Birthweight, childhood social class, and change in adult blood pressure in the 1946 British birth cohort

The association of gestational age and birthweight with blood pressure, cardiac structure, and function in 4 years old: a prospective birth cohort study

BACKGROUND

Current evidence relating birthweight and gestational age to cardiovascular risk is conflicting. Whether these factors have independent or interactive impacts on cardiovascular parameters during early childhood remains unclear. The goal of this study was to explore whether there were any independent and interactive effects of gestational age and birthweight on blood pressure, left ventricle (LV) structure, and function in 4 years old.

METHODS

This study included 1194 children in the Shanghai Birth Cohort from 2013 to 2016. Information about the mothers and children was recorded at time of birth using a questionnaire. Follow-up measurements, including anthropometric, blood pressure, and echocardiography, were taken between 2018 and 2021, when the children were 4 years old. Multiple linear or logistic regressions and restricted cubic spline were used to explore the association of birthweight and gestational age with cardiovascular measurements.

RESULTS

Gestational age had a significant negative correlation with both systolic blood pressure [β =  - 0.41, 95% CI: (- 0.76, - 0.07)] and mean arterial pressure [β =  - 0.36, 95%CI: (- 0.66, - 0.07)]. The risk of prehypertension decreased with increased gestational age [OR = 0.54, 95% CI: (0.32, 0.93)]. The relationship between birthweight with blood pressure was U-shape (P for non-linear < 0.001). The wall thickness, volume, mass, and cardiac output of LV increased with birthweight, though the ejection fraction [β =  - 1.02, 95% CI: (- 1.76, - 0.27)] and shorten fraction [β = 0.72, 95% CI: (- 1.31, - 0.14)] decreased with birthweight. The risk of LV hypertrophy was not associated with birthweight [OR = 1.59, 95% CI: (0.68, 3.73)].

CONCLUSIONS

In this study, we found different associations of birthweight and gestational age with cardiovascular measurements in the offspring at 4 years old. Gestational age influenced blood pressure independent of birthweight. Heart size and function at 4 years old was influenced mostly by birthweight and not by gestational age.

Low birth weight and small for gestational age are associated with complications of childhood and adolescence obesity: Systematic review and meta-analysis

In recent decades, the incidence of type 2 diabetes (T2D) has increased dramatically in children and adolescents, posing a real public health problem. Beyond unhealthy diets and sedentary lifestyles, growing evidence suggests that some perinatal factors, such as low birth weight (LBW), are associated with higher risk of T2D in adulthood. In this regard, it remains unclear whether the increased risk is already present in childhood and adolescence. We conducted a systematic review and meta-analysis to clarify the association of LBW or being small for gestational age (SGA) with insulin resistance in childhood and adolescence. The systematic review resulted in 28 individual studies, and those with the same outcome were included within two random-effects meta-analyses. Compared with children or adolescents born with adequate size for gestational age, those SGA had 2.33-fold higher risk of T2D (95% confidence interval [CI]: 1.05-5.17). Furthermore, LBW and being SGA were associated with 0.20 higher mean homeostasis model assessment of insulin resistance (HOMA-IR) values (95% CI: 0.02-0.38). Given the high prevalence of preterm babies, from a population perspective, these results may be of great importance as they point to the existence of a potentially vulnerable subgroup of children and adolescents that could benefit from screening tests and early preventive strategies.

Prevalence and early-life determinants of mid-life multimorbidity: evidence from the 1970 British birth cohort

BACKGROUND

We sought to: [1] estimate the prevalence of multimorbidity at age 46-48 in the 1970 British Cohort Study-a nationally representative sample in mid-life; and [2] examine the association between early-life characteristics and mid-life multimorbidity.

METHOD

A prospective longitudinal birth cohort of a community-based sample from the 1970 British Cohort Study (BCS70). Participants included all surviving children born in mainland Britain in a single week in April 1970; the analytical sample included those with valid data at age 46-48 (n = 7951; 2016-2018). The main outcome was multimorbidity, which was operationalised as a binary indicator of two or more long-term health conditions where at least one of these conditions was of physical health. It also included symptom complexes (e.g., chronic pain), sensory impairments, and alcohol problems.

RESULTS

Prevalence of mid-life multimorbidity was 33.8% at age 46-48. Those with fathers from unskilled social occupational class (vs professional) at birth had 43% higher risk of mid-life multimorbidity (risk ratio = 1.43, 95% confidence interval 1.15 to 1.77). After accounting for potential child and family confounding, an additional kilogram of birthweight was associated with 10% reduced risk of multimorbidity (risk ratio = 0.90, 95% confidence interval 0.84 to 0.96); a decrease of one body mass index point at age 10 was associated with 3% lower risk (risk ratio = 1.03, 95% confidence interval 1.01 to 1.05); one standard deviation higher cognitive ability score at age 10 corresponded to 4% lower risk (risk ratio = 0.96, 95% confidence interval 0.91 to 1.00); an increase of one internalising problem at age 16 was equated with 4% higher risk (risk ratio = 1.04, 95% confidence interval 1.00 to 1.08) and of one externalising problem at age 16 with 6% higher risk (risk ratio = 1.06, 1.03 to 1.09).

CONCLUSION

Prevalence of multimorbidity was high in mid-life (33.8% at age 46-48) in Britain. Potentially modifiable early-life exposures, including early-life social circumstances, cognitive, physical and emotional development, were associated with elevated risk of mid-life multimorbidity.

Early Origins of Body Mass in Later Life: Examining Childhood Risks and Adult Pathways

Prior research reveals that negative early-life experiences play a major role in the development of obesity in later life, but few studies identify mechanisms that alter the lifetime risk of obesity. This study examines the influence of negative childhood experiences on body mass index (BMI) and obesity (BMI ≥30) during older adulthood and the psychosocial and behavioral pathways involved. Using a nationally representative sample, we examine the influence of cumulative misfortune as well as five separate domains of misfortune on BMI and obesity. Results show that four of the five domains are associated with BMI and obesity either directly, indirectly, or both. The influence of cumulative misfortune on the outcomes is mediated by three adult factors: socioeconomic status, depressive symptoms, and physical activity. The mediators identified here provide targets for intervention among older adults to help offset the health risks of excess BMI attributable of early-life exposure to misfortune.

Factors Associated with Primary Hypertension in Pediatric Patients: An Up-to-Date

BACKGROUND

Arterial hypertension in children is considered a common alteration nowadays, mainly because obesity is a growing worldwide problem closely related to increased blood pressure. Childhood hypertension can be classified as primary or secondary, depending on the etiology. Primary or essential hypertension still has its pathophysiology not fully elucidated, and there is no consensus in the literature on most underlying mechanisms. In this review, genetic and environmental factors, including sodium and potassium intake, socioeconomic status, ethnicity, family structure, obesity, sedentary lifestyle, prematurity and low birth weight, prenatal and postnatal exposures are highlighted.

OBJECTIVE

The present study aimed to perform an update on primary hypertension in childhood, providing clinicians and researchers an overview of the current state of the literature regarding the influence of genetic and environmental factors.

METHODS

This integrative review searched for articles on genetic and environmental factors related to primary hypertension in pediatric patients. The databases evaluated were PubMed and Scopus.

RESULTS

The studies have provided insights regarding many genetic and environmental factors, in addition to their association with the pathophysiology of primary hypertension in childhood. Findings corroborated the idea that primary hypertension is a multifactorial disease. Further studies in the pediatric population are needed to elucidate the underlying mechanisms.

CONCLUSION

The study of primary hypertension in pediatrics has utmost importance for the adoption of preventive measures and the development of more efficient treatments, therefore reducing childhood morbidity and the incidence of cardiovascular diseases and other health consequences later in life.

