多元多水平模型及其在血压影响因素研究中的应用

目的探讨多元多水平模型在血压影响因素研究中的应用。方法利用MLwin2.02软件对获得的数据进行二元三水平模型拟合。结果收缩压和舒张压在地区水平上的相关系数为0.949,在个体水平上的相关系数为0.701;收缩压和舒张压随着年龄的增加而增加,但年龄增大对收缩压的影响幅度更大,β分别为0.720(收缩压)和0.118(舒张压),χ2=4284.56,P<0.001;男性的收缩压和舒张压水平均高于女性,但男性人群尤以舒张压水平升高更为明显,β分别为2.208(收缩压)和3.113(舒张压),χ2=31.35,P<0.001。结论多元多水平模型可以灵活有效地处理层次结构的数据,适合于血压影响因素研究。     

Ethnic differences in blood pressure level between Japanese school children in Bolivia and native Bolivians

Blood pressure levels were measured in 626 children (138 Japanese, 477 Bolivian and 11 of mixed blood) in a Japanese agricultural settlement in Bolivia. Systolic (SBP) and diastolic (DBP) blood pressure was higher in Japanese children than in Bolivian children at each measured age by 4.09 mmHg (P = 0.0001) and 2.25 mmHg (P = 0.0038), respectively, using analysis of covariance. Although the slope of the regression line both for SBP and for DBP with age tended to be greater in Japanese, this was not statistically significant. There were no ethnic differences in height, weight or body mass index, however, which are usually indicators that correlate well with blood pressure. Ethnic differences in blood pressure were also shown at each of the measured values of height (SBP: 3.93, DBP: 2.19) and weight (SBP: 4.03, DBP: 2.23). Factors causing these ethnic differences are discussed in relation to cultural and genetic considerations.     

Cardiovascular risk factors in a French Canadian population: resolution of genetic and familial environmental effects on blood pressure using twins, adoptees, and extensive information on environmental correlates

Genetic and environmental influences on systolic (SBP), diastolic (DBP), and mean arterial (MBP) blood pressure were examined using an expanded version of a path model in which parents and their singleton, twin, and adopted offspring were incorporated, and which also included an environmental index as an estimate of the underlying familial environmental component. Estimates of genetic heritability are lower in parents (10-15%) than in offspring (40-50%). Cultural heritability was significant for SBP (0.31) and MBP (0.40), and an intergenerational effect was found for DBP, with higher estimates in parents (0.42) than in offspring (0.21). Marital resemblance was significant, and no support was found for differential maternal and paternal cultural transmission. Two novel results arising from this study are 1) gender-specific sibling effects, with greater female than male resemblance for SBP and MBP and the opposite pattern for DBP, and 2) the suggestion of extra twin resemblance arising on account of additional shared environments and resulting in greater like-sex than opposite-sex twin resemblance. The major conclusions drawn from this study are that 1) parameter estimates are stable with or without the use of extensive environmental indices, and 2) the addition of twins and adoptees did not significantly impact the results, with the exception of a possible influence of the adoptees in estimates of cultural heritability for DBP. Combining both these features (i.e., extended relatives and environmental indices) enables testing for additional sources of familial aggregation, which is not possible using the traditional nuclear family approach and results in a more accurate assessment of the relative roles of heredity and environment on blood pressure than has been previously possible.     

Seasonal changes in ambulatory blood pressure in employees under different indoor temperatures.

OBJECTIVE--The effect of indoor temperature control on summer and winter ambulatory blood pressure levels at work was studied. METHOD--Ambulatory systolic blood pressure (SBP) and diastolic blood pressure (DBP) were monitored once in summer and once in winter in 101 healthy normotensive subjects aged 28-63 years, engaged in similar physical work, from two plants with and three without air conditioning. Subjects were interviewed about health related habits, and measurements of environmental and occupational conditions were obtained. RESULTS--After controlling for possible confounders, mean SBP and DBP during work were significantly higher in winter than in summer (delta SBP = 3.4 mm Hg, P = 0.035; delta DBP = 3.3 mm Hg, P < 0.003). The seasonal change in SBP and DBP showed an independent association with the presence or absence of air conditioning of the industrial plants (SBP: beta = 0.194, P < 0.0001; DBP: beta = 0.054, P = 0.038). The percentage of subjects with increases of more than 10 mm Hg from summer to winter was higher in plants without than with air conditioning. CONCLUSIONS--(1) In normotensive subjects ambulatory working BP varies by season, with higher values in winter. If validated for hypertensive subjects, it may be necessary to tailor drug treatment to these variations. (2) The findings make it clear that drawing valid conclusions from comparisons of BPs between groups requires controlling for several factors, particularly season of the year. (3) Climatic conditions in the industrial plant influence the magnitude of seasonal variations in BP. Work in plants without air conditioning places a considerable added load on the employee's cardiovascular system.     

