Abstract
Abstract only Stroke is a serious complication of diabetes. Intensive treatment of diabetes increases the risk of recurrent hypoglycemia (RH). Hypoglycemia exposure causes prothrombotic effects. Earlier, we demonstrated that exposure to single hypoglycemia (SH), 5-day RH (once every day), and twice-a-week RH for 6 weeks increases stroke risk in male insulin-treated diabetic (ITD) rats. In the present study, we determined the effect of SH and RH on stroke risk/thrombosis in female rats. Streptozotocin diabetic female rats were treated for hyperglycemia using insulin pellets (Figure A). Rats were randomly assigned to either hyperinsulinemic euglycemia (ITD+RH+Glucose, control) or hyperinsulinemic hypoglycemia (ITD+RH) groups (3 h duration) (Figure B). Separate groups tested the effect of SH, RH for 5 days, or RH for 6 weeks. Based on the results of the male studies, stroke risk after SH, 5-day RH, and 6-week RH were assessed on days 1, 7, and 3 post-last hypoglycemia, respectively. Groups were balanced (confirmed by Chi square test) in terms of the proportion of animals at different stages of the estrous cycle. To assess the risk of stroke, the carotid artery and jugular vein were linked with a shunt containing a suture, and the weight of the clot accumulated on the suture following 15 min of blood flow was quantified as a measure of stroke risk/thrombosis. The clot weight in the SH-exposed ITD group was significantly higher by 47% (22±3 mg, n=9, p<0.05) when compared to its respective control (15±1 mg, n=8). The clot weight determined 7 days after the 5-day ITD+RH group (18±1 mg, n=7) was significantly (p<0.05) higher than its control group (15±1 mg, n=9). The clot weight in the 6-week ITD+RH group was significantly higher by 47% (20±2 mg, n=9, p<0.01) when compared to its control (14±1 mg, n=7) (Figure C). Our results show that similar to male rats, SH and RH increase stroke risk in female ITD rats. We are currently evaluating the underlying mechanisms. Acknowledgment: NIH (NS122808).