Relationship Between Time-Dependent Proteinuria and Risk of Stroke in Population With Different Glucose Tolerance Status.

Background Proteinuria often changes and is known as a "time-dependent exposure." The effect of time-dependent proteinuria on the risk of future stroke remains unclear. Proteinuria is often detected in patients with diabetes mellitus. The present study was designed to evaluate the association between time-dependent proteinuria and the risk of stroke in a patient cohort with different glucose tolerance status. Methods and Results A total of 82 938 participants, who were free of myocardial infarction or stroke and underwent fasting blood glucose and urinary protein measurements at baseline in the Kailuan study, were enrolled. Proteinuria was determined using urine dipstick tests at baseline and subsequent follow-ups. Time-dependent proteinuria was defined as the status of urine protein updated through the follow-up examinations, separately. Time-dependent Cox regression models were used to analyze the relationship between time-dependent proteinuria and the risk of stroke. During a median follow-up of 8.37 years, 2538 participants developed stroke. After adjusting for confounding factors, the hazard ratio (95% CI) for stroke in time-dependent proteinuria among all participants, and the normoglycemia, prediabetes, and diabetes mellitus populations were 1.68 (1.49-1.89), 1.73 (1.47-2.05), 2.15 (1.70-2.72), and 1.30 (1.03-1.65), respectively. There were interaction effects in patients with normoglycemia and prediabetes compared with those with diabetes mellitus. Findings were similar for ischemic and hemorrhagic strokes and were confirmed in sensitivity analyses. Conclusions Time-dependent proteinuria is an independent risk factor of stroke, especially in the normoglycemia and prediabetes populations.