Abstract: FR-PO652

Metformin Use Does Not Increase Risk of Clinical Acidosis in Diverse Population of CKD Patients

Session Information

Category: Diabetes

  • 502 Diabetes Mellitus and Obesity: Clinical

Authors

  • Ferrandino, Rocco, Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Van Vleck, Tielman T, Mount Sinai School of Medicine, New York, New York, United States
  • Leventhal, Jeremy S., Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Ferket, Bart, Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Uribarri, Jaime, Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Nadkarni, Girish N., Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Coca, Steven G., Icahn School of Medicine at Mount Sinai, New York, New York, United States
Background

Metformin use in type 2 diabetes (T2D) patients with Stage 3a chronic kidney disease (CKD3a) has been cautioned because of concerns for associated metabolic acidosis. We used a large multiethnic urban cohort to assess both rates of acidosis and absolute difference in serum bicarbonate in new users of metformin compared to non-users.

Methods

We identified T2D with CKD3a from the Mount Sinai CKD Registry and propensity-matched metformin new-user: non-user pairs 1:1 on baseline data. We calculated incidence rate ratios (IRR) of acidosis (bicarbonate level ≤22 MEQ/L and serum anion gap (SAG)≥12) using negative binomial regression. We examined the longitudinal effect of metformin use on patient bicarbonate levels using linear mixed effect modeling.

Results

We had data on 1494 patients (747 matched pairs). Median age was 74, 45.2% was male, baseline eGFR was 49.6. Baseline bicarbonate was similar in both metformin user (25.7 MEQ/L) and non-users (25.0 MEQ/L). Acidosis events in new metformin users and non-users were 13.8 and 23.0 events/100 patient years over follow up. Adjusted IRR over follow up were 0.73 (95% CI 0.61 – 0.88), respectively. The serum bicarbonate over follow up was statistically higher but not clinically different in the user vs. non-user group (Difference= 0.18, SE=0.08, P=0.02).

Conclusion

In a large healthcare cohort of T2D patients with CKD3a, new prescription of metformin was not associated with either acidosis events or lower bicarbonate levels compared to non-users, suggesting that concerns for metformin associated lactic acidosis in this population may not be warranted.

Figure 1. A. Unadjusted and adjusted IRRs for acidosis events are reduced in metformin users. B. Descriptive statistics of incidence and laboratory values during acidosis events.

Funding

  • Other NIH Support