1. Social and Biological Determinants of Blood Pressure in Afro-Caribbean Youth
Trevor S Ferguson, MBBS, DM, MSc, FACP
Senior Lecturer (Epidemiology), Caribbean Institute for Health Research, UWI
Honorary Consultant (General Internal Medicine), UHWI
Caribbean Institute of Nephrology
10th Annual International Conference on Nephrology and Hypertension
January 19 & 20, 2018

2. GLOBAL BURDEN OF HYPERTENSION
Hypertension is a global public problem causing ≈ 9.4 million deaths worldwide every year
Causes at least 45% of deaths from heart disease and 51% of stroke deaths
Globally, the overall prevalence of HTN in adults aged ≥18 yrs was around 22% in 2014
Prevalence was highest in Africa - 30% and lowest prevalence was in the Americas - 18%
Prevalence is higher in low income countries
Hypertension causes 9.4 million deaths worldwide every year and was responsible for at least 45% of deaths from heart disease and 51% of stroke deaths. Worldwide prevalence is approximately 40% for adults 25 years and older. Prevalence of HTN is highest in the African Region (46%); lowest in the Americas (35%). Additionally High-income countries have a lower prevalence 35% vs. 40%.
Source: A Global Brief on Hypertension. WHO/DCO/WHD/2013.2
WHO Global Health Observatory (Blood Pressure)

3. Source: Global Status Report On Noncommunicable Diseases 2014
MALES
Jamaica = 24.5%
Source: Global Status Report On Noncommunicable Diseases 2014

4. Source: Global Status Report On Noncommunicable Diseases 2014
FEMALES
Jamaica = 19.2%
Source: Global Status Report On Noncommunicable Diseases 2014

5. Prevalence of hypertension by world regions in 1975-2015
Overall prevalence of HTN decreasing
But # of adults with HTN  from 594 M in 1975 – 1.13 B in 2015
 seen in high income and some middle income countries but unchanged in other regions
Some evidence for  prevalence in Sub-Saharan Africa and Southeast Asia
Source: NCD Risk Factor Collaboration. Worldwide trends in blood pressure from 1975 to 2015; The Lancet;  

6. Hypertension is the leading risk factor for global disease burden
Figure shows the burden of disease attributable to 20 leading risk factors in 2010, expressed as percent of global DALYs
Hypertension accounted for 7% of global DALYs
Data form the 2010 Global Burden of Diseases study showed that hypertension is the leading risk factor for global disease burden accounting for 7% of global DALYs (disability adjusted life years). Tobacco smoking and household air pollution were the other two leading risk factors.
Figure: Burden of disease attributable to 20 leading risk factors in 2010, expressed as a percentage of global disability-adjusted life-years. For men (A), women (B), and both sexes (C).
Source: The Lancet 2012; 380: (DOI: /S (12) )

7. Hypertension is a major cause of mortality in the Caribbean
Leading causes of death in Jamaica and CAREC member countries in 2004
Data from CAREC and the RGD in Jamaica showed that in 2004 hypertension was the 4th leading cause of death in the Caribbean. It should be noted that in addition to the deaths directly linked to hypertension, hypertension would also be responsible for about a half the deaths from stroke and IHD.
Hypertensive diseases - 4th leading cause of death
Also major contributor to stroke & IHD deaths
Ferguson & Tulloch-Reid. Curr Cardio Risk Rep (2010) 4:76–82

8. Definition & Classification of High BP
JNC 7 (2003)
ACC/AHA 2017
BP Category
BP Values
Normal
SBP <120 mmHg & DBP <80 mmHg
Prehypertension
SBP mmHg or DBP mmHg
Hypertension
Stage 1
SBP mmHg or DBP mmHg
Stage 2
SBP ≥ 160 mmHg or
DBP ≥ 100 mmHg
BP Category
BP Values
Normal
SBP <120 mmHg & DBP <80 mmHg
Elevated BP
SBP mmHg or DBP <80 mmHg
Hypertension
Stage 1
SBP mmHg or DBP mmHg
Stage 2
SBP ≥ 140 mmHg
or DBP ≥ 90 mmHg

9. Hypertension Prevalence in Jamaica
Year of Study
Lead Investigator
Sample
Sample Size
Age Range
Prevalence Estimate
1993
Figueroa1
National
958
15-49 yrs.
13.4%*
Wilks2
2012
15-74 yrs.
20.9%
2848
25.2%
*Self-reports
Figueroa et al. West Indian Med J 1999; 48 (I): 9 -15
Ferguson et al. West Indian Med J Jul;60(4):422-8.

