BackgroundThe relative effect of hemoglobin A1c, blood pressure, and low‐density lipoprotein‐cholesterol (LDL‐C) (“ABC” factors) on the prevention of cardiovascular diseases (CVD) among patients with type 2 diabetes mellitus is poorly understood. This study aimed to evaluate the association of key clinical parameters on CVD risk using a multifactorial optimal control approach in Chinese primary care patients with type 2 diabetes mellitus.Methods and ResultsA population‐based retrospective cohort study was conducted on 144 271 Chinese type 2 diabetes mellitus primary care patients, aged 18 to 79 and without prior clinical diagnosis of CVD in 2008–2011. Cox regressions were conducted to examine the association between the combinations of ABC targets (hemoglobin A1c <7%, blood pressure <130/90 mm Hg, and LDL‐C <2.6 mmol/L) and risks of CVD (overall), coronary heart disease, stroke, and heart failure. Achieving more ABC targets incrementally reduced the incidence of total CVD and individual disease including coronary heart disease, stroke, and heart failure, irrespective of other patient characteristics. Compared with suboptimal control in all ABC levels, achieving any 1, 2, and all 3 ABC targets reduced the relative risk of CVD by 13% to 42%, 31% to 52%, and 55%, respectively. Among those achieving only 1 ABC target, LDL‐C reduction was associated with the greatest CVD risk reduction (42%), followed by blood pressure reduction (18%), and hemoglobin A1c reduction (13%).ConclusionsTo achieve the greatest risk reduction for the incidence of CVD, the ultimate goal of treatment should be to achieve target control of hemoglobin A1c, blood pressure, and LDL‐C. If it is not possible to achieve all 3 targets, efforts should be prioritized on treating the LDL‐C to minimize CVD risk.