Socioeconomic inequalities in blood pressure: co-ordinated analysis of 147,775 participants from repeated birth cohort and cross-sectional datasets, 1989 to 2016

BACKGROUND

High blood pressure (BP) is a key modifiable determinant of cardiovascular disease and a likely determinant of other adverse health outcomes. While socioeconomic inequalities in BP are well documented, it remains unclear (1) how these inequalities have changed across time, given improvements over time in the detection and treatment of high BP (hypertension); (2) whether BP inequalities are present below and above hypertension treatment thresholds; and (3) whether socioeconomic position (SEP) across life has cumulative effects on BP. We sought to address these gaps using evidence from two complementary sources: birth cohort and repeated cross-sectional datasets.

METHODS

We used three British birth cohort studies-born in 1946, 1958, and 1970-with BP measured at 43-46 years (in 1989, 2003, and 2016), and 21 repeated cross-sectional datasets-the Health Survey for England (HSE), with BP measured among adults aged ≥ 25 years (1994-2016). Adult education attainment was used as an indicator of SEP in both datasets; childhood father's social class was used as an alternative indicator of (early life) SEP in cohorts. Adjusting for the expected average effects of antihypertensive medication use, we used linear regression to quantify SEP differences in mean systolic BP (SBP), and quantile regression to investigate whether inequalities differed across SBP distributions-below and above hypertension treatment thresholds.

RESULTS

In both datasets, lower educational attainment was associated with higher SBP, with similar absolute magnitudes of inequality across the studied period. Differences in SBP by education (Slope Index of Inequality) based on HSE data were 3.0 mmHg (95% CI 1.8, 4.2) in 1994 and 4.3 mmHg (2.3, 6.3) in 2016. Findings were similar for diastolic BP (DBP) and survey-defined hypertension. Inequalities were found across the SBP distribution in both datasets-below and above the hypertension threshold-yet were larger at the upper tail; in HSE, median SBP differences were 2.8 mmHg (1.7, 3.9) yet 5.6 mmHg (4.9, 6.4) at the 90th quantile. Adjustment for antihypertensive medication use had little impact on the magnitude of inequalities; in contrast, associations were largely attenuated after adjustment for body mass index. Finally, cohort data suggested that disadvantage in early and adult life had cumulative independent associations with BP: cohort-pooled differences in SBP were 5.0 mmHg (3.8, 6.1) in a score combining early life social class and own education, yet were 3.4 mmHg (2.4, 4.4) for education alone.

CONCLUSION

Socioeconomic inequalities in BP have persisted from 1989 to 2016 in Britain/England, despite improved detection and treatment of high BP. To achieve future reductions in BP inequalities, policies addressing the wider structural determinants of high BP levels are likely required, particularly those curtailing the obesogenic environment-targeting detection and treatment alone is unlikely to be sufficient.

The Effect of Flaxseed Enriched Yogurt on the Glycemic Status and Cardiovascular Risk Factors in Patients with Type 2 Diabetes Mellitus: Randomized, Open-labeled, Controlled Study

Flaxseed is one of the rich sources of α-linolenic acid and lignan. Flaxseed and its components have antioxidant, hypolipidemic and hypoglycemic effects. The study aimed to investigate the effect of flaxseed enriched yogurt on glycemic control, lipid profiles and blood pressure in patients with type 2 diabetes. A randomized, open-labeled, controlled clinical trial was conducted on 57 patients with type 2 diabetes. Participants were assigned to receive 200 g 2.5% fat yogurt containing 30-g flaxseed or plain yogurt daily for 8 weeks. Anthropometrics and biochemical parameters were evaluated at the beginning and end of the study. After 8 weeks of supplementation, Hemoglobin A1c was significantly decreased in the intervention group compared to control (p = 0.007). Also, at the end of the study, significant differences were seen between the flaxseed enriched yogurt and control groups in triglycerides and total cholesterol concentrations (p = 0.04 and p = 0.01), systolic blood pressure and diastolic blood pressure (p = 0.02 and p = 0.002, respectively). However, we did not find any difference between 2 groups in low-density lipoprotein, high-density lipoprotein, body weight and waist circumference (p > 0.05). Our results showed that the addition of flaxseed to yogurt can be effective in the management of type 2 diabetes.

Trial Registration

ClinicalTrials.gov Identifier: NCT02436369.

Effects of ginger supplementation on anthropometric, glycemic and metabolic parameters in subjects with metabolic syndrome: A randomized, double-blind, placebo-controlled study

Background

Metabolic syndrome (MetS) is one of the worldwide most chronic endocrine disorders. The disease can also lead to several other chronic disorders such as type 2 diabetes mellitus, cardiovascular diseases, renal diseases and cancers. This study aimed to evaluate the safety and efficacy of ginger powder on biochemical and anthropometric parameters in patients with MetS.

Methods

This randomized controlled clinical trial was conducted on 37 patients with MetS. We supplemented the individuals with MetS with either 2 g per day ginger powder or placebo for 12 weeks. Biochemical and anthropometric parameters before and after the intervention were compared between the two groups.

Results

After 12 weeks of treatment, the levels of triglyceride (TG), FBS, and insulin resistance were significantly improved in the patients receiving ginger in compare to the placebo group (P < 0·05). Moreover, significant changes were observed in terms of weight, waist circumference, LDL, HDL, total cholesterol, systolic and diastolic blood pressure and energy intake between the groups.

Conclusion

In general, our findings demonstrated that the ginger supplementation offers beneficial effects on patients with MetS, at least, in part due to the modulatory effects on TG, FBS, and insulin resistance.

Intragenerational Social Mobility and Changes in Blood Pressure: Longitudinal Analysis From the ELSA-Brasil Study

BACKGROUND

During the past 4 decades, the highest worldwide blood pressure (BP) levels have shifted from high-income countries to low- and middle-income countries. We investigated the association of intragenerational social mobility with changes in BP and also with the incidence of hypertension over a 4-year follow-up.

METHODS

Data for 6,529 baseline participants from ELSA-Brasil born between 1938 and 1975 were used. Based on a social mobility matrix, occupational social mobility was defined as the change in occupational social class between participants' first occupation and current occupation (stable high; upward; downward; stable low). Incident hypertension was defined as systolic blood pressure (SBP) ≥ 140 mm Hg or diastolic blood pressure (DBP) ≥ 90 mm Hg or use of antihypertensive medication. Hypertensive participants at baseline were excluded. Mixed effects regression models were used.

RESULTS

Compared to the stable high group, the downwardly mobile group showed a higher increase over time in both SBP (β = 1.49, 95% CI 0.60; 2.37) and DBP (β = 0.96, 95% CI 0.32; 1.59) after adjustments for background characteristics and also proximal risk factors such as health-related behaviors and body mass index as time-dependent covariates, and diabetes. In contrast, upward mobility had no influence on BP changes (β = 0.67, 95% CI -0.07; 1.41 for SBP, and β = 0.47, 95% CI -0.05; 1.00 for DBP). Social mobility was not associated with the incidence of hypertension.

CONCLUSIONS

We showed socioeconomic inequalities in BP progression over the life course. The longitudinal changes in BP varied by social mobility groups in the context of low- and middle-income countries, where high BP has become most prevalent.

Association of Early-Life Factors With Life-Course Trajectories of Resting Heart Rate: More Than 6 Decades of Follow-up

IMPORTANCE

Higher resting heart rate (RHR) is associated with increased risk of cardiovascular and all-cause mortality. Limited attention has been paid to early-life determinants of life-course RHR.

