Frequency of dawn phenomenon and its associations with age, HbA1c and diabetes duration in Japanese type 1 diabetes mellitus (T1DM) using the continuous glucose monitoring system (CGMS)

Aims We defined the dawn phenomenon is an increase in either insulin requirements or the plasma glucose concentration, in the absence of preceding hypoglycemia or waning insulin levels, occurring between the hours of 0400 and 0800. According to previous studies, the frequency of dawn phenomenon is reported to be approximately 54.0% inpatients with type 1 diabetes mellitus (T1DM),and the poor glycemic control is associated with an exaggerated dawn phenomenon.The present studies were undertaken to assess the associations between dawn phenomenon and age at the time of the study, HbA1c and diabetes duration in Japanese T1DM showing the dawn phenomenon.