Systolic and diastolic blood pressures as predictors of coronary heart disease mortality in the Whitehall study.

Systolic and diastolic blood pressures were compared as predictors of death due to coronary heart disease using data on the 10 year mortality outcome from the 18 403 male civil servants, aged 40-64, in the Whitehall study. There were 727 deaths due to coronary heart disease. At entry to the study the systolic pressure in these men was significantly higher than the diastolic pressure, and a standardised index of relative risk for death from coronary heart disease was greater for systolic blood pressure. After adjustment for age the top quintile of systolic pressure (greater than 151 mm Hg) identified 5% more men at risk of death from coronary heart disease than for the top diastolic quintile (greater than 95 mm Hg). The findings suggested that clinicians should pay more attention to systolic levels as a criterion for making diagnostic and therapeutic decisions.     

Socioeconomic gradient in morbidity and mortality in people with diabetes: cohort study findings from the Whitehall Study and the WHO Multinational Study of Vascular Disease in Diabetes.

OBJECTIVE: To assess whether the inverse socioeconomic mortality gradient observed in the general population persists in diabetic people. DESIGN: The Whitehall cohort study and the London cohort of the WHO multinational study of vascular disease in diabetes. SETTING: London. SUBJECTS: 17,264 male civil servants (17,046 without diabetes, 218 with diabetes) aged 40-64 examined in 1967-9, and 300 people with diabetes aged 35-55 from London clinics examined in 1975-7. Both cohorts were followed up until January 1995. MAIN OUTCOME MEASURES: Mortality from all causes, cardiovascular disease, and ischaemic heart disease. RESULTS: In both cohorts people in the lower social groups were older, had higher blood pressure, and were more likely to smoke. In the Whitehall study, the prevalence of heart disease was higher in the lowest social group compared with the highest group, by 6% among non-diabetic people (P = 0.0001) and by 14% among diabetic subjects (P = 0.02). In the WHO study proteinuria was more common in the lowest social group compared with the highest (27% v 15%, P = 0.01), as was retinopathy (54% v 48%, P = 0.5). There was a clear socioeconomic gradient in all cause mortality in both cohorts, with death rates being about twice as high in the lowest compared with the highest social groups. In the Whitehall study this gradient was similar in both diabetic and non-diabetic subjects, and it persisted for mortality from cardiovascular disease and from ischaemic heart disease. About half of the increased risk of death in the lowest social group was accounted for by blood pressure and smoking. CONCLUSIONS: We confirm the existence of an inverse socioeconomic mortality gradient in diabetic people and suggest that this is largely due to conventional cardiovascular risk factors.     

Explaining socioeconomic differences in sickness absence: the Whitehall II Study.

OBJECTIVE--To describe and explain the socioeconomic gradient in sickness absence. DESIGN--Analysis of questionnaire and sickness absence data collected from the first phase of the Whitehall II study. Grade of employment was used as a measure of socioeconomic status. SETTING--20 civil service departments in London. SUBJECTS--6900 male and 3414 female civil servants aged 35-55 years. MAIN OUTCOME MEASURES--Rates of short spells (< or = 7 days) and long spells (> 7 days) of sickness absence. RESULTS--A strong inverse relation between grade of employment and sickness absence was evident. Men in the lowest grade had rates of short and long spells of absence 6.1 (95% confidence interval 5.3 to 6.9) and 6.1 (4.8 to 7.9) times higher than those in the highest grade. For women the corresponding rate ratios were 3.0 (2.3 to 3.9) and 4.2 (2.5 to 6.8) respectively. Several risk factors were identified, including health related behaviours (smoking and frequent alcohol consumption), work characteristics (low levels of control, variety and use of skills, work pace, and support at work), low levels of job satisfaction, and adverse social circumstances outside work (financial difficulties and negative support). These risk factors accounted for about one third of the grade differences in sickness absence. CONCLUSION--Large grade differences in sickness absence parallel socioeconomic differences in morbidity and mortality found in other studies. Identified risk factors accounted for a small proportion of the grade differences in sickness absence. More accurate measurement of the risk factors may explain some of the remaining differences in sickness absence but other factors, as yet unrecognised, are likely to be important.     

