Employment Grade Research Articles

Dietary patterns, insulin resistance, and incidence of type 2 diabetes in the Whitehall II Study.

OBJECTIVE—The aim of this study was to identify a dietary pattern associated with insulin resistance and investigate whether this pattern was prospectively associated with type 2 diabetes.RESEARCH DESIGN AND METHODS—Analysis was based on 7,339 participants of the Whitehall II study. Dietary intake was measured using a 127-item food frequency questionnaire. We used the reduced rank regression method to determine dietary patterns using the homeostasis model assessment of insulin resistance as the intermediate or response variable. The association between the dietary pattern identified and incidence of type 2 diabetes was investigated using Cox proportional hazard regression models.RESULTS—We identified a dietary pattern characterized by high consumption of low-calorie/diet soft drinks, onions, sugar-sweetened beverages, burgers and sausages, crisps and other snacks, and white bread and low consumption of medium-/high-fiber breakfast cereals, jam, French dressing/vinaigrette, and wholemeal bread. Higher dietary pattern scores were associated with increased risk of type 2 diabetes (hazard ratio for top quartile 2.95 [95% CI 2.19–3.97]; adjusted for age, sex, and energy misreporting). This relationship was attenuated after adjustment for ethnicity, employment grade, health behaviors (smoking, alcohol use, and physical activity) but remained significant after further adjustment for blood pressure and BMI (1.51 [1.10–2.09]).CONCLUSIONS—A dietary pattern associated with insulin resistance predicts type 2 diabetes risk after adjustment for a range of confounders. This study adds to the evidence that dietary patterns are an important risk factor for type 2 diabetes.

Arterial stiffness and inflammatory response to psychophysiological stress

The processes through which psychological stress influences cardiovascular disease are poorly understood, but may involve activation of hemodynamic, neuroendocrine and inflammatory responses. We assessed the relationship between carotid arterial stiffness and inflammatory responses to acute psychophysiologic stress. Participants were 155 healthy men and women aged 55.3, SD 2.7 years. Blood samples for the assessment of plasma fibrinogen, tumor necrosis factor (TNF) α and interleukin (IL) 6 were drawn at baseline, immediately following standardized behavioral tasks, and 45 min later. Carotid artery stiffness was measured ultrasonically three years later, and blood pressure and heart rate responses were recorded. The tasks induced substantial increases in blood pressure and heart rate, together with increased fibrinogen, TNFα and IL-6 concentration. Carotid stiffness was positively associated with body mass, waist/hip ratio, blood pressure, low density lipoprotein cholesterol, and C-reactive protein, and inversely with high density lipoprotein and grade of employment. Baseline levels of inflammatory variables were not related to carotid artery stiffness. But carotid stiffness was greater in participants with larger fibrinogen ( p = 0.037) and TNFα ( p = 0.036) responses to psychophysiological stress. These effects were independent of age, gender, grade of employment, smoking, body mass, waist/hip ratio, systolic and diastolic pressure, high and low density lipoprotein cholesterol, and C-reactive protein. There were no associations between carotid stiffness and stress responses in IL-6, blood pressure, or heart rate. We conclude that individual differences in inflammatory responses to psychophysiological stress are independently related to structural changes in artery walls that reflect increased cardiovascular disease risk.

Impact of Coronary Heart Disease on Health Functioning in an Aging Population: Are There Differences According to Socioeconomic Position?

To examine differences in the effect of coronary heart disease (CHD) on health functioning according to socioeconomic position. Research on social inequality in health has tended to concentrate on differences in disease prevalence and mortality rather than on the impact of disease on functioning. As outcomes improve for those with CHD, it is important to know how their health is affected in the long term. The analysis uses questionnaire data from phase 3 (1991-1993) to phase 7 (2003-2005) of the Whitehall II Study of civil servants (n = 8292). Differences between those in higher and lower employment grades in the relationship between CHD and physical and mental health functioning were measured according to the Short Form 36 General Health Survey (SF-36). A growth curve model of change in SF-36 physical and mental health from five repeated-measures over the 12-year period was then estimated. The differences in SF-36 health between those with and without preexisting CHD depended on employment grade. For those with CHD, physical health was initially poorer in lower grades than in higher ones; this difference persisted throughout. The mental health of respondents with CHD in the lowest grades deteriorated over time whereas for members of the higher grades, the prevailing trend was for improving mental health. CHD has a more detrimental effect on physical and mental health functioning among those in more disadvantaged socioeconomic positions.

Explaining the social gradient in long-term sickness absence: a prospective study of Danish employees

Objectives:To identify differences in risk of sickness absence between socioeconomic groups, and to examine to what extent these differences can be explained by health behaviour and work environment factors.Design, setting...

