Objective: To investigate the impact of high plasma LDL-C level with or without metabolic syndrome (MS) on the incidence of stroke in Chinese adults.
Methods: Totally 42 626 subjects (25-75 years old) from Chinese National Health and Nutrition Survey in 2002 were stratified four groups based on plasma LDL-C level:<2.00 mmol/L group, 2.00-2.50 mmol/L group, 2.51-3.31 mmol/L group, and >or=3.32 mmol/L group. The prevalence of MS (with 2005 International Diabetes Federation criteria) and stroke and the risk factors of stroke were compared among the four groups.
Results: (1) The prevalence of MS and stroke increased with rising of LDL-C level. The prevalence of MS in LDL-C>or=3.32 mmol/L group increased 2.5 times (7.9% vs 20.1%) as compared with that in LDL-C<2.00 mmol/L group and the prevalence of stroke increased 4.2 times (0.5% vs 2.1%), all P<0.01. (2) In subjects with similar LDL-C level, the prevalence of stroke was significantly higher in a subgroup with MS than that without (P<0.01). (3) After adjustment for age, sex and smoking, logistic regression analysis showed that both LDL-C level and MS were positively associated with the development of stroke; the odds ratio (OR) was 2.35 and 3.15 (P<0.0001), respectively. (4) Compared with the subgroup of LDL-C<2.00 mmol/L without MS, OR for stroke in the subgroups of LDL-C 2.00-2.50 mmol/L, 2.51-3.31 mmol/L, and >or=3.32 mmol/L without MS was 1.03, 1.89, and 2.08, whereas the OR for stroke in the subgroups with MS and similar level of LDL-C was 4.38, 5.23 and 6.15; this indicated that the risk of stroke in subjects with MS increased by 3-4 times compared with subjects without (P<0.0001).
Conclusion: Both high LDL-C level and MS are independent risk factors of stroke, but the risk of stroke will be further increased in the presence of high LDL-C level plus MS. It is suggested that combined intervention therapy of LDL-C and MS will play an important role in the prevention of stroke.