Seasonal Blood Pressure Variations in Persons with Hypertension Seen in the Medical Out-Patients Department of Benue State University Teaching Hospital Makurdi, North Central, Nigeria

ABSTRACT

Seasonal variation in blood pressure in hypertensive and healthy individuals has been reported in the context of winter and summer seasons in western countries. Cold temperatures in winter are associated with higher blood pressure levels while warm temperatures in summer have been associated with lower blood pressure levels. This is significant because (ambient cold temperature) has been linked to increased risk of cardiovascular disease ( CVD) morbidity and mortality.  The equivalent seasons for winter and summer in West Africa are the Rain and Dry seasons respectively. Not much has been done in terms of evaluating the impact of variations in seasons on blood pressure levels in our environment. Hence this study to determine the seasonal variation of blood pressure among hypertensives accessing care in Benue State University Teaching Hospital ( BSUTH), Makurdi was carried out. This was a retrospective study involving hypertensive patients seen in the medical outpatients' department of the hospital between 1st November, 2018 and 31st October, 2019 in which patients' hospital records were reviewed.  The systolic, diastolic  Mean Arterial Blood Pressure ( MAP), and weight readings were retrieved from the case notes and recorded. The dry season was taken as the period between 1stNovember, and 31st March, while the rainy season was taken as the period between 1st April and 31st October. Statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 21. There was a statistically significant increment in all mean systolic, diastolic, and MAP  readings obtained during the rainy season compared to the dry season. Mean systolic blood pressure was 112.57 ± 18.7 in the rainy season compared to 100.70 ± 55.0 in the dry season (p<0.05). In conclusion, it was observed that seasonal variation in blood pressure exists in hypertensive patients seen at BSUTH with higher values during the rainy season. Further studies are needed to evaluate the impact of seasonal variation on the adjustment of anti-hypertensive medications and on CVD morbidity and mortality.