Diagnosis-specific sickness absence as a predictor of mortality: the Whitehall II prospective cohort study

Objective To investigate whether knowing the diagnosis for sickness absence improves prediction of mortality.Design Prospective cohort study established in 1985-8. Sickness absence records including diagnoses were obtained from computerised registers.Setting...

Effects on Blood Pressure Do Not Explain the Association Between Organizational Justice and Coronary Heart Disease in the Whitehall II Study

To examine whether lower BP mediates the inverse association between organizational justice and incident coronary heart disease (CHD). Previous studies suggest lower blood pressure (BP) and reduced risk of CHD among employees with high organizational justice (the perception of being treated fairly by supervisors). Prospective occupational cohort study of 4250 men and 1812 women free of CHD and hypertension at study entry (the Whitehall II study). Justice was assessed at phase 1 (1985-1988) and phase 2 (1989-1990); systolic and diastolic BP at phases 1, 3 (1992-1993), and 5 (1997-1999); hypertension at phases 3 and 5; and incident CHD from phase 2 to phase 5 (231 events, mean follow-up 9.6 years). A higher level of organizational justice was associated with a slightly lower mean level of diastolic BP over time. After adjustment for age, sex, ethnicity, and employment grade, higher organizational justice was associated with lower CHD incidence. This association was not attenuated after further adjustment for measures of BP and hypertension, although these measures were associated with increased CHD risk. This study suggests that sustained lower levels of BP do not represent a key mechanism through which organizational justice protects against CHD. The importance of this study is that it eliminates a strong candidate mediator of the association between organizational justice and CHD and thus allows future research to concentrate on other mechanisms.

Association of Smoking Behavior and Socio‐Demographic Factors, Work, Lifestyle and Mental Health of Japanese Civil Servants

Few studies have examined the individual and social impact of smoking behavior in the Japanese population. The purpose of this study was to clarify the association between smoking behavior and socio-demographic factors, lifestyle, mental health and work characteristics of Japanese civil servants. A self-administered questionnaire survey of 1,439 employees (821 men and 618 women) aged 20-64 yr was conducted in a local government department in 2001. The questionnaire included items on socio-demographic factors, education level, grade of employment, lifestyle, affect balance scale, and work characteristics. Smoking status was divided into current smoker, ex-smoker and never smoked. Multiple logistic regression analysis was performed to evaluate the relationship between smoking and the other items. Men presented a higher smoking prevalence rate than women (53.1% vs. 4.9%). In men, a strong relationship between current smoker and advanced age (40 yr or older), low education level, less physical activity, irregular breakfast and negative affect balance was found. Among men with a low education, the prevalence of smoking cessation was significantly lower in comparison to men with a high education. In women, being young (20-29 yr), unmarried (single or other), having a hobby, and irregular breakfast were associated with smoking behavior. Furthermore, smoking cessation was significantly associated with having a hobby and negative affect balance. The above results suggest that socio-demographic, lifestyle and mental health characteristics are independently associated with current smoking. These factors should be considered in smoking cessation policies as program components.

Poverty, Human Development, and Basic Biology

Poverty, Human Development, and Basic Biology

Hypertension Is Not the Link Between Job Strain and Coronary Heart Disease in the Whitehall II Study

Hypertension is assumed to be one of the mechanisms through which job strain (a combination of high work demands and low job control) increases coronary heart-disease risk. However, direct tests of this hypothesis are lacking. We examined whether hypertension mediated the association between job strain and incident coronary heart disease among 5630 men and 2456 women free of coronary heart disease at study entry. Job strain was assessed at phase 1 (1985 to 1988); hypertension and systolic and diastolic blood pressure (BP) were assessed at phases 1, 3 (1992 to 1993), and 5 (1997 to 1999); and incident coronary heart disease was assessed from the end of phase 1 to phase 7 (2003 to 2004) (698 events; median follow-up, 16.1 years). After adjustment for age, sex, ethnicity, and employment grade, job strain was associated with an increased incidence of coronary heart disease. Further adjustments, for hypertension, systolic BP, and diastolic BP at phase 1 and across phases 1, 3, and 5, and the slope of hypertension and BP over time, had little effect on this association, although measures of hypertension and BP were strongly related to incident coronary heart disease. Data, including repeated casual measurements of hypertension and BP, suggest that the development of chronic hypertension is not a key mechanism linking job strain and coronary heart disease. Further research on ambulatory measurements is needed to determine whether episodic BP elevations have a role in this association.

