Table 1. Patient characteristics.

	Case 1	Case 2	Case 3	Case 4	Case 5	Case 6	Mean ± SD
Demographics
Age (years)	81	81	72	54	63	64	69±11
Gender	F	F	F	M	F	F	-
Coexisting medical conditions
McCabe scale	0	0	0	1	0	0	-
Knaus score	B	B	B	C	D	A	-
Charlson comorbidity index	3	5	1	2	2	1	2.3±1.5
Chronic renal failure	No	No	Yes	Yes	No	No	-
Nephrotoxic drugs
Diuretics	No	Yes	No	Yes	Yes	Yes	-
Angiotensin converter inhibitors	Yes	No	No	Yes	No	Yes	-
Nonsteroidal anti-inflammators	No	No	No	No	No	No	-
Aspirin	No	No	No	Yes	No	Yes	-
Metformin
Daily dose (mg)	2250	3000	1700	1000	3000	3000	2375±842

F, female; M, male; McCabe scale (life expectancy), 0: none or nonfatal underlying disease, 1: ultimately fatal disease (death≤5 years), 2: rapidly fatal disease (death≤1 year); Knaus score (functional status), A: no daily activity limitation, the patient was in good health, B: moderate limitation of activity because of a chronic medical problem, C: strong limitation of activity due to disease, D: severe limitation and/or restriction of activity due to disease; Charlson comorbidity index, components (weights): myocardial infarct (1), congestive heart failure (1), peripheral vascular disease (1), cerebrovascular disease (1), dementia (1), chronic pulmonary disease (1), connective tissue disease (1), ulcer disease (1), mild liver disease (1), diabetes (1), hemiplegia (2), moderate or severe renal disease (2), diabetes with end-organ damage (2), any tumor (2), leukemia (2), lymphoma (2), moderate or severe liver disease (3), metastatic solid tumor (6), AIDS (6).