Presence of diabetes related complication at the time of NIDDM diagnosis: an important prognostic factor.

We studied the short-term natural history of patients with newly diagnosed non-insulin dependent diabetes mellitus (NIDDM), and the prognostic role of history of NIDDM related complication at the time of first NIDDM diagnosis in relation to the development of a new complication or death. We performed a cohort study using data from the General Practice Research Database in the UK. We identified patients aged 30 to 74 years with a newly diagnosed NIDDM between 1990 and 1992 and followed them from the day of NIDDM diagnosis until June 1995. Among the 1077 patients identified, 437 (41%) developed a NIDDM complication during the follow-up. NIDDM complications were more frequent among males and in the elderly. Sixty-seven percent of the study cohort was initially free of any complication while the remaining 360 patients presented already one or more NIDDM complication at the time of their NIDDM diagnosis. History of diabetic related complication was associated with an increased risk of developing a new NIDDM complication (RR: 1.8; 95% CI: 1.5-2.2). Mortality was also greater among patients with history of NIDDM complication (RR: 1.5; 95% CI: 1.0-2.2). Patients with a history of any disorder related to diabetes before their clinical diagnosis of NIDDM are at increased risk of developing a NIDDM complication after the NIDDM diagnosis, as well as at increased risk of dying compared to diabetic patients with no history.