The global cardiovascular risk transition: associations of four metabolic risk factors with national income, urbanization, and Western diet in 1980 and 2008

Abstract

Background: It is commonly assumed that cardiovascular disease risk factors are associated with affluence and Westernization. We investigated the associations of body mass index (BMI), fasting plasma glucose, systolic blood pressure, and serum total cholesterol with national income, Western diet, and, for BMI, urbanization in 1980 and 2008.

Methods and results: Country-level risk factor estimates for 199 countries between 1980 and 2008 were from a previous systematic analysis of population-based data. We analyzed the associations between risk factors and per capita national income, a measure of Western diet, and, for BMI, the percentage of the population living in urban areas. In 1980, there was a positive association between national income and population mean BMI, systolic blood pressure, and total cholesterol. By 2008, the slope of the association between national income and systolic blood pressure became negative for women and zero for men. Total cholesterol was associated with national income and Western diet in both 1980 and 2008. In 1980, BMI rose with national income and then flattened at ≈Int$7000; by 2008, the relationship resembled an inverted U for women, peaking at middle-income levels. BMI had a positive relationship with the percentage of urban population in both 1980 and 2008. Fasting plasma glucose had weaker associations with these country macro characteristics, but it was positively associated with BMI.

Conclusions: The changing associations of metabolic risk factors with macroeconomic variables indicate that there will be a global pandemic of hyperglycemia and diabetes mellitus, together with high blood pressure in low-income countries, unless effective lifestyle and pharmacological interventions are implemented.

Figure 1

Mean age-standardized levels of metabolic risk factors in relation to per-capita gross domestic product (GDP). GDP is in international dollar, which accounts for differences in purchasing power across countries, and is adjusted for inflation. The thick line shows the mean association and the gray area the 95% uncertainty interval of this relationship, calculated using a non-parametric (Loess) regression as described in Methods and Supplemental Material. Individual data points show country means. See Table S1 for country data.

Figure 2

Mean age-standardized BMI in relation to the proportion of a country’s population that lived in urban areas. Associations of other risk factors with urbanization are available from the authors by request. See Table S1 for country data.

Figure 3

Mean age-standardized levels of metabolic risk factors in relation to Western diet (WD). See Methods for how percentiles were calculated. See Table S1 for country data.

Figure 4

Mean age-standardized SBP, TC, and FPG in relation to mean age-standardized BMI. See Table S1 for country data.

Figure 5

Age standardized prevalence of smoking in relation to per-capita gross domestic product (GDP) in 2008. Smoking data are from the WHO Global status report on noncommunicable diseases 2010.