Associations between adiposity, family history of CHD and blood pressure in 3–8 year-old children

Cardiovascular Risk Assessment of Elevated Blood Pressure for Screening and Early Detection in Children 6 to 9 Years of Age in the Valencian Community: ANIVA Study

Elevated blood pressure (EBP), hypertension (HT), and prehypertension (PHT), along with the rising prevalence of overweight/obesity in children, correlate with a heightened risk of cardiovascular complications. This study focuses on assessing the prevalence of overweight/obesity and EBP and identifying potential indicators for effective early screening and detection of EBP in children aged 6 to 9 years old. This cross-sectional study was conducted with 1142 students from different schools across the Valencian Community in Spain. Data collection involved administering a questionnaire alongside direct anthropometric measurements of each student. The collected data underwent comprehensive statistical analysis, including frequencies, percentages, means, and chi-square automatic interaction detector (CHAID) analysis. In the sample, 7.5% of the children had HT and 6.8% had PHT, meaning 14.3% presented with EBP. Additionally, 17.0% of the children were classified as overweight and 3.9% as obese. Body mass index >23.1, body fat percentage >20.79%, and Kidmed scores <8 were identified as potential markers for early detection of EBP. The study reveals a significant incidence of EBP and overweight/obesity. Implementing screening protocols for early detection of EBP is imperative to forestall future cardiovascular events. Moreover, lifestyle modifications emerge as the most crucial approach for managing these risk factors.

Waist-to-height ratio and skipping breakfast are predictive factors for high blood pressure in adolescents

The purpose of this study was to estimate the prevalence of high blood pressure (HBP) in adolescents of the Valencian Autonomous Community (VC) in Spain. Besides, its association with other risk factors related to cardiovascular disease (CVD) or arterial hypertension (AHT) in order to increase our knowledge of public health and to provide advice about healthy diets. We conducted a multicentre, observational, cross-sectional, epidemiological study in a sample of 4402 adolescents from 15 schools during the 2015-2016 school year. The participants were aged between 11 and 18 years, and any individuals already diagnosed with AHT were excluded. In addition to the Physical Activity Questionnaire for Adolescents (PAQ-A), Evaluation of the Mediterranean Diet Quality Index (KIDMED), a lifestyle habits survey, the waist-to-height ratio (WtHR), and body mass index (BMI) were calculated for each participant. Informed Consent was obtained from Parents of the adolescents involved in the current study. The study received approval from the University ethics committee and all procedures were conducted in accordance with the tenets of the Declaration of Helsinki. Chi-squared, Student t-tests, and ANOVA statistical analyses showed that 653 (14.8%) adolescents had previously undiagnosed HBP and that was significantly associated with male sex (p < 0.001), age over 15 years (p < 0.05), and height, weight, waist circumference, WtHR, BMI, and skipping breakfast. Based on the data we obtained in this study, the modifiable factors that influence HBP in adolescents were WtHR, BMI, and skipping breakfast.

Prevalence and Risk Factors of Hypertension Among Children Attending Out Patient Department of a Tertiary Care Hospital in Karachi

Introduction: The childhood obesity epidemic has caused the global prevalence of hypertension (HTN) in children to increase from 2% to 4%. However, there is limited data regarding this issue in Pakistan. Hence this cross-sectional study aims to document the prevalence of HTN and its risk factors among children visiting the out patient department (OPD) of a government hospital in Karachi, which is one of the largest cities in Pakistan. Methods: One thousand children aged between 4 and 12 years who visited the OPD in October 2019 were included. Blood pressures (BPs) for each child were measured manually and recorded. Their guardians were then interviewed to assess the risk factors present in each child. Data collected were analyzed using SPSS (Statistical Package for the Social Sciences). Results: Among all the children, those between 4 and 7 years of age had a higher prevalence of HTN (19.2%; 9.2% stage 1 and 10.0% stage 2) than children aged between 8 and 12 years (14.5%; 8.0% stage 1 and 6.5% stage 2). Obese children between the age of 4 and 7 years (OR = 3.11) were more likely to develop HTN. Moreover, children with a positive family history of HTN were 1.43 times more likely to have HTN and 1.32 times more likely to have pre-HTN. There was no significant association of gender, artificial feeding, low birth weight, and maternal smoking with HTN. Conclusion: The prevalence is particularly higher in children aged between 4 and 7 years (19.2%) and there is a strong association between high BMI (body mass index), family history of HTN, and high-fat diet intake with HTN in children. There was no significant variation of prevalence between both genders.

