Clinical and biochemical outcomes of type 2 diabetes mellitus in Canterbury, New Zealand: A 6-year cohort study

There is a paucity of data regarding outcomes of Type 2 diabetes mellitus. A cohort of 447 Type 2 diabetic subjects (208 male, 239 female; age range 30-82 years, median 62 years; and of predominantly European origin) was characterised in a clinic survey in 1989. Individual status (dead or alive) at 1 June 1995 was ascertained. At 6 years, 289 subjects were confirmed as alive and 133 as dead-only 25 were untraceable. Of those subjects identified as alive, follow-up clinical and biochemical data were obtained for 253 (87.5%) individuals. Tn those subjects, glycated haemoglobin deteriorated from 63.1 +/- 18.7 mmol/mol haem in 1989 to 71.7 +/- 24.4 in 1995, P < 0.0001. An increased prevalence of retinopathy was evident at 6-year follow-up, 59.7% cases in 1995 compared with 39.5% in 1989, P < 0.001. Similarly there was an increased prevalence of coronary artery disease (CAD) (33.6 vs 18.2% of cases), albuminuria (26.5 vs 19% of cases. P < 0.001), and hypertension (71.5 vs 54.9% of cases; P < 0.001) in 1995 vs 1989, respectively. Multiple logistic regression analysis showed that glycated haemoglobin (odds ratio (OR) for 18 mmol/mol haem change, 1.78; 95% CI, 1.15-2.85), hypertension (OR, 3.33; 95% CI, 1.40-8.41) and known duration of diabetes (OR for 7 year change, 2.12; 95% CI, 1.24-3.80) were predictors for development of retinopathy. There is therefore a deterioration in glycaemic control in Type 2 diabetes over 6 years and an increased prevalence of complications that present strategies in a multidisciplinary specialist diabetes clinic are unable to prevent on a sustainable basis. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.