Negative Aspects of Close Relationships and Heart Disease

The aims of the study were to (1) analyze the association between negative aspects of close relationships and increased risk for coronary heart disease and (2) examine whether the association is stronger among women and people of lower social position. Prospective cohort study of 9011 British civil servants (6114 men and 2897 women). Negative aspects of close relationships and other social support measures (confiding/emotional and practical) were assessed with the Close Persons Questionnaire during phase 2 (1989-1990) or phase 1 (1985-1988). Associations between negative aspects of close relationships and incident coronary events were determined during an average follow-up period of 12.2 years. Covariates included sociodemographic characteristics (age, sex, marital status, and employment grade), biological factors (obesity, hypertension, diabetes mellitus, and cholesterol level), psychosocial factors (negative affectivity, depression, and work stress), and health behaviors (smoking, alcohol intake, exercise, and fruit and vegetable consumption). After adjustment for sociodemographic characteristics, biological factors, and other dimensions of social support, individuals who experienced negative aspects of close relationships had a higher risk of incident coronary events (hazard ratio, 1.34; 95% confidence interval, 1.10-1.63). The association was attenuated but remained statistically significant after additional adjustment for negative affectivity and depression (hazard ratio, 1.25; 95% confidence interval, 1.02-1.55). Although women and men in a lower employment grade were more likely to be exposed to negative aspects of close relationships, sex and social position had no statistically significant interaction effects. Confiding/emotional and practical support were not associated with incident coronary events. Adverse close relationships may increase the risk of heart disease.

Dietary glycemic index and glycemic load are associated with high-density-lipoprotein cholesterol at baseline but not with increased risk of diabetes in the Whitehall II study

Background: Findings of the effect of dietary glycemic index (GI) and glycemic load (GL) on the risk of incident diabetes are inconsistent.Objective: We examined the associations of dietary GI and GL with clinical variables at baseline and the incidence of diabetes.Design: The 7321 white Whitehall II participants (71% men) attending screening in 1991–1993, free of diabetes at baseline, and with food-frequency questionnaire data were followed for 13 y.Results: At baseline, dietary GI and GL were associated inversely with HDL cholesterol, and GI was associated directly with triacylglycerols. Dietary GI and GL were related inversely to fasting glucose and directly to 2-h postload glucose, but only the association between GI and 2-h postload glucose was robust to statistical adjustments for employment grade, physical activity, smoking status, and intakes of alcohol, fiber, and carbohydrates. High-dietary GI was not associated with increased risk of incident diabetes. Hazard ratios (HRs) across sex-specific tertiles of dietary GI were 1.00, 0.95 (95% CI: 0.73, 1.24), and 0.94 (95% CI: 0.72, 1.22) (adjusted for sex, age, and energy misreporting; P for trend = 0.64). Corresponding HRs across tertiles of dietary GL were 1.00, 0.92 (95% CI: 0.71, 1.19), and 0.70 (95% CI: 0.54, 0.92) (P for trend = 0.01). The protective effect on diabetes risk remained significant after adjustment for employment grade, smoking, and alcohol intake but not after further adjustment for carbohydrate and fiber intakes.Conclusion: The proposed protective effect of low-dietary GI and GL diets on diabetes risk could not be confirmed in this study.

Burying the Evidence: How Great Britain is Prolonging the Occupational Cancer Epidemic

The U.K. authorities are failing to acknowledge or deal effectively with an epidemic of work-related cancers. The government's Health and Safety Executive (HSE) underestimates the exposed population, the risks faced as a result of those exposures, and the potential for prevention. The HSE fails to acknowledge the social inequality in occupational cancer risk, which is concentrated in manual workers and lower employment grades, or the greater likelihood these groups will experience multiple exposures to work-related carcinogens. It continues to neglect the largely uninvestigated and unprioritized risk to women and currently has neither a requirement nor a strategy for reducing the numbers and volumes of cancer-causing substances, processes, and environments at work. The result is that the U.K. faces at least 20,000 and possibly in excess of 40,000 new cases of work-related cancer every year, leading to thousands of deaths and an annual cost to the economy of between pounds 29.5bn and pounds 59bn. This paper outlines flaws in the HSE's approach and makes recommendations to address effectively the U.K.'s occupational cancer crisis.