10. Prehypertension in Jamaica
30% in JHLS-1
35% in JHLS-2
29% among youth years old in JYRRBS
20% among young adults years on in Birth Cohort
Prevalence higher in men compared to women
Ferguson et al. BMC Cardiovascular Disorders 2008, 8:20
Ferguson et al. West Indian Med J 2011; 60 (4): 429

11. Consequences of hypertension
Mortality – acute myocardial infarction, heart failure, ischaemic and haemorrhagic stroke, end stage renal disease
Morbidity – ischaemic heart disease, hypertensive heart disease, non-fatal stroke, chronic kidney disease
Social and economic – high health care costs, especially for treating complications; lost of income; increased dependency

12. Aetiology of Hypertension

13. Risk / Causal Factors in Hypertension Multifactorial Life Course Model
Parental SES, Neighbourhood SES, Own SES, Environmental exposures
Social factors across the life course
Adult Blood Pressure
Genetic & non-modifiable risk factors
Intrauterine growth & early life factors
Childhood growth
Adult characteristics & behaviours
Single gene mutations
Familial genetic factors
Sex
Age
Race/Ethnicity
Maternal nutrition
Fetal nutrition
Fetal growth
Birth size
Prematurity
Rapid catch up growth
Childhood obesity and weight gain
Body size & adiposity
Insulin resistance
Salt intake
Nutrition
Physical Inactivity
Alcohol consumption
Smoking
Stress

14. Early life influences on Hypertension

15. Early life origins of chronic disease
Early life factors are now recognised as important predictors of hypertension and other NCDs in adults
Barker et al demonstrated an inverse relationship between measures of intra-uterine growth (chiefly birth weight) CVD, type 2 diabetes and dyslipidemia
Initial studies focused on middle age and older adults in developed countries, but similar findings have now been replicated in several counties
A large body of evidence has accumulated over the past two decades showing that early life factors play an important role in the development of adult diseases.
Early life factors are now recognised as important predictors of hypertension, other NCDs, and their risk factors, in adults. Barker and colleagues were the first to demonstrate an inverse relationship between birth weight and other measures of intra-uterine growth and cardiovascular disease, type 2 diabetes and dyslipidemia in middle aged adults. Similar findings have now been seen in several counties.

16. Early life origins of hypertension
Early life influences identified include:
Intrauterine growth
Placental size
Infant and postnatal growth
Perinatal socioeconomic factors

17. Birth weight and hypertension
Data from Helsinki Birth Cohort – included 2003 persons examined at 62 years
This slide shows the relationship between birth weight and previously diagnosed hypertension among 2003 persons from the Helsinki Birth Cohort at age 62 years. Low birth weight was associated with an almost four-fold increase in the risk of previously diagnosed hypertension, with a statistically significant trend. While there was an increase in the risk of newly diagnosed hypertension this was not statistically significant,
Eriksson et al. Childhood Growth and Hypertension in Later Life. Hypertension. 2007;49:

18. Parental social class and hypertension
Data from Helsinki Birth Cohort – included 2003 persons examined at 62 years
An important addition to the literature on the early life origins of adult disease was the work looking at the role of socioeconomic factors. Initial critique of the original studies suggested that the birth weight effect was really a due to confounding by socioeconomic status. Further studies however demonstrated that birth weight effect was still significant after adjusting for socioeconomic status and that SES itself had an independent effect. This table shows data from Barker and colleagues which demonstrated that the odds of hypertension was two-fold higher among persons whose fathers were laborers compared to those whose fathers were in the upper middle income social class.
Barker et al. Maternal and Social Origins of Hypertension Hypertension. 2007;50:

19. Low Birth weight and subsequent blood pressure: a meta-analysis (OR for HTN for LBW vs. NBW)
Since the work of Barker and his team a large number of studies have looked at this relationship. Most have shown a clear inverse association between birth weight and measured SBP and DBP, but some have shown conflicting results. This slide shows the results from a recent meta-analysis. Among 20 studies included in the analysis odds of hypertension was increased by 21% for persons with low birth weight compared to persons with normal birth weight. Mean SBP was on average 2.3 mmHg higher among persons with low birth weight compared to those with normal birth weight.
Odds of hypertension was increased by 21% for persons with LBW compared to persons with NBW
Mean SBP was on average 2.3 mmHg higher among persons with LBW compared to those with NBW
Mu et al. Archives of Cardiovascular Disease (2012) 105, 99—113

