Reducing blood pressure (BP) has been shown to have therapeutic benefits, although it is unclear what those benefits are for people with diabetes. The main goal of this study was to determine the practical significance of lowering blood pressure for preventing cardiovascular disease in people with both diabetes and hypertension. Researchers looked back at the medical records of 754,677 people with hypertension (median age 47 years; 75.8% male) and found that they were in stages 1 or 2. Baseline fasting plasma glucose (FPG) levels were used to classify participants as either having normal FPG (FPG<100 mg/dL; n=517,372), prediabetes (FPG:100-125 mg/dL; n=197,836), or diabetes mellitus (FPG≥126 mg/dL; n=39,469). Primary outcomes were heart failure (HF), while secondary outcomes included ischemic heart diseases (IHD), such as myocardial infarction, angina pectoris, and stroke. There were 18,429 HFs, 17,058 IHDs, and 8,795 strokes recorded over a mean follow-up period of 1111±909 days. Reduction in BP of less than 120/80 mmHg at 1 year was associated with a lower risk of developing HF(HR:0.77, 95% CI:0.72-0.82), ischemic heart disease (HR:0.84, 95% CI:0.79-0.89), and stroke (HR:0.75, 95% CI:0.69-0.82) in people with normal fasting plasma glucose levels (FPG), but no such reduction was seen in people with diabetes (HR:0.98, 95% CI:0.81-1.17). In persons with prediabetes or DM, the effect of lowering blood pressure on the occurrence of heart failure was decreased, as shown by interaction studies. Multiple sensitivity tests corroborated these findings. As glucose tolerance declined, the protective effect of lower blood pressure on the development of HF was blunted. Preventing cardiovascular disease (especially HF) in hypertensive people with prediabetes or DM requires determining the best way to manage their hypertension.