Effort–reward imbalance and relational injustice at work predict sickness absence: The Whitehall II study

Objectives Sickness absence is a major occupational health problem, but evidence for associations between potentially modifiable psychosocial work factors and sickness absence is still scarce. We studied the impact of relational justice and effort–reward imbalance on subsequent rates of sickness absence. Methods The Whitehall II prospective cohort study of British civil servants, 10,308 men and women, was established between 1985 and 1988. Indicators of effort–reward imbalance and the relational component of organizational justice were constructed from questions included at baseline. Participants were classified into three groups (low, intermediate, and high) for both effort–reward imbalance and relational justice. Short (≤7 days) and long (>7 days) spells of sickness absence during 1985–1989 and 1991–1995 were used to study immediate and longer term effects of work characteristics. Results After adjustment for age, employment grade, and baseline health, men and women with low relational justice had increased risks of long spells of sickness absence of 14% and 28% in comparison to men and women experiencing high levels of justice. Similar effect sizes (25% and 21%) were found for high vs. low effort–reward imbalance. Both work measures also predicted short spells of sickness absence. Effort–reward imbalance (men and women) and relational justice (women only) each predicted long spells of sickness absence independently of the other. Conclusions Both relational justice and effort–reward imbalance are important determinants of sickness absence. Workplace interventions to improve these aspects of working conditions have the potential to reduce levels of sickness absence.

Unfairness and the social gradient of metabolic syndrome in the Whitehall II Study

Objectives Little work has investigated the relationship between unfairness and risk factors for heart disease. We examine the role of unfairness in predicting the metabolic syndrome and explaining the social gradient of the metabolic syndrome. Methods The design is a prospective study with an average follow-up of 5.8 years. Participants were 4128 males and 1715 females of 20 civil service departments in London (Whitehall II study). Sociodemographics, unfairness, employment grade, behavioral risk factors, and other psychosocial factors were measured at baseline (Phase 3, 1991–1993). Waist circumference, triglycerides, high-density lipoprotein (HDL) cholesterol, fasting glucose, and hypertension were used to define metabolic syndrome at follow-up (Phase 5, 1997–2000), according to the National Cholesterol Education Program/Adult Treatment Panel III guidelines. Results Unfairness is positively associated with waist circumference, hypertension, triglycerides, and fasting glucose and negatively associated with serum HDL cholesterol. High levels of unfairness are also associated with the metabolic syndrome [odds ratio (OR)=1.72, 95% CI=1.31–2.25], after adjustment for age and gender. After additional adjustment for employment grade, behavioral risk factors, and other psychosocial factors, the relationship between high unfairness and metabolic syndrome weakened but remained significant (OR=1.37, 95% CI=1.00–1.93). When adjusting for unfairness, the social gradient of metabolic syndrome was reduced by approximately 10%. Conclusion Unfairness may be a risk factor for the metabolic syndrome and its components. Future research is needed to study the biological mechanisms linking unfairness and the metabolic syndrome.

Association Between Physical Fitness, Parasympathetic Control, and Proinflammatory Responses to Mental Stress

To examine the association between physical fitness, cardiac parasympathetic control, and inflammatory cytokine responses to mental stress. Exercise and physical fitness may act as a buffer to the detrimental effects of psychosocial stress exposure. Participants were 207 men and women (52 +/- 3 years) drawn from the Whitehall II epidemiological cohort. Participants completed two mental stressors consisting of a 5-minute Stroop task and a 5-minute mirror tracing task. Blood samples were obtained during baseline and 45 minutes post stress. Heart rate variability (HRV) was measured during baseline, stress, and recovery. Physical fitness was assessed from a submaximal exercise test. Interleukin (IL)-6 and IL-1 receptor antagonist were increased significantly at 45 minutes post stress. Multiple linear regression analysis, adjusted for age, body mass index, gender, smoking, alcohol, grade of employment, and basal levels of inflammatory markers demonstrated that exercise heart rate (a fitness indicator) was related to IL-6 (beta = 0.24; p = .005) and tumor necrosis factor (TNF)-alpha responses to stress (beta = 0.27; p = .002). Exercise heart rate was also related to the HRV response to stress (beta = -0.23; p = .02). A higher systolic blood pressure response to exercise was a predictor of TNF-alpha responses to stress (beta = 0.18; p = .03). Physical fitness (as indexed by lower exercise heart rate) is associated with smaller inflammatory cytokine responses to acute mental stress, an effect that may be partly mediated through parasympathetic pathways. This may be one of the mechanisms by which physical fitness confers protection against cardiovascular risk.

