A European study described by its authors as one of the most in-depth looks yet at the link between socioeconomic status and diabetes risk indicates that people in lower-paying jobs have more weight problems that increase their risk of diabetes — a major cause of death and premature death worldwide.

The researchers in the study, published Tuesday in the British Medical Journal (BMJ), set out to measure the contribution of several major risk factors for Type 2 diabetes to socioeconomic differences across society.

Body mass index (BMI) is calculated on the basis of weight and height. BMI is calculated this way: weight(kg)/height(m)2\

Health Canada classifies health risk according to these BMI levels:

  • Underweight: Less than 18.5 (increased risk).
  • Normal weight: 18.5-24.9 (least risk).
  • Overweight: 25.0-29.9 (increased risk).
  • Obese: 30 (high risk) to 40 and up (extremely high).

Their work was driven by the fact the World Health Organization estimated in 2011 that as many as 346 million people were living with the disease, and 90 per cent of them had Type 2, which has a huge impact on health-care costs, and is a prime risk factor for cardiovascular disease, various cancers and possibly mood disorders and dementia.

"Thus, identification of those groups at increased risk of Type 2 diabetes, together with an understanding of the mechanisms involved, remains a public health priority," write the researchers from Switzerland, England, France, Hungary and Scotland.

The prospective Whitehall II cohort study looked at 7,237 civil service workers in London, with an average age of 49, who did not have diabetes at the onset of the study. 

Lifestyle changes 'urgently needed'

The researchers assessed health behaviours (including smoking, alcohol consumption, diet and physical activity), BMI (a screening tool for assessing health risk based on a person's height and weight), and biological risk markers such as blood pressure and lipid levels in the 7,237 study participants. These risk factors were measured repeatedly over an average of 14 years, during which there were 818 diagnoses of diabetes.

The study found civil servants in the lowest occupational category had a 1.86-fold greater risk of developing diabetes compared to colleagues in the highest occupational category.

The researchers determined socioeconomic status by looking at the types of jobs the workers were doing, and their education, salary, social status and level of responsibility at work.

Health behaviours and body mass index (BMI) are modifiable risk factors that explain almost half of the association between socioeconomic status and incidence of Type 2 diabetes, the researchers write.

Changing lifestyle key to preventing disease

In the study, health behaviours and BMI were found to be responsible for up to 45 per cent of the socioeconomic differential in both men and women. Taking biological risk markers into account, that rose to 53 per cent.

But by far, BMI was the most important single contributing factor, accounting for about 20 per cent of socioeconomic differences.

Given the findings, efforts to tackle lifestyle factors that put people at high risk of diabetes are "urgently needed," the researchers write.

"The fact that unhealthy behaviours and body mass index explained up to 45 per cent of the socioeconomic gradient in Type 2 diabetes in this population in early old age has important public health implications." 

"Type 2 diabetes can be delayed or prevented among people at high risk who make intensive lifestyle modifications. Further efforts should be made to promote and enable the adoption of healthy lifestyles among the disadvantaged fractions of society."

The BMJ study was released the same day as a Canadian study that also examined workplace links to diabetes. The study by Toronto researchers concluded excessive work stress such as having little or no control over what you do on the job plays a role in whether someone develops diabetes, and that women are most at risk.