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Biomedical subjects

Martin J Shipley

Publications and source records attributed to Martin J Shipley.

At least 19 recordsLinked to original sources
PubMed2006

Adult height and lung function as markers of life course exposures: associations with risk factors and cause-specific mortality.

BACKGROUND AND OBJECTIVE: Pulmonary function and height may be regarded as adult indices of exposures accumulated across the entire life course and in early life, respectively. As such, we hypothesised that pulmonary function would be more strongly related to mortality than height. Studies of the association of height and lung function with mortality--which are currently modest in number--will clarify the relative utility of these risk indices and the mechanisms underlying observed patterns of disease risk. DESIGN, SETTING, AND PARTICIPANTS: Data were drawn from the Whitehall study, a prospective cohort study of 18,403 middle-aged non-industrial London-based male government employees conducted in the late 1960s. Data were collected on stature, spirometry measures (including forced expiratory volume in one second [FEV1]) and a range of covariates. These analyses are based on the 3083 non-smoking men with complete data. MAIN OUTCOME MEASURES: Mortality ascribed to all-causes, cardiovascular disease, respiratory disease and site-specific cancers. RESULTS: Both height and FEV1 were associated with a range of physiological, behavioural and socio-economic risk factors. Relations with these risk factors were seen more frequently for FEV1 and, where they occurred, were of somewhat higher magnitude. During a maximum of 35 years follow-up, half the non-smokers had died (n = 1545). FEV1 (HR(per one SD increase); 0.89; 0.84, 0.95) was somewhat more strongly related to total mortality than height (0.96; 0.91, 1.01) in a fully adjusted model, but this difference did not attain statistical significance at conventional levels (p-value for difference = 0.15). Of the eight independent disease-specific outcomes examined, the only convincing evidence of a differential effect was for deaths from respiratory causes which was unsurprisingly more strongly related to FEV1 than height (p-value for difference = 0.03). CONCLUSIONS: In the present study, height and FEV1 were essentially similarly related to both risk factors and mortality outcomes, thus not providing support for our hypothesis. Both factors would appear to have some utility as markers of early life exposures.

Body Height↗
PubMed2006

Birth weight, components of height and coronary heart disease: evidence from the Whitehall II study.

BACKGROUND: Previous studies have suggested that shorter leg length, not trunk length, may explain the inverse association between height and coronary heart disease (CHD) risk. However, investigation of the importance of birth weight for these associations has been limited. This study examines associations of measures of stature and birth weight with CHD risk factors (measures of blood pressure and lipids, 2 h glucose, waist-hip ratio and fibrinogen) and incident non-fatal coronary events in middle age. METHODS: Data were derived mostly from the Phase 5 (1997-99) clinical screening of the Whitehall II study of British civil servants. The main cross-sectional analyses included 1084 women and 2290 men with complete data. RESULTS: In women total height and leg length were the measures that tended to be most strongly associated with CHD risk factors, while in men leg length demonstrated the closest associations. Although associations between trunk length and CHD risk factors were weaker, trunk length was the component of height that appeared to be most closely associated with coronary events. Associations between birth weight and CHD risk factors and coronary events were generally weaker than for any measure of stature. Adjustment for birth weight had little effect on associations between components of stature and CHD risk factors or events. CONCLUSION: Findings from this relatively privileged cohort confirmed that shorter leg length underlies the inverse association between height and CHD risk factors in middle-aged women and men. Furthermore, in this study population shorter trunk length was more closely associated with incident, non-fatal coronary events.

Adult↗
PubMed2006

Relation between blood glucose and coronary mortality over 33 years in the Whitehall Study.

OBJECTIVE: Glucose intolerance is a risk factor for coronary disease, but there is uncertainty about the shape of the dose-response relationship between glucose level and risk of coronary mortality. We examined the prospective relation of 2-h postload blood glucose (2hBG) with coronary and other major causes of mortality over 33 years. RESEARCH DESIGN AND METHODS: A 50-g oral glucose tolerance test (OGTT) was performed at baseline (1967-1969) in 17,869 male civil servants aged 40-64 years. RESULTS: There were 3,561 coronary deaths during 451,787 person-years of observation. All-cause, cardiovascular, and respiratory mortality were elevated among participants with glucose intolerance. The hazard of coronary mortality rose from 2hBG = 4.6 mmol/l (83 mg/dl [95% CI 4.2-5.3]). The dose-response relation was best fitted by a single slope above this level, with no evidence of nonlinearity, compared with Cox models using other threshold levels, and those containing log 2hBG terms. There was no evidence for a dose-response relationship below 2hBG = 4.6 mmol/l. Between this level and 11.1 mmol/l (200 mg/dl), the age-adjusted hazard ratio was 3.62 (95% CI 2.3-5.6). The graded relationship was attenuated by 45% after adjustment for baseline coronary heart disease (CHD), BMI, systolic blood pressure, blood cholesterol, smoking, physical activity, lung function, and employment grade. CONCLUSIONS: A threshold model with linear slope best described the dose-response relationship between postload blood glucose and CHD mortality risk.

