The Investigation of Age at Onset as a Risk Factor for Mortality in Persons with Insulin-dependent Diabetes Mellitus Using Cox Proportional Hazards Models

Abstract

Proportional hazards models measuring the effect of age at onset of insulin-dependent diabetes mellitus on mortality risk are presented. The study population consisted of 924 insulin-dependent diabetic patients who were seen within 1 year of diagnosis at Children's Hospital of Pittsburgh between 1950 and 1981 and were more than 20 years old at follow-up. Age at diabetes onset was categorized as prepubertal or pubertal, defined by age. Individuals with pubertal onset of diabetes had a significantly higher risk of mortality compared with those with prepubertal onset by diabetes duration but not by attained age. It is proposed that age at onset is an independent determinant of mortality in diabetic individuals and may represent either heterogeneity within insulin-dependent diabetes mellitus with respect to long-term prognosis or an interactive effect of diabetes duration and puberty on prognosis.

Markedly increased renal disease mortality and incidence of renal replacement therapy among IDDM patients in Japan in contrast to Allegheny County, Pennsylvania, USA

“…Since there were some differences in demographic characteristics between the two cohorts as presented in Table 1 and these characteristics have been previously found to be associated with overall mortality [13,14], they were included in multivariate models to adjust for their independent effect. The Cox proportional hazard model was employed to adjust for sex, age at onset, calendar year of onset, and duration of diabetes.…”

All-Cause Mortality in the Canterbury (New Zealand) Insulin-Treated Diabetic Registry Population

“…Some studies report no relationship between age at onset and chances of survival, especially when controlling for duration of diabetes (3,37), whereas others found relative mortality decreased with increasing age at onset and increased with duration of diabetes up to ϳ20 years' duration, after which it declined (1,2,7). However, the problem of colinearity between attained age, age at diagnosis, and duration of diabetes in proportional hazard regression modeling makes interpretation of results difficult (1,17). In Canterbury, attained age, sex, and diabetes group were the key predictors of diabetes mortality.…”

“…The aims of this study were as follows: 1) to establish all-cause age-sex-specific death rates and life expectancies of insulintreated diabetic individuals; 2) to compare these with those of the general Canterbury population; 3) to examine the importance of demographic and clinical risk factors as predictors of mortality (1,2,17); and 4) given the current debate over the heterogeneity of type 1 autoimmune diabetes (18)(19)(20)(21), to determine whether differences in mortality exist between different clinical subgroups of insulin users.…”

Geographical variation of presentation at diagnosis of Type I diabetes in children: the EURODIAB Study

“…With the exception of some reports identifying a young age at onset, risk factors for DKA are not known [1,10,26,27].…”