OBJECTIVE

To describe trajectories of RHR in the same individuals from age 6 to 69 years.

DESIGN, SETTING, AND PARTICIPANTS

Data were from the Medical Research Council National Survey of Health and Development population-based cohort of individuals who were followed up from birth in 1946 until 2015. Analysis was conducted between September 2016 and June 2017. Multilevel models were used to estimate life-course mean RHR trajectory by sex and to investigate associations with early childhood factors. The maximal sample included participants who had at least 1 measure of RHR since study entry and a measure of birth weight (N = 4779; observations = 26 182).

EXPOSURES

Information on early-life factors was ascertained prospectively: childhood socioeconomic position, birth weight, body mass index (calculated as weight in kilograms divided by height in meters squared) change from age 2 to 6 years (conditioned on body mass index at age 2 years), duration of breastfeeding, and markers of neurodevelopment (age at first walking independently and cognitive ability at age 8 years).

MAIN OUTCOMES AND MEASURES

Resting heart rate measured on 8 occasions between age 6 and 69 years (3 occasions in childhood and 5 in adulthood).

RESULTS

Of 4779 participants, 2492 (52.1%) were women, and 2287 (47.9%) were men. Mean estimated RHR decreased with increasing age and plateaued in adulthood. In sex-adjusted analyses, higher birth weight and conditional body mass index change were associated with lower RHR at age 6 years and across the life course (-0.56 bpm [95% CI, -0.95 to -0.17] per 1 kg higher birth weight and -0.30 bpm [95% CI, -0.48 to -0.13] per 1 kg/m2 change in body mass index). Associations between socioeconomic position and breastfeeding on RHR trajectory emerged in adulthood such that by age 69 years, RHR was 1.48 bpm (95% CI, 0.45 to 2.51) higher in participants from a disadvantaged vs advantaged background and -1.34 bpm (95% CI, -2.39 to -0.29) lower for those who were breastfed for 8 months or longer vs never. A later age at first walking was associated with higher RHR at age 6 years (1.49 bpm [95% CI, 0.39 to 2.59] higher for those 18 months or older vs those younger than 12 months) but with lower RHR in adulthood (-1.18 bpm [95% CI, -2.75 to 0.39] at age 69 years).

CONCLUSIONS AND RELEVANCE

Early life is a key period in determining future RHR trajectories with associations with potentially modifiable factors persisting into the seventh decade of life.

Does the association between birth weight and blood pressure increase with age? A longitudinal study in young adults

OBJECTIVES

To assess whether the association between birth weight and blood pressure (BP) increases with age using three different statistical methods.

METHODS

A representative sample of 1232 study participants born between 1974-1978 in Limache, Chile were assessed in 2000-2002, of whom 796 were reassessed in 2010-2012. An 'amplification effect' was assessed by the change in the β coefficient in the two periods, the association between birth weight and the difference of BP overtime, and the interaction between birth weight and BP in the two periods.

RESULTS

Birth weight was negatively associated with SBP in 2000-2002 (β = -2.46, 95% confidence interval (CI) -3.77 to -1.16) and in 2010-2012 (β = -3.64, 95% CI -5.20 to -2.08), and with DBP in 2000-2002 (β = -1.26, 95% CI -2.23 to -0.29) , and 2010-2012 (β = -1.64, 95% CI -2.84 to -0.45) after adjustment for sex, physical activity, and BMI. There was no association between birth weight and the difference in BP between the two periods or the interaction between birth weight, BP, and time interval.

CONCLUSION

Birth weight is a factor associated with BP in adults. This association increased with age, but amplification was shown only with one of the three methods.

Receipt of public assistance during childhood and hypertension risk in adulthood

PURPOSE

We examined if receipt of public assistance during childhood lowered risk for hypertension by mid-life in a cohort of African Americans in the Southeastern United States.

METHODS

We used multiple logistic regression models to assess the relationship between receipt of public assistance during childhood and adult hypertension among 405 male and 737 female adult participants enrolled between 1988 and 2001 in the Pitt County Study, a community-based prospective cohort study of African Americans in North Carolina. Statistical analyses were adjusted for child and adult sociodemographic measures as well as adult psychosocial and lifestyle factors.

RESULTS

Women who grew up in economically disadvantaged families and who received public assistance during childhood had a 66% decreased odds of hypertension by mid-life compared with women similarly disadvantaged in childhood but who did not receive public assistance, odds ratio = 0.34; 95% confidence interval: 0.14-0.83. No association was observed for African American men.

CONCLUSIONS

Receipt of anti-poverty federal assistance during childhood was associated with reduced risk for hypertension by mid-life among African American women. It is possible that social expenditures on public assistance programs for families in need could produce long-term health benefits for children.

Blood Pressure Trajectories From Childhood to Young Adulthood Associated With Cardiovascular Risk: Results From the 23-Year Longitudinal Georgia Stress and Heart Study

The purpose of this study is to identify subgroups of individuals with similar trajectories in blood pressure (BP) from childhood to young adulthood and to determine the relationship of BP trajectories with carotid intima-media thickness (IMT) and left ventricular mass index (LVMI). BP was measured ≤16 times during a 23-year period in 683 participants from childhood to young adulthood. IMT and LVMI were measured in 551 participants and 546 participants, respectively. Using latent class models, 3 trajectory groups in BP from childhood to young adulthood were identified, including high-increasing, moderate-increasing, and low-increasing groups. We found that trajectory of systolic BP was a significant predictor of both IMT and LVMI with increased rate of growth in systolic BP associated with higher levels of IMT and LVMI (P_{for trend} <0.001). Similar to the BP trajectory groups from childhood to young adulthood, 3 trajectory groups in BP during childhood (≤18 years) were identified, and participants in the high-increasing group had thicker IMT (P<0.001) and increased LVMI (P=0.043) in comparison with those in the low-increasing group. Results were similar for mid-BP trajectories but not for diastolic BP trajectories. Our results suggested that different BP trajectories exist from childhood to young adulthood, and the trajectories were independently associated with IMT and LVMI. We, for the first time, reported the association between systolic BP trajectories derived from childhood with subclinical cardiovascular risk in young adulthood, indicating that monitoring trajectories of BP from childhood may help identify a high cardiovascular risk population in early life.

Hypertension in the Pediatric Intensive Care Unit

Hypertension in the pediatric intensive care unit (PICU) is common and it contributes to the overall morbidity and mortality. Patients may present with hypertensive emergencies or hypertension can manifest itself later in PICU course. Although hypertension can be seen in most patients during hospitalization, patients with some specific diseases and conditions are more prone to hypertension. Hypertension should be recognized promptly and treated accordingly. Different pathophysiologic mechanisms can be responsible for the hypertension and management differs based on the underlying etiology. Any patient with a hypertensive emergency must be admitted to PICU, and treatment and diagnostic workup should be initiated immediately.

Pathways between birth weight and later body size in predicting blood pressure: Australian Aboriginal Cohort Study 1987-2007

BACKGROUND

Although a large number of previous studies suggest an association between birth weight and later blood pressure, others do not. Controversy surrounds the relative importance of these associations, in particular in relation to more modifiable factors in later life and whether the association would be seen in a, relatively disadvantaged, Indigenous population. The aim of this study, within the Aboriginal Birth Cohort study, was to examine the relative contributions and mediating pathways of birth weight, and later growth and lifestyle factors to variation in blood pressure at age 16-20 years.

METHODS

Detailed information was collected prospectively, including maternal smoking, birth weight, childhood BMI. At age 16-20 years, 451 underwent clinical examination, including the measurement of diastolic and systolic blood pressures. These data were analyzed using linear regression and path analyses, incorporating adjustment for potential confounders.