Optimal form of operationalizing BMI in relation to all-cause and cause-specific mortality: the original Whitehall study

Objective: The shape of the association between BMI (kg/m²) and mortality has important methodological implications as it partially determines the optimal form for operationalizing BMI for use in analyses. We examined various BMI operationalizations in relation to mortality from all causes and specific causes. Methods and Procedures: A clinical examination with measurements of height and weight was conducted at baseline (1967–1970) for 18,860 working men aged 40–69, in the total cohort and 7,865 men in the healthy subcohort, that is, those who had no unexplained weight loss, no cardiovascular (CVD) or respiratory disease, were nonsmokers and did not die during the first 5 years of follow‐up (the original Whitehall study). A mean follow‐up of 35 years for mortality gave rise to 13,498 deaths of which 4,766 were in the healthy subcohort. Results: There was a dose‐response relation between BMI and CVD and coronary heart disease (CHD) mortality in the total cohort and healthy subcohort, with an increasingly steep slope at the high end of the BMI distribution. For noncardiovascular, cancer, and respiratory mortality, an excess risk was also associated with a BMI <18.5; in the healthy subcohort, this was true only for respiratory deaths. The association between BMI and all‐cause mortality was J‐shaped in the total cohort and healthy subgroup and even after excluding underweight participants. Discussion: For associations with all‐cause and cause‐specific mortality, a linear and quadratic term in combination provided a more parsimonious BMI operationalization than the WHO definition, obese‐nonobese dichotomy or BMI treated as a continuous linear variable.     

Socioeconomic Status and Subclinical Coronary Disease in the Whitehall II Epidemiological Study

Background

There are pronounced socioeconomic disparities in coronary heart disease, but the extent to which these primarily reflect gradients in underlying coronary artery disease severity or in the clinical manifestation of advanced disease is uncertain. We measured the relationship between socioeconomic status (SES) as indexed by grade of employment and coronary artery calcification (CAC) in the Whitehall II epidemiological cohort, and tested the contribution of lifestyle, biological and psychosocial factors in accounting for this association.

Methods and Findings

CAC was assessed in 528 asymptomatic men and women aged 53–76 years, stratified into higher, intermediate and lower by grade of employment groups. Lifestyle (smoking, body mass index, alcohol consumption, physical activity), biological (blood pressure, lipids, fasting glucose, inflammatory markers) and psychosocial factors (work stress, financial strain, social support, depression, hostility, optimism) were also measured. Detectable CAC was present in 293 participants (55.5%). The presence of calcification was related to lifestyle and biological risk factors, but not to grade of employment. But among individuals with detectable calcification, the severity of CAC was inversely associated with grade of employment (p = 0.010), and this relationship remained after controlling for demographic, lifestyle, biological and psychosocial factors. Compared with the higher grade group, there was a mean increase in log Agatston scores of 0.783 (95% C.I. 0.265–1.302, p = 0.003) in the intermediate and 0.941 (C.I. 0.226–1.657, p = 0.010) in the lower grade of employment groups, after adjustment for demographic, lifestyle, biological and psychosocial factors.

Conclusions

Low grade of employment did not predict the presence of calcification in this cohort, but was related to the severity of CAC. These findings suggest that lower SES may be particularly relevant at advanced stages of subclinical coronary artery disease, when calcification has developed.     

Do socioeconomic differences in mortality persist after retirement? 25 year follow up of civil servants from the first Whitehall study.

