Sakamoto M, et al. – Upon initial data analysis of over 100,000 individuals with type 2 diabetes mellitus (T2DM) in Japan, researchers determined achievement rates on a monthly basis and examined related factors in this diabetic cohort. Eligible study participants included patients whose HbA_1c, blood pressure (BP), and low-density lipoprotein (LDL)-cholesterol were measured ≥ 12 times over 24 months. Achievement of all targets was expressed as the "all ABC achievement". A total of 4,678 patients examined for the final analysis. According to findings, all ABC achievement rate for guideline targets changed on a monthly basis. The use of insulin and sulfonylurea were independently linked to the reduction of all ABC achievement rates in summer and winter. When managing T2DM in ordinary clinical practices, seasonal variations in all ABC achievement rates should, therefore, be taken into account.