In addition, results from the IVW method revealed that HT onset could decrease the level of CCR2 on monocyte (OR = 0.875, 95% CI = 0.773–0.990, P = 0.035), which was consistent with MR Egger (OR = 0.875, 95% CI = 0.893–0.911, P = 0.046). This evidence concerns the gene CCR2 and hematocrit.