Table 1. The impact of metformin on the development of myeloma in MGUS.

A) Association of metformin and other diabetes therapy with incident myeloma in patients with MGUS.
	Cases N=124	Controls N=760	Unadjusted OR	Adjusted § OR
No diabetes	113	633	Ref	Ref
Diabetes, no therapy	6	38	0.95 (0.38-2.35)	0.96 (0.38-2.38)
Diabetes, metformin exposed	4	65	0.39 (0.14-1.10)	0.39 (0.14-1.13)
Diabetes, other therapy without metformin exposure**	1	24	0.17 (0.02-1.29)	0.17 (0.02-1.28)
B) Association of metformin duration with incident MM in patients with MGUS and diabetes*.
	Cases (n=11)	Controls (n=127)	Unadjusted OR	Adjusted ** OR
Diabetes, never exposed to metformin	7	62	Ref	Ref
Diabetes, metformin exposure < 24 mos	2	17	1.04 (0.20- 5.48)	1.01 (0.18-5.65)
Diabetes, metformin exposure > 24 mos	2	48	0.37 (0.07-1.87)	0.40 (0.08-2.04)

^§Adjusted for obesity (BMI>30mg/m2) and smoking (ever).

^*This analysis was unmatched.

^**Unconditional logistic regression was used adjusted for age, sex, obesity and smoking.