Fig. 4

Forest plot of relationships between serum lipid parameters and cognitive impairment in the subgroups stratified by gender and age (models 5, 6 and 7). The population was divided into two gender-based subgroups (male and female) in model 5, two age-based subgroups (≤ 55 and > 55) in model 6, four both gender and age-based subgroups (female, ≤ 55; female, > 55; male, ≤ 55 and male, > 55) in model 7. Every serum lipid parameter (high TC, high LDL-C, low HDL-C and high TG) was included in every subgroup of these 3 models. The confounding variables considered in model 5, 6 and 7 were as follows: years of education, tobacco use, alcohol consumption, lack of physical activity, CHD, MAP, BMI, and FBG. Abbreviations: OR, odds ratio; CI, confidence interval; TC, total cholesterol; LDL, low-density lipoprotein; HDL, high-density lipoprotein; TG, triglycerides; CHD, coronary heart disease; MAP, mean arterial pressure; BMI, body mass index; FBG, fasting blood glucose