OBJECTIVE: To assess the risk of death associated with work based and non-work based measures of socioeconomic status before and after retirement age. DESIGN: Follow up study of mortality in relation to employment grade and car ownership over 25 years. SETTING: The first Whitehall study. SUBJECTS: 18,133 male civil servants aged 40-69 years who attended a screening examination between 1967 and 1970. MAIN OUTCOME MEASURE: Death. RESULTS: Grade of employment was a strong predictor of mortality before retirement. For men dying at ages 40-64 the lowest employment grade had 3.12 times the mortality of the highest grade (95% confidence interval 2.4 to 4.1). After retirement the ability of grade to predict mortality declined (rate ratio 1.86; 1.6 to 2.2). A non-work based measure of socioeconomic status (car ownership) predicted mortality less well than employment grade before retirement but its ability to predict mortality declined less after retirement. Using a relative index of inequality that was sensitive to the distribution among socioeconomic groups showed employment grade and car ownership to have independent associations with mortality that were of equal magnitude after retirement. The absolute difference in death rates between the lowest and highest employment grades increased with age from 12.9 per 1000 person years at ages 40-64 to 38.3 per 1000 at ages 70-89. CONCLUSIONS: Socioeconomic differences in mortality persist beyond retirement age and in magnitude increase with age. Social differentials in mortality based on an occupational status measure seem to decrease to a greater degree after retirement than those based on a non-work measure. This suggests that alongside other socioeconomic factors work itself may play an important part in generating social inequalities in health in men of working age.     

Sickness absence as a global measure of health: evidence from mortality in the Whitehall II prospective cohort study

Objective To examine the association between sickness absence and mortality compared with associations between established health indicators and mortality.Design Prospective cohort study. Medical examination and questionnaire survey conducted in 1985-8; sickness absence records covered the period 1985-98.Setting 20 civil service departments in London.Participants 6895 male and 3413 female civil servants aged 35-55 years.Main outcome measure All cause mortality until the end of 1999.Results After adjustment for age and grade, men and women who had more than five medically certified absences (spells > 7 days) per 10 years had a mortality 4.8 (95% confidence interval 3.3 to 6.9) and 2.7 (1.5 to 4.9) times greater than those with no such absence. Poor self rated health, presence of longstanding illness, and a measure of common clinical conditions comprising diabetes, diagnosed heart disease, abnormalities on electrocardiogram, hypertension, and respiratory illness were all associated with mortality—relative rates between 1.3 and 1.9. In a multivariate model including all the above health indicators and additional health risk factors, medically certified sickness absence remained a significant predictor of mortality. No linear association existed between self certified absence (spells 1-7 days) and mortality, but the findings suggest that a small amount of self certified absence is protective.Conclusion Evidence linking sickness absence to mortality indicates that routinely collected sickness absence data could be used as a global measure of health differentials between employees. However, such approaches should focus on medically certified (or long term) absences rather than self certified absences.     

Health behaviours, socioeconomic status, and mortality: further analyses of the British Whitehall II and the French GAZEL prospective cohorts

Background

Differences in morbidity and mortality between socioeconomic groups constitute one of the most consistent findings of epidemiologic research. However, research on social inequalities in health has yet to provide a comprehensive understanding of the mechanisms underlying this association. In recent analysis, we showed health behaviours, assessed longitudinally over the follow-up, to explain a major proportion of the association of socioeconomic status (SES) with mortality in the British Whitehall II study. However, whether health behaviours are equally important mediators of the SES-mortality association in different cultural settings remains unknown. In the present paper, we examine this issue in Whitehall II and another prospective European cohort, the French GAZEL study.

Methods and Findings

We included 9,771 participants from the Whitehall II study and 17,760 from the GAZEL study. Over the follow-up (mean 19.5 y in Whitehall II and 16.5 y in GAZEL), health behaviours (smoking, alcohol consumption, diet, and physical activity), were assessed longitudinally. Occupation (in the main analysis), education, and income (supplementary analysis) were the markers of SES. The socioeconomic gradient in smoking was greater (p<0.001) in Whitehall II (odds ratio [OR]  = 3.68, 95% confidence interval [CI] 3.11–4.36) than in GAZEL (OR  = 1.33, 95% CI 1.18–1.49); this was also true for unhealthy diet (OR  = 7.42, 95% CI 5.19–10.60 in Whitehall II and OR  = 1.31, 95% CI 1.15–1.49 in GAZEL, p<0.001). Socioeconomic differences in mortality were similar in the two cohorts, a hazard ratio of 1.62 (95% CI 1.28–2.05) in Whitehall II and 1.94 in GAZEL (95% CI 1.58–2.39) for lowest versus highest occupational position. Health behaviours attenuated the association of SES with mortality by 75% (95% CI 44%–149%) in Whitehall II but only by 19% (95% CI 13%–29%) in GAZEL. Analysis using education and income yielded similar results.

