Tag Archives: Inflammatory markers

Who suffers most from the health effects of long-term work stress?

As populations across the developed world grow older, Governments are keen to find ways to enable workers to stay active and fit for longer. We know work-related stress can lead to long-term health problems: but which types of employment histories are particularly harmful, and how do the effects play out over time? A new study by Morten Wahrendorf, Tarani Chandola and colleagues points to a need for early intervention with disadvantaged groups of workers.

Most studies on occupational stress focus on a particular point in time. But what if the effects of troubled working lives build up over many years, in terms of adverse employment trajectories over an extended time period? Some workers suffer repeated periods of unemployment throughout their working lives, for instance. We wanted to know how different types of work histories might be linked to health problems in later life.

We were able to examine these questions using data from the French CONSTANCES cohort study, which allowed us to combine information on participants’ employment histories from age 25-45 with health-related information.

Can stressful working lives lead to health issues over a long period? To address this question, we looked at a sub-sample of just over 90,000 people of the CONSTANCES study who had been in work between the ages of 25 and 45, and who had not had to leave work or take a break due to ill health during that period.

The information we had included the numbers of temporary jobs participants held and the number of job changes they had; how many times they were unemployed and how long they spent out of work. We could also see what sort of job they had and whether or not they gained promotion – this enabled us to identify if they suffered from job instability or other types of cumulative disadvantage.

Wear and tear

Participants in the study were also asked to fill in health questionnaires as well as undertaking medical examinations and giving blood samples. This enabled us to calculate their ‘allostatic load’ (AL) – a biological measure of the wear and tear on the body (i.e. the damage to the body) which accumulates as an individual is exposed to chronic stress throughout working life. And that is associated with long-term conditions such as heart disease, type-2 diabetes and depression.

In this study we were able to include measures on a total of 10 items to measure allostatic load, including blood pressure, lung function, waist-to-hip ratio, cholesterol levels, kidney function, fasting blood sugar and the immune and inflammatory system.

Men and women were considered separately and we were able to look at whether participants were in a stable relationship as well as their level of education.

Our key findings were as follows:

– Both men and women who suffered disadvantage at work had a higher allostatic load: it was possible to measure physical health effects linked to work stress. Women who had skilled or semi-skilled jobs had a higher load than managers or professionals. Both men and women suffered if they had been out of the labour market for six years or more.

  Men who were rejected for promotion had slightly higher scores, as did women who had a high number of temporary jobs.

  • Frequent job moves were not associated with ill-effects on health: these might be made for positive reasons such as promotion.
  • The effects remained even after we controlled for other career characteristics. They were the same for all the different health indicators we looked at, bar one: kidney function.
  • The impact on health was particularly high for those who had continuously been in low-skilled, high-stress types of work, with repeated or lengthy periods of unemployment.

Adversity

Our study suggests that people who suffer adversity in their working lives over an extended period are more likely to suffer long-term health conditions in later life. It underlines the importance of those links between chronic work stress and disease. 

The potential benefits of promoting healthy work conditions, particularly among more disadvantaged groups and at early stages of their working lives, are clear from this study. The potential benefits will support both employees, in helping them to stay healthy for longer, and employers, who could cut rates of sickness and retirement through ill-health.

Adverse employment histories and allostatic load: associations over the working life is by Morten Wahrendorf , Tarani Chandola , Marcel Goldberg, Marie Zins, Hanno Hoven and Johannes Siegrist, and is published in the Journal of Epidemiology and Community Health.

Work and family – how it affects our health

How our working and family lives affect our health as we get older is of increasing interest to us all. Researchers at the ESRC International Centre for Lifecourse Studies have used the 1958 Cohort Study to look at levels of inflammation (indicators of being at risk of illnesses such as heart disease) and and how people combine their work and family lives to see if any patterns emerge that could tell us more.

In this episode of the ICLS Podcast, Dr Rebecca Lacey explains the background and context of the research and what the team has found.

You can also listen to a policy seminar talk about the research.

Can unemployment kill?

At the height of the recent recession around 2.7 million people were unemployed, and youth unemployment accounted for nearly 40 per cent of that total. Given growing evidence that unemployment is linked to long term illness and increased mortality, we can expect health implications for those affected. In a week when unemployment rose for the first time in over a year, Amanda Hughes presents new evidence from the ESRC International Centre for Lifecourse Studies on the links between unemployment and killer diseases such as heart disease.

