Serum folate modified the association between low-density lipoprotein cholesterol and carotid intima-media thickness in Chinese hypertensive adults.

BACKGROUND AND AIMS

While folate is known for its importance in cardiovascular health, it is unknown whether folate status can modify the association between low-density lipoprotein cholesterol (LDL-C) and carotid intima-media thickness (CIMT). We aimed to investigate this question in a Chinese hypertensive population, who are at high-risk of low folate and atherosclerosis.

METHODS AND RESULTS

This report included 14,970 hypertensive adults (mean age 64.5 years; 40.3% male) from the China Stroke Primary Prevention Trial (CSPPT) and analyzed the fasting serum LDL-C and folate, and CIMT data obtained at the last follow-up visit. LDL-C was calculated using the Friedewald equation. Serum folate levels were measured by chemiluminescent immunoassay. CIMT was measured by ultrasound. Non-parametric smoothing plots, multivariate linear regression analysis, subgroup analyses and interaction testing were performed to examine the LDL-C-CIMI relationship and effect modification by folate. Consistent with graphic plots, multivariate linear regression showed that LDL-C levels were independently and positively associated with CIMT (β = 7.69, 95%CI: 5.76-9.62). More importantly, the relationship between LDL-C and CIMT was significantly attenuated with increasing serum folate levels (1st tertile: β = 10.06, 95%CI: 6.67-13.46; 2nd tertile: β = 6.81, 95%CI: 3.55-10.07; 3rd tertile: β = 5.96, 95%CI: 2.55-9.36; P-interaction = 0.045). Subgroup analyses showed the association between LDL-C and CIMT across serum folate tertiles was robust among various strata (all P-interaction >0.05).

CONCLUSIONS

Among Chinese hypertensive adults, the serum folate levels could modify the association between LDL-C and CIMT. Our findings, if further confirmed, have important clinical implications.