Conclusions

Health behaviours were strong predictors of mortality in both cohorts but their association with SES was remarkably different. Thus, health behaviours are likely to be major contributors of socioeconomic differences in health only in contexts with a marked social characterisation of health behaviours. Please see later in the article for the Editors'' Summary     

Is the SF-36 a valid measure of change in population health? Results from the Whitehall II Study.

OBJECTIVE: To measure within-person change in scores on the short form general health survey (SF-36) by age, sex, employment grade, and disease status. DESIGN: Longitudinal study with a mean of 36 months (range 23-59 months) follow up, with screening examination and questionnaire to detect physical and psychiatric morbidity. SETTING: 20 civil service departments originally located in London. PARTICIPANTS: 5070 male and 2197 female office based civil servants aged 39-63 years. MAIN OUTCOME MEASURES: Change in the eight scales of the SF-36 (adjusted for baseline score and length of follow up) and effect sizes (adjusted change standard deviation of differences). RESULTS: Within-person declines (worsening health) with age were greater than estimated by cross sectional data alone. General mental health showed greater declines among younger participants (P for linear trend < 0.001). Employment grade was inversely related to change; lower grades had greater deteriorations than higher grades (P < 0.001 for each scale in men; P < 0.05 for each scale in women except general health perceptions and role limitations due to physical problems). The greatest declines were seen among participants with disease at baseline, with the effects of physical and psychiatric morbidity being additive. Effect sizes ranged from 0.20 to 0.65 in participants with both physical and psychiatric morbidity. CONCLUSIONS: Health functioning, as measured by the SF-36, changed in hypothesised directions with age, employment grade, and disease status. These changes occurred within a short follow up period, in an occupational, high functioning cohort which has not been the subject of intervention, suggesting that the SF-36 is sensitive to changes in health in general populations.     

Pressor reactions to psychological stress and prediction of future blood pressure: data from the Whitehall II Study.

OBJECTIVE--To examine whether reactions of blood pressure to psychological stress predict future blood pressure. DESIGN--Blood pressure was recorded at a medical screening examination after which pressor reactions to a psychological stress task were determined. Follow up measurement of blood pressure was undertaken, on average, 4.9 years later. SETTING--20 civil service departments in London. SUBJECTS--1003 male civil servants aged between 35 and 55 years at entry to the study. MAIN OUTCOME MEASURE--Blood pressure at follow up screening. RESULTS--Reactions of systolic blood pressure to stress correlated positively with systolic blood pressure at follow up screening (r = 0.22, P < 0.01). The dominant correlate of follow up blood pressure was blood pressure at initial screening (r = 0.60; P < 0.01 between initial and follow up systolic blood pressure; r = 0.59, P < 0.01 between initial and follow up diastolic blood pressure). Stepwise multiple regression analysis indicated that reactions to the stressor provided minimal prediction of follow up blood pressure over and above that afforded by blood pressure at initial screening. In the case of follow up systolic blood pressure, systolic reactions to stress accounted for only 1% of follow up variance; systolic blood pressure at initial screening accounted for 34%. With regard to diastolic blood pressure at follow up, the independent contribution from diastolic reactions to stress was less than 1%. CONCLUSION--Pressor reactions to psychological stress provide minimal independent prediction of blood pressure at follow up. Measurement of reactivity is not a useful clinical index of the course of future blood pressure.     

