Extreme poverty linked to unexpected high cardiovascular risks

A study published in the journal Nature Human Behavior estimates the prevalence of cardiovascular disease risk factors among adults living in extreme poverty.

Study: The prevalence of cardiovascular disease risk factors among adults living in extreme poverty. Image Credit: Cozine / Shutterstock

Background

It is generally believed that adults living in extreme poverty in low- and middle-income countries have a lower prevalence of cardiovascular disease and its risk factors, including obesity, diabetes, hypertension, dyslipidemia, and smoking.

Adults living in extreme poverty generally consume plant-based foods with lower calorific values and are involved in occupations demanding high-intensity physical activities. These lifestyle patterns are possibly responsible for a lower cardiovascular disease risk.

An accurate estimation of the prevalence of cardiovascular risk factors in this subpopulation is particularly important for guiding health policy and healthcare delivery. However, only limited data on this matter is currently available from nationally representative surveys.

In this study, scientists have estimated the prevalence of five major cardiovascular disease risk factors, including hypertension, diabetes, obesity, dyslipidemia, and smoking, among adults living below the World Bank’s international line for extreme poverty (those with income <$1.90 per day) across the world.    

Study design

The scientists pooled individual-level data from 105 nationally representative household surveys across 78 countries. This represents 85% of the global population living in extreme poverty. They identified this subpopulation by sorting the individual-level data by country-specific measures of household income or wealth.  

Data obtained from a total of 32,695,579 participants was analyzed in the study. Of all participants, 7,922,289 were living in extreme poverty (income <$1.90 per day), 806,381 on $1.90–3.19 per day, 748,078 on $3.20–5.49 per day, and 922,870 on $5.50 or more per day.   

Important observations

The estimated prevalence of five major cardiovascular disease risk factors among adults living in extreme poverty was 17.5% for hypertension, 4.0% for diabetes, 10.6% for current smoking, 3.1% for obesity, and 1.4% for dyslipidemia.

Among adults earning higher incomes (>$5.50 per day), the prevalence of hypertension, diabetes, current smoking, obesity, and dyslipidemia was estimated to be 20.8%, 7.6%, 21.1%, 14.2%, and 17%, respectively.

In low-income and upper-middle-income countries, the prevalence of these risk factors among adults living in extreme poverty was not considerably lower than that among those with higher incomes.  

Specifically, no significant difference in diabetes prevalence was observed between extremely poor adults and those with higher incomes in low-income and upper-middle-income countries. However, in lower-middle-income countries, a higher prevalence of diabetes was observed among those with higher incomes. A similar pattern was observed for hypertension prevalence.  

Like diabetes prevalence, a low prevalence of current smoking and dyslipidemia was observed across poverty levels in low-income countries, and a high prevalence was observed across population income groups in upper-middle-income countries. Only in lower-middle-income countries was a variation in the prevalence of these risk factors observed across poverty levels.

The prevalence of obesity, on the other hand, showed a positive association with the levels of poverty.

Demographic variation in prevalence  

The stratification of cardiovascular disease risk factor prevalence among impoverished adults by residency type revealed that urban dwellers have a higher prevalence of diabetes than rural dwellers.

A similar stratification by sex revealed that men have a slightly higher prevalence of hypertension, a significantly higher prevalence of smoking, and a significantly lower prevalence of obesity than women.

A stratification by education revealed a higher prevalence of smoking among those with a high school education or above compared to those with no schooling.

Treatments of cardiovascular risk factors

Among impoverished adults with hypertension, about 15% reported taking blood pressure-lowering medicines, and 5% reported achieving hypertension control. Among those with diabetes, about 19% reported taking blood glucose-lowering medicines. Among those who need statin (cholesterol-lowering medicine) for secondary prevention of cardiovascular disease, only 1% reported taking the medicine.

Lower use of hypertension, anti-diabetic, and statin medicines was observed among each poverty level in low-income countries. The probability of taking these medicines was consistently lower among adults living in more extreme poverty levels in lower-middle-income countries. These patterns were less prominent in upper-middle-income countries.

Study significance

The study finds a high prevalence of cardiovascular disease risk factors among adults living in extreme poverty. This observation contradicts the current perception of a low prevalence of these risk factors in this subpopulation mainly because of their highly active lifestyle and low-calorie food habits.

The study can inform equity discussions for resource allocation and the design of effective interventions.