title: Cause-specific mortality in a cohort of Brazilian patients with type 1 diabetes.
abstract: OBJECTIVE
  To assess cause-specific mortality in a cohort of patients with type 1 diabetes (T1D) followed at an university hospital (tertiary level, Rio de Janeiro city) and an outpatient clinic (secondary level, Bauru city) both in Brazil's southeast, and associations of survival with gender, age at diagnosis, self-reported ethnicity and diabetes duration.
  
  
  METHODS
  Our study is based on a cohort of patients with T1D whose vital status was determined as of December 31, 2015. The causes of mortality were determined by death certificates and outpatient clinic records.
  
  
  RESULTS
  Among 986 patients, (54.4%) females, (74.8%) Caucasians, 886 (89.9%) were alive, 62 (6.3%) had died, and in 38 (3.9%) the vital status was unknown. Median age at death [interquartile range] and diabetes duration until death were 30.0 [13] and 15.6 [10] years, respectively. Considering those who died (n = 62), most patients (about 70%) died from end-stage renal disease, macrovascular disease or acute complications of diabetes, mainly diabetic ketoacidosis. The other causes of mortality were infections, fatal accidents and non-diabetes-related. The standardized mortality ratio was 3.13 [2.35-4.08] in those aged under 40. In a multivariate Cox model, "age < 40 years" and "year of diagnosis" were the only significant variables with hazard ratios of 6.259 [(3.100-12.639), p < 0.001] and 0.915 [(0.880-0.951), p < 0.001], respectively.
  
  
  CONCLUSIONS
  Our study shows that patients with T1D had a threefold increase in mortality. The specific causes of mortality were mainly diabetes-related chronic complications; however, acute complications, especially diabetic ketoacidosis, persisted as an important cause of mortality.
authors.affiliation: Diabetes Unit, Department of Internal Medicine, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Marilia B
authors.initials: MB
authors.lastname: Gomes
authors.affiliation: Diabetes Unit, Department of Internal Medicine, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Ana P
authors.initials: AP
authors.lastname: Almeida
authors.affiliation: Diabetes Unit, Department of Internal Medicine, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Deborah C
authors.initials: DC
authors.lastname: Santos
authors.affiliation: Diabetes Unit, Department of Internal Medicine, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Eliete
authors.initials: E
authors.lastname: Leão
authors.affiliation: Diabetes Unit, Department of Internal Medicine, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Edna F
authors.initials: EF
authors.lastname: Cunha
authors.affiliation: Bauru's Diabetics Association, Rua Saint Martin 27-07, Bauru, São Paulo, CEP 17012-433, Brazil. carlosnegrato@uol.com.br.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Negrato
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D002423:Cause of Death; D015331:Cohort Studies; D048909:Diabetes Complications / Q000145:classification / Q000401:mortality*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000401:mortality*; D016883:Diabetic Ketoacidosis / Q000401:mortality; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality; D008297:Male; D008875:Middle Aged; D044465:White People / Q000706:statistics & numerical data; D055815:Young Adult
keywords: Diabetes-related acute complications; Diabetes-related chronic complications; Macrovascular complications; Microvascular complications; Mortality; Type 1 diabetes