RESULTS

Increased BMI at age 18 years was significantly associated with both increasing systolic and diastolic blood pressures. BMI had the highest relative importance and mediated the effects from earlier in life, including birth weight. Being female and living in remote residence were also independently associated with a reduction in systolic blood pressure.

CONCLUSION

Blood pressure in this cohort is primarily influenced by contemporaneous BMI, which in this population at this age is generally lower than that seen in non-Indigenous populations in developed countries. However, other factors, including birth weight, do appear to play a role that is mediated through later BMI.

Association of socioeconomic status change between infancy and adolescence, and blood pressure, in South African young adults: Birth to Twenty Cohort

OBJECTIVE

Social epidemiology models suggest that socioeconomic status (SES) mobility across the life course affects blood pressure. The aim of this study was to investigate the association between SES change between infancy and adolescence, and blood pressure, in young adults, and the impact of early growth on this relationship.

SETTING

Data for this study were obtained from a 'Birth to Twenty' cohort in Soweto, Johannesburg, in South Africa.

PARTICIPANTS

The study included 838 Black participants aged 18 years who had household SES measures in infancy and at adolescence, anthropometry at 0, 2, 4 and 18 years of age and blood pressure at the age of 18 years.

METHODS

We computed SES change using asset-based household SES in infancy and during adolescence as an exposure variable, and blood pressure and hypertension status as outcomes. Multivariate linear and logistic regressions were used to investigate the associations between SES change from infancy to adolescence, and age, height and sex-specific blood pressure and hypertension prevalence after adjusting for confounders.

RESULTS

Compared to a persistent low SES, an upward SES change from low to high SES tertile between infancy and adolescence was significantly associated with lower systolic blood pressure (SBP) at the age of 18 years (β=-4.85; 95% CI -8.22 to -1.48; p<0.01; r(2)=0.1804) after adjusting for SES in infancy, small-for-gestational-age (SGA) and weight gain. Associations between SES change and SBP were partly explained by weight gain between birth and the age of 18 years. There was no association between SES mobility and diastolic blood pressure, mean arterial pressure or hypertension status.

CONCLUSIONS

Our study confirms that upward SES change has a protective effect on SBP by the time participants reach young adulthood. Socioeconomic policies and interventions that address inequality may have the potential to reduce cardiovascular disease burden related to BP in later life.

Early growth and changes in blood pressure during adult life

Previous studies suggest that the inverse association between birth weight and adult blood pressure amplifies with age. Rapid childhood growth has also been linked to hypertension. The objective of this study was to determine whether the association between childhood growth and adult blood pressure amplifies with age. The study comprised 574 women and 462 men from the Helsinki Birth Cohort Study who attended a clinical study in 2001–2004 and a follow-up in 2006–2008. Mean age at the clinic visits was 61.5 and 66.4 years, respectively. Blood pressure was measured at both occasions. Conditional growth models were used to assess relative weight gain and linear growth. We studied the associations between conditional growth and blood pressure as well as the presence of hypertension. Relative weight gain and linear growth between ages 2 and 11 years were inversely associated with systolic blood pressure at mean age 66.4 years, after adjustment for sex, blood pressure at mean age 61.5 years, as well as other covariates. A one s.d. increase in linear growth between 2 and 11 years was associated with an OR of 0.61 for hypertension at mean age 66.4 years. Contrary to previous studies, we have shown an inverse association between childhood growth and adult blood pressure. There were, however, no associations between childhood growth and systolic blood pressure at mean age 61.5 years indicating that the beneficial effects of a more rapid than expected childhood growth might become more apparent with increasing age.

Childhood to Early-Midlife Systolic Blood Pressure Trajectories: Early-Life Predictors, Effect Modifiers, and Adult Cardiovascular Outcomes

Previous studies examining blood pressure change over time have modeled an average population trajectory. Recent research among older adults suggests there may be subgroups with different blood pressure trajectories. Identifying subgroups at risk of developing adult hypertension early in life can inform effective risk reduction efforts. We sought to identify different systolic blood pressure trajectories from childhood, their correlated risk factors, and early-midlife cardiovascular outcomes. Blood pressure data at ages 7, 11, 18, 26, 32, and 38 years from a longitudinal, representative birth cohort study (n=975) were used to identify 4 distinct trajectory groups via group-based trajectory modeling: normal (21.8%), high-normal (43.3%), prehypertensive (31.6%), and hypertensive (4.2%). The categories refer to blood pressure beginning at the age of 7 years and most recently measured at the age of 38 years. Family history of high blood pressure (odds ratio [OR], 43.23; 95% confidence interval [CI], 5.27-354.65), male sex (OR, 109.48; 95% CI, 26.82-446.96), being first born (OR, 2.5; 95% CI, 1.00-8.69) and low birth weight (OR, 2.79; 95% CI, 2.49-3.09) were associated with hypertensive group membership (compared with the normal group). Higher body mass index and cigarette smoking resulted in increasing blood pressure across trajectories, particularly for the higher blood pressure groups. Prehypertensive and hypertensive trajectory groups had worse cardiovascular outcomes by early midlife. Harmful blood pressure trajectories are identifiable in childhood, associated with both antecedent and modifiable risk factors over time, and predict adult cardiovascular disease risk. Early detection and subsequent targeted prevention and intervention may reduce the lifecourse burden associated with higher blood pressure.

A life course approach to cardiovascular aging

A life course approach in epidemiology investigates the biological, behavioral and social pathways that link physical and social exposures and experiences during gestation, childhood, adolescence and adult life, and across generations, to later-life health and disease risk. We illustrate how a life course approach has been applied to cardiovascular disease, highlighting the evidence in support of the early origins of disease risk. We summarize how trajectories of cardiometabolic risk factors change over the life course and suggest that understanding underlying 'normal' or 'healthy' trajectories and the characteristics that drive deviations from such trajectories offer the potential for early prevention and for identifying means of preventing future disease.

Birth weight, early childhood growth and lung function in middle to early old age: 1946 British birth cohort

BACKGROUND

Findings from previous studies investigating the relationship between birth weight and adult lung function have been inconsistent, and data on birth weight and adult lung function decline are lacking. Few studies have investigated the relation between early childhood growth and adult lung function.

METHODS

FEV1 and FVC were measured at ages 43 years, 53 years and 60-64 years in the 1946 British birth cohort study. Multiple linear regression models were fitted to study associations with birth weight and weight gain at age 0-2 years. Multilevel models assessed how associations changed with age, with FEV1 and FVC as repeated outcomes.

RESULTS

3276 and 3249 participants were included in FEV1 and FVC analyses, respectively. In women, there was a decreasing association between birth weight and FVC with age. From the multilevel model, for every 1 kg higher birth weight, FVC was higher on average by 66.3 mL (95% CI 0.5 to 132) at 43 years, but significance was lost at 53 years and 60-64 years. Similar associations were seen with FEV1, but linear change (decline) from age 43 years lost statistical significance after full adjustment. In men, associations with birth weight were null in multilevel models. Higher early life weight gain was associated with higher FEV1 at age 43 years in men and women combined but not in each sex.

CONCLUSIONS

Birth weight is positively associated with adult lung function in middle age, particularly in women, but the association diminishes with age, potentially due to accumulating environmental influences over the life course.

The rising prevalence of self-reported hypertension among Chinese subjects: a population-based study from 121 895 household interviews

BACKGROUND

Hypertension is one of the most important public health issues worldwide.

AIM

We assessed the prevalence rates of self-reported hypertension in Hong Kong between 2001 and 2008 and evaluated factors associated with its prevalence.

DESIGN

Serial cross-sectional surveys.

