Does Incident Solar Ultraviolet Radiation Lower Blood Pressure?

Area of Science:

• Environmental Health
• Cardiovascular Research
• Dermatology

Background:

• Hypertension is a major global health concern, contributing significantly to premature mortality and morbidity.
• While risk factors are emphasized, not all are fully understood, modifiable, or preventable.
• Seasonal blood pressure variations suggest environmental factors like sunlight and temperature play a role.

Purpose of the Study:

• To investigate the association between environmental ultraviolet (UV) radiation exposure and systolic blood pressure (SBP).
• To test the hypothesis that incident solar UV radiation may lower blood pressure.
• To explore potential new risk factors for hypertension in hemodialysis patients.

Main Methods:

• Analysis of data from 342,457 chronic hemodialysis patients across 2178 US dialysis centers over three years.
• Utilized National Oceanic and Atmospheric Administration (NOAA) data for incident UV radiation and temperature at clinic locations.
• Employed linear mixed-effects models, adjusting for temperature, patient demographics, BMI, and serum electrolytes.

Main Results:

• Pre-dialysis SBP exhibited seasonal variations, with approximately 4 mm Hg higher SBP in black patients.
• Both UVA and UVB radiation showed a significant inverse linear association with SBP, independent of temperature.
• Ambient temperature also demonstrated a significant inverse linear relationship with SBP.

Conclusions:

• Incident solar UV radiation is associated with lower SBP in hemodialysis patients, beyond the effect of temperature.
• This finding suggests that insufficient sunlight exposure could be a novel risk factor for hypertension.
• The results may have implications for understanding hypertension risk in the general population.