The natural response of your body in cold weather is to restrict blood vessels in order to retain heat and maintain core body temperature. Because the heart needs to work harder to pump blood via restricted blood arteries, blood pressure may rise. Cold weather can hinder physical activity since people are less likely to exercise outside. Physical activity is a crucial part of managing high blood pressure, and lack of exercise can result in poor blood pressure control.
A study of more than 60,000 persons’ electronic health data in the United States discovered that systolic, or top-number, blood pressure climbed slightly during the winter compared to the summer. The health records were of adults being treated for high blood pressure from 2018 to 2023 at six healthcare centers of varying sizes located in the southeast and midwestern United States.
According to a new study to be presented at the American Heart Association’s Hypertension Scientific Sessions 2023, held Sept. 7-10, 2023, in Boston, blood pressure among patients diagnosed with hypertension appeared to slightly increase, while rates of systolic, or top number, blood pressure being controlled during an outpatient visit appeared to slightly decrease. The meeting is the foremost scientific exchange focusing on recent advancements in basic and clinical research on hypertension and its links to heart and renal illness, stroke, obesity, and genetics.
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.
Robert B. Barrett
Nearly half of adults in the United States have high blood pressure, according to the American Heart Association’s 2023 Statistical Update. Previous studies discovered that blood pressure fluctuates with the seasons. The majority of the change is in systolic blood pressure, which is the top number in a blood pressure reading and measures the pressure in/against blood vessels during heartbeats. The researchers wanted to know if blood pressure management, defined in this study as less than 140/90 mm Hg in hypertensive individuals, varied by season.
“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, a software engineer at the American Medical Association in Greenville, South Carolina.
“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.”
The researchers examined electronic health records from 60,676 persons treated for hypertension at six different healthcare facilities between July 2018 and June 2023. Throughout the review period, all participants stayed on their initial antihypertensive medication classes. The centers, mostly in the Southeast and Midwest, ranged from modest federally sponsored nonprofit health centers or clinics to big academic medical centers.
Seasonal blood pressure readings were analyzed to assess differences in blood pressure control between the winter and summer months (December through February vs. June through August, respectively) as part of an American Medical Association-supported quality-improvement program for clinicians and health care centers. Participants in the study were 62 years old on average, with 52.3% identifying as white and 59.7% as female.
According to the examination of the health data, participants’ systolic blood pressure increased by up to 1.7 mm Hg in the winter months compared to the summer months. Furthermore, they discovered that blood pressure management rates dropped by up to 5% during the cold months.
The authors suggested that future research may look into the frequency of heart disease and deaths during each season.
One of the study’s drawbacks is that the electronic health records did not capture a comprehensive health history for each participant, and the information gathered for each patient was only accessed from the facility where they were treated.