In 1984 a study was published which had linked census data to mortality records and found that men unemployed in the week of the 1971 census were 36 per cent more likely to have since died than men of the same age who had been in work. Accounting for differences in social background only explained part of the excess, raising the question: can unemployment kill, and if so how?

That unemployment might damage health was not a new idea. Marie Jahoda’s research on unemployment in the 1930s had shown that the non-financial benefits of work, such as defining aspects of status and identity and providing regular social contact, are for many people crucial to mental wellbeing. And since job loss usually brings a sharp drop in income, it is intuitive that unemployment could affect physical health by reducing quality of diet or opportunities for exercise.

But there tends to be more scepticism as to whether serious physical illness or mortality could be causally influenced by the undoubtedly stressful experience of unemployment. Might those unemployed men have developed serious illness when employed, lost their jobs as a result, and then died from their illness? Or might their increased mortality simply be caused by unemployed people smoking and drinking more? In neither case could it be claimed that unemployment itself has caused any deaths.

New approach

Since the 1980s, the tools available to scientists researching the health impacts of social conditions have moved on considerably. One new approach involves molecules called ‘inflammatory markers’ which circulate in the bloodstream and appear to be influenced by stressful experiences.

Elevated concentrations have been found in the recently bereaved and caregivers; inflammatory markers are also typically higher for people of disadvantaged socioeconomic position as measured by income or occupational social class. Crucially, raised concentrations of these molecules are linked to atherosclerosis and predict heart disease, presenting a possible causal pathway between a stressful social environment and increased mortality.

It was for this reason that we wanted to see if two inflammatory markers – C-reactive protein and fibrinogen – were elevated in jobseekers compared to employed counterparts.

We used the Health Survey for England and Scottish Health Survey, annual government surveys used to track changes in the health of both countries’ populations. To isolate elevations in these molecules due to unemployment-related stress, we considered a number of additional factors beyond participants’ age and gender.

To rule out elevations due to serious illness predating job loss, we considered whether participants had a long-term illness of any type. To rule out elevations caused by disadvantaged socioeconomic position more generally, we took into account housing tenure and occupational social class from current or most recent job.

Finally, to test whether elevations might be explained by worse health-related behaviours of jobseekers, we took into account participants’ smoking, alcohol consumption and body mass index.

Stress markers

In our sample of over 23,000 men and women of working age, unemployed people had elevated circulating levels of both molecules even after consideration of these factors. These differences were moreover clinically relevant, since unemployed participants were 40 per cent more likely to have C-reactive protein over 3mg/L, the level at which cardiovascular risk becomes elevated.

Effects were not uniform across the population. Firstly, older jobseekers (48-64) were more affected than younger jobseekers. This might indicate that unemployment is more stressful for jobseekers facing age discrimination, or equipped with outdated skills.

Since older jobseekers will have accumulated more unemployment over their lifetimes than younger counterparts, it could alternatively indicate that long-term or repeated unemployment is especially damaging to this aspect of health.

Secondly, we found substantial differences in results by country, with much greater elevations in both molecules for jobseekers in Scotland than in England. Data from the Labour Force Survey and the British Household Panel Study show that during the years of data collection (1998-2010) unemployment was higher in Scotland than England, and unemployment spells on average longer, which suggests two possible explanations.

Firstly, the jobseekers in Scotland may have been unemployed for longer, or had more recent unemployment spells, than English counterparts. Secondly, unemployment could be more stressful in times and places where the background rate is higher, since jobseekers will rationally perceive their prospects for re-employment as worse.

Since these surveys only collect information from people at one point in time, it was not possible in this analysis to investigate effects in the context of people’s employment histories. But unpicking these explanations will be crucial if we are to better understand the conditions under which unemployment is most likely to damage health, and which groups are most at risk.

Crucially, given last week’s news of a 21,000 rise in unemployment for the first time in a year  to 1.7 million people, policy makers interested in the long term health of the population should not divert their gaze from its wider consequences.

Photo credit: Kate Hiscock

Further information

Amanda Hughes is a Senior Research Officer at the Institute for Social and Economic Research at the University of Essex.

Elevated inflammatory biomarkers during unemployment: modification by age and country in the UK is research by Amanda Hughes, Anne McMunn, Mel Bartley and Meena Kumari and is published in the Journal of Epidemiology and Community Health.

References

Unemployment and mortality in the OPCS Longitudinal study is research by K.A Moser, A.J Fox, and D.R. Jones, and is published in the Lancet.

Unemployment durations: evidence from the British Household Panel Survey is research by K. Long and is published in Economic & Labour Market Review.