Contrasting Associations Between Diabetes and Cardiovascular Mortality Rates in Low-, Middle-, and High-Income Countries: Cohort Study Data From 143,567 Individuals in 21 Countries in the PURE Study
Research design and methods: Prospective Urban Rural Epidemiological (PURE) enrolled 143,567 adults aged 35 to 70 years from 4 high income countries (HIC), 12 middle income countries (MIC) and 5 low income countries (LIC). The mean follow-up was 9.0±3.0 years.
Results: Among those with diabetes, CVD rates (LIC 10.3, MIC 9.2, HIC 8.3 per 1000 person years, p<0.001), all-cause mortality (LIC 13.8, MIC 7.2, HIC 4.2 per 1000 person years, p<0.001) and CV mortality (LIC 5.7, MIC 2.2, HIC 1.0 per 1000 person years, p<0.001) were considerably higher in LIC compared to MIC and HIC. Within LIC, mortality was higher in those in the lowest tertile of wealth index (low 14.7%, middle 10.8%, high 6.5%). In contrast to HIC and MIC, the increased CV mortality in those with diabetes in LIC remained unchanged even after adjustment for behavioural risk factors and treatments [Hazards ratio (95% Confidence Interval): 1.89 (1.58 – 2.27) to 1.78 (1.36 – 2.34)].
Conclusions: CVD rates, all-cause and CV mortality were markedly higher among those with diabetes in LIC compared to MIC and HIC with mortality risk remaining unchanged even after adjustment for risk factors and treatments. There is an urgent need to improve access to care to those with diabetes in LIC to reduce the excess mortality rates, particularly among those in the poorer strata of society.