Factors in Home Blood Pressure Variability in Diabetes

Certain modifiable risk factors affect variability in home blood pressure in patients with type 2 diabetes mellitus (DM), according to the results of a new study. These factors include heart rate, smoking status, and use of antihypertensive medication.

“Recent studies have shown that variability in home blood pressure has an important role in the progression of organ damage,” noted researchers at the Kyoto Prefectural University of Medicine in Japan.

The researchers conducted a cross-sectional, multicenter study that assessed the relationship between home blood pressure variability and various factors using univariate and multivariate linear regression analyses in more than 1100 patients, average age 66 years, who had type 2 DM.

The patients took 3 home blood pressure readings each morning and evening for 14 consecutive days.

On multivariate analysis, higher heart rate at the time of taking blood pressure was associated with greater variability in morning systolic and diastolic blood pressure, as well as evening diastolic blood pressure, according to their post-hoc analysis.

“An increased sympathetic nerve activity induces an increase in heart rate through the production of epinephrine and norepinephrine,” the researchers noted, adding that this represents one of the mechanisms involved in determining blood pressure variability.

Those who were current smokers also had more variable morning blood pressure. The type of antihypertensive drug taken by the patients also influenced morning and evening systolic blood pressure and evening diastolic blood pressure.

Patients who drank alcohol every day had increased variability in evening systolic and diastolic blood pressure relative to those who never drank alcohol.

Several unmodifiable factors also were linked to blood pressure variability. These were age, which was associated with all but evening diastolic blood pressure; female sex, which was associated with morning and evening systolic readings; and longer duration of DM, which was associated with all blood pressure variability measures.

In contrast with the findings of a previous study, alcohol intake was not related to morning blood pressure variability, and neither was obesity or hyperlipidemia. The researchers also note that they lacked information on insomnia and sleep duration, both of which have been linked to blood pressure variability.

“Our findings implicate the factors that might be intervened, such as heart rate, smoking status, and use of antihypertensive medication, in addition to age, sex, and duration of diabetes mellitus, are associated with variability in home blood pressure in patients with type 2 diabetes,” the researchers noted.

They suggest that primary care physicians be alert to the presence of these factors in their patients and consider treating them in the hope of reducing blood pressure variability.

The researchers published their results on February 6, 2014, in the Journal of Human Hypertension.