Table 4.

Breast Cancer Events and HbA1C Stratified by Self-Reported Type 2 Diabetes Mellitus in a Cohort of US Breast Cancer Survivors (N = 3,088)

Self-Report of Diabetes	HbA1C												Total Events
	< 6.5% (n = 2,818)			6.5% to 6.9% (n = 94)			≥ 7.0% (n = 91)			Missing HbA1C (n = 85)
	No. of Participants	No. of Breast Cancer Events	%	No. of Participants	No. of Breast Cancer Events	%	No. of Participants	No. of Breast Cancer Events	%	No. of Participants	No. of Breast Cancer Events	%	No. of Participants	No. of Breast Cancer Events	%
No diabetes	2,287	353	15.4	71	14	19.7	47	7	14.9	76	17	18.4	2,481	391	15.6
Diabetes, no medication	5	0	0	2	0	0	6	2	33.3	0	0	0	13	2	15.3*
Diabetes, medication	4	2	50	7	2	28.6	31	10	32.2	1	0	0	43	14	32.6*
Missing†	522	109	21	14	2	14	7	0	0	8	1	12.5	551	112	20.3‡

Abbreviation: HbA1C, hemoglobin A1C.

^*Because of small numbers, diabetes strata were combined (total events, n = 16/56, 28.6%; comparison with no diabetes, Cox model P = .01).

^†Includes five women who completed the baseline health status questionnaire but did not complete question on diabetes.

^‡Comparison with no diabetes, Cox model P = .65.