Hypoglycemia Incidence in Older Adults by Estimated GFR

Background: Bedside estimates of the risk for hypoglycemia by estimated glomerular filtration rate (eGFR), urine albumin-creatinine ratio (ACR), and use of antihyperglycemic medications would be helpful.

Study design: Population-based cohort study.

Setting & participants: Older adults (mean age, 75 years) in Ontario, Canada, from April 2002 through March 2013.

Factors: eGFR stage, ACR stage, and use of antihyperglycemic medications.

Outcome: 3-year incidence rate of a hospital encounter with hypoglycemia (emergency department or inpatient encounter).

Results: In users and nonusers of antihyperglycemic medications, there was a graded increase in risk for hypoglycemia by eGFR stage. Incidence rates in antihyperglycemic medication users were 82 (95% CI, 71-94), 122 (95% CI, 115-130), 235 (95% CI, 218-254), 379 (95% CI, 349-413), 596 (95% CI, 524-678), and 785 (95% CI, 689-894) encounters per 10,000 person-years when eGFR was ≥90, 60 to <90, 45 to <60, 30 to <45, 15 to <30, and <15mL/min/1.73m² or the patient was receiving dialysis, respectively (P<0.001). Corresponding values in nonusers were 2 (95% CI, 2-4), 3 (95% CI, 3-4), 3 (95% CI, 2-4), 7 (95% CI, 5-9), 14 (95% CI, 9-22), and 55 (95% CI, 43-71) encounters/10,000 person-years, respectively (P<0.001). A similar relationship was evident by eGFR and ACR risk category.

Limitations: Only hypoglycemia episodes that were associated with a hospital encounter were assessed. Results cannot be generalized to younger patients.

Conclusions: In older adults, the risk for hypoglycemia is higher in those with lower kidney function. Our results may aid the patient-provider dialogue and inform future studies to prevent hypoglycemia in an at-risk population.