Adult↗
PubMed2005

Cause-specific mortality in old age in relation to body mass index in middle age and in old age: follow-up of the Whitehall cohort of male civil servants.

BACKGROUND: The relevance of body mass index (BMI) to cause-specific mortality in old age is uncertain. OBJECTIVES: To examine cause-specific 5 year mortality in old age by BMI in old age and middle age (40-69 years). METHODS: Cox proportional hazards for mortality rates among 4862 former male civil servants in relation to quartiles of BMI measured when screened in 1968-70 and when resurveyed in 1997-98 (median age 76 years). RESULTS: The association between all-cause mortality after resurvey and BMI in old age was U-shaped with hazard ratios (HRs) of 1.3 (95% CI 1.1-1.5) for the lightest and heaviest categories relative to the middle two. Among 'healthy' men the lightest (<22.7 kg/m2) had greatest all-cause mortality. The heaviest men (>26.6 kg/m2) had increased risk of cardiovascular disease (CVD) mortality in the first two years or for the whole period if never-smokers. Respiratory mortality was inversely associated with BMI in old age [adjusted HR for trend per BMI category increase 0.6 (0.5-0.7)] but cancer mortality lacked a clear pattern. Net gain or loss of 10 kg or more between middle and old age was a strong predictor of all-cause and CVD mortality. CONCLUSIONS: The shape of the association between BMI in old age and mortality differs by cause of death. Major weight change over time is a warning signal for higher CVD mortality. Having BMI<22.7 kg/m2 in old age is associated with above-average mortality rates even if apparently healthy.

Aged↗
PubMed2005

Justice at work and reduced risk of coronary heart disease among employees: the Whitehall II Study.

BACKGROUND: Justice is a fundamental value in human societies, but its effect on health is poorly described. We examined justice at work as a predictor of coronary heart disease (CHD). METHODS: Prospective occupational cohort study of 6442 male British civil servants aged 35 to 55 years without prevalent CHD at baseline in phase 1 (1985-1988). Baseline screening included measurements of conventional risk factors. Perceived justice at work and other work-related psychosocial factors were determined by means of questionnaire at phases 1 and 2 (1989-1990). Follow-up for CHD death, first nonfatal myocardial infarction, or definite angina occurring from phase 2 through 1999 was based on medical records (mean follow-up, 8.7 years). RESULTS: Cox proportional hazard models adjusted for age and employment grade showed that employees who experienced a high level of justice at work had a lower risk of incident CHD than employees with a low or an intermediate level of justice (hazard ratio, 0.65; 95% confidence interval, 0.47-0.89). The hazard ratio did not materially change after additional adjustment for baseline cholesterol concentration, body mass index, hypertension, smoking, alcohol consumption, and physical activity. Although other psychosocial models such as job strain and effort-reward imbalance predicted CHD in these data, the level of justice remained an independent predictor of incident CHD after adjustment for these factors. CONCLUSION: Justice at work may have benefits for heart health among employees.

Adolescent↗
PubMed2005

Work, retirement and physical activity: cross-sectional analyses from the Whitehall II study.

BACKGROUND: To explore the relationship between work, retirement and physical activity. METHODS: Cross-sectional analyses of data from self-completed questionnaires by 6224 civil servants aged 45-69 years participating in phase 5 of the Whitehall II longitudinal study. RESULTS: There appeared to be a dose-response relationship between hours worked and the prevalence of physical activity, with a lower prevalence of recommended physical activity amongst participants working full time (> or =30 h/week), higher prevalence rates amongst those working part time (<30 h/week), and the highest rates amongst participants who were not working at all. Physical activity rates did not increase greatly amongst study participants who had retired from the Civil Service but had gone on to do further full-time work, however, the higher physical activity rates of participants working part time, or not at all, were further enhanced amongst those who had also retired. CONCLUSIONS: These findings suggest that full-time work is associated with lower rates of recommended physical activity levels in this cohort of middle-aged white-collar office workers. Lower grade occupations are also less likely to meet the recommended physical activity levels. While retirement is associated with higher rates of recommended physical activity levels, this benefit is evident amongst those who work part time, or not at all, during their retirement, for whom the benefits of retirement and lower working hours on rates of physical activity appear additive. The frequency of different types of physical activity is associated with different occupational grades, with more sport and gardening being done by the higher occupational grades.

Aged↗
PubMed2005

Self-reported job insecurity and health in the Whitehall II study: potential explanations of the relationship.

