Lifestyle, education inequality effect heart disease
Lifestyle factors, such as weight, blood pressure, and smoking, explain around 40 percent of the protective effect of education on heart disease risk in later life, according to a new study published by The BMJ. However, more than half of this effect remains unexplained.
Researchers investigated the role of body mass index (BMI), systolic blood pressure, and smoking in explaining the protective effect of education on cardiovascular risk. They carried out observational and genetic analysis of data from over 200,000 adults in the UK Biobank, a large population-based study of more than half a million British men and women, in addition to a two-sample Mendelian randomization approach from predominantly European studies.
The research team’s approach used genetic information to avoid some of the problems that afflict observational studies, making the results less prone to unmeasured or confounding factors, and therefore more likely to be reliable in understanding cause and effect.
In both observational and Mendelian randomization analyses, the researchers found consistent evidence that BMI, blood pressure, and smoking mediated the effect of education, explaining up to 18 percent, 27 percent, and 34 percent, respectively. When all three risk factors were combined, researchers found about 40 percent of the relationship between education and cardiovascular disease. Similar results were found for risk of stroke, heart attack, and all other types of cardiovascular disease, according to the study abstract.
The researchers suggest that intervening on these risk factors would lead to reductions in cardiovascular disease attributable to lower levels of education. However, they note that over half of the overall effect of education remain unexplained, and point to some study limitations. For example, the main analysis did not consider factors such as exercise, diet, cholesterol, and blood sugar levels, and as participants were mostly white Europeans, findings may not be applicable to other populations.
Regardless, the research team says they stress that results were consistent across the two approaches and in additional sensitivity analyses. These findings have notable implications for policymakers as they identify potential strategies for reducing education inequalities in health, the authors say in the study.
Further research identifying other related factors and the interplay between them, and in more diverse populations, will be necessary to reducing inequalities in cardiovascular disease, researchers said.