Low socioeconomic position has been linked with a deterioration in the quality of ageing equivalent to a loss of 4-7 years of good physical health by age 60, findings of a new study published in the BMJ have revealed.
Men aged 60 with lower economic status – such as those working in manual occupations – had the same walking speed as men aged 66.6 with a higher economic status (e.g. those working in non-manual occupations). Measured by walking speed, this is a 6.6-year loss of good physical function. Women lost 4.6 years, a smaller but still relevant decrease.
This negative impact was comparable to that provoked by other major risk factors: by age 60, insufficient physical activity led to a loss of 5.7 years in the function of men and 5.4 in women, while the reduction due to obesity was 5.1 for men and 7.5 for women. The loss ascribed to diabetes was, respectively, 5.6 and 6.3. The effect of other risk factors such as hypertension (2.3 and 3 years of lost function) and tobacco use (3 and 0.7 years lost) was smaller.
Silvia Stringhini, researcher at Lausanne University Hospital in Switzerland and lead author of the study, said: “Our study added further evidence to the role of poor social and economic circumstances as powerful risk factors, which may seriously impact on healthy ageing.
“Previous studies have shown that different risk factors, including socioeconomic disadvantage, tend to cluster in the same individuals. However, our results suggest that the association of low occupational profile with physical functioning is not attributable to other risk factors.”
The study was carried out by Lifepath, a project funded by the European Commission, which investigates the biological pathways underlying social differences in healthy ageing.
Lifepath researchers analysed data from 37 studies comprised of a total of 109,107 men and women aged between 45 and 90 years. The 24 countries involved were in Europe, the United States, Latin America, Africa, and Asia, including UK. They used walking speed as an indicator of physical function since it declines with age and is a good predictor of survival, hospital admission, and cognitive decline. To assess an individual’s socioeconomic condition, the information of their last known occupational title was collected during enrolment.
Paolo Vineis, professor at the Imperial College of London and leader of the Lifepath project, said: “Another relevant finding was the difference between high-income countries on the one hand, and low- and middle-income countries on the other, with the former showing higher number of years of functioning lost due to socioeconomic disadvantage.
“This could be due to regional differences in the social patterning of major risk factors, such as physical inactivity, obesity, and diabetes.”
Current global health policies are targeted towards established risk factors of health, such as smoking and physical inactivity. The negative impact of these factors is mainly assessed using hard parameters such as mortality, while broader measures of wellbeing like physical function has received less attention so far. “We should not limit our analysis to the length of our lives, but also to the quality of our ageing”, says Mika Kivimaki, professor at the University College of London. “By focusing on healthy ageing and functional wellbeing, we aim to provide further evidence for broader health policies dealing with socioeconomic adversity, in addition to standard risk factors.”