Claudia Thomas

Shift work and risk factors for cardiovascular disease: a study at age 45 years in the 1958 British birth cohort

This study examined associations between exposure to shift-work and risk factors for cardiovascular disease (CVD) and whether the associations are explained by socio-economic circumstances, occupational factors or health behaviours. Biological risk factors for CVD were measured in 7,839 participants of the 1958 British birth cohort at age 45xa0years who were in paid employment. Regular (≥1/week) shift-workers included 46% working evenings (1800–2200), 28% weekends, 13% nights (2200–0400) and 14% early mornings (0400–0700). Adverse levels of several CVD risk factors were found in association with increasing participation in any shift-work. Men regularly working all four shift-work types had increased CVD risk factors of approximately 0.1–0.2 standard deviations (e.g. 0.8xa0kg/m2 for body mass index; 1.2xa0cm for waist circumference) than those not regularly working shifts; for women, there was a positive linear trend for triglyceride levels, but a negative trend for diastolic blood pressure. Separate analyses of shift-work types showed associations primarily for night/morning working rather than evening/weekend working. Men had adverse levels of all CVD risk factors except blood pressure and total-cholesterol in association with night or early morning work and women had adverse triglyceride levels. Adjustment for socioeconomic, occupational factors and health behaviours explained most associations except for adiposity and C-reactive protein. Our results highlight night and early morning working associations with an adverse profile of CVD risk factors, which are partly explained by socioeconomic, other occupational factors and health behaviours.

Association between Younger Age When First Overweight and Increased Risk for CKD

There is little information on how the duration of overweight or obesity during life affects the risk for CKD. To investigate whether prolonged exposure to overweight during adult life increases the risk of later CKD in a cumulative manner, we analyzed data from the Medical Research Council National Survey of Health and Development, a socially stratified sample of 5362 singleton children born in 1 week in March 1946 in England, Scotland, and Wales. Multiple imputation expanded the analysis sample from the initial 1794 participants with complete data to 4584. This study collected self-reported body mass index (BMI) at ages 20 and 26 years and measured BMI at ages 36, 43, 53, and 60-64 years. The outcome of interest was CKD at age 60-64 years, suggested by estimated GFR (eGFR) <60 ml/min per 1.73 m(2) and/or urine albumin-to-creatinine ratio (UACR) ≥ 3.5 mg/mmol. In analyses adjusted for childhood and adulthood social class, first becoming overweight at younger ages was associated with higher odds of developing CKD by age 60-64 years. Compared with those who first became overweight at age 60-64 years or never became overweight, those first overweight at age 26 or 36 years had approximately double the odds of developing CKD. The strength of this association decreased with increasing age when first overweight (P for trend <0.001). These associations were consistent for creatinine-based eGFR, cystatin C-based eGFR, and UACR. Taken together, these results suggest that preventing overweight in early adulthood may have a considerable effect on the prevalence of CKD in the population.

Socio-economic position and type 2 diabetes risk factors: patterns in UK children of South Asian, black African-Caribbean and white European origin.

Background Socio-economic position (SEP) and ethnicity influence type 2 diabetes mellitus (T2DM) risk in adults. However, the influence of SEP on emerging T2DM risks in different ethnic groups and the contribution of SEP to ethnic differences in T2DM risk in young people have been little studied. We examined the relationships between SEP and T2DM risk factors in UK children of South Asian, black African-Caribbean and white European origin, using the official UK National Statistics Socio-economic Classification (NS-SEC) and assessed the extent to which NS-SEC explained ethnic differences in T2DM risk factors. Methods and Findings Cross-sectional school-based study of 4,804 UK children aged 9–10 years, including anthropometry and fasting blood analytes (response rates 70%, 68% and 58% for schools, individuals and blood measurements). Assessment of SEP was based on parental occupation defined using NS-SEC and ethnicity on parental self-report. Associations between NS-SEC and adiposity, insulin resistance (IR) and triglyceride differed between ethnic groups. In white Europeans, lower NS-SEC status was related to higher ponderal index (PI), fat mass index, IR and triglyceride (increases per NS-SEC decrement [95%CI] were 1.71% [0.75, 2.68], 4.32% [1.24, 7.48], 5.69% [2.01, 9.51] and 3.17% [0.96, 5.42], respectively). In black African-Caribbeans, lower NS-SEC was associated with lower PI (−1.12%; [−2.01, −0.21]), IR and triglyceride, while in South Asians there were no consistent associations between NS-SEC and T2DM risk factors. Adjustment for NS-SEC did not appear to explain ethnic differences in T2DM risk factors, which were particularly marked in high NS-SEC groups. Conclusions SEP is associated with T2DM risk factors in children but patterns of association differ by ethnic groups. Consequently, ethnic differences (which tend to be largest in affluent socio-economic groups) are not explained by NS-SEC. This suggests that strategies aimed at reducing social inequalities in T2DM risk are unlikely to reduce emerging ethnic differences in T2DM risk.

