Tag Archives: Cortisol

Work stress and ill health – what’s the link?

Lots of studies have suggested stress can be a cause of ill health – and that leads to people ceasing to work before they reach retirement age. But most have offered only a snapshot on the issue. José Ignacio Cuitún Coronado and  Tarani Chandola from the University of Manchester describe a major new study, which has shed new light on how work stress can affect an employee’s health over a longer period.

Many animals have the ability to adapt to environmental changes and pressures so that they’re better prepared the next time they happen. Bears can put on fat as winter approaches, for instance, to help them stave off hunger and stay warm.

And human beings can do this too. Stressful situations trigger chemical responses which can help to give us extra resources when things are tough. Our neuroendocrine systems, for instance, trigger hormonal responses which enhance our physical performance when we need it most.

But these valuable systems can have a down-side. In our research, we wanted to look at how repeated exposure to stressful situations might contribute to health problems, particularly in people nearing the end of their working lives. We call this stress-induced effect ‘Allostatic Load’ – the wear and tear” on the body that accumulates as an individual is exposed to repeated or chronic stress because of fluctuating hormonal responses.

Given that many governments are looking for ways to extend working lives, there’s particular interest in finding out how stress can affect the health of older workers. We were able to tap into a rich source of information – the English Longitudinal Study of Ageing (ELSA), which has followed a representative sample of almost 10,000 over-50s since 2002.

These participants have been interviewed regularly and one of the things they’ve been asked to report is whether they’ve experienced a sense of imbalance between the effort they put into their jobs and the rewards they get out.

This gave us a sample of 2663 older adults, all over 50 and living in England, who’d reported these feelings at least once and who’d been assessed as having had an adverse reaction to them. We wanted to know whether repeated episodes had a bigger effect than just one, and whether the effect would be just as strong for past episodes as it was for more recent ones.

Health testing

Between 2004-5 and 2014-16 the group were asked about stress at work, but they also underwent physical tests to see how the various systems in their bodies were bearing up.

They were visited by nurses who carried out a battery of tests including taking hair samples to assess levels of the stress-related hormone cortisol, carrying out blood pressure checks to provide information on their cardio-vascular systems, white blood cell counts to assess their immune systems and cholesterol checks on their metabolic systems. Participants also had measurements taken of their waist to height ratios – a good indicator of coronary heart disease risk factors.

Overall, we found the more occasions of work-stress a participant had reported, the greater their ‘Allostatic Load’ index – that is, the greater the amount of biological wear and tear.

Moreover, the evidence suggests that employees who had experienced stress more recently, towards the end of their working lives, had higher levels of health risk when compared to those who had experienced it earlier in their careers.

This suggests there is an association between repeated reports of stress at work and biological stress mechanisms, which in turn could lead to stress-related disorders such as coronary heart disease, type 2 diabetes or depression. This also suggests that previous cross-sectional studies which reported small or inconsistent associations may have suffered because they were only measuring one effect at one time.

Work-related stress is one of the reasons for labour market exit – and our findings would suggest that earlier, snapshot studies may have underestimated the true effect of work-related stress on health over a lifetime.

As this is an observational study, we cannot make any causal claims. There may be other factors that we have not taken into account that may explain the association between stress and disease risk. For example, sleep problems may be relevant – though they may also be part of the journey from stress to ill-health.

But equally it is possible that cumulative exposure to work stress is resulting in damage to employees’ physical health, which is then leading to disability and an early exit from the world of work. So, if we want to extend working lives then reducing work-related stress could be one of the keys to achieving that goal.

Allostatic Load and Effort-Reward Imbalance: Associations over the Working-Career, by José Ignacio Cuitún Coronado, Tarani Chandola and Andrew Steptoe, is published in the International Journal of Environmental Research and Public Health.

Why retirement might not be as stress-free as you hoped!