METHODS

Territory-wide Household surveys in the Hong Kong population in the years 2001, 2002, 2005 and 2008 were included. Population-adjusted prevalence of self-reported hypertension were compared across calendar years. The independent association of these variables with hypertension was evaluated by multivariate regression analysis with self-reported hypertension as a binary outcome.

RESULTS

There were 121 895 subjects interviewed, among which 103 367 were adults aged ≥15 years. The age- and gender-adjusted prevalence of self-reported hypertension in 2001, 2002, 2005 and 2008 among male adults was 4.73, 6.68, 7.96 and 9.82%, respectively, and among female adults, the prevalence was 6.13, 8.28, 10.00 and 11.58%, respectively. Advanced age (adjusted odds ratios [AOR]: 47.1, 95% CI 33.6-66.0 for the age group 40-65 years; AOR 256.2, 95% CI 182.4-360.0 for the age group 66-100 years; referent 0-39 years), female gender (AOR 0.81, 95% CI 0.74-0.88 for male) and a low median household income (AOR 1.56, 95% CI 1.31-1.85 for income ≤ US$1289; referent ≥ US$6444) were significantly associated with hypertension (all P < 0.001).

CONCLUSIONS

This is the first study to show differences between socioeconomic groups in this Chinese population with higher rates among women and the less affluent. Similarly, it is the first to show gender differences with higher rates among women.

Effects of synbiotic supplementation on insulin resistance in subjects with the metabolic syndrome: a randomised, double-blind, placebo-controlled pilot study

To evaluate the effects of synbiotic supplementation on insulin resistance and lipid profile in individuals with the metabolic syndrome, we conducted a randomised, double-blind, placebo-controlled pilot study on thirty-eight subjects with the metabolic syndrome; they were supplemented with either synbiotic capsules containing 200 million of seven strains of friendly bacteria plus fructo-oligosaccharide or placebo capsules twice a day for 28 weeks. Both the synbiotic (G1) and the placebo (G2) groups were advised to follow an energy-balanced diet and physical activity recommendations. Parameters related to the metabolic syndrome and insulin resistance were measured every 7 weeks during the course of the study. After 28 weeks of treatment, the levels of fasting blood sugar and insulin resistance improved significantly in the G1 group (P< 0·001). Both the G1 and G2 groups exhibited significant reductions in TAG levels ( - 71·22 v. - 10·47 mg/dl ( - 0·80 v. - 0·12 mmol/l) respectively; P< 0·001) and total cholesterol levels ( - 21·93 v. - 14·2 mg/dl ( - 0·57 v. - 0·37 mmol/l) respectively; P= 0·01), as well as increases in HDL levels (+7·7 v. +0·05 mg/dl (+0·20 v. +>0·01 mmol/l) respectively; P< 0·001). The mean differences observed were greater in the G1 group. No significant changes were observed in LDL levels, waist circumference, BMI, metabolic equivalent of task and energy intake between the groups. The present results indicate that synbiotic supplementation increases the efficacy of diet therapy in the management of the metabolic syndrome and insulin resistance.

Association between resting heart rate across the life course and all-cause mortality: longitudinal findings from the Medical Research Council (MRC) National Survey of Health and Development (NSHD)

BACKGROUND

Resting heart rate (RHR) is an independent risk factor for mortality. Nevertheless, it is unclear whether elevations in childhood and mid-adulthood RHR, including changes over time, are associated with mortality later in life. We sought to evaluate the association between RHR across the life course, along with its changes and all-cause mortality.

METHODS

We studied 4638 men and women from the Medical Research Council (MRC) National Survey of Health and Development (NSHD) cohort born during 1 week in 1946. RHR was obtained during childhood at ages 6, 7 and 11, and in mid-adulthood at ages 36 and 43. Using multivariable Cox regression, we calculated the HR for incident mortality according to RHR measured at each time point, along with changes in mid-adulthood RHR.

RESULTS

At age 11, those in the top fifth of the RHR distribution (≥97 bpm) had an increased adjusted hazard of 1.42 (95% CI 1.04 to 1.93) for all-cause mortality. A higher adjusted risk (HR, 95% CI 2.17, 1.40 to 3.36) of death was also observed for those in the highest fifth (≥81 bpm) at age 43. For a >25 bpm increased change in the RHR over the course of 7 years (age 36-43), the adjusted hazard was elevated more than threefold (HR, 95% CI 3.26, 1.54 to 6.90). After adjustment, RHR at ages 6, 7 and 36 were not associated with all-cause mortality.

CONCLUSIONS

Elevated RHR during childhood and midlife, along with greater changes in mid-adulthood RHR, are associated with an increased risk of all-cause mortality.

Birth weight and adult health in historical perspective: evidence from a New Zealand cohort, 1907-1922

We provide new historical evidence on the developmental origins of health and disease in a cohort of boys born between 1907 and 1922 in Wellington, New Zealand. Using a dataset of 1523 birth records that include birth weight and length we find 852 (58%) of the adult cohort in World War II records measuring stature, body mass and blood pressure. On average, the boys weighed 3.5 kg at birth, similar to Australian and American babies of the era, and nearly identical to full-term New Zealand babies in the 1990s. Using OLS regression models we estimate the effect of birth weight on adult stature and systolic blood pressure. We find an increase in birth weight of 1 kg is associated with an increase in stature of 2.6 cm (95% confidence interval [CI] 1.6 cm-3.6 cm), and a decrease in systolic blood pressure of 2.1 mm/Hg (95% CI - 5.00 to 0.67). This is the earliest cohort by fifty years for whom the fetal origins hypothesis has been examined in early adulthood. Our estimates of the effect of birth weight on blood pressure are towards the upper end of the range of published estimates in modern cohorts.

Association between cardiovascular disease and socioeconomic level in Portugal

INTRODUCTION

Cardiovascular disease is the leading cause of morbidity, mortality and disability in Portugal. Socioeconomic level is known to influence health status but there is scant evidence on socioeconomic inequalities in cardiovascular disease in Portugal.

AIM

To analyze the distribution of cardiovascular disease in the Portuguese population according to socioeconomic status.

METHODS

We conducted a cross-sectional study using data from the fourth National Health Survey on a representative sample of the Portuguese population. Socioeconomic inequalities in cardiovascular disease, risk factors and number of medical visits were analyzed using odds ratios according to socioeconomic status (household equivalent income) in the adult population (35-74 years). Comparisons focused on the top and bottom 50% and 10% of household income distribution.

RESULTS

Of the 21 807 individuals included, 53.3% were female, and mean age was 54 ± 11 years. Cardiovascular disease, stroke, ischemic heart disease, hypertension, diabetes, obesity and physical inactivity were associated with lower socioeconomic status, while smoking was associated with higher status; number of medical visits and psychological distress showed no association. When present, inequality was greater at the extremes of income distribution.

CONCLUSIONS

The results reveal an association between morbidity, lifestyle and socioeconomic status. They also suggest that besides improved access to effective medical intervention, there is a need for a comprehensive strategy for health promotion and disease prevention that takes account of individual, cultural and socioeconomic characteristics.

