Vascular complications of diabetes: natural history and corresponding risks of dementia in a national cohort of adults with diabetes.

aimsThis study aimed to determine the trajectory of diabetic vascular diseases and to investigate the association between vascular diseases and dementia.

methodsWe included adults aged ≥ 50 years with newly diagnosed type 2 diabetes (n = 173,118) from 2001 to 2005 who were followed-up until December 31, 2013 in the Taiwan's National Health Insurance Research Database. Multivariable Cox regression models were constructed to estimate hazard ratios (HRs) and confidence limits (CLs) for all-cause dementia in relation to the number, types, and occurrence patterns of vascular disease.

resultsWithin 1 year of diabetes diagnosis, 26.3% of adults developed their first vascular disease. During the 1,864,279 person-years of follow-up, 17,426 adults had all-cause dementia, corresponding to an incidence of 97.9 cases/10,000 person-years in 127,718 adults with at least one vascular disease and 67.5 cases/10,000 person-years in 45,400 adults without vascular diseases. Across all age groups, adults who subsequently developed a vascular disease in two one-year windows since diabetes diagnosis had the highest incidence of all-cause dementia. In comparison with adults without vascular diseases, HR for all-cause dementia was 1.99 (CL: 1.92-2.07) for those with one vascular disease only; 2.04 (CL: 1.98-2.13) for two or more vascular diseases; 3.56 (CL: 3.44-3.70) for stroke only; and 2.06 (CL: 1.99-2.14) for neuropathy alone. Similar associations were also observed with a smaller magnitude for adults with nephropathy, retinopathy, cardiovascular disease, or peripheral arterial disease.

conclusionsPatients with diabetes-related complications, particularly stroke and neuropathy, and those with rapidly developed vascular diseases appeared to have a high risk of dementia.