BMI, obesity, and sickness absence in the Whitehall II study

Objective: To study BMI and change in BMI from age 25 as predictors of sickness absence. Research Methods and Procedures: Data were collected from 2564 women and 5853 men, who were British civil servants (35 to 55 years) on entry to the Whitehall II study (Phase 1, 1985 to 1988). Employer's records provided annual medically certified (long, >7 days) and self‐certified (short, 1 to 7 days) spells of sickness absence. BMI at age 25 and Phase 1 were examined in relation to absences from Phase 1 to the end of 1998 (mean follow‐up, 7.0 years). Results: After adjustment for employment grade, health‐related behaviors, and health status, overweight (BMI = 25.0 to 29.9 kg/m²) and obesity (BMI > 30.0 kg/m²) at Phase 1 were significant predictors of short and long absences in both sexes; rate ratios (95% confidence intervals) ranged from 1.13 (1.05 to 1.21) to 1.51 (1.30 to 1.76) compared with a BMI of 21.0 to 22.9 kg/m². Additionally, a BMI of 23.0 to 24.9 kg/m² at Phase 1 predicted long absences in women, and underweight (BMI < 21.0 kg/m²) predicted short absences in men. Obesity at age 25 predicted long absences, and obesity at Phase 1 predicted short and long absences in both sexes. Chronic obesity was a particularly strong predictor of long absences in men, with a rate ratio of 2.61 (1.88 to 3.63). Discussion: Findings from this well‐characterized cohort suggest that the obesity epidemic in industrialized countries may result in significant increases in sickness absence. Further research is needed to determine the underlying mechanisms. Policy to reduce sickness absence needs to tackle the problem of excess weight in the working population.     

Mortality from coronary heart disease and stroke in relation to degree of glycaemia: the Whitehall study.

In the Whitehall study of 18 403 male civil servants aged 40-64 years the 10 year mortality rates from coronary heart disease and stroke showed a non-linear relation to two hour blood glucose values, with a significantly increased risk for glucose intolerant subjects with concentrations above the 95th centile point (5.4-11.0 mmol/l; 96-199 mg/100 ml) and for diabetics (blood glucose greater than or equal to 11.1 mmol/l; greater than or equal to 200 mg/100 ml). Multiple logistic analysis showed that between one half and three quarters of the relative risks for deaths from coronary heart disease and stroke were "unexplained" by between group differences in risk factors such as age, blood pressure, obesity, smoking, cholesterol concentration, and electrocardiographic abnormalities. Within the glucose intolerant and diabetic groups the risk factors most strongly related to subsequent death from coronary heart disease were age and blood pressure, with less consistent relations for smoking, cholesterol concentration, and obesity. This study confirms the importance of hypertension as a cardiovascular risk factor in groups with glucose intolerance and diabetes, and this may have important preventive implications.     

Reasons Why People Change Their Alcohol Consumption in Later Life: Findings from the Whitehall II Cohort Study

Purpose

Harmful alcohol consumption among the ageing population is an important public health issue. Very few studies ask drinkers why they change their consumption in later life. The aim of this paper was to determine whether a group of people aged over 60 years increased or decreased their alcohol consumption over the past decade and to determine the reasons for their change. We also examined whether the responses varied by age, sex and socio-economic position (SEP).

Subjects and Methods

Data were taken from 6,011 participants (4,310 men, 1,701 women, age range 61 to 85 years) who completed questionnaires at phase 11 (2012-2013) of the Whitehall II Cohort Study.

Results

Over half the study members reported a change in alcohol consumption over the past decade (40% decreased, 11% increased). The most common reasons given for decreases were as a health precaution and fewer social occasions. Common reasons for increases were more social occasions and fewer responsibilities. The lowest SEP group was less likely to increase consumption compared to high SEP (RR 0.57, 95% CI 0.40 to 0.81). Women were more likely to increase consumption in response to stress/depression than men (RR1.53, 95% CI 1.04 to 2.25). Compared to high SEP, the lowest SEP group was less likely to reduce as a health precaution (RR 0.61, 95% CI 0.38 to 0.76).

Conclusions

Alcohol consumption in late life is not fixed. Reasons for change vary by age, sex and SEP. Such information could be used to tailor intervention strategies to reduce harmful consumption.