohol intake and arterial pressure. The difference between the systolic pressure levels of the male heavy drinkers and those of the male moderate and non-drinkers was only 0.1 mmHg.Excessive alcohol consumption, in this case, mainly in the form of wine, was therefore associated with higher systolic pressure levels. However, it seems that abstaining from alcohol for even a brief period may modify this relation considerably.     

A prospective study of blood pressure and risk of cataract in men

PURPOSE: Cataract is the leading cause of blindness worldwide. Blood pressure has been identified as a risk factor in some, but not all, previous studies. We aimed to test prospectively the hypothesis that high blood pressure increases risk of age-related cataract. METHODS: Participants in the Physicians' Health Study of 22,071 men aged 40 to 84 years in 1982 completed annual questionnaires that provided medical history including self-reported blood pressure, treatment for hypertension, and cataract. Over 12 years, 1392 cataracts were confirmed by medical record review among 17,762 physicians with complete data and no reported cataract at baseline. We used proportional hazards regression models to examine relations of systolic blood pressure (SBP), diastolic blood pressure (DBP), hypertension, as well as antihypertensive medications with cataract, after control for potential confounding factors. RESULTS: In models adjusting for age and randomized treatment assignment, there was a significant relationship of SBP, but not DBP, hypertension, or antihypertensive medications (each p > or = 0.23) with incident cataract. Estimates were attenuated after adjusting for multiple potential confounders, although the relationship of SBP with incident cataract remained significant. The multivariate adjusted rate ratio (95% confidence interval) of cataract for SBP > or = 150 versus < 120 mm Hg was 1.31 (1.04-1.66), p for trend = 0.04. For DBP > or = 90 versus < 70 mm Hg, the estimate was 1.11 (0.84-1.45), p for trend = 0.33.CONCLUSIONS: Overall, these data suggest that the relationship of blood pressure with cataract is not strong, and is subject to confounding by other risk factors. The modest magnitude of the association with SBP and lack of significant relationships with DBP and hypertension may suggest a non-causal relationship of blood pressure with cataract.     

The child-adolescent blood pressure study: I. Distribution of blood pressure levels in Seventh-Day-Adventist (SDA) and non-SDA children.

Distribution of systolic and diastolic blood pressures (measured with an automated blood pressure recorder) of two large groups of children-3,159 from Seventh-Day Adventist (SDA) schools and 4,681 from non-SDA schools-are reported. They boys and girls were from four different ethnic groups and attended grades one through 10 in 29 Southern California schools. The analysis of the data failed to show significant differences in mean blood pressure levels between the two groups of children at all ages, despite marked differences in life-style between the two groups, and despite the fact that adults from the two population groups have marked differences in mortality from diseases associated with elevated blood pressure. A comparison between boys and girls showed significantly higher trends in mean systolic blood pressure for boys after age 12. Inter-ethnic comparisons of blood pressure revealed that Black children of both sexes had slightly higher mean blood pressure levels at all ages.     

A prospective study of high blood pressure and cardiovascular disease in women

The relation of self-reported high blood pressure to the subsequent development of coronary heart disease and stroke was examined in a cohort of 119,963 women, aged 30-55 years, who were initially free from cardiovascular disease. Participants in the Nurses' Health Study reported high blood pressure and other cardiovascular risk factors on baseline questionnaires mailed in 1976. During six years of follow-up, there were 308 incident cases of coronary heart disease (66 fatal and 242 nonfatal myocardial infarctions) and 175 strokes (50 fatal and 125 nonfatal). Fatal as well as nonfatal coronary heart disease and stroke were all significantly more frequent among the women who had reported high blood pressure. After adjusting simultaneously for age and other risk factors, the relative risks were 3.5 (95% confidence interval (Cl) 2.8-4.5) for total coronary heart disease and 2.6 (95% Cl 1.8-3.5) for total stroke. This association was evident at all levels of relative weight. The results emphasize the importance of high blood pressure as an independent predictor of coronary heart disease and stroke in middle-aged women and suggest that the increased risk occurs in both lean and obese women.     

A study of hysterectomy in a family practice.

This paper reports on a study of women in a family practice who have undergone hysterectomy as compared with a group of matched controls. Significant differences were found in the greater number of major surgical procedures (other than hysterectomy) and the reporting of chronic and recurrent symptoms for the study group. Study group women were also found to have a greater number of identified intrapersonal and family problems. There was no significant difference, however, in the number of identified chronic organic problems. Differences which did not reach statistical significance suggest that women in the study group may be more likely to be living without a male partner, to be using long-term medication, and to be smokers. A most important finding was that the group of women who had undergone hysterectomy had also had 2.6 times the number of major surgical operations than the controls, excluding the hysterectomy. There were no differences between the two groups with respect to a number of other factors studied, eg, education, religion, history of psychiatric admission, obesity.     

