Presentations

Abstract

Introduction: Seasonal variation in blood pressure (BP) has been widely observed in a multitude of populations with implications for hypertension management and diagnostic sensitivity in both research and clinical practice. Globally, it has been shown that individuals who are of a lower socioeconomic status or lack access to consistent protection from cold temperatures may be subject to an amplified seasonal BP change. Currently, the American homeless population has been observed to have worse hypertension control and hold a greater risk for developing cardiovascular disease than the general population. Characterizing seasonal BP variation in this vulnerable group may further inform the context by which effective hypertension diagnosis and management occur. This study aims to identify associations between blood pressure and the daily average temperature as affected by season in individuals presenting to the Eastern Virginia Medical School (EVMS) Street Health clinics, in Norfolk, VA.

Methods: Medical record extraction from two EVMS Street Health clinics located in Norfolk, VA held between September 28, 2019 and December 15, 2023 yielded 606 patients, of which 301 patients met inclusion criteria. Systolic blood pressure (SBP), diastolic blood pressure (DBP), date, sex, and age were data points necessary for a visit to be included in the analysis. Mean daily temperature was sourced from data publicly available through the National Oceanic and Atmospheric Administration. American Heart Association criteria for hypertension was used (value of 130/80mmHg or greater). Interquartile range (IQR) method for outlier detection limited the visit per patient to six BP readings. Significance testing was preformed using a Spearman's Rank Correlation test.

Results: Among the 690 visits to the EVMS Street Health clinics (mean age: 53.1 years; 74% male), 523 (75.8%) met criteria for hypertension. Decreased mean daily temperature was found to be associated with both increased SBP (p=0.006) and DBP (p=0.037).

Conclusion: Patients reporting to EVMS Street Health clinics were found to be hypertensive at a greater rate than the estimated national average of 46.7% (NHANES 2017-2018). Likewise, a statistically significant association was found between decreased mean daily temperature and increased SBP and DBP. Many individuals who report to EVMS Street Health clinics are of a lower socioeconomic status and are housing insecure. As a result, these patients often spend extended periods of time outdoors. These data suggest providers should consider the relationship between seasonal context and the time at which hypertension is diagnosed and managed in this vulnerable cohort.