The study authors investigated shapes of the associations of systolic blood pressure and diastolic blood pressure levels with risk of cardiovascular events and mortality. The population used in the study consisted of a large primary care-based sample of diabetic patients who were currently using blood pressure medication to control their diastolic and systolic readings.
The researchers gathered patient data from 1999 through 2008 from 84 primary care centers, investigating 34, 009 consecutive cardiovascular disease-free type 2 diabetes patients aged 35 years or older with a mean population age of 64 years. They followed the cohort group until the end of 2009 in national registries for the incidence of major cardiovascular events. Data collection included recording a composite endpoint of myocardial infarction, stroke, heart failure, or cardiovascular mortality or total mortality as well as looking at the associated blood pressures.
Results from the study showed that during up to 11 years of follow-up, 6,344 patients or approximately 18.7% had a first cardiovascular event, and 6,235 died which was 18.3%. The associations of annually updated systolic blood pressure and diastolic blood pressure with risk of major cardiovascular events were described by the researchers as U-shaped. The lowest risk of cardiovascular events was observed at a systolic blood pressure of 135–139 mmHg and a diastolic blood pressure of 74–76 mmHg, and the lowest mortality risk at a systolic blood pressure of 142–150 mmHg and a diastolic blood pressure of 78–79 mmHg, in both antihypertensive drug-untreated and drug-treated persons.
In conclusion the authors suggested that in a large primary care-based sample of patients with type 2 diabetes, the association of systolic blood pressure and diastolic blood pressure with the risk of major cardiovascular events and mortality were U-shaped. This means any blood pressure out of a normal range as described above too high or too low will be problematic for a patient and increase the likelihood of a cardiovascular event.
Sundström, Johan . "Blood pressure levels and risk of cardiovascular events and mortality in type-2 diabetes: cohort study of 34,009 primary care patients." Journal of Hypertension . 31.8 (2013): n. page. Web. 15 Jul. 2013.