Sakamoto M, et al. - In this retrospective study, researchers assessed achievement rates on a monthly basis in persons with type 2 diabetes mellitus (T2DM) and examined related factors. This investigation initially analyzed data on 104,601 persons with T2DM throughout Japan. For this analysis, they included patients whose HbA1c, blood pressure (BP), and low-density lipoprotein (LDL)-cholesterol were measured ≥12 times during a 24-month period. Achievement of all targets was expressed as the "all ABC achievement". There were 4,678 patients analyzed. Investigators found that the all ABC achievement rate for guideline targets changed on a monthly basis. In both summer and winter, insulin use and sulfonylurea use were independently related to the decreased all ABC achievement rates. When managing T2DM in ordinary clinical practices, seasonal variations in the all ABC achievement rate should be considered.