20. Early life origins of hypertension: Studies from Jamaica
Previous studies examined associations between blood pressure and birth weight and other early life factors
Fetal growth and cardiovascular risk in Jamaican school children 6-16 years – Forrester et al BMJ 1996
Birth weight and postnatal linear growth retardation on blood pressure at years – Walker et al JECH 2001
Limited data on the effect of early life or life-course factors in older adolescents or adults

21. Social Determinants of Hypertension

22. Socioeconomic status and hypertension
Several studies have documented associations between HTN and SES or other social factors, including neighbourhood characteristics
Recent meta-analysis of 51 studies published in 2015
Overall increased risk of HTN with lower SES
Income - pooled OR 1.19, 95% CI 0.96–1.48
Occupation - pooled OR 1.31, 95% CI 1.04–1.64
Education - pooled OR 2.02, 95% CI 1.55–2.63
Associations were significant in high-income countries
Association more consistent among women
Source: Leng et al. Socioeconomic status and hypertension: a meta-analysis; J Hypertens 33:221–229. DOI: /HJH

23. Knowledge Gaps Most studies done in developed countries
Limited data for developing countries and for African origin populations
Limited data for young adults

24. Manuscript Series by ERU team
Early life predictors of blood pressure in Afro-Caribbean young adults: the Jamaica 1986 Birth Cohort Study
Effect of growth velocity and change in adiposity in childhood and adolescence on blood pressure in Afro- Caribbean youth: the Vulnerable Windows Cohort Study
Factors associated with elevated blood pressure or hypertension in Afro-Caribbean youth

25. Paper - 1: Early Life Social and Biological Determinants of Blood Pressure at years old: The Jamaica 1986 Birth Cohort Study
We turn now to the most recent analysis from the 1986 Birth Cohort where we looked at early life early life social and biological determinants of blood pressure at years old.

26. The 1986 Jamaica Birth Cohort
Assembled from a subgroup of participants in the Jamaica Perinatal Mortality Survey
Original survey enrolled consecutive births in all fourteen parishes in Jamaica during Sept – Oct 1986
Birth Cohort - sub-sample of participants from the parishes of Kingston and St. Andrew, and St. Catherine
Last follow up participants enrolled; 794 participants included in analyses on birth weight and blood pressure

27. Paper 1 - Objective To investigate how birth weight,
parental socioeconomic circumstances (SEC), current SEC, and current body size,
influence blood pressure in young adults at years old

28. Proportion (%) of male and female infants in 500 g birth weight categories

29. Relationship between systolic blood pressure, birth weight and other characteristics in multi-level regression models2
Variable
Males
Females
 (95% CI)
Birth weight Z-score
-1.16 (-2.15, -0.17)*
-1.34 (-2.21, -0.47)**
Current Age (years)
1.39 (-0.24, 3.03)
1.73 (0.42, 3.05)*
BMI (kg/m2)
0.83 (0.60, 1.07)***
0.39 (0.25, 0.54)***
Current Height (cm)
0.08 (-0.07, 0.24)
0.17 (0.04, 0.31)*
Maternal age at child’s birth
0.21 (0.04, 0.39)*
0.00 (-0.14, 0.14)
Maternal occupation
Highly Skilled/Skilled
Reference
Semi-skilled/Unskilled
3.67 (0.49, 6.85)*
1.81 (-0.65, 4.29)
Unemployed
4.81 (1.99, 7.64)**
2.10 (-0.37, 4.39)
Housewife
3.37 (0.64, 6.11)*
1.85 (-0.57, 4.26)
In the fully adjusted model, one standard deviation increase in BWT was associated with 1.16 mmHg reduction in SBP among men (95%CI 2.15 to 0.17; p=0.021) and 1.34 mmHg reduction in SBP among women (95%CI 2.21 to 0.47; p=0.003). Participants whose mothers had lower SEC had higher SBP compared to those with mothers of high SEC (β, mmHg for men, p<0.05 for all SEC categories, and for women, p>0.05)
1Coefficients represent change in systolic or diastolic blood pressure (mmHg) for each unit change in the various characteristics.
2Cluster variable for multilevel model was place of birth (29 clusters, usually a hospital or maternity centre)
* p<0.05; ** p<0.01; *** p<0.001; BMI = body mass index
Ferguson et al. (2015) Birth weight and maternal socioeconomic circumstances were inversely related to systolic blood pressure among Afro-Caribbean young adults. J Clin Epidemiol Feb 12. doi: /j.jclinepi

