Table 1. Metformin Use and Adjusted Risk of Prostate Cancer (PCa) Recurrence After Primary Therapy.

	N=1734	%	HR, 95% CI
Any Metformin Use
No Diabetes mellitus and no metformin use	1265	73	1.0, referent
Diabetes mellitus but never took metformin	103	6	0.75, 0.42-1.32
Metformin use	366	21	0.91, 0.65-1.28
Timing of Metformin Use relative to PCa treatment
No Diabetes mellitus and no metformin use	1265	73	1.0, referent
Metformin user before and < 1 year after treatment	34	2	0.74, 0.26-2.08
Metformin user only after treatment	181	11	1.12, 0.77-1.65
Metformin user before and after treatment	143	8	0.55, 0.31-0.96*
Days of metformin use
No Diabetes mellitus and no metformin use	1265	73	1.0, referent
Days of metformin
0-539	92	5	1.02, 0.59-1.74
540-1349	91	5	1.38, 0.85-2.24
1350-2249	91	5	0.94, 0.54-1.64
• • •	92	5	0.42, 0.21-0.83*
Cumulative dosages of metformin taken
No Diabetes mellitus and no metformin use	1265	73	1.0, referent
Total Sum metformin taken (mg)
0-315,000	92	5	1.16, 0.70-1.95
315,000-855,000	90	5	1.34, 0.82-2.20
855,000 – 1,560,000	93	5	0.85, 0.48-1.51