血糖波动对糖尿病大鼠理化指标及甲状腺功能的影响

Effect of blood glucose fluctuation on biochemistry indexes and thyroid function in diabetic rats

目的观察持续高血糖及血糖波动对糖尿病(DM)大鼠理化指标及甲状腺功能的影响,探讨血糖波动对DM大鼠甲状腺组织损伤的程度及可能的损伤机制。方法用高糖高脂饲料叠加腹腔注射STZ建立DM大鼠模型,并分为持续性高血糖组、血糖波动组,另设正常对照组(C组),每组各10只。12周后检测血生化、甲状腺功能并处死,取双侧甲状腺称重,计算甲状腺的重量指数(mg/100g)。结果持续高血糖组与血糖波动组糖化血红蛋白A_(1c)(HbA_(1c))相近(P>0.05)。血糖波动组甘油三酯(TG)、空腹血糖(FPG)、总胆固醇(TC)明显低于持续高血糖组,差异均有统计学意义(均P<0.05)。持续高血糖组和血糖波动组的游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)、甲状腺重量指数均明显低于正常组,且差异有统计学意义(均P<0.05);持续高血糖组、血糖波动组之间差异无统计学意义(P>0.05)。各组间促甲状腺素(TSH)差异无统计学意义(P>0.05)。结论无论血糖波动,还是持续高血糖均可降低DM大鼠FT3、FT4水平,糖代谢紊乱可能是导致DM大鼠甲状腺损伤的机制。

Objective To investigate the effect of blood glucose fluctuation on the biochemistry indexes and thyroid function in diabetic rats. Methods Diabetes mellitus model was induced by injection of STZ and high glucose and lipid feeding in rats. The rats were divided into consistence hyperglycemia group（n=10）, blood glucose fluctuation group（n=10） and control group. Animals were sacrificed after 12 weeks of experiment starting. Results The CHOL, FPG and HbA1 cin DM rats were significantly higher than those in control（P〈0.05）.TRIG in persistence hyperglycemia group was significantly higher than that in control group（P〈0.01）. The TRIG, FPG and CHOL in blood glucose fluctuation group were significantly lower than those in persistence hyperglycemia group（P〈0.05）, while there were no significant difference in HbA_（1c） between two groups. Free T3,free T4 and thyroid gland weight index in persistence hyperglycemia and blood glucose fluctuation groups were significantly lower than those in control group（P〈0.05）, while there was no significance difference between persistence hyperglycemia group and blood glucose fluctuation group. There was no significance difference in TSH levels among 3 groups. Conclusion Low level of free T3 and T4exists in diabetic rats, and disturbance of carbohydrate metabolism may be the possible mechanism thyroid function damage.