Table 4 Attenuation of strength of the association of very low HbA_1c levels (<5 % (<31 mmol/mol)) with all-cause and cardiovascular mortality by adding potential confounders to the “simple” model in the NHANES

Age + sex (“simple” model)

1.201 (1.057; 1.328)

1.221 (1.005; 1.409)

N/A

Age + sex + race/ethnicity

1.184 (1.042; 1.341)

1.203 (0.989; 1.453)

Yes

Age + sex + alcohol consumption

1.192 (1.051; 1.353)

1.212 (1.000; 1.469)

Yes

Age + sex + BMI

1.172 (1.033; 1.330)

1.197 (0.988; 1.450)

Yes

Age + sex + physical activity

1.208 (1.065; 1.370)

1.231 (1.016; 1.491)

No

Age + sex + hemoglobin

1.166 (1.027; 1.324)

1.188 (0.980; 1.440)

Yes

Age + sex + ferritin

1.193 (1.052; 1.354)

1.211 (0.999; 1.467)

Yes

Age + sex + total cholesterol

1.192 (1.051; 1.353)

1.226 (1.012; 1.486)

No

Age + sex + erythrocyte protoporphyrin

1.177 (1.036; 1.337)

1.208 (0.995; 1.466)

Yes

Age + sex + GGT

1.178 (1.038; 1.337)

1.206 (0.995; 1.462)

Yes

Age + sex + AST

1.199 (1.057; 1.361)

1.222 (1.009; 1.481)

No

Age + sex + ALT

1.199 (1.057; 1.360)

1.215 (1.003; 1.472)

Yes

Age + sex + race/ethnicity + alcohol consumption + BMI + ferritin + erythrocyte protoporphyrin + GGT + ALT

1.081 (0.950; 1.230)

1.106 (0.909; 1.345)

All variables of Table 1

1.103 (0.968; 1.256)

1.120 (0.921; 1.363)