Relationship of blood pressure to cardiovascular death: the effects of pulse pressure in the elderly

PURPOSE: To investigate the relationship of systolic and diastolic blood pressure to fatal myocardial infarction, fatal stroke and other death related to cardiovascular diseases (CVD). METHODS: The study was based on a prospective longitudinal study conducted by the Veterans Administration at the Boston Outpatient Clinic. Participants are male volunteers from the greater Boston area. Main outcome measures are fatal myocardial infarction, fatal stroke and other deaths related to cardiovascular diseases. The method of pooled logistic regression was used for statistical analysis. RESULTS: For younger men (age 21-59), after adjusting for effects of other risk factors, when systolic and diastolic blood pressure were considered separately, SBP was predictive of cardiovascular death (SBP: RR = 1.23; 95% CI = (1.05, 1.45) per 10 mmHg of increase), and DBP showed a nonsignificant positive trend in relation to cardiovascular death (DBP: RR = 1.27; 95% CI = (0.95, 1.69) per 10 mmHg of increase). For older men (age 60-85), when SBP and DBP were considered separately, SBP (RR = 1.26; 95% CI = (1.02, 1.55) per 15 mmHg of increase) was directly related, but DBP (RR = 1.05; 95% CI = (0.83, 1.32) per 8 mmHg of increase) was not related to cardiovascular death. However, for the elderly group, when SBP and DBP were considered jointly in the regression model, then the regression coefficient of DBP (beta = -0.018, p = 0.30) was of approximately the same absolute magnitude as that of SBP (beta = 0.021, p = 0.02) but opposite in sign. For younger men, when SBP and DBP were considered jointly, SBP (beta = 0.021, p = 0.049) but not DBP (beta = -0.001, p = 0.953) was positively related to cardiovascular death. CONCLUSIONS: We found that, for the elderly, pulse pressure (SBP-DBP) may be a more accurate predictor of cardiovascular death than either SBP or DBP alone. The relative risk per 35 mmHg of increase of pulse pressure, which equals the approximate interval from the 10th to the 90th percentile in the elderly group, is 2.1 with 95% CI = (1.1, 3.8). In younger subjects, SBP, but not DBP, is an independent predictor of fatal CVD.     

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.     

Hereditary and environmental influences on blood pressure values of premenopausal women and their college-age daughters.

Blood pressure (BP) and environmental (dietary/lifestyle) variables were measured in 62 healthy normotensive pairs of premenopausal mothers (44.3 years) and their college-age consanguineous daughters (18.7 years) to estimate the relative contributions of genetic vs environmental factors on BP. As expected, the mothers had significantly higher systolic (SBP) and diastolic (DBP) blood pressures than the daughters (p less than 0.004 and 0.012, respectively). Among the dietary/lifestyle variables measured, mothers were found to have significantly higher mean weight and body mass index (BMI) (p less than 0.009 and 0.001, respectively), and significantly lower lean body mass (LBM) and calcium intake than their daughters (p less than 0.003 and 0.037, respectively). Significant correlations were found between mean BP of the mothers and their mean weight and BMI. No significant correlations existed for the daughters. The familial resemblances between BP of the mothers and daughters were relatively low, i.e., 0.14 for SBP and 0.19 for DBP. From these findings we conclude that the higher BP values with increased age among this healthy female population primarily result from an increase in BMI and a shift from lean to fat mass, as measured by midarm circumference. Our results suggest that environmental factors, i.e., excessive energy intake over time, accompanied by decreased physical activity, are primarily responsible for the greater indices of body fat and the higher BPs observed in this sample of healthy premenopausal women.     

