Can stress cause type 2 diabetes?
The idea that stress can cause type 2 diabetes is not new but recent media coverage of Dave Dowdeswell from the UK who, along with his doctors, believe the only explanation for his diabetes is extreme stress, has prompted discussion around this idea as another possible explanation for why many fit and otherwise healthy people can develop type 2 diabetes.
At 44 Mr Dowdeswell, a keen windsurfer and diver, was not overweight and had no family history of diabetes. However, in the 12 months prior to his diagnosis of type 2 diabetes he had experienced a series of traumatic life events. His doctors believe the extreme stress he lived through could have been the trigger for diabetes.
One theory is that the stress hormone cortisol may alter the body’s sensitivity to insulin. While scientists are not in agreement over whether this means stress itself is a direct cause of diabetes or just a risk factor, there are some compelling arguments and research is continuing in this area.
A recent contribution to the debate comes from research funded by the Department of Defense in the US that find links between post traumatic stress disorder (PTSD) in soldiers returning from Iraq and Afghanistan and an increase in type 2 diabetes, hypertension and obesity. The study is still in its preliminary stages and other factors are being investigated as to why some people develop PTSD in the first place (such as stress response genetics) but initial findings make a definite link between war-related stress and depression on poor general health outcomes.
In 2013 a 35 year prospective follow-up study of 7,500 middle-aged men in Sweden found a strong link between stress and diabetes risk. Levels of stress were graded by the participants and it was found that men who reported permanent stress had a 45% higher risk of developing diabetes, compared to men who reported to have no, or periodic stress. The link between stress and diabetes was statistically significant, even after adjusting for age, socioeconomic status, physical inactivity, BMI, systolic blood pressure and use of blood pressure-lowering medication.
Additional studies have also looked at stress as a pathway to developing diabetes and found evidence that chronic stress can initiate changes in the immune system that may result, or increase the likelihood, of developing type 2 diabetes.
“We still know very little about the mechanisms by which different forms of stress increases the risk as well as the progression of diabetes,” said Diabetes Educator Shannon Lin of Diabetes NSW. “Although many reports and studies have shown there is a strong link between poor mental health wellbeing and diabetes. It is important for future research to examine not only how stress links to diabetes, but also whether stress can increase unhealthy behaviours that impact on the development and the progression of diabetes. Much more detail is needed before we can make a clear link.
“However I urge people under high levels of stress to consult with a health professional like their doctor because we know at the very least continued stress can have serious health impacts.”