Early-life overweight trajectory and CKD in the 1946 British birth cohort study

Background Few studies have examined the impact of childhood obesity on later kidney disease, and consequently, our understanding is very limited. Study Design Longitudinal population-based cohort. Setting & Participants The Medical Research Council National Survey of Health and Development, a socially stratified sample of 5,362 singletons born in 1 week in March 1946 in England, Scotland, and Wales, of which 4,340 were analyzed. Predictor Early-life overweight latent classes (never, prepubertal only, pubertal onset, or always), derived from repeated measurements of body mass index between ages 2 and 20 years. Outcomes & Measurements The primary outcome was chronic kidney disease (CKD), defined as creatinine- or cystatin C–based estimated glomerular filtration rate (eGFRcr and eGFRcys, respectively) <60 mL/min/1.73 m2 or urine albumin-creatinine ratio (UACR) ≥3.5 mg/mmol measured at age 60-64 years. Associations were explored through regression analysis, with adjustment for socioeconomic position, smoking, physical activity level, diabetes, hypertension, and overweight at ages 36 and 53 years. Results 2.3% of study participants had eGFRcr <60 mL/min/1.73 m2, 1.7% had eGFRcys <60 mL/min/1.73 m2, and 2.9% had UACR ≥3.5 mg/mmol. Relative to being in the never-overweight latent class, being in the pubertal-onset– or always-overweight latent classes was associated with eGFRcys-defined CKD (OR, 2.04; 95% CI, 1.09-3.82). Associations with CKD defined by eGFRcr (OR, 1.27; 95% CI, 0.71-2.29) and UACR (OR, 1.33; 95% CI, 0.70-2.54) were less marked, but in the same direction. Adjustment for lifestyle and health factors had little impact on effect estimates. Limitations A low prevalence of CKD resulted in low statistical power. No documentation of chronicity for outcomes. All-white study population restricts generalizability. Conclusions Being overweight in early life was found to be associated with eGFRcys-defined CKD in later life. The associations with CKD defined by eGFRcr and UACR were less marked, but in the same direction. Reducing or preventing overweight in the early years of life may significantly reduce the burden of CKD in the population.

Novel coronary heart disease risk factors at 60–64 years and life course socioeconomic position: The 1946 British birth cohort

Social disadvantage across the life course is associated with a greater risk of coronary heart disease (CHD) and with established CHD risk factors, but less is known about whether novel CHD risk factors show the same patterns. The Medical Research Council National Survey of Health and Development was used to investigate associations between occupational socioeconomic position during childhood, early adulthood and middle age and markers of inflammation (C-reactive protein, interleukin-6), endothelial function (E-selectin, tissue-plasminogen activator), adipocyte function (leptin, adiponectin) and pancreatic beta cell function (proinsulin) measured at 60–64 years. Life course models representing sensitive periods, accumulation of risk and social mobility were compared with a saturated model to ascertain the nature of the relationship between social class across the life course and each of these novel CHD risk factors. For interleukin-6 and leptin, low childhood socioeconomic position alone was associated with high risk factor levels at 60–64 years, while for C-reactive protein and proinsulin, cumulative effects of low socioeconomic position in both childhood and early adulthood were associated with higher (adverse) risk factor levels at 60–64 years. No associations were observed between socioeconomic position at any life period with either endothelial marker or adiponectin. Associations for C-reactive protein, interleukin-6, leptin and proinsulin were reduced considerably by adjustment for body mass index and, to a lesser extent, cigarette smoking. In conclusion, socioeconomic position in early life is an important determinant of several novel CHD risk factors. Body mass index may be an important mediator of these relationships.

Ethnic and socioeconomic influences on childhood blood pressure: the Child Heart and Health Study in England.

Objectives: Compared to UK white European adults, UK black African-Caribbean adults have higher mean SBP and DBP; UK South Asian adults have higher mean DBP but lower SBP. Information on blood pressure (BP) in UK children from different ethnic groups is limited. The aim of this study was to compare BP levels in UK children of black African-Caribbean, South Asian and white European origin. Methods: BP and body build were measured in 5666 children in a cross-sectional study of UK primary school children of South Asian, black African-Caribbean and white European origin aged 9–10 years. Ethnic and socioeconomic differences in BP were obtained from multilevel linear regression models. Results: After adjustment for height and adiposity, black African-Caribbean children had lower mean SBP than white Europeans [difference 1.62u200ammHg, 95% confidence interval (CI) 0.86–2.38u200ammHg], whereas mean DBP was similar (difference 0.58u200ammHg, 95% CI −0.12 to 1.28u200ammHg). The lower SBP was particularly marked in black African rather than Caribbean children (Pu200a=u200a0.002). South Asian children had lower mean SBP (difference 1.10u200ammHg, 95% CI 0.34–1.86u200ammHg) than white Europeans and higher mean DBP (difference 1.07u200ammHg, 95% CI 0.37–1.76u200ammHg). The higher mean DBP was particularly marked among Indian and Bangladeshi, rather than Pakistani, children (Pu200a=u200a0.01). BP was unrelated to socioeconomic circumstances; ethnic differences in BP were not affected by socioeconomic adjustment. Conclusion: A BP pattern similar to that in adults is present in UK South Asian but not in UK black African-Caribbean children at 9–10 years.