Hereditary and environmental influences on blood pressure values of premenopausal women and their college-age daughters

Blood pressure (BP) and environmental (dietary/lifestyle) variables were measured in 62 healthy normotensive pairs of premenopausal mothers (44.3 years) and their college-age consanguineous daughters (18.7 years) to estimate the relative contributions of genetic vs environmental factors on BP. As expected, the mothers had significantly higher systolic (SBP) and diastolic (DBP) blood pressures than the daughters (p less than 0.004 and 0.012, respectively). Among the dietary/lifestyle variables measured, mothers were found to have significantly higher mean weight and body mass index (BMI) (p less than 0.009 and 0.001, respectively), and significantly lower lean body mass (LBM) and calcium intake than their daughters (p less than 0.003 and 0.037, respectively). Significant correlations were found between mean BP of the mothers and their mean weight and BMI. No significant correlations existed for the daughters. The familial resemblances between BP of the mothers and daughters were relatively low, i.e., 0.14 for SBP and 0.19 for DBP. From these findings we conclude that the higher BP values with increased age among this healthy female population primarily result from an increase in BMI and a shift from lean to fat mass, as measured by midarm circumference. Our results suggest that environmental factors, i.e., excessive energy intake over time, accompanied by decreased physical activity, are primarily responsible for the greater indices of body fat and the higher BPs observed in this sample of healthy premenopausal women.     

Dietary zinc intake is inversely associated with systolic blood pressure in young obese women

Zinc may participate in blood pressure regulation and in the pathogenesis of hypertension. The study examined the relationship between zinc status and blood pressure in obese Korean women. Forty obese women (body mass index (BMI) ≥ 25 kg/m²) aged 19-28 years participated in this study. Zinc intake was estimated from one 24 hour recall and 2-day diet records. Serum and urinary zinc concentrations were determined by atomic absorbance spectrophotometry. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using an automatic sphygmometer. Metabolic variables, such as waist circumference, triglyceride, high density lipoprotein (HDL) cholesterol, fasting glucose, and fasting insulin, were also measured. Dietary zinc intake of obese women was averagely 7.5 mg/day. Serum zinc and urinary zinc concentrations were 13.4 µmol/L and 378.7 µg/day, respectively. Averages of SBP and DBP were 119 mmHg and 78 mmHg. Dietary zinc intake was negatively correlated with SBP after adjusting for energy intake (P < 0.05), but serum and urinary zinc concentrations were not found to be correlated with SBP or DBP. Multivariate linear regression analysis showed that dietary zinc intake was inversely associated with SBP in obese women after adjusting for body weight, energy intake and sodium intake (P = 0.0145). The results show that dietary zinc intake may be an independent risk factor of elevated SBP in obese Korean women.     

Low plasma pyridoxal 5'-phosphate concentration and MTHFR 677C-->T genotypes are associated with increased risk of hypertension

Few studies have linked homocysteine, B vitamins and/or genetic defects to the risk of hypertension. The purpose of this study was to investigate homocysteine, B-vitamins, and genetic mutation in relation to the risk of hypertension. Subjects were assigned to the hypertension (HTN) group (n = 50) or non-hypertension (non-HTN) group (n = 123). All subjects' blood pressure (systolic blood pressure, SBP; diastolic blood pressure, DBP), biochemical values, plasma homocysteine, pyridoxal 5'-phosphate (PLP), serum folate, vitamin B12 concentrations, and methylenetetrafolate reductase (MTHFR) 677C-->T gene polymorphism were measured. Results showed that subjects with T-allele were positively associated with DBP (beta = 4.22, p = 0.04) but the significance became weaker (p = 0.06) after homocysteine and B vitamins were additionally adjusted. A significant association of plasma PLP with SBP remained (beta = -0.06, p = 0.01) even after homocysteine and T-allele genotypes were additionally adjusted (beta = -0.07, p = 0.02). The combined presence of low PLP (< 30 nmol/L) and carried T-allele enhanced the risk of hypertension and the risk magnitude was substantially greater (OR, 16.44, p < 0.001). Taken together, the results show that low plasma PLP levels and MTHFR 677C-->T genotypes might be significant risk factors for hypertension.     

