Higher serum ferritins are associated with higher blood pressure: A cross-sectional study

The aim of the study was to investigate the association between serum ferritin and hypertension among American adults from National Health and Nutrition Examination Survey (NHANES) 1999 to 2018. A total of 16,125 participants were included. Weighted logistic regression and subgroup analyses were performed to explore the association. We found that serum ferritin was closely correlated to hypertension. Individuals with high serum ferritin were more likely to have higher systolic or diastolic blood pressure (SBP, DBP) than those with lower serum ferritin. Restricted cubic spline showed a significant non-linear association between serum ferritin and SBP/DBP. Higher level of serum ferritin (Q3 74.1-147 μg/L and Q4 > 147 μg/L) was found to have positive association with high SBP [Q3 (OR: 1.246, 95% CI:1.020-1.523), Q4 (OR: 1.354, 95% CI:1.096-1.674)], and hypertension [Q3 (OR: 1.283, 95% CI:1.099-1.499), Q4 (OR: 1.424, 95% CI:1.197-1.63)] in the whole population. In people aged between 20 and 60, subjects with high serum ferritin were significantly associated with a higher risk of hypertension, but in those over 60, the relationship between serum ferritin level and hypertension is negative. A non-linear association between serum ferritin and SBP, as well as DBP, was discovered. There was age difference in association between serum ferritin and hypertension in American adults, and further researches were needed to understand the mechanisms behind the difference.