30. Predicted systolic blood pressure by birth weight and mothers occupation category
Male
Female
These figures show predicted SBP by maternal occupation at birth and birth weight z-scores, based on the final SBP model. Among men, there was a consistent gradient in SBP by maternal occupation and birth weight SD distribution, with SBP consistently highest for those whose mothers were unemployed and lowest for those whose mothers were in a highly skilled/skilled occupation. Among women, the trend was less delineated by maternal occupation. SBP was lowest among whose mothers were in a highly skilled/skilled occupation category but there was little difference in SBP between the other groups.
skilled/highly skilled
semi-skilled/unskilled
unemployed
housewife
Ferguson et al. (2015) Birth weight and maternal socioeconomic circumstances were inversely related to systolic blood pressure among Afro-Caribbean young adults. J Clin Epidemiol Feb 12. doi: /j.jclinepi

31. CONCLUSIONS FROM PAPER 1
Intrauterine growth and early life SEC are important predictors of blood pressure in young adults
Early life factors should be considered in the development of policies and interventions to reduce the burden of HTN and other NCDs

32. DOHAD Conference October 17, 2017
Paper 2
Effect of linear growth rate and change in adiposity in childhood and adolescence on blood pressure in Afro-Caribbean youth
Trevor Ferguson, Tamika Royal-Thomas, Lisa Chin-Harty, Minerva Thame, Terrence Forrester, Michael Boyne, Rainford Wilks
Caribbean Institute for Health Research, The University of the West Indies, Jamaica
Department of Medicine, The University of the West Indies, Jamaica
Department of Child and Adolescent Health, The University of the West Indies, Jamaica
UWI Solutions for Developing Countries, The University of the West Indies, Jamaica
DOHAD Conference October 17, 2017
Good afternoon everyone, Let me thank the conference organisers for providing this opportunity to present our research.

33. Objectives
To evaluate the effect of postnatal linear growth and change in body mass index from birth to adolescence on systolic and diastolic blood pressure in Afro-Caribbean youth
We therefore undertook this study in order to evaluate the effect of postnatal linear growth and change in body mass index from birth to adolescence on systolic and diastolic blood pressure in Afro-Caribbean youth.

34. Methods Participants from Vulnerable Windows Cohort Study in Jamaica
Mothers recruited during 1st trimester of pregnancy in 1992 and 1993; children (singleton only) followed from birth at regular intervals (6 wks; 3mths; q3mths – 2yrs; then q6mths)
This analysis included 366 persons age 15 years or older
Growth and adiposity measurements calculated for four growth periods: early infancy (0-6 months), late infancy (6 months - 2 years), early childhood (2-8 years), and late childhood (8-15 years)
The study was conducted using data from participants in the Vulnerable Windows Cohort Study In Jamaica. In this study, mothers of participants were recruited during the first trimester of pregnancy in 1992 and 1993 and then followed from birth at six month to 1 year intervals.
Data for analysis for this paper includes 366 persons age 15 years or older.
Growth and adiposity measurements were calculated for four growth periods. These were: early infancy (0-6 months), late infancy (6 months - 2 years), early childhood (2-8 years), and later childhood (8-15 years).

35. Methods
Growth rates were computed using conditional models which calculated how much body size at the end of a growth period differed from that predicted by the body size at the beginning of the period
Calculated growth rates were standardized by converting them to z-scores
Linear mixed models were used to estimate the effect of growth rates on SBP and DBP
Growth rates were computed by calculating how much body size at the end of a growth period differed from that predicted by the body size at the beginning of the period. Calculated growth rates were standardized by converting them to z-scores. We then used linear mixed models to estimate the effect of growth rates on SBP and DBP. Models accounted for repeated measures within individuals with random intercepts and random slopes. Multiple imputation was used to fill in missing values.

