OBJECTIVETo understand the mediating effect of blood lipids on the correlation between body fat and blood pressure among overweight adults.

METHODSOverweight and obese subjects aged 20-55 years who had lived in Beijing for at least 1 year were recruited in this study, Body mass index (BMI) was used as a screening indicators. The percentage of body fat (PBF) was measured for the subjects by using dual energy X-ray absorptiometry (DXA). Mediating effect analysis was conducted to analyze the mediating effect of blood lipids on correlation between PBF and systolic blood pressure (SBP) as well as diastolic blood pressure (DBP).

RESULTSAfter adjusting for age, PBF was positively correlated with SBP and DBP in both males (β = 0.208 3, β = 0.205 2, P < 0.001) and females (β = 0.188 4, β = 0.209 6, P < 0.001). In male subgroup, PBF was negatively correlated with HDL-C level, but positively correlated with LDL-C level (β = -0.142 2, P < 0.01 and β = 0.180 5, P < 0.001), while in female subgroup, PBF was positively correlated with both TC level and LDL-C level (β = 0.172 1, P < 0.001 and β = 0.233 5, P < 0.001). With PBF controlled, TC and TG levels were positively correlated with DBP in both males and females (β = 0.095 6, 0.090 5 for males, β = 0.117 6, 0.083 1 for females, P < 0.05), and TG level was positively correlated with SBP in females (β = 0.127 2, P < 0.001). Further analysis indicated there was a significant mediating effect of LDL-C on correlation between PBF and DBP in females, with the mediating effect value of 0.019 4 (P < 0.05). The ratio of mediating effect was 9.26%.

CONCLUSIONPBF was positively correlated with blood pressure, but blood lipids had no mediating effect on the correlation between PBF and blood pressure in males, while LDL-C level had mediating effect on PBF and blood pressure in females.