Associations between adiposity indicators and hypertension among children and adolescents with intellectual disability-A case-control study

BACKGROUND

Adiposity is closely related to hypertension (HTN) in paediatric population. However, which adiposity indicator is most associated with HTN among children and adolescents with intellectual disability remains unknown. The aim of this study was to evaluate the associations between HTN prevalence and different adiposity indicators: body mass index (BMI) percentile, body fat percentage (BFP), waist circumference (WC), hip circumference (HC), waist-hip ratio (WHR) and waist-to-height ratio (WHtR) in students with intellectual disability.

METHODS

Cross-sectional study included a sample of 568 schoolchildren with intellectual disability, aged 7-18 years. Blood pressure, BMI, body composition, WC and HC were determined using standardized equipment.

RESULTS

Multivariate logistic regression showed that male gender, adolescence, high HC and excessive BFP were significant independent factors that increased risk of HTN occurrence in population with intellectual disability.

CONCLUSIONS

Findings indicated that HC and BFP, in particular, may be helpful tools to detect HTN in population with intellectual disability.

Screening of Egyptian obese children and adolescents for insertion/deletion (I/D) polymorphism in angiotensin-converting enzyme gene

Background

/aims: The role of angiotensin-converting enzyme (ACE) gene polymorphism in the development of obesity and hypertension in children has not been widely studied. We aimed to screen Egyptian obese children and adolescents for insertion/deletion (I/D) polymorphism in the ACE gene.

Methods

One hundred forty-two children and adolescents were included (70 with simple obesity and 72 controls). Blood pressure was measured, and anthropometric parameters were assessed in all included children and adolescents. Fasting lipid profile, fasting glucose, and insulin were measured. DNA extraction and ACE I/D polymorphism genotyping were also performed.

Results

Obese children had a higher frequency of DD genotype (30% in obese versus 11.1% in controls, P = .01) and D alleles (61.8% in obese versus 48.6% in controls, P = .01). Obese children with hypertension and prehypertension had higher frequency of DD genotype than II genotype and higher D alleles than I alleles. DD genotype and D allele were independently associated with hypertension (OR: 9.86 and 11.57, respectively, P < .001), while dyslipidemia and insulin resistance were not associated with the ACE I/D gene polymorphism.

Conclusion

DD genotype and D-allele of the ACE gene polymorphism were associated with obesity and with hypertension and pre-hypertension in Egyptian children.

Correlates of elevated blood pressure in healthy children: a systematic review

The prevalence of hypertension in children is increasing globally. Addressing this will require a robust understanding of associated risk factors. To this end, we conducted a systematic review to identify correlates of elevated blood pressure (BP) in children. Literature searches were conducted using pre-defined search terms from three academic databases. The abstract and full text of identified studies were screened for eligibility by two independent reviewers. A total of 100 studies were included in this systematic review. An assessment tool was first used to assess study quality; a narrative synthesis was then performed. We found a broad range of physiological, social and behavioural factors associated with elevated BP in children. The most common correlate observed was adiposity, suggesting that childhood obesity may be implicated in the increased prevalence of hypertension observed in children. However, the broad range of other factors identified underscores the multi-factorial aetiology of hypertension. Data from a broad range of studies showed that the correlates of hypertension in children are multi-factorial. Therefore, approaches aimed at preventing hypertension must in turn be multi-factorial to ensure that the burden of hypertension in childhood is addressed.

Human cytomegalovirus infection and coronary heart disease: a systematic review

Background

Human cytomegalovirus (HCMV) infection is closely associated with coronary heart disease.

Main body of the abstract

In 1987, Adam et al. were the first to report an association between HCMV infection and atherosclerosis (AS), and later, many serum epidemiology and molecular biology studies showed that HCMV-infected endothelial cells play an important role in the development of AS. As patients with HCMV are generally susceptible to coronary heart disease, and with the increasing elderly population, a review of recent studies focusing on the relationships of HCMV infection and coronary heart disease is timely and necessary.

Short conclusion

The role of HCMV infection in the development of AS needs further study, since many remaining issues need to be explored and resolved. For example, whether HCMV promotes the development of coronary AS, and what the independent factors that lead to coronary artery AS by viral infection are. A comprehensive understanding of HCMV infection is needed in order to develop better strategies for preventing AS.

