The Role of Solar Activity in Endothelial Activation and Inflammation in the NAS Cohort

Abstract

BACKGROUND AND AIM: Solar activity, which induces disturbances of the Earth’s magnetic field, periodically oscillates between minimum and maximum sunspot activity in cycles of approximately 11-years. Exposure to broad-spectrum electromagnetic solar activity can adversely affect human physiology, leading to adverse health outcomes. Recent epidemiological studies have shown that solar and geomagnetic activity are associated with chronic diseases, including cardiovascular diseases (CVD). However, the impact of solar activity on biomarkers for CVD, including biomarkers for endothelial function and inflammation in a large cohort, has not been previously studied. This study investigated the associations between solar and geomagnetic activity and circulating biomarkers of systemic inflammation and endothelial activation in the Normative Aging Study (NAS) cohort. METHODS: Mixed effects models with moving day averages from day 0 to day 28 were used to study the associations between solar activity [sunspot number (SSN) and interplanetary magnetic field (IMF)], geomagnetic activity [planetary K index (Kp index)] and various inflammatory and endothelial markers. Biomarkers included intracellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), C-reactive protein (CRP), and fibrinogen. RESULTS: After adjusting for demographic and meteorological variables, we observed significantly positive associations between sICAM-1 and sVCAM-1 concentrations and solar and geomagnetic activity parameters: IMF, SSN, and Kp index. Additionally, a negative association was observed between fibrinogen and Kp index and a positive association was observed for CRP and SSN. CONCLUSION: These results demonstrate that solar and geomagnetic activity might be upregulating endothelial activation and inflammation. KEYWORDS: Endothelial Activation, Inflammation, Solar Activity, Geomagnetic Activity, Geomagnetic Disturbance