BENGALURU: Physical activity has a protective effect against cardiovascular diseases (CVD) in high-income countries where physical activity is mainly recreational. But it is not known if this is also observed in lower-income countries, where physical activity is mainly non-recreational, says the PURE (Prospective Urban Rural Epidemiology) study published recently in The Lancet.
The study sought to find the effect of physical activity on mortality and cardiovascular diseases in 1,30,000 people from 17 high-, middle- and low-income countries. Incidentally, this study started in Bengaluru way back in 2003 and then panned out to the rest of the country and the rest of the world.
“We examined whether different amounts and types of physical activity are associated with lower mortality and CVD in countries with different economic levels,” the study says.
Those surveyed were aged between 35 and 70 years. “The sample size from Karnataka was 2,400 from urban areas and 1,024 from slum areas. Five researchers from St Joseph’s Research Institute were investigators as part of the world study. The study concluded that higher carb diet caused higher mortality. The paper reported a total of 5,796 deaths out of a population of 1,35,335 individuals from 18 countries,” said Dr Sumathi Swaminathan, one of the five investigators from Karnataka.
Prof Salim Yusuf, one of the lead investigators of the study’s international component, working in McMaster University, Canada, is an alumnus of St Joseph’s Research Institute. This was one of the reasons why Bengaluru was chosen for the pilot study in 2003, said Dr Prem Kumar, a researcher from SJRI and another of the investigators in study.
“The first phase of the study was conducted in Bengaluru and the learning from early experiences were replicated at other sites in India and other countries. We are still following the original group of people we recruited for the study in 2003. Every three years we go back to see their diet, physical activity, tobacco use, mental health and how they are related to their immediate physical and social environment. So both individual and environmental factors determine the development of chronic disease,” Kumar said.
The PURE study concluded, “Higher recreational and non-recreational physical activity was associated with a lower risk of mortality and CVD events in individuals from low-, middle- and high-income countries. Increasing physical activity is a simple, widely applicable, low cost global strategy that could reduce deaths and CVD in middle age.”
Learnings from Bengaluru
“At that time it was about whether it was feasible to get very detailed information at individual level like risk factors for development of chronic disease, family characteristics, immediate community level characteristics -- whether all of this is feasible to collect in a one-time sitting in urban non-slum cities, urban slums and rural settings is something we learnt in the pilot. From the initial enthusiasm of those surveyed here other sites also started studying,” said Kumar.
“We learnt that they are willing to give information about their lifestyle, individual characteristics, personal, physical and mental health, they not only answered questions but also agreed to physical measurements like height, weight, blood pressure, EKG, lung function test, abdominal circumference,” he said.