胰岛素瘤患者动态血糖谱的特点及意义

目的分析胰岛素瘤患者动态血糖监测系统(CGMS)血糖谱的特点,探讨CGMS在胰岛素瘤诊断中的价值。方法应用CGMS对6例经病理证实的胰岛素瘤患者(胰岛素瘤组)进行连续3 d的血糖监测,分析CGMS的平均血糖水平(MBG)、M-valueof Schlichtkrull(M-value)、血糖分布频率及低血糖事件,监测结果与5例新诊断2型糖尿病伴低血糖患者(糖尿病组)及6例正常糖调节者(对照组)进行比较。结果①胰岛素瘤组M-value显著高于对照组(P<0.01),而MBG两组间无显著性差异(P>0.05)。糖尿病组M-value及MBG均高于胰岛素瘤组及对照组(P<0.05或P<0.01)。②6例胰岛素瘤患者CGMS监测期间共发生36次低血糖事件,持续时间为3.6 h/d,其中21次(58.3%)发生于夜间;5例糖尿病患者共发生7次低血糖事件,持续时间为0.17 h/d,其中4次(57.1%)发生于夜间。③对照组99.2%的血糖波动于3.9～7.8 mmol/L;胰岛素瘤组血糖2.8～3.9mmol/L及≤2.8 mmol/L的分布频率均显著高于糖尿病组(P<0.01),而7.8～11.1 mmol/L及≥11.1 mmol/L的分布频率则低于糖尿病组(P<0.05和P<0.01)。结论CGMS可进一步分析低血糖的时间分布、类型及原因,结合M-value等血糖参数,有助于胰岛素瘤诊断水平的提高。

Characteristics and clinical significance of daily blood glucose profiles of insulinoma detected by continuous glucose monitoring system

Objective To analyse the characterisitics of daily blood glucose profiles of insulinoma using continuous glucose monitoring system(CGMS) and to investigate the value of CGMS in the diagnosis of insulinoma. Methods The blood glucose of 6 patients with pathologically-confirmed insulinoma(insulinoma group) were detected by CGMS for 3 consecutive days.The mean blood glucose(MBG),M-value of Schlichtkrull(M-value),frequency distribution of glucose levels and the hypoglycemic episodes of CGMS were measured,and the results were compared with those of normal glucose regulation(n=6,control group) and patients with newly-diagnosed type 2 diabetes with reactive hypoglycemia(n=5,diabetes group). Results The M-value of insulinoma group was significantly higher than that of control group(P<0.01),while there was no significant difference in MBG between the two groups(P>0.05).The M-value and MBG of diabetes group were higher than those of insulinoma group and control group(P<0.05 or P<0.01).As a whole,36 hypoglycemic episodes lasting 3.6 hours per day occurred in the 6 patients with insulinoma,of which 58.3%(21 episodes) took place during the night hours.While 7 hypoglycemic episodes lasting 0.17 hours per day were observed in the 5 patients with diabetes,of which 4 episodes(57.1%)were detected during the night hours.99.2% of the findings of the blood glucose of control group fell in the range between 3.9 and 7.8 mmol/L.The frequencies of glucose below 2.8 mmol/L and between 2.8 and 3.9 mmol/L of insulinoma group were significangly higher than those of diabetes group(P<0.01),while those above 11.1 mmol/L and between 7.8 and 11.1 mmol/L were lower than those of diabetes group(P<0.01 and P<0.05). Conclusion The time distribution,type and cause of hypoglycemia could be well analysed by CGMS,and parameters for blood glucose such as M-value revealed by CGMS could help in the diagnosis of insulinoma.