Type 2 Diabetes: Also a "Clock Matter"?

We investigated whether chronotype is associated with glycemic control, antidiabetic treatment, and risk of developing complications in patients with type 2 diabetes (T2DM). The diabetologists filled out an online questionnaire on the Google Form platform to collect the following parameters of subjects with T2DM: body mass index (BMI), fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), diabetes history, antidiabetic treatment, diabetic complications, and chronotype categories. We enrolled 106 subjects with T2DM (M/F: 58/48; age: 63.3 ± 10.4 years; BMI: 28.8 ± 4.9 kg/m2). Thirty-five point eight% of the subjects showed a morning chronotype (MC), 47.2% an intermediate chronotype (IC), and 17% an evening chronotype (EC). EC subjects reported significantly higher HbA1c (p < 0.001) and FPG (p = 0.004) values, and higher prevalence of cardiovascular complications (CVC) (p = 0.028) and of subjects taking basal (p < 0.001) and rapid insulin (p = 0.01) compared to MC subjects. EC subjects reported significantly higher HbA1c (p < 0.001) and FPG (p = 0.015) than IC subjects. An inverse association was found between chronotype score, HbA1c (r = -0.459; p < 0.001), and FPG (r = -0.269; p = 0.05), remaining significant also after adjustment for BMI, age, and disease duration. EC is associated with higher prevalence of CVC and poorer glycemic control independently of BMI and disease duration in subjects with T2DM.