Ahhhh retirement: finally time to relax, enjoy life, unwind and feel less stressed. That is certainly how many people will be expecting or hoping that their retirement will pan out when it happens. But research by Tarani Chandola from the University of Manchester and colleagues at UCL and the University of Essex, shows that whilst dreams of a less stressful life in retirement may come true for those in higher status jobs, they are less likely to do so for those in low status occupations. Here he explains the research, which uses innovative methods to see whether retirement really is the stress buster many of us hope it will be.

We have known for some time that people from poorer backgrounds in low status jobs generally have poorer health across their lives and tend to suffer from greater levels of stress. Those health inequalities widen as people get older, but it had been assumed that retirement might see a closing of the gap, because poorer workers have higher levels of work stress, but this appears not to be the case, something that researchers have found hard to explain.

As most countries are now raising retirement age and, with it, the age at which workers can collect their State Pension, it is really important that we understand the impact these policies might have on the health and wellbeing of employees, particularly those in disadvantaged working conditions.

In this research, rather than just making use of self-reported health information from workers, we wanted to get right under their skin to look at what signs of stress there were in their bodies in the run up to and after retirement. We wanted to compare the stress levels of those who had just retired to those still in work and we also wanted to compare the stress levels of workers in high and low grade jobs.

We were able to do this by looking at the changing levels of a stress related hormone called cortisol.

Whitehall Study

Our information came from The Whitehall Study, which has tracked the working lives of thousands of UK civil servants since the 1980s. As well as being a good fit for the research because of the type of information available, using a longitudinal survey like this enabled us to observe the same people over this important period of in their lives.

We focused on just over 1000 of the study’s participants who were aged around 60 and who, as part of the Study, provided a series of saliva samples across a day. Using these saliva samples, we could measure their changing levels of cortisol over the day. Waking up in the morning results in the release of cortisol, which declines to almost negligible levels by bedtime. The steeper the declines in a person’s cortisol measurement across the day, the less stressed they were. People with relatively higher levels of cortisol at bedtime are more stressed and have a flatter rate of decline of cortisol.

Their employment grade was categorised as ‘high’, middle or ‘low’ according to the civil service banding system.

Civil servants who were employed in the lowest status jobs had the highest levels of stress, whilst those in the highest status jobs were the least stressed. We could also see that, after retirement, when we might have expected biological stress levels to fall for all the workers, this was only the case for those in the top jobs. Lower grade workers who had just retired were just as stressed as their peers who were still working.

Stresses and strains of working life

Worryingly, far from being a time when the stresses and strains of working life melt away, retirement seems to bring little or no relief for those in lower grade occupations. It seems the health inequalities observed between those in high and low grade jobs are magnified not only as workers get older, but even in retirement, when we might think the opposite would occur. In other words, at a time when the gap might be expected to close, in fact it widens.

It’s important to note that we took a wide range of other factors into account when we looked at the lives of the people in the study, including their broader health, whether they had a serious life-limiting illness, whether they were married etc., but our results remained strong, giving us considerable confidence in our findings.

Of course, there can be many different factors at play as we prepare to retire. Workers who retire from low status jobs often face financial and other pressures, whilst their better paid peers enjoy good pensions and have the resources to engage in leisure and social activities.

Another key point to make is that if this is the picture for people working in the civil service, where working conditions are considered very good and certainly a great deal better than most other employment areas, things are likely to be worse in other types of job where working conditions are less favourable.

For those looking to tackle inequality and unfairness in the workplace and wider society, our findings add to a growing body of evidence of how they are magnified across the lifecourse. They serve to remind us also that if we want everyone to enjoy a relaxed, happy and fulfilled retirement, then those inequalities must be addressed early with policies that are based on solid evidence.

Retirement and Socioeconomic Differences in Diurnal Cortisol: Longitudinal Evidence From a Cohort of British Civil Servants is research by Tarani Chandola, Patrick Rouxel, Michael Marmot and Meena Kumari and is published in The Journals of Gerontology: J Gerontol B Psychol Sci Soc Sci, 2017, Vol. 00, No. 00, 1–10