36. Participants and measurements
Analyses included 162 males and 204 females
Mean age 16.7 years (range 15.0, 21.2 years). 
Each individual had on average 5.2 BP measurements (range 1-10)
The analysed sample included 162 males and 204 females., with mean age of 16.7 years and range. Each individual had an average 5.2 BP measurements (range 1-10). In total, there were 1910 SBP measurements and 1908 DBP measurements included in the analyses.

37. Regression Coefficient
Final multivariable model with regression coefficients for the effect of linear growth on systolic BP at age ≥15 years
Variable
Regression Coefficient
95% Confidence Interval
P-value
Birth length z-score
0.72
-0.25, 1.68
0.145
Linear growth rate 0-6 month
1.00
0.14, 1.88
0.024
Linear growth rate 6 mths – 2 yrs
-0.17, 1.61
0.113
Linear growth rate 2 yrs – 8 yrs
0.62
-0.22, 1.46
0.144
Linear growth rate 8 years – 15 yrs
0.07
-1.12, 1.27
0.907
Gestational age at birth (days)
-0.07
-0.15, 0.01
0.069
Age (years)
-1.08
-1.37, -0.78
<0.001
Sex (male vs. female)
7.21
5.01, 9.40
BMI at age 15 (kg/m2)
0.34
0.16, 0.52
This slide shows the final multivariable model for the effect of linear growth on systolic blood pressure. Statistically significant association was found only for the 0-6 months growth period. Age at the time of BP measurement, sex and BMI at age 15 were also significant. Contrary to expectation, the coefficients for age was negative, indicate lower SBP with age between

38. Regression Coefficient
Final multivariable model with regression coefficients for the effect of change in BMI on systolic BP at age ≥15 years
Variable
Regression Coefficient
95% Confidence Interval
P-value
BMI at birth z-score
0.28
-0.60, 1.16
0.527
Change in BMI 0-6 month
0.59
-0.18, 1.36
0.131
Change in BMI 6 mths – 2 yrs
1.52
0.72, 2.32
<0.001
Change in BMI 2 yrs – 8 yrs
1.17
0.45, 1.88
0.002
Change in BMI 8 yrs – 15 yrs
0.66
0.01, 1.32
0.048
Gestational age at birth (days)
-0.06
-0.13, 0.01
0.095
Socioeconomic status score at birth
-0.02
-0.20, 0.17
0.866
Age (years)
-1.08
-1.38, -0.78
Sex (male vs. female)
7.34
5.63, 9.05
Height at age 15
0.05
-0.01, 0.11
0.134
We now turn to the results for change in BMI and SBP. After adjusting for covariates, faster gain in BMI the 6 months to 2 years, 2-8 years and 8-15 years growth periods were significantly associated with SBP, with the largest effect being in the 6 month – 2 years growth period.

39. Results for Diastolic BP
Findings were generally similar for diastolic blood pressure, but were smaller in magnitude

40. Conclusion
Both faster linear growth and greater rate of increase in BMI were associated with higher BP
Associations were stronger and more consistent for increase in BMI
Findings suggest that postnatal growth trajectories should be closely monitored and faster than expected gain in adiposity should be discouraged
In summary therefore, both faster linear growth and greater rate of increase in BMI were associated with higher SBP and DBP, however the associations were stronger and more consistent for increase in BMI.
These findings suggest that that postnatal growth trajectories should be closely monitored during childhood and faster than expected gain in adiposity should be discouraged

41. Paper 3
Factors associated with elevated blood pressure or hypertension in Afro-Caribbean youth: a cross-sectional study
Under review at PeerJ

42. Paper 3 - Objectives
To evaluate the association between putative risk factors and elevated BP or hypertension (EBP/HTN), defined as BP ≥120/80 mmHg, among Afro-Caribbean youth.
To estimate the relative risk for having EBP/HTN among participants with putative CVD risk factors
To evaluate whether there were significant sex differences in risk factors for EBP/HTN

43. Paper 3 - Methods
Cross-sectional analysis from Jamaica 1986 Birth Cohort
898 young adults, years old
BP was measured with a mercury sphygmomanometer after participants had been seated for 5 min.
Anthropometric measurements were done and venous blood obtained to measure fasting glucose, lipids and insulin.

