Fig. 2

Dose-response relationship of HbA1c levels with all-cause mortality in subjects without diabetes mellitus in the NHANES with (a) adjustment for age and sex and (b) adjustment for all potential confounders (“full” model including biomarkers of iron deficiency and liver function). Solid line, estimation; points in solid lines, knots; horizontal dashed line, null effect value (hazard ratio = 1); curved dashed lines, boundaries of 95 % confidence interval band of estimation