BACKGROUND: Whether the type of diabetes, race, and year and age of diagnosis affect the incidence of diabetic vascular complications is unknown. That both type 1 and type 2 diabetes occur in the young Japanese population prompted us to investigate whether the type of diabetes and the year of diagnosis are related to the incidence of nephropathy. METHODS: Of the 17,256 diabetic patients who visited the outpatient clinic at our diabetes center between 1965 and 1990, 1578 (9.1%) had early-onset diabetes (diagnosed before the age of 30); of these, 620 (39%) had type 1, and 958 (61%) had type 2 diabetes. The incidence of nephropathy was analyzed in the patients according to postpubertal duration and year of diagnosis. RESULTS: The cumulative incidence of nephropathy after 30 years of postpubertal diabetes was significantly higher (P < 0.0001) in type 2 diabetic patients (44.4%, 95% CI, 37.0 to 51.8%) than in type 1 diabetic patients (20.2%, 95% CI, 14.9 to 25.8%). The incidence of nephropathy among type 1 diabetic patients has declined during the past two decades, whereas it has not among type 2 diabetic patients. The rate ratio for type 2 diabetic patients diagnosed between 1980 and 1984 relative to type 1 diabetic patients diagnosed in the same period was 2.74 (95% CI, 1. 17 to 6.41). CONCLUSIONS: The incidence of nephropathy has declined in Japanese patients with type 1 but not in those with type 2 diabetes. In young Japanese patients, because of the higher incidence of nephropathy in type 2 diabetes and the higher prevalence of type 2 than type 1 diabetes, type 2 diabetes is likely the major cause of diabetic nephropathy.
BACKGROUND: Whether the type of diabetes, race, and year and age of diagnosis affect the incidence of diabetic vascular complications is unknown. That both type 1 and type 2 diabetes occur in the young Japanese population prompted us to investigate whether the type of diabetes and the year of diagnosis are related to the incidence of nephropathy. METHODS: Of the 17,256 diabeticpatients who visited the outpatient clinic at our diabetes center between 1965 and 1990, 1578 (9.1%) had early-onset diabetes (diagnosed before the age of 30); of these, 620 (39%) had type 1, and 958 (61%) had type 2 diabetes. The incidence of nephropathy was analyzed in the patients according to postpubertal duration and year of diagnosis. RESULTS: The cumulative incidence of nephropathy after 30 years of postpubertal diabetes was significantly higher (P < 0.0001) in type 2 diabeticpatients (44.4%, 95% CI, 37.0 to 51.8%) than in type 1 diabeticpatients (20.2%, 95% CI, 14.9 to 25.8%). The incidence of nephropathy among type 1 diabeticpatients has declined during the past two decades, whereas it has not among type 2 diabeticpatients. The rate ratio for type 2 diabeticpatients diagnosed between 1980 and 1984 relative to type 1 diabeticpatients diagnosed in the same period was 2.74 (95% CI, 1. 17 to 6.41). CONCLUSIONS: The incidence of nephropathy has declined in Japanese patients with type 1 but not in those with type 2 diabetes. In young Japanese patients, because of the higher incidence of nephropathy in type 2 diabetes and the higher prevalence of type 2 than type 1 diabetes, type 2 diabetes is likely the major cause of diabetic nephropathy.
Authors: E J Mayer-Davis; C Davis; J Saadine; R B D'Agostino; D Dabelea; L Dolan; S Garg; J M Lawrence; C Pihoker; B L Rodriguez; B E Klein; R Klein Journal: Diabet Med Date: 2012-09 Impact factor: 4.359
Authors: Dana Dabelea; Jeanette M Stafford; Elizabeth J Mayer-Davis; Ralph D'Agostino; Lawrence Dolan; Giuseppina Imperatore; Barbara Linder; Jean M Lawrence; Santica M Marcovina; Amy K Mottl; Mary Helen Black; Rodica Pop-Busui; Sharon Saydah; Richard F Hamman; Catherine Pihoker Journal: JAMA Date: 2017-02-28 Impact factor: 56.272