44. Paper 3 - Methods
Data on socioeconomic status (SES) were obtained via questionnaire.
CVD risk factor status was defined using standard cut-points or the upper quintile of the distribution.
Relative risks were computed using odds ratios (OR) from logistic regression models.
Multiple imputation by chained equations used to fill in missing values

45. Distribution of BP Categories by 2017 ACC/AHA Criteria
Prevalence HTN: Males 17% males; 8% females
P<0.001 for male: female difference

46. Prevalence of Elevated BP or Hypertension SBP ≥120 mmHg or DBP ≥80 mmHg

47. Factors associated with elevated BP or HTN among MALES in multivariable logistic regression models
Odds Ratio
95% CI
P-Value
Age (years)
1.74
0.007
BMI Category
Normal weight ( kg/m2)
1.0 -
Underweight (<18.5 kg/m2)
0.64
0.20 – 2.00
0.441
Overweight ( kg/m2)
1.76
0.90 – 3.43
0.096
Obese (≥30kg/m2)
8.48
2.64 – 27.2
<0.001
High Glucose (upper quintile)
2.01
1.20– 3.37
0.008
HOMA-IR (log transformed, upper quintile)
2.08
0.94 – 4.58
0.069
High hsCRP
0.45
0.17 – 1.17
0.101
Household possessions
High (15-17 items)
Moderate (10-14 items)
0.62
0.33 – 1.18
0.147
Low (0-9 items)
1.21
0.59 – 2.45
0.604
Physical Activity Level
High Physical Activity Level
Moderate Physical Activity Level
0.55
0.33 – 0.93
0.026
Low Physical Activity Level
0.49
0.24 – 0.97
0.042
Estimates derived from sex-specific models which included all variables in the table. N=409. Multiple imputation used to fill in missing values

48. Factors associated with elevated BP or HTN among FEMALES in multivariable logistic regression models
Odds Ratio
95% CI
P-Value
Age (years)
2.55
1.60 – 4.08
<0.001
Height (cm)
1.07
0.003
BMI Category (vs. Normal weight)
Underweight
1.70
0.74 – 3.91
0.211
Overweight
1.31
0.63 – 2.72
0.461
Obese
1.44
0.58 – 3.56
0.436
High Triglycerides (upper quintile)
1.98
1.03– 3.81
0.040
HOMA-IR (log transformed, upper quintile)
2.07
1.03 – 4.12
0.039
White blood cell count
1.14
0.99 – 1.31
0.076
Household possessions [vs. high (15-17 items)]
Moderate (10-14 items)
4.63
1.31 – 16.4
0.017
Low (0-9 items)
2.61
0.70 – 9.77
0.154
Physical Activity Level [vs High PAL]
Moderate Physical Activity Level
0.71
0.31 – 1.65
0.429
Low Physical Activity Level
0.42
0.18 – 0.97
0.043
Alcohol Consumption [vs Never Drank Alcohol]
Rarely Drinks Alcohol (<once/week)
0.41
0.18 – 0.90
0.026
Drinks Alcohol 1-2 times/week
0.46
0.19– 1.15
0.099
Drinks Alcohol ≥3 times/week
0.28
0.11 – 0.76
0.012
Estimates derived from sex-specific models which included all variables in the table. N=489. Multiple imputation used to fill in missing values
Estimates derived from sex-specific models which included all variables in the table. N=489. Multiple imputation used to fill in missing values

49. PAPER 3 - CONCLUSION
Factors associated with elevated BP among Jamaican young adults include measures of obesity and insulin resistance, with some significant differences by sex
Lower SES was associated with elevated BP among females only
Reducing obesity and improving insulin sensitivity may reduce hypertension risk in Afro-Caribbean populations

50. SUMMARY Hypertension remains a global public health problem
Understanding the determinants of hypertension in youth can help in developing interventions to reduce the impact of hypertension on public health
Early life factors including birth weight, postnatal growth and maternal SEC contribute to the risk of elevated blood pressure or hypertension in youth
Obesity, measures of insulin resistance (glucose, triglycerides, HOMA-IR) and SES are associated with elevated BP in youth
These factors should be considered in efforts to prevent hypertension

51. Acknowledgements Prof Rainford Wilks
Dr Novie Younger-Coleman, Prof Michael Boyne, Prof Seeromanie Harding, Prof Clive Osmond
Dr Tamika Royal-Thomas
Other investigators (1986 Birth Cohort, VWS, JHLS-I & III, YRRBS), collaborators and co- authors

52. QUESTIONS / DISCUSSION