Biguanides (BGs) rarely cause lactic acidosis, but it is induced by contrast media inhibiting renal excretion of BGs. However, there are few reported data on clinical influence of BGs to serum lactate levels under the use of contrast media, and risk for contrast-induced nephropathy (CIN) under BGs use is unknown. We included type 2 diabetes patients who underwent emergent coronary angiography (eCAG) or emergent percutaneous coronary intervention (ePCI) in New Tokyo Hospital from Jan. 1, 2015, to Dec. 31, 2021. We omitted cases confirmed with conditions that contraindicate metformin (Met) previously and selected 529 cases with pre-exam laboratory value of serum creatinine (SCr), albumin, hemoglobin, HbA1c, B-Type Natriuretic Peptide (BNP) and C-reactive protein, and creatine kinase-MB (CK-MB) within 48 hours. We retrospectively evaluated serum lactate and risk factors for CIN in this cohort by Welch’s t-test. Within 3 hours, two cases started hemodialysis and serum lactate was measured in 241 cases. There was no significant difference in maximum serum lactate between 63 Met users and 178 non-Met users, though the average and median were higher in Met users. Next, we evaluated risk factors for CIN. Within 72 hours, five cases died and SCr was follow-upped in 485 cases. BNP (p<0.05), HbA1c (p<0.05), and maximum CK-MB (p<0.01) were significantly higher in 68 CIN cases than in 417 non-CIN cases, but Met use or amount showed no significant difference. However, in 129 Met users, multiple CAG or PCI was significantly more frequent in CIN cases than in non-CIN cases (p<0.05). In diabetes patients undergoing eCAG or ePCI, Met use does not affect serum lactate significantly, and BNP, HbA1c, and maximum CK-MB are correlated to CIN. Multiple CAG or PCI may be related to CIN in Met users, and a further study with larger population is needed to evaluate this possibility.
Y. Kono: None. M. Haraguchi: None. S. Chou: None.
