Cause-specific mortality by race in low-income Black and White people with Type 2 diabetes

To investigate, with extended follow-up, cause-specific mortality among low-income Black and White Americans with Type 2 diabetes who have similar socio-economic status.

Black and White Americans aged 40-79 years with Type 2 diabetes (n = 12 498) were recruited from community health centres as part of the Southern Community Cohort Study. Multivariable Cox analysis was used to estimate mortality hazard ratios and 95% CIs for subsequent cause-specific mortality, based on both underlying and contributing causes of death.

During the follow-up (median 5.9 years), 13.3% of the study population died. The leading causes of death in each race were ischaemic heart disease, respiratory disorders, cancer, renal failure and heart failure; however, Blacks were at a lower risk of dying from ischaemic heart disease (hazard ratio 0.70, 95% CI 0.54-0.91) or respiratory disorders (hazard ratio 0.70, 0.53-0.92) than Whites but had higher or similar mortality attributable to renal failure (hazard ratio 1.57, 95% CI 1.02-2.40), heart failure (hazard ratio 1.47, 95% CI 0.98-2.19) and cancer (hazard ratio 0.87, 95% CI 0.62-1.22). Risk factors for each cause of death were generally similar in each race.

These findings suggest that the leading causes of death and their risk factors are largely similar among Black and White Americans with diabetes. For the two leading causes of death in each race, however, ischaemic heart disease and respiratory disorders, the magnitude of risk is lower among Black Americans and contributes to their higher survival rates.