Incidence of Stroke According to Presence of Diabetic Nephropathy and Severe Diabetic Retinopathy in Patients With Type 1 Diabetes

Abstract

OBJECTIVEType 1 diabetes is associated with a markedly increased risk of stroke, but only a few studies on the incidence of stroke in type 1 diabetes exist. Therefore, we assessed the incidence of stroke in patients with type 1 diabetes and studied the impact of diabetic nephropathy (DN) and severe diabetic retinopathy (SDR) on this risk.RESEARCH DESIGN AND METHODSWe studied 4,083 patients with type 1 diabetes from the Finnish Diabetic Nephropathy Study. Mean age was 37.4 ± 11.8 years, duration of diabetes was 21.6 ± 12.1 years, and 52% were men. Strokes were identified from medical records, death certificates, and the National Hospital Discharge Register and classified based on medical files and brain images.RESULTSDuring 36,680 person-years of follow-up, 149 (4%) patients suffered an incident stroke (105 infarctions and 44 hemorrhages). Of the infarctions, 58 (55%) were lacunar. The incidence of stroke, cerebral infarction, and cerebral hemorrhage was 406 (95% CI 344–477), 286 (234–347), and 120 (87–161) per 100,000 person-years, respectively. In an adjusted analysis, microalbuminuria increased the risk of stroke with a hazard ratio (HR) of 3.2 (1.9–5.6), macroalbuminuria 4.9 (2.9–8.2), and end-stage renal disease 7.5 (4.2–13.3), and SDR increased the risk with an HR of 3.0 (1.9–4.5). The risk of cerebral infarction, cerebral hemorrhage, and lacunar infarction increased in a similar manner. The proportion of lacunar versus nonlacunar infarction did not change across DN groups.CONCLUSIONSThe presence of SDR and DN, independently, increases the risk of stroke, cerebral infarction, and cerebral hemorrhage in patients with type 1 diabetes.

Different Risk Factor Profiles for Ischemic and Hemorrhagic Stroke in Type 1 Diabetes Mellitus

“…The study design is an observational follow-up study, and a detailed description of the research design and population has previously been reported. 8 At baseline, both the attending physicians and the patients themselves completed questionnaires regarding the patient's medical condition, medical history, and lifestyle. For the present study, we included all the 4083 patients with type 1 diabetes mellitus in the FinnDiane database without a history of stroke at baseline, as well as with complete information on stroke during follow-up available.…”

“…We have earlier shown that both the severity of diabetic nephropathy (DN) and the presence of severe diabetic retinopathy (SDR) increase the risk of any stroke, ischemic stroke, lacunar infarction, and hemorrhagic stroke. 8 However, comprehensive studies on independent risk factors for each subtype of stroke are still missing.Therefore, we aimed to study the independent risk factors for stroke, and also for the subtypes ischemic stroke, lacunar Background and Purpose-Despite the fact that patients with type 1 diabetes mellitus have a markedly increased risk of experiencing a stroke, independent risk factors for stroke and its subtypes in these patients have remained unclear. Methods-A total of 4083 patients with type 1 diabetes mellitus from the Finnish Diabetic Nephropathy (FinnDiane) Study, without a history of stroke at baseline, were included.…”

“…We have earlier shown that both the severity of diabetic nephropathy (DN) and the presence of severe diabetic retinopathy (SDR) increase the risk of any stroke, ischemic stroke, lacunar infarction, and hemorrhagic stroke. 8 However, comprehensive studies on independent risk factors for each subtype of stroke are still missing.…”

Why do some patients with type 1 diabetes live so long?

“…However, the presence of retinopathy increases the risk of stroke [22] . Severe diabetic retinopathy was common in the "Golden Years Cohort" [10] .…”

“…Overall, there was a significant or macroalbuminuria is a significant risk factor for CAD, cardiovascular mortality and all cause mortality, and there is a strong independent relationship between albuminuria and CAD (Table 1) [7] . The occurrence of stroke in subjects with type 1 diabetes is also increased by the presence of nephropathy [microalbuminuria: HR = 3.2 (1.9-5.6), macroalbuminuria: HR = 4.9 (2.9-8.2), End Stage Renal Disease: HR = 7.5 (4.2-13.3)] [22] . The DCCT/EDIC Study showed a sustained effect of good glycaemic control [23] on the reduction in albumin excretion 7 years after the conclusion of the DCCT study, with an 83% risk reduction in those patients initially treated with intensive therapy, confirming the concept of "metabolic memory".…”