This paper examines the potential of demographic, personal, material and behavioural characteristics, other psychosocial features of the work environment and job satisfaction to explain associations between self-reported job insecurity and health in a longitudinal study of British white-collar civil servants. Strong associations were found between self-reported job insecurity and both poor self-rated health and minor psychiatric morbidity. After adjustment for age, employment grade and health during a prior phase of secure employment, pessimism, heightened vigilance, primary deprivation, financial security, social support and job satisfaction explained 68% of the association between job insecurity and self-rated health in women, and 36% in men. With the addition of job control, these factors explained 60% of the association between job insecurity and minor psychiatric morbidity, and just over 80% of the association with depression in both sexes.

Adult↗
PubMed2005

Adult socioeconomic position and the association between height and coronary heart disease mortality: findings from 33 years of follow-up in the Whitehall Study.

In the Whitehall Study, which followed 17,139 male civil servants over 33 years, the association between tall stature and coronary heart disease (CHD) mortality differed between employment grades. In men without CHD at study entry, the hazard ratio per 15-cm increase in height was 0.77 (95% confidence interval [CI]=0.69, 0.85; P<0.001) for the highest grades, but 0.84 (95% CI=0.69, 1.03; P=.10) for middle and 0.95 (95% CI=0.75, 1.20; P=.65) for low grades, suggesting that childhood and adult social conditions may interact in their influence on coronary risk.

Adult↗
PubMed2005

Working while ill as a risk factor for serious coronary events: the Whitehall II study.

OBJECTIVES: Although sick, some people take no time off work, a phenomenon called "sickness presenteeism." This study examined the association between sickness presenteeism and incidence of serious coronary events. METHODS: The analyses were based on a cohort of 5071 male British civil servants without previous myocardial infarction. Baseline screening included measurements of health status and coronary risk factors. Absence records were assessed for the 3 years subsequent to baseline screening. The outcome of interest was incident nonfatal myocardial infarction or fatal coronary heart disease (mean length of follow-up=9.1 years). RESULTS: Seventeen percent of unhealthy employees took no absence during the 3-year follow-up. Their incidence of serious coronary events was twice as high as that of the unhealthy employees with moderate levels of sickness absenteeism (after adjustment for conventional risk factors, hazard ratio 1.97, 95% confidence interval=1.02, 3.83). CONCLUSIONS: Employers and employees should be aware of the potential harmful effects caused by sickness presenteeism.

Adult↗
PubMed2004

Diabetes status and post-load plasma glucose concentration in relation to site-specific cancer mortality: findings from the original Whitehall study.

OBJECTIVE: While several studies have reported on the relation of diabetes status with pancreatic cancer risk, the predictive value of this disorder for other malignancies is unclear. METHODS: The Whitehall study, a 25 year follow-up for mortality experience of 18,006 men with data on post-challenge blood glucose and self-reported diabetes, allowed us to address these issues. RESULTS: There were 2158 cancer deaths at follow-up. Of the 15 cancer outcomes, diabetes status was positively associated with mortality from carcinoma of the pancreas and liver, while the relationship with lung cancer was inverse, after controlling for a range of potential covariates and mediators which included obesity and socioeconomic position. After excluding deaths occurring in the first 10 years of follow-up to examine the effect of reverse causality, the magnitude of the relationships for carcinoma of the pancreas and lung was little altered, while for liver cancer it was markedly attenuated. CONCLUSIONS: In the present study, diabetes status was related to pancreatic, liver, and lung cancer risk. Cohorts with serially collected data on blood glucose and covariates are required to further examine this area.

Blood Glucose↗
PubMed2004

Organisational justice and change in justice as predictors of employee health: the Whitehall II study.

OBJECTIVE: Organisational justice has been proposed as a new way to examine the impact of psychosocial work environment on employee health. This article studied the justice of interpersonal treatment by supervisors (the relational component of organisational justice) as a predictor of health. DESIGN: Prospective cohort study. Phase 1 (1985-88) measured relational justice, job demands, job control, social support at work, effort-reward imbalance, and self rated health. Relational justice was assessed again at phase 2 (1989-90) and self rated health at phase 2 and phase 3 (1991-93). SETTING: 20 civil service departments originally located in London. PARTICIPANTS: 10 308 civil servants (6895 men, 3413 women) aged 35-55. OUTCOME MEASURE: Self rated health. MAIN RESULTS: Men exposed to low justice at phase 1 or adverse change in justice between phase 1 and phase 2 were at higher risk of poor health at phase 2 and phase 3. A favourable change in justice was associated with reduced risk. Adjustment for other stress indicators had little effect on results. In women, low justice at phase 1 predicted poor health at phase 2 and phase 3 before but not after adjustment for other stress indicators. Adverse change in justice was associated with worse health prospects irrespective of adjustments. CONCLUSIONS: The extent to which people are treated with justice in workplaces seems to predict their health independently of established stressors at work. Evidence on reduced health risk after favourable change in organisational justice implies a promising area for health interventions at workplace.

