Leptin expression in Peripheral Blood Mononuclear Cells (PBMCs) is related with blood pressure variability

Background: Leptin is an adipokine initially considered as a molecule related exclusively to obesity but advances in research revealed its multiple roles in other physio-pathological mechanisms and particularly in the inflammatory ones. The aim of the present study was to demonstrate the presence of leptin in human Peripheral Blood Mononuclear Cells (PBMCs) and to quantify its mRNA in this type of tissue, closely related to inflammation. Methods: Leptin mRNA was present in PBMCs of healthy individuals. Its expression was further studied in 83 individuals in relation to constitutional factors, anthropometric variables, blood pressure, lipid profile, glucose and markers of inflammation (C-reactive protein, lymphocyte count). Results: Expression levels were significantly associated with systolic blood pressure (SBP) (p = 0.03) and diastolic blood pressure (DBP) (p = 0.003). Using a multiple regression analysis model, we showed that leptin mRNA levels explained 11% of the variation of SBP (p = 0.007) and of DBP (p = 0.003). These percentages remained at the same magnitude for SBP (9%) and for DBP (10%). after introducing BMI in the model. Conclusion: We report here for the first time, leptin expression in human PBMCs of healthy individuals. The associations found with blood pressure suggest a possible role of leptin in blood pressure regulation via PBMCs. (C) 2008 Elsevier B.V. All rights reserved.