The associations of high birth weight with blood pressure and hypertension in later life: a systematic review and meta-analysis

The 'fetal origin hypothesis' suggests that metabolic diseases are directly related to poor nutritional status in early life. Thus, a high birth weight (HBW) may pose a lower risk than normal birth weight. Overweight and overnutrition are among the most widely recognized risk factors of metabolic diseases. To explore the possible effects of HBW on blood pressure and hypertension, a systematic review was performed. The PubMed and Embase databases were searched for relevant studies. The outcomes included systolic blood pressure (SBP), diastolic blood pressure (DBP) and hypertension. We included all of the studies that assessed the differences in outcomes for children aged >1 year between those born with normal birth weight (birth weight between 2500 and 4000 g or between the 10th and 90th percentiles for their gestational age) and those born with HBW (birth weight4000 g or 90th percentile for their gestational age). The outcomes were analyzed descriptively and by conducting a meta-analysis. Thirty-one studies satisfied the inclusion criteria. The mean difference in blood pressure and the relative risk of hypertension between individuals with HBW and individuals with normal birth weight was inversely associated with age. SBP and DBP, as well as the prevalence of hypertension, were higher in younger children with HBW but lower in older adults with HBW compared with individuals with normal birth weight. The findings suggested that an individual with HBW is prone to hypertension and higher blood pressure during childhood. However, a 'catch-down' effect in the elevation of blood pressure is observed in subjects with HBW as they grow older. Thus, older individuals with HBW are less susceptible to hypertension than those with normal birth weight.

Low birth weight is associated with higher blood pressure variability from childhood to young adulthood: the Bogalusa Heart Study

The association between birth weight and long-term within-individual variability of blood pressure (BP) was examined in a longitudinal cohort of 1,454 adults (939 whites and 515 blacks; adulthood age = 19-50 years) enrolled in the Bogalusa Heart Study in Bogalusa, Louisiana, in 1973-2010. BP variability was depicted as standard deviation, coefficient of variation, and deviation from age-predicted values using 6-15 serial BP measurements from childhood to adulthood over an average of 25.7 years. Birth weight was significantly and negatively associated with adulthood BP levels, long-term BP levels, and rate of change. Importantly, low birth weight was significantly associated with increased BP variability in terms of standard deviation, coefficient of variation, and deviation. As evaluated using the regression coefficients, a 1-kg lower birth weight was associated with increases in systolic BP variability measures (-0.38 mm Hg, P = 0.04 for standard deviation; -0.004 mm Hg, P = 0.01 for coefficient of variation; and -0.16 mm Hg, P = 0.04 for deviation) after adjustment for race, age, sex, mean BP levels, and gestational age; similar trends in the associations were noted for diastolic BP variability measures. In conclusion, these findings suggest that birth weight affects not only BP levels but also the magnitude of within-individual BP fluctuations over time through fetal programming in BP regulation mechanisms.

Sex differences in the association of childhood socioeconomic status with adult blood pressure change: the CARDIA study

OBJECTIVE

To examine sex differences in the relation of childhood socioeconomic status (CSES) to systolic (SBP) and diastolic blood pressure (DBP) trajectories during 15 years, spanning young (mean [M] [standard deviation {SD}] = 30 [3] years) and middle (M [SD] = 45 [3] years) adulthood, independent of adult SES.

METHODS

A total of 4077 adult participants reported father's and mother's educational attainments at study enrollment (Year 0) and own educational attainment at enrollment and at all follow-up examinations. Resting BP also was measured at all examinations. Data from examination Years 5 (when participant M [SD] age = 30 [3] years), 7, 10, 15, and 20 are examined here. Associations of own adult (Year 5), mother's, and father's educations with 15-year BP trajectories were examined in separate multilevel models. Fully controlled models included time-invariant covariates (age, sex, race, recruitment center) and time-varying covariates that were measured at each examination (marital status, body mass, cholesterol, oral contraceptives/hormones, and antihypertensive drugs). Analyses of parental education controlled for own education.

RESULTS

When examined without covariates, higher education - own (SBP γ = -0.03, DBP γ = -0.03), mother's (SBP γ = -0.02, DBP γ = -0.02), and father's (SBP γ = -0.02, DBP γ = -0.01) - were associated with attenuated 15-year increases in BP (p < .001). Associations of own (but not either parent's) education with BP trajectories remained independent of standard controls. Sex moderated the apparent null effects of parental education, such that higher parental education-especially mother's, predicted attenuated BP trajectories independent of standard covariates among women (SBP γ = -0.02, p = .02; DBP γ = -0.01, p = .04) but not men (SBP γ = 0.02, p = .06; DBP γ = 0.005, p = .47; p interaction SBP < .001, p interaction DBP = .01).

CONCLUSIONS

Childhood socioeconomic status may influence women's health independent of their own adult status.

Population heterogeneity in trajectories of midlife blood pressure

BACKGROUND

We investigated whether there are subgroups with different underlying (latent) trajectories of midlife systolic blood pressure (BP), diastolic BP, and pulse pressure in a UK cohort.

METHODS

Data are from 1840 men and 1819 women with BP measured at ages 36, 43, and 53 years. We used unconditional growth mixture models to test for the presence of latent trajectory classes. Extracted classes were described in terms of a number of known lifetime risk factors, and linked to the risk of undiagnosed angina (Rose questionnaire) at age 53 years.

RESULTS

In both sexes for systolic BP, diastolic BP, and pulse pressure, there was a large "normative" class (>90% of the sample) characterized by gentle annual increases (eg, an increase in male systolic BP of 0.9 mm Hg/year [95% confidence interval = 0.9 to 1.0]), with a smaller class for whom the rate of increase was high (eg, an increase in male systolic BP of 3.1 mm Hg/year [2.8 to 3.4]). In women, there was an additional class for whom BP was high at age 36 and remained high. Persons in the "normative" classes were, on average, heavier at birth and taller at age 7 years, had a lower midlife body mass index, and were less likely to be on antihypertensive medication compared with those in other classes. Among those with no diagnosed cardiovascular disease, those in the classes with more strongly increasing systolic BP and pulse pressure were at greatest risk of angina.

CONCLUSION

Our study suggests that in midlife the majority of the population have a gentle underlying increase in BP, but that there also exists an important subgroup in whom BP increases much more markedly. These classes may be useful for identifying those most at risk for cardiovascular disease.

Physical activity and sedentary behaviour at different life stages and adult blood pressure in the 1958 British cohort

OBJECTIVES

To investigate whether physical activity or sedentary behaviour at different life stages is associated with blood pressure (BP) in mid-adulthood; activity levels have accumulative associations with BP; and adult body mass index (BMI) mediates associations.

METHODS

Information on activity and television-viewing was available at several ages (23, 33, 42, 45 years) and BP at 45 years for the 1958 British birth cohort (n = 9927). Associations were examined with and without adjustment for covariates.

RESULTS

Active adults, generally, had lower mean systolic and diastolic BP and risk of hypertension than nonactive, although varying by age. After adjustment for covariates, systolic and diastolic BP for active men at 23 years or at 45 years were 1-2 mmHg lower; similar associations were seen for women active at 33 years. Some but not all associations attenuated with further adjustment for BMI: odds ratio (OR) for hypertension associated with 23 years activity changed from 0.82 [95% confidence interval (CI) 0.74, 0.91] to 0.79 (0.70, 0.90) after BMI adjustment. Independent associations of activity at more than one age were found, such that prevalence of hypertension was higher in men active at 23 years but not at 45 years, than men sustaining activity (39 vs. 31%). Sitting at work was unrelated to BP, but there was a trend of higher BP with greater television-viewing: for example risk of hypertension was higher by 10-12% per h/day television-viewing at 45 years after adjustment for covariates, attenuating after allowance for BMI.

CONCLUSION

Our study suggests that there are benefits to BP of becoming and sustaining active lifestyles and minimizing television-viewing over many years of adulthood, with a mediating role for BMI.

