Impaired glucose tolerance as a risk factor for stroke in a cohort of non-institutionalised people aged 70 years

OBJECTIVE: to determine whether impaired glucose tolerance (IGT) is associated with an increased likelihood for ischaemic stroke. DESIGN: prospective cohort study. PARTICIPANTS: a sample of 1,032 non-institutionalised people aged 70 years in the Turku Elderly Study, Turku, Finland. MEASUREMENTS: the association between IGT (defined as plasma glucose level between 7.80 and 11.09 mmol/l 2 h after administration of 75 g of an oral glucose load) and diabetes mellitus (DM) (defined as the current use of insulin or an oral hypoglycaemic medication, a fasting plasma glucose level of >/=7 mmol/l or a plasma glucose level of >/=11.1 mmol/l 2 h after administration of an oral glucose load) with 12-year follow-up for the development of ischaemic stroke. RESULTS: a total of 742 (71.9%) subjects had normal glucose tolerance, 127 (12.3%) subjects had IGT and 163 (15.8%) had DM. Patients were examined in the year 1990 and followed up for stroke occurrence until death or until the end of 2002. Mean follow-up time was 9.6 years (SD +/-3.3 years). In total, 119 patients (11.5%) suffered a stroke during the follow-up. In logistic regression model, previous stroke, previous TIA, DM and atrial fibrillation were risk factors for stroke occurrence. CONCLUSION: stroke tended to happen more often in the IGT group than in the normal group, but the difference was not statistically significant. Statistically significant risk factors for stroke in elderly people are previous TIA or stroke, DM and atrial fibrillation.