https://diabetes.acponline.org/archives/2016/08/12/3.htm

Very low systolic blood pressure associated with less CV risk in diabetes patients

Patients with type 2 diabetes and a systolic blood pressure of 110 to 119 mm Hg appeared to have a lower risk of cardiovascular disease than patients who had systolic blood pressures of 130 to 139 mm Hg, according to a registry study.


Having a lower systolic blood pressure than is currently recommended was associated with lower risk of cardiovascular events in patients with type 2 diabetes and no history of cardiovascular disease (CVD), according to a recent study.

In a register-based sample of 187,106 Swedish patients, researchers found that those with a systolic blood pressure of 110 to 119 mm Hg appeared to have a lower long-term risk of myocardial infarction (MI), CVD, and coronary heart disease (CHD) than patients in the reference group, who had systolic blood pressures of 130 to 139 mm Hg. The results were published online Aug. 4 by The BMJ.

During a mean follow-up period of 5 years, 12,152 patients (6.5%) died, and 3,663 (30%) of the deaths were classified as cardiovascular. The group with systolic blood pressure of 110 to 119 mm Hg had a significantly lower risk of nonfatal acute MI (hazard ratio [HR], 0.76; P=0.003), any acute MI (HR, 0.85; P=0.04), nonfatal CVD (HR, 0.82; P=0.002), any CVD (HR, 0.88; P=0.04), and nonfatal CHD (HR, 0.88; P=0.03) than the reference group. The researchers observed similar but nonsignificant results for stroke and total CHD. Patients in the group with lower blood pressure, however, had the highest rates of mortality from infection; diseases of the nervous, respiratory, and digestive systems; and external causes of morbidity.

Lower blood pressure was also associated with a significantly increased risk of heart failure and total mortality; these were the only J-shaped relation between systolic blood pressure and the endpoints studied. However, systolic blood pressure produced, more or less, a J-shaped relation with all studied outcomes when the models included patients with previous disease, a secondary analysis showed.

“These findings strengthen the hypothesis that the J curve phenomenon is caused by more patients with comorbidities in the lowest blood pressure groups,” the study authors wrote. Patients in the lowest blood pressure group who died had indications of other risks, including a high rate of smoking and treatment with loop diuretics, spironolactone, and drugs for heart disease.

The authors noted that a limitation of their study is its exclusion of individuals with complications and those over 75 years old. They added that the register-based design also could not fully account for unreported disease that leads to low blood pressure and increased CV risk, thereby potentially underestimating the prophylactic effect of lower blood pressure.