Separating within and between effects in family studies: an application to the study of blood pressure in children

In epidemiology the analyses of family or twin studies do not always fully exploit the data, as information on differences between siblings is often used while between-families effect are not considered. We show how cross-sectional time-series linear regression analysis can be easily implemented to estimate within- and between-families effects simultaneously and how these effects can then be compared using the Hausman test. We illustrate this approach with data from the Uppsala family study on blood pressure in children with age ranging from 5.5 to 12.3 years for the younger and from 7.5 to 13.8 years for the older siblings. Comparing the effect of differences in birth weight on blood pressure within-family (in full siblings) and between-families (in unrelated children) allows us to study the contributions of fixed and pregnancy-specific maternal effects on birth weight and consequently on blood pressure. Our data showed a 0.88 mmHg decrease (95 per cent confidence interval: -1.7 to -0.03 mmHg) in systolic blood pressure for one standard deviation increase in birth weight between siblings within a family and 0.88 mmHg (95 per cent confidence interval: -1.6 to -0.2 mmHg) decrease in systolic blood pressure for one standard deviation increase in birth weight between unrelated children. These estimates were controlled for sex, age, pubertal stage, body size and pulse rate of the children at examination and for maternal body size and systolic blood pressure. The within- and between-families effects were not significantly different, p = 0.19, suggesting that fixed and pregnancy-specific factors have similar effects on childhood systolic blood pressure.     

Body fat distribution, blood pressure, and hypertension. A prospective cohort study of men in the normative aging study.

The relation between the abdominal accumulation of body fat, blood pressure, and hypertension was assessed prospectively among 1972 male participants in the Veterans Administration Normative Aging Study. Body mass index (BMI = weight [kg]/height [m]2) and the ratio of abdominal circumference to hip breadth (AC/HB), measured at regular exams, were used as indices of total adiposity and body fat distribution, respectively. Considering blood pressure as a continuous outcome variable (in models that allowed for intraclass correlation), the AC/HB ratio was significantly positively associated with both diastolic and systolic blood pressure (P < 0.001), adjusting for age and BMI. Blood pressure was dichotomized and hypertension risk was assessed using the proportional hazards model, adjusting for age and BMI. Seven hundred cases of hypertension were recorded by study physicians during 35,496 person-years of follow-up. The risk of hypertension increased approximately three-fold (95% confidence interval, 1.7 to 5.2) with a change of one unit in the AC/HB ratio. These estimates were little changed when the effects of smoking and alcohol intake were considered. Thus, the abdominal accumulation of body fat, apart from overall level of adiposity, was associated with both increased blood pressure and an increased risk of hypertension.     

A blood pressure survey in Nuevo Laredo,Mexico.

A blood pressure survey was carried out in 1976 in the city of Nuevo Laredo, Mexico, which involved 6,351 persons 30-69 years old. The study sample was recruited so as to represent an approximation of the overall distribution of occupational classes in the urban population. Members of the population sample were relatively young and of low educational attainment. To the extent that comparisons among surveys are feasible, mean blood pressure levels and hypertension rates were roughly comparable to those found in the white population of the United States. Although no firm conclusions can be drawn from the survey, a trend toward somewhat higher hypertension rates within the professional and managerial class was observed in some age groups in Laredo.     

Body fat, resting and exercise blood pressure and the angiotensinogen M235T polymorphism: the heritage family study.

OBJECTIVE: The association of resting and exercise blood pressure (BP) and fat mass with the angiotensinogen (AGT) M235T polymorphism was investigated in 522 sedentary Caucasian subjects from 99 families. RESEARCH METHODS AND PROCEDURES: Resting BP was measured on two separate days, three times each day, and the mean of six valid measurements was used. Exercise BP was measured during a cycle ergometer test at a constant power output (50 W). Body composition was derived from under-water weighing and the AGT M235T polymorphism was typed with a polymerase chain reaction-based method. RESULTS: Neither resting nor exercise BP was associated with the AGT genotypes. In mothers, the homozygotes for the T allele showed 8.8 kg and 7.1 kg greater (p=0.017) age-adjusted body fat mass (FM) than the MM homozygotes and heterozygotes, respectively. Sixty-nine percent of all TT homozygotes were found in the highest FM tertile, whereas only 16% of the MM homozygotes fell in the same tertile (p = 0.008). Moreover, a significant interaction was seen between FM and T-allele carrier status in women with regard to resting diastolic BP (p = 0.002). Among women with a FM> or =24 kg, carriers of the T allele showed a 6.3 mmHg higher diastolic blood pressure (DBP) than non-carriers whereas no difference was found in women with a FM less than 24 kg. A similar trend toward an interaction term was evident with resting systolic blood pressure (p = 0.011) and exercise DBP (p = 0.012). Body fat was not associated with the AGT polymorphism in fathers or in offspring. DISCUSSION: These data suggest that the AGT M235T polymorphism is associated with body fatness in women, and that the relationship between DBP and AGT M235T polymorphism is dependent on FM in middle-aged sedentary normotensive women.