Risk Factors Associated with Symptomatic Hypoglycemia in Type 2 Diabetes Mellitus Patients

Objective: To identify risk factors associated with symptomatic hypoglycemia (SH) (< or = 72 mg/dL) in patients with type 2 diabetes mellitus (t2DM) treated at a general hospital during July 2003 to December 2004.

Material And Methods: Ninety four t2DM patients (incident cases) with a primary diagnosis of SH matched with 188 t2DM patients (incident controls) with a diagnosis other than hypoglycemia were included in a case-control study. Demographic and clinical variables entered into an automated binary logistic regression model from which odds ratio (OR) and 95% confidence intervals (95% CI) for variables with a p value < 0.05 were obtained.

Results: The binary logistic model determined that age had a "protective" effect, while duration of t2DM, educational level (Illiteracy-primary education, OR 3.7, [95% CI 1.4 to 10]; p = 0.009), attending physicians' specialty (family physician, OR 2.8, [1.02 to 7.9]; p = 0.04), chronic renal failure presence (OR 3.0, [1.2 to 7.7]; p = 0.01), antihyperglycemic treatment (combined therapy, OR 5.2, [2.3 to 11.8]; p < 0.01), fasting (OR 19.8, [9.1 to 43.1]; p < 0.001) and history of hypoglycemia (OR 2.9, [1.3 to 6.5]; p = 0.01) were all risk factors associated with SH. The variable "exposure to polypharmacy" was excluded from the logistic model (OR 4.86; [0.7 to 35.1]; p = 0.11).

Conclusions: According to our results, physicians should be cognizant of the possibility that the odds of SH might be increased when treating patients with t2DM fulfilling factors, such as those identified in this investigation.