Prevalence of high blood pressure and association with obesity in Spanish schoolchildren aged 4-6 years old

Background

The prevalence of high blood pressure in children is increasing worldwide, largely, but not entirely, driven by the concurrent childhood obesity epidemic. The aims of this study were to examine the prevalence of prehypertension and hypertension in 4-to-6-year-old Spanish schoolchildren, and to evaluate the association between different blood pressure (BP) components with different adiposity indicators.

Methods

Cross-sectional study including a sample of 1.604 schoolchildren aged 4-to-6-years belonging to 21 schools from the provinces of Ciudad Real and Cuenca, Spain. We measured height, weight, body mass index (BMI), fat mass percentage (%FM), triceps skinfold thickness (TST), waist circumference (WC), systolic and diastolic BP, mean arterial pressure and pulse pressure.

Results

The estimates of prevalence of prehypertension and hypertension were 12.3% and 18.2%, respectively. In both sexes, adiposity indicators were positively and significantly associated with all BP components (p<0.001), thus schoolchildren in the higher adiposity categories had significantly higher BP levels (p<0.001).

Conclusions

Our results show a high prevalence of high blood pressure in Spanish children. Moreover, high levels of adiposity are associated with high blood pressure in early childhood, which support that it could be related to cardiovascular risk later in life.

Subcutaneous fat mass in infancy and cardiovascular risk factors at school-age: The generation R study

OBJECTIVE

To examine the associations of infant subcutaneous fat with cardiovascular risk factors at school-age.

METHODS

In a population-based prospective cohort study among 808 children, total subcutaneous fat (sum of biceps, triceps, suprailiacal, and subscapular skinfold thicknesses) and central-to-total subcutaneous fat ratio (sum of suprailiacal and subscapular skinfold thicknesses/total subcutaneous fat) at 1.5 and 24 months were estimated. At 6 years, body mass index, blood pressure, cholesterol, triglycerides, and insulin levels were measured.

RESULTS

Infant subcutaneous fat measures were not associated with childhood blood pressure, triglycerides, or insulin levels. A 1-standard-deviation score (SDS) higher total subcutaneous fat at 1.5 months was, independently of body mass index, associated with lower low-density lipoprotein (LDL)-cholesterol levels at 6 years. In contrast, a 1-SDS higher total subcutaneous fat at 24 months was associated with higher total-cholesterol [difference 0.13 (95% confidence interval (CI) 0.03, 0.23) SDS] and LDL-cholesterol levels [difference 0.12 (95% CI 0.02, 0.21) SDS] at 6 years. There were no associations of central-to-total subcutaneous fat ratio with childhood cholesterol levels.

CONCLUSIONS

These results suggest that infant total subcutaneous fat is weakly associated with cholesterol levels at school-age. Further studies are needed to assess the long-term cardiometabolic consequences of infant body fat.

Ability of different adiposity indicators to identify children with elevated blood pressure

OBJECTIVE

Body composition measured by dual-energy X-ray absorptiometry (DXA) is believed to be superior to crude measures such as BMI or waist circumference (WC) to assess health risks associated with adiposity in adults. We compared the ability of BMI, WC, waist-to-height ratio (WHtR), percentage body fat from skinfold thickness, and measures of total and central fat assessed by DXA to identify children with elevated blood pressure (BP).

STUDY DESIGN

The QUALITY Study follows 630 Caucasian families (father, mother, and child originally aged 8-10 years). BP, height, weight, WC, and skinfold thickness were measured according to standardized protocols. Elevated BP was defined as systolic or diastolic BP at least 90th age, sex, and height-specific percentile. Total and central fat were determined with DXA. The area under the receiver operating characteristic (ROC) curve (AUC) statistic was computed from logistic models that adjusted for age, sex, height, Tanner stage, and physical activity.

RESULTS

All adiposity indicators were highly correlated. WC and WHtR did not show superior ability over BMI to identify children with elevated SBP (P = 0.421 and 0.473). Measures of total and central fat from DXA did not show an improved ability over BMI or WC to identify children with elevated SBP (P = 0.325-0.662).

