The comparison of different quantitative criteria of the Dawn Phenomenon and its impact on blood glucose fluctuation in type 2 diabetes / 中华内分泌代谢杂志

ABSTRACT

[Summary] A total of 128 individuals with type 2 diabetes underwent continuous glucose monitoring for 3 consecutive days.The dawn phenomenon was defined by three different parameters according to the previous research(1)the absolute increase of glucose level from nocturnal nadir to prebreakfast value(?G) above 20 mg/dl;(2)?G above 10 mg/dl;( 3 ) insulin requirement increased at least 20%.The participants were secondarily separated by presence/absence of a dawn phenomenon based on the definitions above.The impact on blood glucose fluctuation of different groups was assessed according to the standard deviation of blood glucose( SDBG) , the area under curve above 10 mmol/L ( AUC ) , and the mean amplitude of glycemic excursions ( MAGE ) , etc.The frequencies of dawn phenomenon were 64.8%(?G≥20mg/dl), 85.2%(?G≥10 mg/dl), and 59.4%(rise in insulin requirement≥20%)respectively.The impacts on SDBG, AUC, MAGE, and MODD were without statistical difference(P>0.05) between the presence and absence of the dawn phenomenon patients when?G≥10 mg/dl.However, the differences reached statistical significance(P<0.05) when ?G≥20 mg/dl and the increase in insulin requirement≥20%. Besides, the incidence of dawn phenomenon was positively correlated with HOMA-IR, HbA1C , and free C-peptide.Dawn phenomenon is a very frequent event in type 2 diabetes and not only impacts the overall glycemic control but also exaggerates glucose fluctuation.To be clinically relevant, ?G≥20mg/dl should be taken as the quantitative criterion of the dawn phenomenon.