Abstract: AIM To explore the relationship between blood pressure circadian rhythm and monocyte chemoattractant-1, intercellular adhesion molecule-1 and homocysteine in elderly hypertensive patients. METHODSA total of 172 patients with elderly primary hypertension undergoing 24-h ambulatory blood pressure monitoring were included in this study and divided into three groups: dipper group (n=55), non-dipper group (n=71) and reverse dipper group (n=46). Monocyte chemattractant-1 (MCP-1), intercellular adhesion molecule-1 (sICAM-1) and homocysteine (HCY) were detected in all patients. RESULTSThe levels of MCP-1, sICAM-1 and HCY increased, respectively, in all three groups ［(27±13) ng/L, (32±14) ng/L and (37±12) ng/L; (2433±745) ng/L, (2726±573) ng/L and (2862±514) ng/L; (16±8) mmol/L, (19.15±8.4) mmol/L and (22±10) mmol/L; all P<0.05］. Stepwise multivariate linear regression showed that MCP-1, HCY and sICAM-1 may be the influencing factors of blood pressure circadian rhythm (partial regression coefficient (B): -0.001, -2.1×10-5 and -0.002, respectively). CONCLUSIONMCP-1, sICAM-1 and HCY may be the influencing factors of blood pressure circadian rhythm in elderly hypertensive patients.