Costacou T, et al. - The authors aimed to test the hypothesis that only a minority of patients with type 1 diabetes (T1D) developed advanced kidney disease and that incidence was higher among men and lower in those diagnosed at a younger age. Besides, they examined long-term risks as few patients with T1D survived to older ages until recently. In T1D, some degree of kidney disease was virtually universal at long durations and not declining, which had major implications for health care and research strategies. End-stage renal disease (ESRD) had declined, however, continued to affect >25% of the population by 40 years duration.

• During 1950–80, the authors investigated the 50-year cumulative kidney complication risk in a childhood-onset T1D cohort diagnosed (n = 932; mean baseline age 29 years, duration 19 years).
• In this study, participants were 144 who died before baseline, 130 followed with periodic surveys, and 658 followed with biennial surveys and a maximum of 9 examinations for 25 years.
• They defined micro- and macroalbuminuria as an albumin excretion rate of 20-199 and ≥200 μg/min, respectively, and end-stage renal disease (ESRD) as dialysis or kidney transplantation.
• They estimated cumulative incidence at 10-year intervals between 20 and 50 years duration and compared by the calendar year of diabetes onset.

• ESRD affected 60% of the cohort by 50 years of T1D duration; macroalbuminuria, 72%; and microalbuminuria, 88%.
• Except for ESRD, little evidence existed for declines in cumulative incidence in recent cohorts (microalbuminuria 3% increase, macroalbuminuria no change; ESRD 45% decrease by 40 years of T1D duration).
• Onset before age 6 years was correlated with the lowest risk.
• As per the outcomes, incidence generally did not differ by sex.