国家最大容许浓度内二硫化碳暴露对血压和心电图的影响

目的 探讨国家最大容许浓度(MAC)内二硫化碳(CS_2)暴露对血压、心电图的影响及其相互之间的关系.方法 根据工种的不同,将化纤厂职工按CS_2接触浓度分为高浓度接触组(821人)、低浓度接触组(259人),工作场所CS_2浓度控制在MAC范围内.随机抽取同期来医院健康体检人员250人作为对照组.测量臂部收缩压、舒张压,计算脉压、平均动脉压,与常规同步12导联静息心电图描记结果 、性别、年龄、工龄、工种、甘油三酯、胆固醇、血糖结果 汇总,分析接触CS_2后血压升高和心电图异常的危险因素,以及它们之间的关系.结果 高、低浓度接触组间及高浓度接触组与对照组间收缩压、舒张压、平均动脉压均数及异常发生率的差异均有统计学意义(P<0.01);高、低浓度接触组工人舒张压异常发生率均高于收缩压异常发生率近2倍.工种因素在高收缩压、高舒张压组中是最大的危险因素,高浓度接触的危险度是低浓度接触的2倍多,OR值分别为2.086、2.331.高、低浓度接触组与对照组间心电图异常发生率的差异有统计学意义(P<0.01);在低浓度接触组中筛出高收缩压,在高浓度接触组中筛出高舒张压2个OR值(3.531,1.638)较高的危险因素和值得探究的血糖(OR=0.747)保护因素,而低浓度接触的高收缩压组、高浓度接触的高舒张压组又分别筛出工龄、胆固醇等危险因素.与血压相关的心电图左心室高电压诊断在高浓度接触组中仪筛出高舒张压一个危险因素(OR=4.140),在低浓度接触组中仅筛出高收缩压一个危险因素(OR=4.776);在低浓度接触组中高脉压是复极异常的唯一危险因素(OR值达20.417);血糖在起源异常方面是危险因素,而在左心室高电压方面却是保护因素(OR=0.633).结论 CS_2对心血管的损害是一个循序渐进的过程,接触CS_2的早期、或接触浓度很低都会损伤人们的循环系统,在国家MAC内CS_2对心血管的毒性作用仍然随接触时间、接触浓度的增加而增加.CS_2对舒张压的作用大于对收缩压的作用,间接说明CS_2对外周阻力血管的作用可能大于对大动脉的作用.心电网结果 的异常不仅有血压异常后作用于心脏的结果 ,还有CS_2作用于心脏及外周血管的共同表现.     

Genome-wide linkage analysis of blood pressure in Mexican Americans

The genetic mechanisms that control variation in blood pressure level are largely unknown. One of the first steps in understanding those mechanisms is the localization of the genes that have a significant effect on blood pressure. We performed genome scans of systolic (SBP) and diastolic blood pressure (DBP) on a population-based sample of families in the San Antonio Family Heart Study. A likelihood-based Mendelian model incorporating genotype-specific effects of sex, age, age(2), BMI, and blood pressure (SBP or DBP, as appropriate) as covariates was used to perform two-point lodscore (Z) linkage on 399 polymorphic markers. Results showed that the genotype-specific covariate effects were highly significant for both SBP and DBP. Linkage results showed that a quantitative trait locus (QTL) influencing DBP was significantly linked to D2S1790 (Z = 3.92, theta = 0.00) and showed suggestive linkage to D8S373 (Z = 1.92, theta = 0.00). A QTL influencing SBP showed suggestive linkage to D21S1440 (Z = 2.82, theta = 0.00) and D18S844 (Z = 2.09, theta = 0.11). Without the genotype-specific effects in the model, the linkage to D2S1790 was not even suggestive (Z = 1.33, theta = 0.09); thus genotype-specific modeling was crucial in detecting this linkage. A comparison with linkage studies based in other populations showed that the significant linkage to D2S1790 has been replicated at the same marker in the Quebec Family Study. The replicated significant linkage at D2S1790 may begin to establish the locations of the genes that significantly affect blood pressure across several human ethnic groups.     

上海市社区老年高血压患者血压水平影响因素的多水平分析

目的 应用多水平分析模型分析社区老年高血压患者血压水平的影响因素.方法 通过多阶段随机抽样,抽取上海市23个社区的927例老年高血压患者作为研究对象,采用两水平线性多层模型分别分析社区老年高血压患者收缩压(SBP)和舒张压(DBP)的影响因素.结果 研究对象的平均血压水平为SBP(139.2±11.7)mm Hg、DBP(85.6±8.6)mm Hg(I mm Hg=0.133 kPa).在社区水平上,辖区高血压患者/站点医师数(医患比)"高"的社区较医患比"低"的社区患者的SBP低3.86 mm Hg、DBP低2.51 mm Hg.在个体水平上,年龄、性别、超重/肥胖是血压升高的危险因素;规律服药、限盐、疾病管理自我效能的提高可降低血压,特别是在控制其他影响因素后仅限盐1项就可降低SBP 2.44 mm Hg、DBP 2.03 mm Hg.结论 多水平分析模型可以灵活有效地处理具有层次结构的数据,社区因素和个体因素对老年高血压患者的血压水平均有影响.     

