Metabolic Syndrome (MetS) exerts a significant adverse impact on human health, while the Lipid Accumulation Product (LAP) is capable of reflecting the degree of visceral fat accumulation in the human body. Previous studies investigating the relationship between LAP and MetS have mostly been cross-sectional studies, with a lack of evidence from cohort studies. Additionally, the predictive ability of LAP varies across different studies, and its value in predicting the future incidence of MetS requires further exploration.

To analyze the relationship between long-term exposure to the LAP and the risk of developing MetS, and to explore the predictive performance of this index for MetS, thereby providing evidence for the early prevention of MetS.

This study utilized data from the Guizhou Natural Population Cohort Study. The cohort was established between November 2010 and December 2012, and a follow-up survey was conducted on the baseline participants from April 2016 to October 2020. Participants were divided into 4 groups (Q1 to Q4) based on their baseline LAP levels: Q1 (LAP<8.52, n=1 003), Q2 (8.52≤LAP<15.44, n=1 001), Q3 (15.44≤LAP<27.85, n=1 006), and Q4 (LAP≥ 27.85, n=1 003). Cox proportional hazards models were used to analyze the relationship between LAP and MetS in the total population and in subgroups stratified by sex. Hazard ratios (HR) and their corresponding 95% confidence intervals (95%CI) were calculated. Restricted cubic splines were applied to evaluate the dose-response relationship between LAP and the incidence of MetS. Additionally, time-dependent receiver operating characteristic (ROC) curves for LAP in predicting MetS were plotted to assess the predictive performance of this index.

A total of 4 013 study subjects were enrolled, including 1 803 males (44.93%) and 2 210 females (55.07%). The baseline mean age was (43.7±14.6) years, with a mean BMI of (22.45±2.84) kg/m². The median follow-up duration was 6.54 years, during which 889 cases of MetS were observed. The MetS incidence rates in the overall population, males, and females were 31.62 per 1 000 person-years, 33.36 per 1 000 person-years, and 30.19 per 1 000 person-years, respectively. Cox proportional hazards regression analysis showed that after adjusting for relevant confounding factors, the risk of MetS increased with the elevation of the LAP (P _{for trend}<0.05). In the total population, compared with the Q1 group, the adjusted hazard ratios (aHRs) or MetS risk were gradually elevated in the Q2 (aHR=1.26, 95%CI=1.02-1.57), Q3 (aHR=1.35, 95%CI=1.08-1.68), and Q4 (aHR=1.55, 95%CI=1.24-1.94) (P<0.05). In the male, compared with the Q1 group, the Q2 (aHR=1.45, 95%CI=1.09-1.93), Q3 (aHR=1.52, 95%CI=1.12-2.05), Q4 (aHR=1.56, 95%CI=1.13-2.10) all exhibited an increased risk of MetS (P<0.05). In the female, however, a significant increase in MetS risk was only observed in the Q4 (aHR=1.44, 95%CI=1.03-2.01) relative to the Q1 group (P<0.05). Result s from restricted cubic splines indicated a linear dose-response relationship between LAP and MetS risk in the total population (P_overall<0.05, P_nonlinear=0.069) and the male subgroup (P_overall<0.05, P_nonlinear=0.255), while a non-linear dose-response relationship was observed in the female subgroup (P_overall<0.05, P_nonlinear=0.038). The results of time-dependent ROC curves showed that for the prediction of MetS after 7, 8, and 9 years of LAP exposure, the AUC values in the total population were 0.56, 0.56, and 0.57, respectively, in males, the AUC values were 0.55, 0.55, and 0.59, respectively, and in females, the AUC values were 0.57, 0.58, and 0.57, respectively.

Elevated LAP levels increase the risk of MetS in the general population and across different sex groups. However, its predictive efficacy for future MetS development is limited, making it an suboptimal prognostic marker. Thus, more indicators with higher predictive value should be explored.