Next time you hear “cuffing season,” think of blood pressure cuffs. As winter has properly set in with shorter, darker, colder days, you might see the impact on blood pressure control rates.
A new study examined the health records of more than 68,000 adults being treated for hypertension and found that on a population level, BP control rates decreased by up to 5 percent during the winter months compared with control rates in the summer. Each participant remained on their antihypertensive medication class regimen during the review period.
While seasonal variation in BP has been previously studied and documented, investigators were interested in the effect of this variation on population control rates under standard metrics (percent of patients with most recent BP <140/90).
“Despite the smaller degree of systolic blood pressure variation in comparison to previous studies on seasonality in blood pressure, we were surprised to observe a large degree of change in blood pressure control between winter and summer months,” said lead study author Robert B. Barrett. “Individuals with hypertension or values near the range of hypertension may benefit from periodic blood pressure monitoring and improvements in physical activity and nutritional patterns during winter months to offset adverse effects from seasonal blood pressure changes.”
It has generally been observed that blood pressure rates tend to be lower during the summer, making patients susceptible to dehydration and kidney problems if BP gets too low, an effect that can be exacerbated by diuretics. In colder climates, blood vessels will constrict to preserve core body temperature, and for patients whose blood pressure is not already under control, these seasonal variations can present additional challenges. However, a seasonal drop in BP control rates might not be attributable to changes in temperature. The number of daylight hours, body weight, nutritional patterns, and physical activity could all be contributing factors. No matter the season, physicians should educate their patients on how to take accurate blood pressure measurements at home with validated devices so they can design treatment plans with a large sample of data.
Self-measured blood pressure predicts cardiovascular morbidity and mortality better than in-office BP measurements alone, and by providing more readings over a longer period of time, physicians can design more responsive treatment plans that better adjust to changes in the data.
The study authors indicated that further investigation would be required to determine any changes in the frequency of heart disease and deaths during each season. Study limitations include that the electronic health records did not capture a complete health history for each participant.
The American Medical Association is a professional association and lobbying group of physicians and medical students.
