Unknown factors not linked to diet, smoking or poverty may make Scots people more prone to heart disease, research led by University of Edinburgh has revealed.
The findings, which are published in the current edition of the Journal of Epidemiology and Community Health, conclude that although successful campaigns to get Scots to live a healthier lifestyle will reduce rates of heart disease in Scotland, they will not do much to narrow the gap in heart disease rates between Scotland and England. More research is called for into how and why Scots get heart disease at such high rates.
Researchers at the University of Edinburgh, University College London and Imperial College London compared heart disease rates in Scotland and England. As expected, they found the rates are much (62%) higher in Scotland. However, then they tried to explain the higher rates by taking account of differences in wealth, health behaviours such as smoking, drinking and taking exercise and other biological characteristics such as cholesterol levels.
Principal investigator Dr Richard Mitchell, of the University of Edinburgh said: "We found that Scots are more likely to be in worse economic situations, to have had problems with drinking, to smoke --and those who do smoke, smoke more than English smokers-- and less likely to take exercise. However, these differences do not explain much of the higher rate of heart disease in Scotland. Even after taking account of personal economic circumstances, health behaviours and blood chemistry ,including cholesterol levels, the average Scot is still 50% more likely to have heart disease than the average English person. We think that there may be unknown genetic, behavioural or environmental factors which make Scots more at risk of heart disease.
He added: "This was a really surprising result. We expected to find that Scots have higher rates of heart disease just because they tend to be less wealthy and tend to have less healthy lifestyles than their English neighbours.
"People choosing a healthy lifestyle for themselves, and government tackling poverty, are still the best ways to reduce heart disease, but it seems that there may be something else contributing to Scotland's terrible record with this disease. We need to do more work to find out what that 'X-factor' might be.
"This was a powerful study because, unlike other previous work, it looked at a wide variety of the factors which can put someone at risk of heart disease – everything from their employment status, to their lifestyle, to the chemistry of their blood and their mental health. It was also an important study because it used data from men and women from the whole of Scotland and England, rather than from just one or two towns or cities, or just one sex. The study used data from the Scottish Health Survey, and the Health Survey for England. It focused on people aged 45-74 years old because it is at these ages that the biggest differences between the two countries in death rates for heart disease usually occur."