Adult socioeconomic position, C-reactive protein and interleukin-6 in the Whitehall II prospective study

Prior studies on the association of inflammatory markers, such as C-reactive protein (CRP) and interleukin-6 (IL-6), with socioeconomic position (SEP) have been cross-sectional. Thus, the question of whether socioeconomic differences in CRP and IL-6 change over time remains unanswered. We examined the relationship between SEP and changes over 12 years in CRP and IL-6. Data were for 4,750 middle-aged (mean 49.0 years, SD 5.9) civil servants from phases 3 and 7 of the Whitehall II study. Adult SEP was based on last known Civil Service employment grade. Covariates included sociodemographics, behavioural and biological risk factors, presence of diseases/illnesses, prescribed medications, work-related factors, labour market status and early life factors. Steep socioeconomic gradients observed at Phase 3 (p < 0.001) persisted in both CRP and IL-6 12 years later after adjustment for other risk factors. Adjustment for behavioural (diet and smoking), biological (mainly body mass index and total : HDL cholesterol ratio) and early life factors resulted in considerable attenuation but the inverse socioeconomic gradients remained statistically significant. Although CRP and IL-6 concentrations increased substantially over the 12-year period at every level of SEP, CRP and IL-6 did not change differentially according to SEP. Despite overall increases in CRP and IL6, relative differences by SEP remained unchanged so that socioeconomic gradients in both sexes persisted over the period observed.

Association between sleep quality and smoking in Japanese civil servants

The association between smoking and sleep quality was investigated in a sample of 1439 Japanese civil servants. In this cross-sectional survey, the questionnaire used included items on the Pittsburgh sleep quality index (PSQI), smoking status (current, ex- and non-smoker), smoking intensity, grade of employment, physical activity, alcohol consumption, longstanding illness and work characteristics. A general linear model analysis was undertaken to assess the association between smoking status and components of sleep quality. Multiple logistic analysis was used to evaluate the relations between smoking status and smoking intensity with poor sleep in men and women, separately. Significant associations were found between smoking status and components of sleep quality, such as subjective sleep quality and sleep latency in men, as well as sleep latency and sleep medication use in women. The global PSQI score was significantly higher (lower sleep quality) in male ex-smokers versus non-smokers and in female current smokers versus non-smokers. Male current smokers smoking 21–40 cigarettes/day and ex-smokers presented a significantly increased prevalence of poor sleep: adjusted odds ratios (OR) were 1.54 (1.01–2.36) and 2.01 (1.20–3.37), respectively. But in women, only current smokers were associated with a high prevalence of poor sleep: adjusted OR was 2.68 (1.23–5.84). Sleep quality is therefore affected not only by smoking but also by the process of smoking cessation in men. These results suggest that a special attention should be paid to smoking habits in dealing with poor sleep quality.

BMI, Obesity, and Sickness Absence in the Whitehall II Study

To study BMI and change in BMI from age 25 as predictors of sickness absence. 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). After adjustment for employment grade, health-related behaviors, and health status, overweight (BMI = 25.0 to 29.9 kg/m(2)) and obesity (BMI > 30.0 kg/m(2)) 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/m(2). Additionally, a BMI of 23.0 to 24.9 kg/m(2) at Phase 1 predicted long absences in women, and underweight (BMI < 21.0 kg/m(2)) 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). 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.

Socioeconomic status, pathogen burden and cardiovascular disease risk

Objective:Socioeconomic status (SES) is inversely associated with coronary heart disease (CHD) risk. Cumulative pathogen burden may also predict future CHD. The hypothesis was tested that lower SES is associated with...

Walking, Vigorous Activity, and Markers of Haemostasis and Inflammation in Healthy Men and Women

The impact of walking on cardiovascular health, as compared with vigorous physical activity, remains controversial. Regular physical activity is related to lower levels of haemostatic and inflammatory markers although the role of exercise intensity is undetermined. PURPOSE: To examine whether there is an independent association between walking and markers of haemostasis and inflammation after controlling for vigorous physical activity. METHOD: Participants were 227 men and women (52 ± 3 yrs) drawn from the Whitehall II epidemiological cohort, which is a prospective study of British civil servants. Blood was drawn for the assessment of von Willebrand factor antigen (vWF), fibrinogen, interleukin (IL)-6, IL-1 receptor antagonist (IL-1ra), and tumour necrosis factor-α (TNF-α). Self-reported levels and types of physical activity were recorded, including time spent walking per week and frequency of participation in vigorous physical activity. RESULTS: Multiple linear regression analyses, adjusted for age, body mass index, gender, smoking, alcohol, grade of employment, and frequency of vigorous physical activity revealed that time spent walking was independently related to vWF (β = −.14, p = .04), fibrinogen (β =−.13, p = .03), and TNF-α (β =−.14, p = .05). CONCLUSION: Regular walking is associated with lower levels of some haemostatic and inflammatory markers independently of vigorous physical activity in healthy men and women.