CRP and diabetes mellitus: In the current study we have also shown that smoking remains positively correlated with HbA1c in a subsample of participants who are not affected by any metabolic derangements from pre-diabetes (with HbA1c < 5.7%, 39 mmol/mol) and in a subsample with both HbA1c < 5.7% (39 mmol/mol) and CRP levels < 28.5 nmol/L to exclude any influence from low-grade inflammation.