A1C less than 4% increased mortality

Low hemoglobin A1c and risk of all-cause mortality among US adults without diabetes.
Carson AP, Fox CS, McGuire DK, Levitan EB, Laclaustra M, Mann DM, Muntner P.

Department of Epidemiology, University of Alabama at Birmingham, 35294-0022, USA. apcarson@uab.edu

Abstract
BACKGROUND: Among individuals without diabetes, elevated hemoglobin A1c (HbA1c) has been associated with increased morbidity and mortality, but the literature is sparse regarding the prognostic importance of low HbA1c.

METHODS AND RESULTS: National Health and Nutrition Examination Survey III (NHANES III) participants, 20 years and older, were followed up to 12 years (median follow-up, 8.8 years) for all-cause mortality. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for the association between HbA1c levels and all-cause mortality for 14 099 participants without diabetes. There were 1825 deaths during the follow-up period. Participants with a low HbA1c (<4 data-blogger-escaped-.0="" data-blogger-escaped-1.25="" data-blogger-escaped-1.45="" data-blogger-escaped-2.90="" data-blogger-escaped-3.73="" data-blogger-escaped-4.0="" data-blogger-escaped-5.0="" data-blogger-escaped-5.4="" data-blogger-escaped-6.4="" data-blogger-escaped-6.76="" data-blogger-escaped-9.63="" data-blogger-escaped-95="" data-blogger-escaped-adjustment="" data-blogger-escaped-after="" data-blogger-escaped-age="" data-blogger-escaped-all-cause="" data-blogger-escaped-an="" data-blogger-escaped-and="" data-blogger-escaped-associated="" data-blogger-escaped-association="" data-blogger-escaped-attenuated="" data-blogger-escaped-between="" data-blogger-escaped-blood="" data-blogger-escaped-br="" data-blogger-escaped-but="" data-blogger-escaped-cardiovascular="" data-blogger-escaped-cell="" data-blogger-escaped-cholesterol="" data-blogger-escaped-ci="" data-blogger-escaped-compared="" data-blogger-escaped-counterparts="" data-blogger-escaped-diastolic="" data-blogger-escaped-enzymes="" data-blogger-escaped-factors="" data-blogger-escaped-ferritin="" data-blogger-escaped-for="" data-blogger-escaped-function="" data-blogger-escaped-further="" data-blogger-escaped-had="" data-blogger-escaped-hba1c="" data-blogger-escaped-highest="" data-blogger-escaped-increased="" data-blogger-escaped-indices="" data-blogger-escaped-iron="" data-blogger-escaped-levels="" data-blogger-escaped-lifestyle="" data-blogger-escaped-liver="" data-blogger-escaped-lowest="" data-blogger-escaped-mean="" data-blogger-escaped-metabolic="" data-blogger-escaped-mortality="" data-blogger-escaped-multivariable="" data-blogger-escaped-of="" data-blogger-escaped-pressure="" data-blogger-escaped-race-ethnicity="" data-blogger-escaped-red="" data-blogger-escaped-remained="" data-blogger-escaped-risk="" data-blogger-escaped-sex.="" data-blogger-escaped-significant="" data-blogger-escaped-statistically="" data-blogger-escaped-storage="" data-blogger-escaped-the="" data-blogger-escaped-their="" data-blogger-escaped-this="" data-blogger-escaped-to="" data-blogger-escaped-total="" data-blogger-escaped-versus="" data-blogger-escaped-volume="" data-blogger-escaped-was="" data-blogger-escaped-with="">
CONCLUSIONS: In this nationally representative cohort, low HbA1c was associated with increased all-cause mortality among US adults without diabetes. Additional research is needed to confirm these results and identify potential mechanisms that may be underlying this association.