How the Newcastle Thousand Families birth cohort study has contributed to the understanding of the impact of birth weight and early life socioeconomic position on disease in later life

Much has been made of the potential influence of birth weight and early socioeconomic disadvantage in influencing adult health, but little has been published in terms of how important these associations may be with respect to exposures throughout the lifecourse. The objective of this review is to describe the contributions of the Newcastle Thousand Families Study in understanding the relative impacts of factors in early life, particularly birth weight and socio-economic position at birth, in influencing health in later life. The Newcastle Thousand Families Study is a prospective birth cohort established in 1947. It originally included all births to mothers resident in Newcastle upon Tyne, in northern England, in May and June of that year. Study members were followed extensively throughout childhood and intermittently in adulthood. At the age of 49-51 years, study members underwent a large-scale follow-up phase enabling an assessment of how early life may influence their later health, and also incorporating adult risk factors which enabled the relative contributions of factors at different stages of life to be assessed. While some findings from the study do support birth weight and early socio-economic position having influences on adult health status, the associations are generally small when compared to risk factors later in life. Using path analyses on longitudinal data of this nature enables mediating pathways between early life and later health to be assessed and if more studies were to take this approach, the relative importance of early life on adult disease risk could be better understood.

Birth weight and subsequent blood pressure: a meta-analysis

Hypertension is becoming an important health problem in many countries. The 'small baby syndrome hypothesis' suggests that an inverse linear relationship exists between birth weight and later risk of hypertension; however, this relationship is under debate. We conducted a meta-analysis to examine the association between birth weight and subsequent blood pressure. Among 78 studies reporting on the association between birth weight and subsequent blood pressure, 20 articles (reporting 27 original studies) were eligible for inclusion. Low birth weight (< 2500 g) compared with birth weight greater than 2500 g was associated with an increased risk of hypertension (odds ratio [OR] 1.21; 95% confidence interval [CI] 1.13, 1.30); high birth weight (> 4000 g) compared with birth weight less than 4000 g was associated with a decreased risk of hypertension (OR 0.78; 95% CI 0.71, 0.86). When low birth weight (< 2500 g) was compared with birth weight greater than 2500 g, mean systolic blood pressure (SBP) increased by 2.28 mmHg (95% CI 1.24, 3.33); when high birth weight (> 4000 g) was compared with birth weight less than 4000 g, mean SBP decreased by 2.08 mmHg (95% CI -2.98, -1.17). These findings indicate that there is an inverse linear association between birth weight and later risk of hypertension, and that this association primarily exists between birth weight and SBP.

Prevalence of high blood pressure among young rural adults in relation to height in childhood and adult body mass index

OBJECTIVE

Evidence, mostly based on developed countries, indicates that disease risks may be associated with changes in growth processes rather than a one-point phenomenon. In view of the increasing prevalence of hypertension in India, there is a need to understand how patterns of growth during early childhood and adolescence influence blood pressure in adulthood, particularly among rural populations in India.

METHODS

The risk of hypertension was examined in 378 rural men older than 20 years who were measured for anthropometry during early childhood, adolescence, and as young adults in a community-based cohort study.

RESULTS

At the young age of 24 years, 33.9% of men had either high systolic blood pressure (≥130 mmHg) or high diastolic blood pressure (≥85 mmHg), even in absence of obesity. The growth of the subjects during childhood, in whom blood pressure developed later in young adulthood, was characterized by higher body mass index (BMI) throughout early childhood and adolescence as compared with those who had normal blood pressure. The prevalence of high blood pressure, especially diastolic, at this adult age was strongly associated with stunting at 3+ years of age (<-2 SD height of the World Health Organization standard), and risk increased (odds ratio, 12.21; 95% confidence interval, 2.93-50.90; p < 0.001) among those having high BMI (≥23 kg/m(2)) at adult age as compared with those who were not stunted in early life with a low BMI at adult age.

CONCLUSIONS

The primary prevention of the epidemic of high blood pressure in India may require measures to prevent children from being stunted in early childhood and also prevent them from being overweight at young adulthood.

The relatively small contribution of birth weight to blood pressure at age 49-51 years in the Newcastle Thousand Families Study

BACKGROUND

Whereas a large number of previous studies suggest an association between birth weight and later blood pressure, others do not. Controversy surrounds the relative importance of these associations, in particular in relation to more modifiable factors in later life. The aim of this study was to investigate the relative contributions of a range of factors from across life to variations in SBP and DBP in the Newcastle Thousand Families Study.

METHODS AND RESULTS

Detailed information was collected prospectively during childhood, including birth weight, duration breast fed and socioeconomic conditions. At age 49-51 years, 574 study members returned self-completion questionnaires and 412 underwent clinical examination, including measurement of DBP and SBP. These data were analysed using linear regression and path analyses. After adjustment for all other significant variables, decreased birth weight, standardized for sex and gestational age (P = 0.035), increased BMI (P < 0.001) and being male (P = 0.034) were independently associated with raised SBP and DBP. Social class at birth (P = 0.044) was also independently associated with DBP. BMI was found to be the most important predictor, with a small relative contribution of standardized birth weight.

CONCLUSION

Adult blood pressure is influenced by numerous factors, acting both directly and indirectly during an individual's lifetime. Inverse associations of standardized birth weight, although statistically significant, were of relatively small importance, with the majority of variation being explained by more modifiable factors in adulthood, in particular adult BMI.

Cardiovascular disease risk factors in adolescent British South Asians and whites: a pilot study

BACKGROUND

Cardiovascular disease (CVD) and associated mortality are more common in British South Asians than in the British white population. Most of the aspects of the cardiovascular risk profile are modifiable, and are thought to be established in childhood. However, the role of genetics and ethnicity has not been fully elucidated.

OBJECTIVES

This pilot study compared cardiovascular risk profiles in British South Asian and British white adolescents, and investigated the relationships between physical activity, cardiorespiratory fitness, nutrition, and CVD risk profile in both ethnic groups.

METHODS

Cardiovascular risk factors included systolic and diastolic blood pressure, body composition, fasting glucose, cholesterol, and triglycerides. Physical activity was measured using 7-day accelerometry; diet was measured from a 3-day dietary record. Fitness was assessed from running economy, submaximal exercise lactate response, and peak oxygen uptake. Body composition was determined through a bioelectrical impedance analyzer (BIA). Finger-prick blood samples were taken for fasting glucose, cholesterol, and triglycerides.

RESULTS

Twelve British South Asian males (aged 15.2 ± 0.3 years) and 11 British white males (aged 15.1 ± 0.3 years) were recruited. Mean systolic blood pressure in British South Asian adolescents was 6.9 mm Hg higher (95% confidence interval [CI], -13.4 to 0.4 mm Hg) than in their British white counterparts. Following multifactorial adjustment, this increased to 12.4 mm Hg. Fasting blood triglycerides were 1.04 mmol/L (0.52-1.57 mmol/L) higher in Asians; this was nonsignificant following adjustment for dietary factors. The British South Asian adolescents' diet contained 42 g (23-61 g) more fat per day.

CONCLUSIONS

Differences in cardiovascular risk profile between British South Asian and British white males are present in adolescence, with higher fasting blood triglycerides in British South Asian adolescent males being attributed to a higher proportion of dietary fat. Interventions may thus be developed to influence dietary choices during childhood, and therefore potentially reduce CVD in adulthood.

Associations of education with 30 year life course blood pressure trajectories: Framingham Offspring Study

Background

Education is inversely associated with cardiovascular disease incidence in developed countries. Blood pressure may be an explanatory biological mechanism. However few studies have investigated educational gradients in longitudinal blood pressure trajectories, particularly over substantial proportions of the life course. Study objectives were to determine whether low education was associated with increased blood pressure from multiple longitudinal assessments over 30 years. Furthermore, we aimed to separate antecedent effects of education, and other related factors, that might have caused baseline differences in blood pressure, from potential long-term effects of education on post-baseline blood pressure changes.

