Fig. 1

Associations between individual MetS components and risk of liver cancer, allowing for non-linear effects. A. Waist Circumference; B. Glucose; C. Triglycerides; D. High Density Lipoprotein; E. Systolic Blood Pressure; F. Diastolic Blood Pressure. The reference levels of MetS components in these plots (with HR fixed as 1.0) were 90 cm for waist circumference, 1.7 mmol/L for triglyceride, 1.52 mmol/L for HDL-cholesterol, 5.6 mmol/L for fasting glucose, 140.33 mmHg for systolic blood pressure and 81.29 mmHg for diastolic blood pressure. Separate models were fitted using restricted cubic spline with 4 knots at 5th, 35th, 65th, and 95th percentiles for each MetS component, adjusted for age at baseline, gender, education, ethnic, index of multiple deprivation, alcohol consumption, smoking status, physical activity, fruit and vegetable intake, comorbidities, family history of cancer, menopause status (for the female only) and hormone replacement therapy (for the female only) and levels of other MetS component. The “p-overall” represented the overall significance (including linear effect and nonlinear effect) for each MetS component and was derived using a likelihood ratio test comparing the model with linear and cubic spline terms of each MetS component against the model including only all covariates. The “p-non-linear” represented the nonlinear significance of nonlinear effect for each MetS component, and was derived using a likelihood ratio test comparing the model with linear and cubic spline terms of each MetS component against the model with only a linear term of each MetS component, after adjustment all covariates. Estimated HRs per unit derived from best fitting piecewise linear model. For the MetS components (HDL, SBP/DBP) showing U-associations, estimated HRs per unit were performed in two parts according to the point with the lowest risk. Abbreviation: CI, confidence interval; DBP, diastolic blood pressure; HDL, high density lipoprotein; HR, hazard ratio; SBP, systolic blood pressure; TG, triglycerides; WC, waist circumference