Aidan Cassidy

Ethnic differences in and childhood influences on early adult pulse wave velocity: The determinants of adolescent, now young adult, social wellbeing, and health longitudinal study

Early determinants of aortic stiffness as pulse wave velocity are poorly understood. We tested how factors measured twice previously in childhood in a multiethnic cohort study, particularly body mass, blood pressure, and objectively assessed physical activity affected aortic stiffness in young adults. Of 6643 London children, aged 11 to 13 years, from 51 schools in samples stratified by 6 ethnic groups with different cardiovascular risk, 4785 (72%) were seen again at aged 14 to 16 years. In 2013, 666 (97% of invited) took part in a young adult (21–23 years) pilot follow-up. With psychosocial and anthropometric measures, aortic stiffness and blood pressure were recorded via an upper arm calibrated Arteriograph device. In a subsample (n=334), physical activity was measured >5 days via the ActivPal. Unadjusted pulse wave velocities in black Caribbean and white UK young men were similar (mean±SD 7.9±0.3 versus 7.6±0.4 m/s) and lower in other groups at similar systolic pressures (120 mm Hg) and body mass (24.6 kg/m2). In fully adjusted regression models, independent of pressure effects, black Caribbean (higher body mass/waists), black African, and Indian young women had lower stiffness (by 0.5–0.8; 95% confidence interval, 0.1–1.1 m/s) than did white British women (6.9±0.2 m/s). Values were separately increased by age, pressure, powerful impacts from waist/height, time spent sedentary, and a reported racism effect (+0.3 m/s). Time walking at >100 steps/min was associated with reduced stiffness (P<0.01). Effects of childhood waist/hip were detected. By young adulthood, increased waist/height ratios, lower physical activity, blood pressure, and psychosocial variables (eg, perceived racism) independently increase arterial stiffness, effects likely to increase with age.

Can arterial wave augmentation in young adults help account for variability of cardiovascular risk in different British ethnic groups

Objective: Traditional cardiovascular risk factors do not fully account for ethnic differences in cardiovascular disease. We tested if arterial function indices, particularly augmentation index (AIx), and their determinants from childhood could underlie such ethnic variability among young British adults in the ‘DASH’ longitudinal study. Methods: DASH, at http://dash.sphsu.mrc.ac.uk/, includes representative samples of six main British ethnic groups. Pulse wave velocity (PWV) and AIx were recorded using the Arteriograph device at ages 21–23 years in a subsample (n = 666); psychosocial, anthropometric, and blood pressure (BP) measures were collected then and in two previous surveys at ages 11–13 years and 14–16 years. For n = 334, physical activity was measured over 5 days (ActivPal). Results: Unadjusted values and regression models for PWVs were similar or lower in ethnic minority than in White UK young adults, whereas AIx was higher – Caribbean (14.9, 95% confidence interval 12.3–17.0%), West African (15.3, 12.9–17.7%), Indian (15.1, 13.0–17.2%), and Pakistani/Bangladeshi (15.7, 13.7–17.7%), compared with White UK (11.9, 10.2–13.6%). In multivariate models, adjusted for sex, central SBP, height, and heart rate, Indian and Pakistani/Bangladeshi young adults had higher AIx (&bgr; = 3.35, 4.20, respectively, P < 0.01) than White UK with a similar trend for West Africans and Caribbeans but not statistically significant. Unlike PWV, physical activity, psychosocial or deprivation measures were not associated with AIx, with borderline associations from brachial BP but no other childhood variables. Conclusion: Early adult AIx, but not arterial stiffness, may be a useful tool for testing components of excess cardiovascular risk in some ethnic minority groups.

Longitudinal study of cardiometabolic risk from early adolescence to early adulthood in an ethnically diverse cohort

Objective To examine influences of adiposity from early adolescence to early 20s on cardiovascular disease (CVD) risk in the multiethnic Determinants of young Adult Social well-being and Health (DASH) longitudinal study. Methods In 2002–2003, 6643 11–13-year-olds from 51 London schools participated at baseline, and 4785 were seen again at 14–16 years. Recently, 665 (97% of invited) participated in pilot follow-up at 21–23 years, with biological and psychosocial measures and blood biomarkers (only at 21–23 years). Regression models examined interplay between ethnicity, adiposity and CVD. Results At 21–23 years, ∼30–40% were overweight. About half of the sample had completed a degree with little ethnic variation despite more socioeconomic disadvantage in adolescence among ethnic minorities. Regardless of ethnicity, overweight increased more steeply between 14–16 years and 21–23 years than between 11–13 years and 14–16 years. More overweight among Black Caribbean and Black African females, lower systolic blood pressure (sBP) among Indian females and Pakistani/Bangladeshi males compared with White UK peers, persisted from 11–13 years. At 21–23 years, glycated haemoglobin (HbA1c) was higher among Black Caribbean females, total cholesterol higher and high-density lipoprotein (HDL) cholesterol lower among Pakistani/Bangladeshis. Overweight was associated with a ∼+2 mm Hg rise in sBP between 11–13 years and 21–23 years. Adiposity measures at 11–13 years were related to allostatic load (a cluster of several risk markers), HbA1c and HDL cholesterol at 21–23 years. Ethnic patterns in CVD biomarkers remained after adjustments. Conclusions Adolescent adiposity posed significant risks at 21–23 years, a period in the lifespan generally ignored in cardiovascular studies, when ethnic/gender variations in CVD are already apparent.