Life Course Socioeconomic Position: Associations with Cardiac Structure and Function at Age 60-64 Years in the 1946 British Birth Cohort

Although it is recognized that risks of cardiovascular diseases associated with heart failure develop over the life course, no studies have reported whether life course socioeconomic inequalities exist for heart failure risk. The Medical Research Council’s National Survey of Health and Development was used to investigate associations between occupational socioeconomic position during childhood, early adulthood and middle age and measures of cardiac structure [left ventricular (LV) mass index and relative wall thickness (RWT)] and function [systolic: ejection fraction (EF) and midwall fractional shortening (mFS); diastolic: left atrial (LA) volume, E/A ratio and E/e’ ratio)]. Different life course models were compared with a saturated model to ascertain the nature of the relationship between socioeconomic position across the life course and each cardiac marker. Findings showed that models where socioeconomic position accumulated over multiple time points in life provided the best fit for 3 of the 7 cardiac markers: childhood and early adulthood periods for the E/A ratio and E/e’ ratio, and all three life periods for LV mass index. These associations were attenuated by adjustment for adiposity, but were little affected by adjustment for other established or novel cardio-metabolic risk factors. There was no evidence of a relationship between socioeconomic position at any time point and RWT, EF, mFS or LA volume index. In conclusion, socioeconomic position across multiple points of the lifecourse, particularly earlier in life, is an important determinant of some measures of LV structure and function. BMI may be an important mediator of these associations.

OP29 Ethnic and Socioeconomic Influences on Childhood Blood Pressure: The Child Heart and Health Study in England (Chase)

Background Compared to UK white European adults, UK black African-Caribbean adults have higher mean systolic (SBP) and diastolic (DBP) blood pressure; UK South Asian adults have higher mean DBP but lower SBP. However, information on blood pressure in UK children from different ethnic groups is limited. The aim of this study was to compare blood pressure levels in UK children of black African-Caribbean, South Asian and white European origin. Methods A cross sectional study of 5,666 UK primary school children of South Asian, black African Caribbean, and white European origin aged 9 to 10 years was undertaken. Ethnic and socioeconomic differences in SDP and DBP (as means and differences with their 95% confidence intervals) were obtained from multilevel linear regression models fitting school as a random effect in order to take account of the natural clustering of children within school. All analyses were adjusted for sex, age, month of assessment, blood pressure observer, room temperature and time of day of measurement fitted as fixed effects. The effects of adjustment for height, adiposity (fat mass index, sum of skinfolds) fitted as continuous variables, and socioeconomic circumstances on ethnic differences in blood pressure were then explored. Results After adjustment for height and adiposity, black African-Caribbean children had a lower mean SBP than white Europeans (mean difference 1.62 mmHg, 95% CI 0.86, 2.38 mmHg), while mean DBP was similar (mean difference 0.58 mmHg, 95%CI –0.12, 1.28 mmHg). The mean SBP difference was particularly marked in black African children. In similar analyses, South Asian children had a lower mean SBP (mean difference 1.10 mmHg, 95%CI 0.34, 1.86 mmHg) than white Europeans and a higher mean DBP (mean difference 1.07 mmHg, 95%CI 0.37, 1.76 mmHg). The mean DBP difference was particularly marked among Indian and Bangladeshi, rather than Pakistani, children. Blood pressure was largely unrelated to socioeconomic circumstances; the ethnic differences in blood pressure were not affected by socioeconomic adjustment. Conclusion A blood pressure pattern similar to that in adults is present in UK South Asian but not in UK black African-Caribbean children at 9–10 years. This suggests that key determinants of ethnic differences in blood pressure operate at different stages of the life course in these different ethnic groups. Understanding the reasons for the early emergence of ethnic differences in blood pressure (particularly among South Asians) is an important research priority.

