Oral glucose tolerance test should be performed after stroke and transient ischemic attack.

Diabetes mellitus predicts an increased risk of stroke, and acute hyperglycemia during acute stroke predicts the presence of undiagnosed diabetes mellitus. Based on recent investigations, 28% of previously nondiabetic stroke or transient ischemic attack patients have undetected diabetes mellitus, and 29% have impaired glucose tolerance, while only 43% have normal glycemic control. Oral glucose tolerance test is a far more sensitive and reliable test of diabetes mellitus than fasting blood glucose or HbA1c, and is recommended in the World Health Organization criteria for diagnosing diabetes mellitus and impaired glucose tolerance. Secondary prevention of stroke is different in patients with diabetes mellitus and the detection of impaired glucose tolerance would ring alarm bells of impending diabetes mellitus and promote lifestyle changes. As screening with inexpensive oral glucose tolerance test would have a hit rate of one in three patients in revealing undetected diabetes mellitus and another one in three in revealing impaired glucose tolerance, it should be implemented in guidelines as an inexpensive test for monitoring stroke and transient ischemic attack patients.