The effect of flexible settings on participation rates, data quality, and costs in a longitudinal study of ethnically diverse young adults: the London Determinants of young Adult Social wellbeing and Health (DASH) study

Abstract Background The loss of young and disadvantaged people in cohort studies compromises representativeness and scientific and public value. The Determinants of young Adult Social wellbeing and Health (DASH) study is a longitudinal study of young people in London, mainly from ethnic minorities, and has a social epidemiological focus. The cohort is now aged 21–23 years, an important transition phase to adulthood that influences health and wellbeing in later life. We examine the costs and benefits of different settings on motivation for participation. Methods 6643 11–13-year-olds from 51 London schools took part in the baseline survey in 2002–03 and 4781 were seen again at age 14–16 years. So far, 81% (5414 of 6643) of the cohort has been traced through friendship networks, social media, and community campaigns. A feasibility study of best practice for full follow-up was done with 400 participants between June, 2012, and August, 2013, the design of which was informed by systematic reviews. A sample of about 50 people per ethnic group (Indian, Pakistani, Bangladeshi, black Africans, black Caribbeans, white British) was chosen to give a reasonable spread by sex and socioeconomic position and across all boroughs and schools. Flexibility in settings was based on number of interview locations available (least, two; intermediate, three; most, six) and appointment times (weekdays 0900–1700 h, other). Interview locations were general practice surgeries and community pharmacies within 2 km of residential postcodes; Muslims living in east London were offered the choice of a Clinical Research Centre close to a large mosque; and central locations (Clinical Research Facility at University College Hospital and Kings College London). Participants were given GB£25 shopping vouchers and £30 vouchers if they needed childcare, and reimbursed travel expenses. A main questionnaire covered topics such as socioeconomic circumstances, social support, racism, own and parental health, and health behaviours. Dietary intake over the past 24 h was obtained in a recall questionnaire. Physical measures were done and a blood sample was also taken. The primary outcome was participation rate. Secondary outcomes were cost per participant (CPP) and quality of data. A combination of our own study team and surgery nurses was used. Interviewers were trained for 3 days and compliance to protocol was assessed by regular shadowing and analysis of data by interviewer identification code. Findings 97% (400 of 413) of those invited took part. Participation increased with flexibility in choice of interview locations (least 15%, 95% CI 11–19; intermediate 27%, 23–32; most 58%, 53–63) and was substantially boosted by weekend and evening appointments (weekday 0900–1700 h 76%, 71–80; other 24%, 17–30). CPP varied by setting from £229 (95% CI 220–239; Kings College London, 179 participants seen by study team) to £283 (276–289; Clinical Research Facility, 22 seen by their nurses). Compliance to the protocol and the quality measures were high across settings (p>0·05 for 11 of 13 measures). The CPP for those seen (40 participants) by surgery nurses was intermediate at £240 (95% CI 225–255), but the quality measures were least favourable (eg, consent for bloods 82·5%, 95% CI 70·2–94·8 vs 96·0%, 92·7–99·2 for Kings College London). Compliance to protocol was compromised by very busy environments of inner-city surgeries in deprived areas and limited familiarity with population cohorts. Interpretation Flexibility in interview locations and appointment times boosted participation rates. The use of our own study team rather than surgery nurses was associated with lower CPP and better quality data. Participants were not randomly assigned to a setting, which comprised comparisons of setting-specific participation rates. Funding The DASH study is funded by the UK Medical Research Council (MC_U130015185/MC_UU_12017/1) North Central London Research Consortium, Primary Care Research Network.