CONCLUSION

Results support the use of BMI in clinical and public health settings, at least in this age group. As all indicators had a limited ability to identify children with elevated BP, results also support measurement of BP in all children of this age independent of a weight status.

Blood pressure and associated factors in a North African adolescent population. a national cross-sectional study in Tunisia

Background

In southern and eastern Mediterranean countries, changes in lifestyle and the increasing prevalence of excess weight in childhood are risk factors for high blood pressure (BP) during adolescence and adulthood. The aim of this study was to evaluate the BP status of Tunisian adolescents and to identify associated factors.

Methods

A cross-sectional study in 2005, based on a national, stratified, random cluster sample of 1294 boys and 1576 girls aged 15-19 surveyed in home visits. The socio-economic and behavioral characteristics of the adolescents were recorded. Overweight/obesity were assessed by Body Mass Index (BMI) from measured height and weight (WHO, 2007), abdominal obesity by waist circumference (WC). BP was measured twice during the same visit. Elevated BP was systolic (SBP) or diastolic blood pressure (DBP) ≥ 90th of the international reference or ≥ 120/80 mm Hg for 15-17 y., and SBP/DBP ≥ 120/80 mm Hg for 18-19 y.; hypertension was SBP/DBP ≥ 95th for 15-17 y. and ≥ 140/90 mm Hg for 18-19 y. Adjusted associations were assessed by logistic regression.

Results

The prevalence of elevated BP was 35.1%[32.9-37.4]: higher among boys (46.1% vs. 33.3%; P < 0.0001); 4.7%[3.8-5.9] of adolescents had hypertension. Associations adjusted for all covariates showed independent relationships with BMI and WC: - obesity vs. no excess weight increased elevated BP (boys OR = 2.1[1.0-4.2], girls OR = 2.3[1.3-3.9]) and hypertension (boys OR = 3.5[1.4-8.9], girls OR = 5.4[2.2-13.4]), - abdominal obesity (WC) was also associated with elevated BP in both genders (for boys: 2nd vs. 1st tertile OR = 1.7[1.3-2.3], 3rd vs.1st tertile OR = 2.8[1.9-4.2]; for girls: 2nd vs. 1st tertile OR = 1.6[1.2-2.1], 3rd vs.1st tertile OR = 2.1[1.5-3.0]) but only among boys for hypertension. Associations with other covariates were weaker: for boys, hypertension increased somewhat with sedentary lifestyle, while elevated BP was slightly more prevalent among urban girls and those not attending school.

Conclusion

Within the limits of BP measurement on one visit only, these results suggest that Tunisian adolescents of both genders are likely not spared from early elevated BP. Though further assessment is likely needed, the strong association with overweight/obesity observed suggests that interventions aimed at changing lifestyles to reduce this main risk factor may also be appropriate for the prevention of elevated BP.

Body fat percentiles for German children and adolescents

OBJECTIVE

The aim of this study was to define body fat percentiles for German children and adolescents aged 3-16 years using the largest German database.

METHODS

The study population included 11,632 girls and 11,604 boys. Data were pooled from: i) Kiel Obesity Prevention Study (KOPS), acquisition period: 1996-2008, n = 12,237; ii) 'Better diet. More exercise. KINDERLEICHT-REGIONS', acquisition period: 2007, n = 9,405; and iii) examination of Jena schoolchildren, acquisition period: 2005, n = 1,594. Body fat mass was measured by bioelectrical impedance analysis using a population-specific algorithm. Data were weighted to achieve a representative sample for Germany. Percentile curves were constructed by the LMS method and proved by Worm plots and Q-statistic.

RESULTS

In both genders, the higher body fat percentile curves sloped downwards to age 7 years, whereas the lower percentiles declined up to 8.5 years. Thereafter fat mass remained nearly constant with age in boys and increased in girls. The 10th percentile achieved a minimum of 10-11% body fat in both genders, whereas the 90th percentile curve fluctuated between 29 and 44% in boys or 30-43% in girls. The association between fat mass and blood pressure was too weak to define disease-related cut-offs.

CONCLUSION

These body fat percentiles are suitable reference values for German children and adolescents.

Validity of body mass index and waist circumference to detect excess fat mass in children aged 7-14 years

BACKGROUND/OBJECTIVES

To evaluate the screening performance of body mass index (BMI) and waist circumference (WC) for excess adiposity. In addition, the diagnostic accuracy of cutoffs from different international and national reference systems based on BMI and WC was investigated.

