[Correlation study of BMI and blood pressure in Xinjiang oil workers: a cross-lagged pathway analysis with blood lipids as a mediator].

Objective

To define the causal time-series link between blood pressure and the body mass index (BMI) using cross-logged pathway analysis. And to determine the moderating role of blood lipids in the relationship between BMI and blood pressure.

Methods

In January 2022, a study was conducted involving 19, 959 oil workers in Xinjiang who participated in the study in 2022 and completed their follow-up in 2023. The BMI, total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), and blood pressure of the research subjects were measured repeatedly during the follow-up period. The correlations between BMI, TG, HDL and blood pressure at baseline time point and follow-up time point were analyzed by Spearman rank correlation. A cross-lagged pathway analysis model was used to analyze the causal time-series link between BMI, TG, HDL and increased blood pressure in temporal fluctuation. And bootstrap method was adopted to further understand the mediating role of TC and TG in the association between BMI and blood pressure.

Results

The results of the correlation analysis showed that the baseline BMI, TG of the Xinjiang oil workers were positively correlated with the follow-up systolic blood pressure (SBP) and diastolic blood pressure (DBP) (r(s)=0.020, 0.017, 0.015, 0.016, P<0.05), while the baseline HDL was negatively correlated with the follow-up SBP and DBP (r(s)=-0.015, -0.017, P<0.05). The cross-lagged pathway analysis results showed that the baseline BMI of Xinjiang oil workers was positively correlated with the follow-up SBP and DBP levels (ρ=0.085, 0.047, P<0.05), the baseline TG was positively correlated with the follow-up SBP and DBP levels (ρ=0.133, 0.094, P<0.05), and the baseline HDL was negatively correlated with the follow-up SBP and DBP levels (ρ=-0.651, -0.505, P<0.05). The mediating analysis results showed that the levels of TC and TG played a partial mediating role in the relationship between BMI and SBP, DBP among Xinjiang oil workers, and the results were statistically significant (P<0.05) .

Conclusion

The BMI rises occur before the changes in blood pressure among oil workers. In addition, the lipid changes that emerged after the increase of BMI play a partial mediating role in the causal link between BMI and blood pressure.