The influence of racism on cigarette smoking: Longitudinal study of young people in a British multiethnic cohort

Introduction Studies, predominantly from the US, suggest that positive parenting, social support, academic achievement, and ethnic identity may buffer the impact of racism on health behaviours, including smoking, but little is known about how such effects might operate for ethnically diverse young people in the United Kingdom. We use the Determinants of young Adult Social well-being and Health (DASH), the largest UK longitudinal study of ethnically diverse young people, to address the following questions: a) Is racism associated with smoking? b) Does the relationship between racism and smoking vary by gender and by ethnicity? (c) Do religious involvement, parenting style and relationship with parents modify any observed relationship? and d) What are the qualitative experiences of racism and how might family or religion buffer the impact? Methods The cohort was recruited from 51 London schools. 6643 were seen at 11-13y and 4785 seen again at 14-16y. 665 participated in pilot follow-up at 21-23y, 42 in qualitative interviews. Self-report questionnaires included lifestyles, socio-economic and psychosocial factors. Mixed-effect models examined the associations between racism and smoking. Results Smoking prevalence increased from adolescence to age 21-23y, although ethnic minorities remained less likely to smoke. Racism was an independent longitudinal correlate of ever smoking throughout adolescence (odds ratio 1.77, 95% Confidence Interval 1.45–2.17) and from early adolescence to early 20s (1.90, 95% CI 1.25–2.90). Smoking initiation in late adolescence was associated with cumulative exposure to racism (1.77, 95% CI 1.23–2.54). Parent-child relationships and place of worship attendance were independent longitudinal correlates that were protective of smoking. Qualitative narratives explored how parenting, religion and cultural identity buffered the adverse impact of racism. Conclusions Racism was associated with smoking behaviour from early adolescence to early adulthood, regardless of gender, ethnicity or socio-economic circumstances adding to evidence of the need to consider racism as an important social determinant of health across the life course.

Ethnic Differences in and Childhood Influences on Early Adult Pulse Wave Velocity

Early determinants of aortic stiffness as pulse wave velocity are poorly understood. We tested how factors measured twice previously in childhood in a multiethnic cohort study, particularly body mass, blood pressure, and objectively assessed physical activity affected aortic stiffness in young adults. Of 6643 London children, aged 11 to 13 years, from 51 schools in samples stratified by 6 ethnic groups with different cardiovascular risk, 4785 (72%) were seen again at aged 14 to 16 years. In 2013, 666 (97% of invited) took part in a young adult (21–23 years) pilot follow-up. With psychosocial and anthropometric measures, aortic stiffness and blood pressure were recorded via an upper arm calibrated Arteriograph device. In a subsample (n=334), physical activity was measured >5 days via the ActivPal. Unadjusted pulse wave velocities in black Caribbean and white UK young men were similar (mean±SD 7.9±0.3 versus 7.6±0.4 m/s) and lower in other groups at similar systolic pressures (120 mm Hg) and body mass (24.6 kg/m2). In fully adjusted regression models, independent of pressure effects, black Caribbean (higher body mass/waists), black African, and Indian young women had lower stiffness (by 0.5–0.8; 95% confidence interval, 0.1–1.1 m/s) than did white British women (6.9±0.2 m/s). Values were separately increased by age, pressure, powerful impacts from waist/height, time spent sedentary, and a reported racism effect (+0.3 m/s). Time walking at >100 steps/min was associated with reduced stiffness (P<0.01). Effects of childhood waist/hip were detected. By young adulthood, increased waist/height ratios, lower physical activity, blood pressure, and psychosocial variables (eg, perceived racism) independently increase arterial stiffness, effects likely to increase with age.

Ethnic Differences in and Childhood Influences on Early Adult Pulse Wave VelocityNovelty and Significance

Early determinants of aortic stiffness as pulse wave velocity are poorly understood. We tested how factors measured twice previously in childhood in a multiethnic cohort study, particularly body mass, blood pressure, and objectively assessed physical activity affected aortic stiffness in young adults. Of 6643 London children, aged 11 to 13 years, from 51 schools in samples stratified by 6 ethnic groups with different cardiovascular risk, 4785 (72%) were seen again at aged 14 to 16 years. In 2013, 666 (97% of invited) took part in a young adult (21–23 years) pilot follow-up. With psychosocial and anthropometric measures, aortic stiffness and blood pressure were recorded via an upper arm calibrated Arteriograph device. In a subsample (n=334), physical activity was measured >5 days via the ActivPal. Unadjusted pulse wave velocities in black Caribbean and white UK young men were similar (mean±SD 7.9±0.3 versus 7.6±0.4 m/s) and lower in other groups at similar systolic pressures (120 mm Hg) and body mass (24.6 kg/m2). In fully adjusted regression models, independent of pressure effects, black Caribbean (higher body mass/waists), black African, and Indian young women had lower stiffness (by 0.5–0.8; 95% confidence interval, 0.1–1.1 m/s) than did white British women (6.9±0.2 m/s). Values were separately increased by age, pressure, powerful impacts from waist/height, time spent sedentary, and a reported racism effect (+0.3 m/s). Time walking at >100 steps/min was associated with reduced stiffness (P<0.01). Effects of childhood waist/hip were detected. By young adulthood, increased waist/height ratios, lower physical activity, blood pressure, and psychosocial variables (eg, perceived racism) independently increase arterial stiffness, effects likely to increase with age.