SUBJECTS/METHODS

Data from 2132 Jena children aged 7-14 years conducted in 2005/2006 were analyzed. Receiver operating characteristic (ROC) curves were constructed to assess BMI and WC, as screening measures for excess adiposity (derived from skinfolds). Sensitivity, specificity and positive predictive values (PPVs) were calculated for two BMI-based classification systems (IOTF and German reference) and sample-based WC cutoffs.

RESULTS

The BMI as well as the WC performed well in detecting excess fat mass, indicated by areas under the ROC curve (AUC) close to 1.0, with slightly greater AUCs for BMI than for WC in both sexes. The specificity of all reference systems was high for both sexes (95 to 98%). However, their sensitivities were low (53-67% in boys; 51-67% in girls). PPV were higher for the German reference and the sample-based WC cutoffs than for the IOTF reference, and higher in girls than in boys.

CONCLUSIONS

The setting in which the reference system should be used is important for the selection of the reference system. The results support the use of the BMI-based references for monitoring in epidemiological studies. The sample-based cutoffs for WC should be refined for clinical use on national level.

Hypertension in children: new trends and challenges

Childhood HTN (hypertension) has become a widely investigated topic within the last decade due to its increasing prevalence. In the present review, we examine new developments and trends that have significantly contributed to aetiology, diagnosis, evaluation and management of childhood HTN. Many recent reports document an increasing prevalence of HTN, mainly essential HTN, in children worldwide. This is probably related to the increase of childhood obesity, although obesity is not the only factor. Evidence has been accumulating to suggest a rather complex interplay between obesity, uric acid level, dietary sodium intake, inflammation, inheritance and other factors, which lead to increased risk of developing HTN in childhood and adulthood. The detection and monitoring of HTN has significantly improved with the use of ABPM (ambulatory blood pressure monitoring), which allows not only for a more accurate classification and staging of HTN, but also for the calculation of more sophisticated parameters such as the AASI (ambulatory arterial stiffness index). Measurement of arterial stiffness enables assessment of arterial dysfunction, which may precede structural vascular changes evaluated by carotid intima media thickness. Sustained HTN eventually leads to end-organ damage [LVH (left ventricular hypertrophy), central nervous system], which in turn increases the risk of cardiovascular morbidity and mortality. New developments in childhood HTN, as outlined in the present review, will hopefully contribute to better screening and management of HTN in children.

Correlation between fat mass and blood pressure in healthy children

Obesity is a well-known risk factor for arterial hypertension. The aim of this study was to analyze which surrogate marker of adiposity, i.e., body mass index (BMI) or fat mass (FM), as measured by bioimpedance analysis (BIA), best correlated with blood pressure in healthy children. Body weight, height, and casual blood pressure (BP) were measured in 193 healthy children (103 boys), aged 8-16 years. Body composition was determined by BIA. The correlation between BMI and age was linear, whereas the correlation between percentage of FM and age was nonlinear and it was different in boys and girls. Blood pressure standard deviation scores (SDS) correlated with FM SDS (BIA) over the entire normal range (systolic: r = 0.26, p = 0.002; diastolic: r = 0.33, p < 0.01). An evaluation of the children based on BP (three groups: BP < 50th percentile, 50th < BP > 95th percentile; BP > 95th percentile) revealed that hypertensive children had a higher BMI (17.6 vs. 19.4 vs. 26.2 kg/m(2), respectively) and a greater FM (14.0 vs. 16.8 vs. 30.2%, respectively). In conclusion, the divergence in FM in healthy boys and girls can be determined by BIA but not by BMI. In healthy children, BP within the entire normal range correlated with FM, children with established hypertension presented with a significantly higher FM. The study points to FM as an important determinant of BP pressure in obese and non-obese children.

ACE I/D genotype, adiposity, and blood pressure in children

Background

Angiotensin converting enzyme (ACE) is a possible candidate gene that may influence both body fatness and blood pressure. Although several genetic studies have been conducted in adults, relatively few studies have examined the contribution of potential candidate genes, and specifically ACE I/D, on adiposity and BP phenotypes in childhood. Such studies may prove insightful for the development of the obesity-hypertension phenotype early in life. The purpose of this study was to examine differences in body fatness and resting blood pressure (BP) by ACE I/D genotype, and determine if the association between adiposity and BP varies by ACE I/D genotype in children.