Physical Activity and Blood Pressure Patterns: A Cross-Sectional Study on Portuguese School Children Aged 8 Through 13 Years Old

The relation between blood pressure and physical activity was examined. A sample of 474 children (242 boys and 232 girls), aged 8 through 13 years were involved in this study. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were evaluated. An adapted version of the Weekly Activity Checklist was applied to the sample for diagnosis of their physical activity. SBP and DBP increased from 8 to 13 years in both sexes (boys: SBP, 114.8 10.9 to 120.5 9.4 mmHg and DBP, 59.1 8.3 to 62.3 6.8 mmHg; girls: SBP, 115.2 12.1 to 120.2 10.9 mmHg, and DBP, 58.9 9.3 to 60.5 9.6 mmHg). Correlations, after adjustment for age, of physical activity index with SBP (r = -.20, p < .05) and DBP (r = -.17, p < .05) were significant in boys, whereas in girls no significant association was found. This article provides some preliminary data on the blood pressure and physical activity patterns of school children in the Porto (Portugal) region.     

Temporal Associations between Tri-Ponderal Mass Index and Blood Pressure in Chinese Children: A Cross-Lag Analysis

Background: No longitudinal studies have explored the relationship between tri-ponderal mass index (TMI) and blood pressure (BP) in children. This study is aimed to investigate the temporal associations between TMI and BP among children in China. Methods: A longitudinal study was carried out with Chinese children from 2014 to 2019. Data of the anthropometric examination and blood pressure were collected annually. TMI was calculated by dividing weight by the cube of height. BP was measured using a standard mercury sphygmomanometer. We investigated temporal associations between TMI and BP with a cross-lagged panel model using repeated measure data from 2014 (Wave 1), 2016 (Wave 2), and 2018 (Wave 3). Results: Results of the cross-lagged panel model showed that TMI was associated with subsequent BP. Participants with higher levels of TMI presented higher levels of BP (Wave 1: β = 0.737 for systolic blood pressure (SBP) and β = 0.308 for diastolic blood pressure (DBP), Wave 2: β = 0.422 for SBP and β = 0.165 for DBP, p < 0.01). In addition, children with higher BP could also present higher TMI (Wave 1: β = 0.004 for SBP and β = 0.006 for DBP, Wave 2: β = 0.003 for SBP and β = 0.005 for DBP, p < 0.01), but the cross-lag path coefficient indicated that the influence of TMI on BP was stronger than the influence of BP on TMI. Conclusions: There was a temporal association between TMI and BP in Chinese children. Higher TMI predicted higher subsequent BP rather than the reverse relationship.     

The Association of Body Mass Index and Waist Circumference with Blood Pressure Depends on Age and Gender: A Study of 10,928 Non-Smoking Adults in the Greek EPIC Cohort

Body mass index (BMI) and waist circumference are independently associated with blood pressure, but the dependence of these associations on gender and age has not been clarified. We investigated the associations of BMI and waist circumference with systolic (SBP) and diastolic (DBP) blood pressure and assessed possible interactions with gender and age. Data concerning blood pressure and anthropometric variables were collected at enrollment in a cohort study from 10,928 non-smoking adults, all over Greece, who have never received antihypertensive treatment. Multiple regression-derived standardized coefficients were estimated to compare effects among variables. Among men, waist circumference appears more important than BMI in the prediction of SBP (standardized coefficients 2.26 vs. 1.52 mmHg/SD), and to a lesser extent DBP. In contrast, among women, BMI is more important than waist circumference, in the prediction of SBP (standardized coefficients 3.97 vs. 1.56 mmHg/ SD) and to a lesser extent DBP. The different effects of BMI and waist circumference on blood pressure by gender are evident among older individuals (> 55 years); among younger individuals BMI and waist circumference have comparable effects in both genders. Among younger individuals, BMI and waist circumference are independent and equally important predictors of SBP and DBP in both genders, whereas among older individuals waist circumference is the dominant predictor of blood pressure among men and BMI is the dominant predictor of blood pressure among women. Associations are more evident with respect to SBP than DBP.     

The effects of aging and radiation exposure on blood pressure levels of atomic bomb survivors

The Adult Health Study (AHS) is a longitudinal study that has included biennial blood pressure measurements since 1958. In the present study, we applied the mixed effects model for serially measured data on the AHS population to (1) examine age-related changes in blood pressure and (2) detect possible radiation effects. The estimated longitudinal model of systolic blood pressure (SBP) depicted a linear increase from 30 to 80 years of age for both sexes. The diastolic blood pressure (DBP) rose linearly to about 65 years of age and then leveled off. There were marked differences in the longitudinal trends of DBP among birth cohorts, particularly for men, with higher DBP levels in the younger cohort. The present analysis demonstrated a small but statistically significant effect of ionizing radiation on the longitudinal trends of both SBP and DBP. This phenomenon is compatible with the degenerative effect of ionizing radiation on blood vessels.     