Ethnic Differences in and Childhood Influences on Early Adult Pulse Wave VelocityNovelty and Significance: The Determinants of Adolescent, Now Young Adult, Social Wellbeing, and Health Longitudinal Study

Early determinants of aortic stiffness as pulse wave velocity are poorly understood. We tested how factors measured twice previously in childhood in a multiethnic cohort study, particularly body mass, blood pressure, and objectively assessed physical activity affected aortic stiffness in young adults. Of 6643 London children, aged 11 to 13 years, from 51 schools in samples stratified by 6 ethnic groups with different cardiovascular risk, 4785 (72%) were seen again at aged 14 to 16 years. In 2013, 666 (97% of invited) took part in a young adult (21–23 years) pilot follow-up. With psychosocial and anthropometric measures, aortic stiffness and blood pressure were recorded via an upper arm calibrated Arteriograph device. In a subsample (n=334), physical activity was measured >5 days via the ActivPal. Unadjusted pulse wave velocities in black Caribbean and white UK young men were similar (mean±SD 7.9±0.3 versus 7.6±0.4 m/s) and lower in other groups at similar systolic pressures (120 mm Hg) and body mass (24.6 kg/m2). In fully adjusted regression models, independent of pressure effects, black Caribbean (higher body mass/waists), black African, and Indian young women had lower stiffness (by 0.5–0.8; 95% confidence interval, 0.1–1.1 m/s) than did white British women (6.9±0.2 m/s). Values were separately increased by age, pressure, powerful impacts from waist/height, time spent sedentary, and a reported racism effect (+0.3 m/s). Time walking at >100 steps/min was associated with reduced stiffness (P<0.01). Effects of childhood waist/hip were detected. By young adulthood, increased waist/height ratios, lower physical activity, blood pressure, and psychosocial variables (eg, perceived racism) independently increase arterial stiffness, effects likely to increase with age.

PP40 an ethnic minority cohort of young people - feasibility of follow-up in early adulthood?

Background Under-representation of ethnic minorities in cohort studies is common. The Determinants of (now) Adult Social well-being and Health (DASH) study examines how interaction of social and biological exposures influences ethnic differences in physical and mental health over the life course. It started 10 years ago with 6643 11-13y London schoolchildren, 80% ethnic minorities. A feasibility study examined best practice for follow-up of the cohort now aged 21-23y. Methods 300 DASH participants, 50 for each major ethnic group (White British, Black African, Black Caribbean, Indian, Pakistani and Bangladeshi), were invited. They were offered assessments in different locations (GP surgeries, community pharmacies, clinical research facilities, homes, colleges) to collect a range of questionnaire and physical data (e.g. age appropriate mental health measures, 24 hour dietary data, accelerometry, blood biomarkers, arterial stiffness, bio-impedance). Consents were sought for DNA analysis, linkage of NHS records and to contact parents to participate in a generational study. Various retention and engagement initiatives were tried, including social media, a participant advisory group (PAG) and ‘Bring a DASH friend’ (BDF). Results <1% refused, 45% of participants were seen in a university setting, 19% in pharmacies, 28% in GP surgeries, and 7% in clinical research facilities. GP surgeries were keen to support DASH but busy environments compromised quality and pace of data collection. High street pharmacies proved ideal locations for satellite clinics. The primary influence on participants’ choice of location was proximity to home or convenience to stop en route from work. Item non-response for questionnaire-based measures and refusal rates for wearing monitors were low (<1%). Less than 5% refused to have bloods taken, with no ethnic bias. All were keen to get feedback on results, particularly cholesterol level, and consented to storage of bloods for DNA and for linkage of NHS records. 81% of the baseline cohort was traced using multiple measures. Three key initiatives worked best: PAG’s input on appropriateness of measures, retention and advocacy including use of social media; BDF due to continuing contact with school friends; and a community link worker to conduct advocacy activities in community-based spaces such as markets and places of worship, and to engage community champions. All participants agreed to contact with parents. Conclusion These positive findings challenge conventional wisdom on underrepresentation of ethnic minorities in cohort studies. They also suggest effective mechanisms to enhance engagement with diverse communities and exploit the public health value of findings across ethnic groups.