Methods

The study examined 3890 participants of the Framingham Offspring Study (mean age 36.7 years, 52.0% females at baseline) from 1971 through 2001 at up to 7 separate examinations using multivariable mixed linear models.

Results

Mixed linear models demonstrated that mean systolic blood pressure (SBP) over 30 years was higher for participants with ≤12 vs. ≥17 years education after adjusting for age (3.26 mmHg, 95% CI: 1.46, 5.05 in females, 2.26 mmHg, 95% CI: 0.87, 3.66 in males). Further adjustment for conventional covariates (antihypertensive medication, smoking, body mass index and alcohol) reduced differences in females and males (2.86, 95% CI: 1.13, 4.59, and 1.25, 95% CI: -0.16, 2.66 mmHg, respectively). Additional analyses adjusted for baseline SBP, to evaluate if there may be educational contributions to post-baseline SBP. In analyses adjusted for age and baseline SBP, females with ≤12 years education had 2.69 (95% CI: 1.09, 4.30) mmHg higher SBP over follow-up compared with ≥17 years education. Further adjustment for aforementioned covariates slightly reduced effect strength (2.53 mmHg, 95% CI: 0.93, 4.14). Associations were weaker in males, where those with ≤12 years education had 1.20 (95% CI: -0.07, 2.46) mmHg higher SBP over follow-up compared to males with ≥17 years of education, after adjustment for age and baseline blood pressure; effects were substantially reduced after adjusting for aforementioned covariates (0.34 mmHg, 95% CI: -0.90, 1.68). Sex-by-education interaction was marginally significant (p = 0.046).

Conclusion

Education was inversely associated with higher systolic blood pressure throughout a 30-year life course span, and associations may be stronger in females than males.

Prenatal programming-effects on blood pressure and renal function

Impaired intrauterine nephrogenesis-most clearly illustrated by low nephron number-is frequently associated with low birthweight and has been recognized as a powerful risk factor for renal disease; it increases the risks of low glomerular filtration rate, of more rapid progression of primary kidney disease, and of increased incidence of chronic kidney disease or end-stage renal disease. Another important consequence of impaired nephrogenesis is hypertension, which further amplifies the risk of onset and progression of kidney disease. Hypertension is associated with low nephron numbers in white individuals, but the association is not universal and is not seen in individuals of African origin. The derangement of intrauterine kidney development is an example of a more general principle that illustrates the paradigm of plasticity during development-that is, that transcription of the genetic code is modified by epigenetic factors (as has increasingly been documented). This Review outlines the concept of prenatal programming and, in particular, describes its role in kidney disease and hypertension.

Amplification of the association between birthweight and blood pressure with age: the Bogalusa Heart Study

OBJECTIVES

Although low birthweight is associated with elevated blood pressure (BP) levels, whether the strength of this relationship is amplified with age is still debated. This study tested the hypothesis that the magnitude of the birthweight-BP association increases with age from childhood to adulthood.

METHODS

The study cohort included 6251 individuals (64.5% whites and 35.6% blacks, 50.0% males) enrolled in the Bogalusa Heart Study. Individuals were examined 1-15 times for BP from childhood to adulthood, with 24 363 observations. Information on birthweight and gestational age was obtained from Louisiana State birth certificates.

RESULTS

After adjusting for race, sex, age and gestational age, low birthweight (kg) was associated with higher SBP levels (mmHg) in adolescence (aged 12-17 years, regression coefficient β = -0.80, P = 0.004) and adulthood (aged 18-50 years, β = -1.34, P = 0.010). Adjustment for current BMI yielded considerably stronger association. Importantly, the magnitude of the birthweight-SBP relationship, measured as standardized β(unit = SD), was significantly amplified with increasing age, regardless of adjustment for current BMI and race. Further, the strengthened association (the increase in standardized β ranging 0.02-0.12) by adjustment for current BMI was closely related to the BMI-SBP and birthweight-BMI correlations, especially noted in childhood.

CONCLUSION

These findings on the potentiating effect of increasing age on the birthweight-BP relationship suggest that the fetal programming and the increasing cumulative burden with age of unhealthy lifestyle behaviors affect the development of adult hypertension in a synergistic manner.

Childhood social class and adult adiposity and blood-pressure trajectories 36-53 years: gender-specific results from a British birth cohort

BACKGROUND

In this study, the authors investigate gender-specific effects of childhood socio-economic position (SEP) on adiposity and blood pressure at three time points in adulthood.

METHODS

Mixed models were used to assess the association of childhood SEP with body mass index (BMI), waist circumference, systolic blood pressure (SBP) and diastolic blood pressure (DBP) at ages 36, 43 and 53 years in a British birth cohort.

RESULTS

The adverse effect of lower childhood SEP on adiposity increased between ages 36 and 53 years in women (BMI: trend test: p=0.03) and remained stable in men, but the opposite was seen for SBP, where inequalities increased in men (p=0.01). Childhood SEP inequalities in DBP were stable with age in both men and women. Educational attainment mediated some but not all of the effects of childhood SEP on adiposity and SBP, and their rate of change; adult social class was a less important mediator.

CONCLUSION

Childhood SEP is important for adult adiposity and blood pressure across midlife, especially for BMI in women and for blood pressure in men. Thus, pathways to adult health differ for men and women, and public health policies aimed at reducing social inequalities need to start early in life and take account of gender.

Fetal origins of renal disparities

Epidemiologic studies of populations continue to emerge showing that early-life factors influence the risk of developing several chronic diseases of adulthood. Susceptibility to environmental factors is particularly problematic during renal development, which is not complete until 36 weeks of gestation. Environmental deprivation may lead to adaptations including early growth restriction, whereas late insults may alter the kidney during the final stages of development. Because disparities among those who are more likely to have low birth weight mirrors the disparities observed among those more likely to develop kidney-related disorders, fetal origins have been presumed to explain some of the observed disparities. Although current empiric evidence supports a link between fetal programming and childhood/adult kidney disease, affected pathways may vary by race.

Geographic variation in hypertension prevalence among blacks and whites: the multi-ethnic study of atherosclerosis

BACKGROUND

Many studies have examined differences in hypertension across race/ethnic groups but few have evaluated differences within groups.

METHODS

We investigated within-group geographic variations in hypertension prevalence among 3,322 black and white participants of the Multi-Ethnic Study of Atherosclerosis (MESA). Place of birth and place of residence were included in multivariate Poisson regression analyses.

RESULTS

Blacks born in southern states were 1.11 (95% confidence interval (CI): 1.02, 1.23) times more likely to be hypertensive than non-southern states after adjusting for age and sex. Findings were similar, though not statistically significant, for whites (prevalence ratio (PR): 1.15, 95% CI: 0.98, 1.35). Blacks and whites living in Forsyth (blacks, PR: 1.23, 95% CI: 1.07, 1.42; whites, PR: 1.32, 95% CI: 1.09, 1.60) and Baltimore (blacks, PR: 1.14, 95% CI: 1.00, 1.31; whites, PR: 1.24, 95% CI: 1.05, 1.47) were also significantly more likely to be hypertensive than those living in Chicago after adjusting for age and sex. Among blacks, those living in New York were also significantly more likely to be hypertensive. Geographic heterogeneity was partially explained by socioeconomic indicators, neighborhood characteristics or hypertension risk factors. There was also evidence of substantial heterogeneity in black-white differences depending on which geographic groups were compared (ranging from 82 to 13% higher prevalence in blacks compared with whites).

CONCLUSIONS

A better understanding of geographic heterogeneity may inform interventions to reduce racial/ethnic disparities.