Earth’s gravity field and prevalence of varicose veins and chronic venous disease: Systematic review

Aim This study examines the influence of Earth’s gravity field on the prevalence of varicose veins in geophysical area. Material and Methods We performed a systematic review (OVID and Google Scholar) of studies focusing on prevalence of varicose veins to determine the influence of Earth’s gravity field—GRACE GGM05S gravity model—on the disease prevalence. PROSPERO: CRD42021279513. Results 81 studies met inclusion and quality criteria. Areas with stronger gravity have significantly higher prevalence of varicose veins with adjustment for age, gender and body mass index (BMI) ( p-values < 0.02). Adjusted for age, prevalence of varicose veins in areas with gravity field +20 mGal and more is 1.37 time higher than in areas with gravity field less than +20 mGal, p-value 0.005 (95% CI: −12.5 to −2.4): mean disease prevalence for gravity field +20 mGal and more—27.5% (mean age, 40.1 years; mean gravity field, +27.1 mGal; 63.9% females, 37 studies, 123,164 participants) vs mean disease prevalence for gravity field less than +20 mGal – 20.1% (mean age, 42.2 years; mean gravity field, +5.7 mGal; 56.8% females, 44 studies, 205,925 participants). Older age is the main risk factor for varicose veins ( p-values < 0.005). Female gender and high BMI are insignificantly associated with high prevalence of varicose veins ( p-values > 0.4 for gender, p-values > 0.2 for BMI). Conclusion Stronger gravity field is significantly associated with higher prevalence of varicose veins—risk factor. The potential mechanism of this phenomenon is that high gravity field alters systemic venous return, pooling blood and fluid in the peripheral, gravity-dependent regions of the body in upright humans constantly living in the defined geophysical area.