Adult↗
PubMed2003

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.

Adult↗
PubMed2003

Future uncertainty and socioeconomic inequalities in health: the Whitehall II study.

Over the past 20 years, socioeconomic inequalities in mortality have widened, while job security and financial security have decreased. This paper examines the Whitehall II study, a longitudinal study of white-collar British civil servants. In the Whitehall II cohort socioeconomic gradients in morbidity and cardiovascular risk factors at Phase 5 (1997-99) were generally steeper than at Phase 1 (1985-88). We examine the contribution of job and financial insecurity to these at Phase 5 in 6770 women and men, all of whom were white-collar civil servants at Phase 1. Steep, inverse employment grade gradients were observed for all health measures at Phase 5, except cholesterol and systolic blood pressure in women. Gradients in the sub-population of non-employed participants tended to be steeper than gradients for participants in employment, although, with the exception of self-rated health and General Health Questionnaire (GHQ) score in men, differences were non-significant. Steep gradients in job insecurity were observed among employed participants (p<or=0.01), and in financial insecurity among both employed and non-employed participants (p<or=0.001), particularly non-employed men. With the exception of depression, adjustment for job insecurity had little effect on the employment grade gradients in morbidity. However, financial insecurity contributed substantially to gradients in self-rated health, longstanding illness, and depression in both employed and non-employed men, and additionally to GHQ score and diastolic blood pressure in the latter. Adjustment for financial insecurity in non-employed women substantially attenuated gradients in self-rated health, GHQ score and depression. These findings imply that the specific effects of job insecurity in this cohort may be less important than the more general effects of financial insecurity in determining inequalities in health.

Adult↗
PubMed2003

Leisure time physical activity and coronary heart disease mortality in men symptomatic or asymptomatic for ischaemia: evidence from the Whitehall study.

BACKGROUND: Although numerous studies have shown an association between physical activity and coronary heart disease (CHD) mortality in healthy persons, few have reported on this relation in individuals with pre-existing diseases, such as ischaemia. Further, we are unaware of any study to examine if this relationship is modified by the symptomatic nature of the ischaemia. METHODS: To explore these issues, we analysed data from a 25 year follow-up of mortality for 6474 male British civil servants who underwent a resting electrocardiogram and responded to queries regarding angina at study entry. RESULTS: Among men who had ECG abnormalities but no angina (i.e. asymptomatic), activity was associated with a higher rate of CHD mortality. Among men with both angina and ECG abnormalities (i.e. symptomatic), activity was associated with lower CHD mortality but this was not statistically significant at conventional levels. CONCLUSIONS: In the present study, there was a suggestion that the symptomatic nature of ischaemia appeared to modify the effect of physical activity on total and CHD mortality. Although these findings should be examined in other studies, they point to the need for a pre-participation medical examination in active persons or those contemplating embarking on an activity programme.

Adult↗
PubMed2003

Leisure time physical activity and disease-specific mortality among men with chronic bronchitis: evidence from the Whitehall study.

OBJECTIVES: This study examined the association between leisure time physical activity and cause-specific mortality among male Whitehall Study participants with chronic bronchitis. METHODS: Rate ratios were calculated for 4 mortality outcomes, according to level of activity and baseline bronchitis status, in a 25-year follow-up of 6479 men. RESULTS: After multiple adjustment for potential confounding or mediating variables, activity was inversely related to all-cause, cardiovascular, coronary heart disease, and noncardiovascular mortality among men free of chronic bronchitis. Among men with bronchitis, weak, nonsignificant positive associations were observed between activity and these outcomes, with the exception of noncardiovascular mortality. CONCLUSIONS: The suggestion of a positive activity-mortality association among individuals with chronic bronchitis-albeit weak and nonsignificant-requires further investigation.

Bronchitis, Chronic↗
PubMed2002

Can cardiovascular risk factors explain the association between education and cardiovascular disease in young women?

We sought to explain the observed variation in the relationship between education and cardiovascular disease (CVD) among young women in countries at different stages of economic development. Data comprised 2,478 cases of acute myocardial infarction (AMI) or stroke and 6,819 age-matched controls from Africa, Asia, Eastern Europe, and Latin America. The risks of AMI associated with lower education observed in Eastern Europe and higher education in non-European countries were reduced by 92% in Eastern Europe and totally abolished in non-European countries by adjustment for standard cardiovascular risk factors. The inverse associations between education and stroke risk in the three non-African regions were attenuated by 22, 47, and 60% after adjustment. In Africa, the slight inconsistent trend towards lower stroke risk in less well educated women was unaffected by adjustment. These data suggest that standard risk factors explain a substantial proportion if not all of the difference in AMI risk associated with education but a lesser proportion of educationally linked stroke risk.

Adult↗