019 Ethnic differences in type 2 diabetes risk markers in children in the UK are not explained by socio-economic status: Child Heart and Health Study in England

Objectives To examine the influence of socio-economic position on type 2 diabetes risk markers in different ethnic groups and determine whether differences in socio-economic position can explain ethnic differences in type 2 diabetes risk. Design Cross-sectional survey of children in 200 primary schools in London, Birmingham and Leicester (Child Heart and Health Study England, or CHASE) in which standardised anthropometric and fasting blood measurements were made. Ethnic origin was defined by parental self-report. Parents socio-economic position (based on occupation) was measured using the National Statistics Socioeconomic Classification (NS-SEC). Statistical analyses were adjusted for age and sex and included a random effect for school. Participants 4796 children (1153 white European, 1306 South Asian, 1215 black African/Caribbean) aged 9–10u2005years. Main outcome measures Height, adiposity (ponderal index, skinfold thickness, fat mass index, waist circumference), glycated haemoglobin (HbA1c), glucose, insulin resistance, triglyceride, HDL-cholesterol, C reactive protein. Results In the whole study population, NS-SEC showed weak and inconsistent associations with diabetes risk markers. However, there were marked differences between ethnic groups. Low socio-economic position was related to higher adiposity, insulin resistance and triglyceride levels in white Europeans and to a lesser extent South Asians; opposite patterns were observed in black African-Caribbeans (likelihood-ratio tests for interactions between NS-SEC and ethnicity, all p<0.05). There were marked ethnic differences in diabetes risk markers. Compared to white Europeans, South Asian children had higher fat mass index (% difference 7.3; 95% CI 2.8 to 12.0), sum of skinfolds (5.1; 1.1, 9.4), HbA1c (2.1; 1.6, 2.7), glucose (0.8; 0.2, 1.5), insulin resistance (29.6; 23.1, 36.4), triglycerides (12.9; 9.4, 16.5) and C reactive protein (43.3; 28.6, 59.7) and lower HDL-cholesterol (−2.9; −1.3, −4.5). In contrast, black African/Caribbean children had less marked increases in HbA1c, insulin resistance and C reactive protein but conversely, had lower triglycerides and higher HDL-cholesterol; adiposity levels were not consistently increased. However, adjustment for socio-economic position had no material effect on the ethnic differences in metabolic markers observed. Conclusions Although socio-economic position showed little overall association with diabetes risk markers in this multi-ethnic study population, there were appreciable associations within individual ethnic groups. Ethnic differences in socio-economic position did not explain marked ethnic differences in emerging risks of type 2 diabetes between South Asians, black African-Caribbeans and white Europeans; other explanations for these ethnic differences should be sought.

P18 Child maltreatment co-occurrence and associations with household dysfunction: evidence from the 1958 British birth cohort

Background Child maltreatment has been associated with adverse health outcomes, including risk of mental health problems and cardiovascular disease. Little is known about how different forms of maltreatment co-occur and whether different patterns are associated with household dysfunction. Delineation of co-occurrence is important to establish in order that long-term health outcomes can be better identified and understood. Objective To investigate (1) to what extent specific maltreatment subtypes co-occur in a British birth cohort and (2) how these patterns were associated with household dysfunction. Design Longitudinal survey; the 1958 British birth cohort. Setting England, Scotland and Wales. Participants Individuals born during 1u2005week in March 1958. At age 45u2005y, 78% of the remaining cohort (11u2008971) completed questions on childhood experiences. Outcomes Child maltreatment before age 16, including psychological, physical and sexual abuse and witnessing intimate partner violence, collected at age 45u2005y. Eleven indicators of parental neglectful behaviour, collected at 7, 11, 16 and 45u2005y, were aggregated to derive a cumulative neglect score. Information on household dysfunction (eg, parental mental health, alcohol/drug misuse, poverty) was collected during childhood and at 45u2005y. OR presented were adjusted for sex and social class at birth. Results Psychological abuse (10.0%) was the most commonly reported maltreatment, followed by physical abuse (6.1%), witnessing abuse (6.0%) and sexual abuse (1.6%); 24% had a neglect score ≥3. 14% of participants experienced any one subtype of abuse. Of these, almost two thirds (64%) experienced further abuse subtypes and/or had a neglect score ≥3. Witnessing or experiencing abuse increased odds of reporting another maltreatment, for example, psychological and physical abuse OR 37.9 (95% CI 30.8 to 46.5). The odds of reporting any abuse increased with neglect score; for example, for sexual abuse OR ranged from 1.5 (0.9 to 2.6) to 4.5 (2.5 to 8.1). Common household dysfunction variables (eg, conflict and physical punishment) were strong predictors for all abuse subtypes. Other dysfunction measures most strongly associated with maltreatment differed, for example, odds of psychological abuse were increased in association with mother/father with nervous trouble (OR 4.7 (4.1 to 5.4), OR 4.1 (3.4 to 4.8), respectively); odds of neglect were increased for those in institutional care (OR 3.8 (2.7 to 5.4)) or with a family member in prison (OR 3.8 (3.0 to 4.8). Conclusion Forms of maltreatment co-occurred in the cohort, such that cumulative exposure to neglect increased odds of abuse. Maltreated children had elevated exposure to household dysfunction.