Potential Impact of Prescribing Metformin According to eGFR Rather Than Serum Creatinine

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Diabetes care


OBJECTIVE: Many societies recommend using estimated glomerular filtration rate (eGFR) rather than serum creatinine (sCr) to determine metformin eligibility. We examined the potential impact of these recommendations on metformin eligibility among U.S. adults.

RESEARCH DESIGN AND METHODS: Metformin eligibility was assessed among 3,902 adults with diabetes who participated in the 1999-2010 National Health and Nutrition Examination Surveys and reported routine access to health care, using conventional sCr thresholds (eligible if

RESULTS: Among adults with sCr above conventional cutoffs, MDRD eGFR ≥45 mL/min/1.73 m(2) was most common among men (adjusted odds ratio [aOR] 33.3 [95% CI 7.4-151.5] vs. women) and non-Hispanic Blacks (aOR vs. whites 14.8 [4.27-51.7]). No individuals with sCr below conventional cutoffs had an MDRD eGFR/min/1.73 m(2). All estimating equations expanded the population of individuals for whom metformin is likely safe, ranging from 86,900 (CKD-EPIcr) to 834,800 (CG). All equations identified larger populations with eGFR 30-44 mL/min/1.73 m(2), for whom metformin safety is indeterminate, ranging from 784,700 (CKD-EPIcr) to 1,636,000 (CG).

CONCLUSIONS: The use of eGFR or CrCl to determine metformin eligibility instead of sCr can expand the adult population with diabetes for whom metformin is likely safe, particularly among non-Hispanic blacks and men.

Medical Subject Headings

Adult; Aged; Aged, 80 and over; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drug Prescriptions; Female; Glomerular Filtration Rate; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Nutrition Surveys; Practice Guidelines as Topic; Renal Insufficiency, Chronic; Young Adult

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