Late adulthood mortality among African-American and white American people with Type 1 diabetes according to age at diabetes diagnosis.

aimsTo estimate the overall and cause-specific mortality in a population of African-Americans and white Americans with a low socio-economic status who had young-onset insulin-treated diabetes and had survived beyond the age of 40 years, and to examine whether any excess risk varied according to age at diabetes onset.

methodsUsing the Southern Community Cohort Study, we conducted a mortality follow-up of a cohort of mostly low-income participants aged 40-79 years (mean 50 years) at cohort entry with insulin-treated diabetes diagnosed before age 30 years (n=475) and without diabetes (n=62 266). Childhood onset was defined as diabetes diagnosed before age 20 years (n=162), while young-adulthood onset was defined as diabetes diagnosed between ages 20 and 29 years (n=313). Cause-specific mortality was based on both underlying and contributing causes of death, obtained from death certificates. Multivariable Cox analysis was performed.

resultsDuring follow-up (mean 9.5 years), 38.7% of those with and 12.9% of those without diabetes died. Compared with those without diabetes, increases in mortality rate were generally similar among those with childhood- and young-adulthood-onset diabetes for deaths from: all causes (childhood: hazard ratio 4.3, CI 3.3-5.5; young adulthood: hazard ratio 4.9, CI 4.0-5.8); ischaemic heart disease (childhood: hazard ratio 5.7, CI 3.5-9.4; young adulthood: hazard ratio 7.9, CI 5.6-11.0); heart failure (childhood: hazard ratio 7.3, CI 4.2-12.7; young adulthood: hazard ratio 5.4, CI 3.3-8.9); sepsis (childhood: hazard ratio 10.3, CI 6.1-17.3; young adulthood: hazard ratio 8.8, CI 5.7-13.5); renal failure (childhood: hazard ratio 15.1, CI 8.6-26.5; young adulthood: hazard ratio 18.2, CI 12.3-27.1); respiratory disorders (childhood: hazard ratio 3.9, CI 2.3-6.7; young adulthood: hazard ratio 5.3, CI 3.7-7.7); suicide/homicide/accidents (childhood: hazard ratio 2.3, CI 0.72-7.0; young adulthood: hazard ratio 5.8, CI 3.4-10.2); and cancer (childhood: hazard ratio 2.1, CI 0.98-4.4; young adulthood: hazard ratio 1.2, CI 0.55-2.5).

conclusionsWe observed high excess long-term mortality for all-cause, renal failure, ischemic heart disease and heart failure mortality in African-American and white American people with early-onset insulin-treated diabetes.