Background Proteinuria often changes dynamically,showing regression or progression.The impact of changes in proteinuria on future stroke risk remains largely unknown.We hypothesized that changes in proteinuria would be associated with stroke risk in people with diabetes and prediabetes.Methods and Results The study population included 17,380 participants with diabetes or prediabetes enrolled in a prospective Chinese cohort Based on the baseline and 2-year dipstick screening results,participants were classified as having no,remittent,incident or persistent proteinuria.Reduction in proteinuria was defined as baseline minus 2-year proteinuria.Stroke outcomes were assessed in follow-ups.Data were analyzed using Cox proportional-hazards models.During a median follow-up of 6.9 years,we identified 751 people with stroke.Stroke risk was increased for participants with remittent(HR 1.44,95%CI 1.02-2.05),incident(HR 1.50,95%CI 1.21-1.88),and persistent 1+or greater proteinuria(HR 1.69,95%CI 1.21-2.36)compared to those with no proteinuria,after adjustment for traditional risk factors.Trace+incident and persistent proteinuria was also associated with increased stroke risk.Persistent proteinuria is associated with a higher risk of stroke for participants with prediabetes as compared to those with diabetes(P for interaction=0.0114).Proteinuria reduction contributed to decrease of stroke incidences (HR 0.88,95%CI 0.81-0.95).Results were confirmed by sensitivity analysis.Conclusions Persistent,remittent and incident proteinuria are independent indicators to determine stroke risk in either diabetic or prediabetic population.