Methods

152 children (75 girls, 77 boys) were assessed for body composition (% body fat) using dual energy x-ray absorbtiometry and resting BP according to American Heart Association recommendations. Buccal cell samples were genotyped using newly developed PCR-RFLP tests for two SNPs (rs4341 and rs4343) in complete linkage disequilibrium with the ACE I/D polymorphism. Partial correlations were computed to assess the ociations between % body fat and BP in the total sample and by genotype. ANCOVA was used to examine differences in resting BP by ACE I/D genotype and fatness groups.

Results

Approximately 39% of youth were overfat based on % body fat (>30% fat in girls, 25% fat in boys). Body mass, body mass index, and fat-free mass were significantly higher in the ACE D-carriers compared to the II group (p < 0.05). BP was not significantly different by ACE I/D genotypes. In the total sample, correlations between adiposity and BP ranged from 0.30 to 0.46, and were not significantly different between genotypes. When grouped by genotype and body fat category, the overfat D-carrier subjects had significantly higher SBP and MAP compared to the normal fat D-carrier and normal fat II groups (p < 0.05).

Conclusion

ACE D-carriers are heavier than ACE II children; however, BP did not differ by ACE I/D genotype but was adversely influenced in the overfat D-carriers. Further studies are warranted to investigate the genetics of fatness and BP phenotypes in children.

Body fat is associated with blood pressure in school-aged girls with low cardiorespiratory fitness: The European Youth Heart Study

OBJECTIVE

To examine the association between anthropometric measurements of total and central adiposity and blood pressure in school-aged children, and to study whether these associations are modified by the levels of cardiorespiratory fitness.

METHODS

Systolic and diastolic blood pressure, weight, height, skinfold thickness and waist circumference were measured in 873 children aged 9-10 years participating in the Estonian and Swedish part of the European Youth Heart Study. Mean arterial pressure was calculated. Body mass index and skinfold thickness were used as markers of total adiposity, whereas waist circumference and waist-height ratio were used as markers of central adiposity. Cardiorespiratory fitness was estimated by a maximal ergometer bike test, and dichotomized into low and high levels.

RESULTS

Markers of total and central adiposity were positively associated with blood pressure. The results from the regression models showed that the markers of total and central adiposity were significantly associated with systolic blood pressure in girls with low levels of cardiorespiratory fitness. Similar results were observed when mean arterial pressure was the outcome variable. None of the markers of total and central adiposity were significantly associated with blood pressure in girls with high levels of cardiorespiratory fitness or in boys with low or high levels of cardiorespiratory fitness.

CONCLUSIONS

The results show a positive influence of simple anthropometric measurements of total and central adiposity on blood pressure, and suggest that higher cardiorespiratory fitness may attenuate the association between body fat and blood pressure in school-aged children.

Tobacco smoke exposure of pregnant mothers and blood pressure in their newborns: results from the wheezing illnesses study Leidsche Rijn birth cohort

There is evidence to suggest that exposure of pregnant women to tobacco smoke is related to higher childhood blood pressure in their offspring. It is not well known whether this association is set in utero or by shared postnatal environments. The objective of this study was to assess the association between tobacco smoke exposure of pregnant mothers and blood pressure and heart rate of their newborns. In an unselected birth cohort, blood pressure and heart rate were measured in 456 infants at approximately 2 months of age. Smoking exposure of mothers in pregnancy was obtained by questionnaire. Of 456 mothers whose infants had blood pressure measured, 363 (79.6%) were not exposed to tobacco smoke in pregnancy, 63 (13.8%) did not smoke in pregnancy but were exposed by others, and 30 (6.6%) smoked. Infant offspring of mothers who had smoked during pregnancy had 5.4 mm Hg (95% CI: 1.2 to 9.7; P=0.01) higher systolic blood pressure levels than offspring of mothers who were not exposed to tobacco smoke in pregnancy, taking account of birth weight, infant age, gender, nutrition, and age of mother. No associations were found between maternal exposure to tobacco smoke in pregnancy and diastolic blood pressure. A positive association between maternal exposure to tobacco smoke and heart rate was largely explained by confounding. It can be concluded that maternal exposure to tobacco smoke in pregnancy has a substantial increasing effect on systolic blood pressure in early infancy.