Urban dwellers tend to have higher risk for cardiovascular diseases than people living in more rural locations. In a new study published in PLOS Medicine, Johanna Riha and colleagues, researchers from the University of Cambridge and the MRC/UVRI Research Unit in Uganda, have found that even within rural communities in Uganda that all lacked paved roads and running water, people living in villages with relatively more urban features - such as schools and health facilities - were more likely to have risk factors for cardiovascular diseases such as physical inactivity, lower fruit and vegetable consumption, and high body mass index, even after controlling for socioeconomic status.
The authors used data collected in 2011 to examine associations between measures of urbanicity and lifestyle risk factors. The study included 7,340 participants 13 years and older living in 25 villages in rural Uganda. They found that levels of urbanicity varied markedly across the villages, ranging from absence of educational facilities or electricity in households, to villages with a public telephone and a dispensary.
Despite the features of urbanization being relatively modest, living in more urbanized villages was associated with increased prevalence of cardiovascular disease risk factors such as physical inactivity (risk ratio [RR]: 1.19; 95% confidence interval [CI]: 1.14, 1.24), low fruit and vegetable consumption (RR: 1.17; 95% CI: 1.10, 1.23), and high body mass index (RR: 1.48; 95% CI: 1.24, 1.77), even after controlling for other factors such as socioeconomic status.
The authors state, "Our findings not only challenge the prevailing use of dichotomous urban-rural classification systems in epidemiological studies, but also indicate that even small-scale increases in urbanicity levels across rural environments are associated with a higher prevalence of unhealthy behaviours among rural residents." They acknowledge the study was limited by its cross-sectional design.
They conclude, "This is an important finding, considering that over 533 million people live in rural areas across [sub-Saharan Africa] and that any increase in cardiometabolic risk associated with the development process in these areas is likely to have an impact on population health and healthcare services...A better understanding of these associations is crucial because modification of lifestyle risk factors through changes in the physical environment, including local infrastructure, may provide a potential avenue for primary prevention of cardiometabolic diseases in rural populations."
In an accompanying Perspective, Fahad Razak and Lisa Berkman (Harvard University, Cambridge, Mass, US) discuss the study's implications. They state, "These results suggest a much more complex story than what is typically captured through well-trodden urban-rural classifications. The current dominant urban-rural dichotomy can be traced to at least the 1940s when the United Nations began reporting population statistics using this classification scheme, and is perhaps a legacy of a time when differences between urban and rural areas were much more discrete." While they say it is an important and revealing study, they also say that access to health centers, schools, and improved sanitation themselves are not likely to lead to poor health, but rather that unmeasured conditions associated with these indicators lead to increased cardiovascular risk. Furthermore, they say "80% to 85% of this rural population still have body weights in the normal to underweight range, and across all of rural Uganda prevalence of underweight exceeds overweight...Urban development and increases in social resources related to education, disease prevention, and better opportunities for work hold important promises for LMICs still confronting the costs of poverty and lack of health protection infrastructure."