Background: Diabetes is a risk factor for many cancers; chronic hyperglycemia is hypothesized to be, in part, explanatory. We evaluated the association between glycated hemoglobin, a time-integrated glycemia measure, and cancer incidence and mortality in non-diabetic and diabetic men and women.

Methods: We conducted a prospective study of 12,792 cancer-free participants attending the second visit (1990–1992) of the Atherosclerosis Risk in Communities (ARIC) Study. We measured glycated hemoglobin in whole-blood samples using HPLC. Incident cancers were ascertained from registries and hospital records through 2006. We estimated multivariable-adjusted hazard ratios (HR) of cancer incidence and mortality for non-diabetic participants with values ≥5.7% (elevated), non-diabetic participants with <5.0% (low), and diabetic participants all compared with non-diabetic participants with 5.0–5.6% (normal).

Results: We ascertained 2,349 incident cancer cases and 887 cancer deaths. Compared with non-diabetic women with normal glycated hemoglobin, non-diabetic women with elevated values had an increased risk of cancer incidence (HR:1.24; 95% CI:1.07,1.44) and mortality (HR:1.58; 95% CI:1.23,2.05) as did diabetic women (incidence, HR:1.30; 95% CI:1.06,1.60, mortality, HR:1.96; 95% CI:1.40,2.76). Non-diabetic women with low values also had increased risk. Diabetic women with good glycemic control (<7.0%) had a lower cancer risk than those with higher values. Glycated hemoglobin in non-diabetic and diabetic men, and diabetes were not associated with risk.

Conclusions: Our findings support the hypothesis that chronic hyperglycemia, even in the non-diabetic range, increases cancer risk in women, but not men. Maintaining normal glycated hemoglobin overall, and good glycemic control among diabetic adults, may reduce the burden of cancer.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A74.