Oral contraceptives: a risk factor for uncontrolled blood pressure among hypertensive women

The objective of the study was to assess the association between systolic and diastolic blood pressure (SBP and DBP) and the use of oral contraceptives (OC) in hypertensive women. In a prospective cross-sectional study, we evaluated 171 women who were referred to the Hypertension Outpatient Clinic of Hospital de Clínicas de Porto Alegre; 66 current users of OC, 26 users of other contraceptive methods and 79 women who were not using contraception. The average of six blood pressure readings was used to establish the usual blood pressure of the participants. Current OC users were compared with users of other methods and with patients not using contraception. Main outcome measures were SBP and DBP among the different groups, and prevalence of uncontrolled hypertension (SBP >or= 140 mmHg and DBP >or= 90 mmHg). DBP was higher in OC users (100.2 +/- 15.9 mmHg) than in patients using other contraceptive methods (93.4 +/- 14.7 mmHg) and not using contraceptives (93.3 +/- 14.4 mmHg, p = 0.016). Women using OC for more than 8 years presented higher age-adjusted blood pressure levels than women using OC for shorter periods. Patients using OC had poor blood pressure control (p for trend = 0.046) and a higher proportion of them presented moderate-severe hypertension. These results were independent of antihypertensive drug use. In a logistic regression model, we found that current OC use was independently and significantly associated with prevalence of uncontrolled hypertension. It is concluded that hypertensive women using OC present a significant increase in DBP and poor blood pressure control, independent of age, weight and antihypertensive drug treatment.     

Genetic and environmental effects on blood pressure in a Norwegian sample.

Systolic (SBP) and diastolic (DBP) blood pressures were measured in a health screening of the adult population in Nord-Trøndelag, Norway. Correlations were computed for 23,936 pairs of spouses, 43,586 pairs of parent and offspring, 19, 151 pairs of siblings, 1,251 pairs of grandparents-grandchildren, 1,146 pairs of biological uncles/aunts-nephews/nieces (avuncular), 801 non-biological avuncular pairs, 169 pairs of same-sex twins, and smaller groups of other types of relationships. Spouse correlations of 0.08 and 0.09 were approximately constant or slightly decreasing with marital duration. The correlation values for SBP and DBP were approximately 0.16 for parents-offspring, 0.19 to 0.23 for same-sex siblings with similar values for DZ twins, 0.19 and 0.16 for opposite-sex siblings, 0.52 and 0.43 for MZ twins, and close to zero for most of the second-order relationships. Genetic additive variance was estimated at 0.29 and genetic dominance variance at 0.18 with the best model for SBP. The corresponding estimates from the best models for DBP were 0.29 or lower and 0.22 or lower, the sum not exceeding 0.35. There was evidence of a moderate effect of environmental factors shared by same-sex siblings and twins (for DBP), but no cultural transmission, and whether or not adult relatives live together does not affect familial resemblance for BP. The data did not permit a very precise resolution of the relative magnitude of genetic dominance and sibling effects. The correlation structure did not show sex-specific genetic effects. © 1992 Wiley-Liss, Inc.     

Genetic and nongenetic determinants of blood pressure in a southern Brazilian sample

A probabilistic sample representative of the adult population of Rio Grande do Sul, Brazil, was studied to estimate the genetic and nongenetic determinants of blood pressure. Four thousand five hundred and sixty-five individuals, 20 to 74 years old, from 2050 households, were examined. The genetic determination of the SBP (systolic blood pressure) and DBP (diastolic blood pressure) was evaluated in 557 families extracted from this sample. The analysis was performed first with no adjustments for other influencing factors, and then adjusting for the effects of the two significant covariates, age and Quetelet's index, identified through a multiple stepwise regression analysis with nine independent variables. Higher heritability estimates were obtained for DBP (raw data: 0.40; residuals: 0.45) than for SBP (raw data: 0.22; residuals: 0.26). The significant correlation coefficients varied from 0.13 (for father-offspring raw data, total sample), to 0.36 (for siblings, adjusted data, untreated sample). Slight differences were observed between the total and pharmacologically untreated samples in relation to correlation and heritability estimates.