Association of hypoglycemic symptoms with patients' rating of their health-related quality of life state: a cross sectional study

Abstract

Background: To evaluate the association between patient-reported hypoglycemic symptoms with ratings of their health-related quality of life state and patient-reported adverse events in patients with type 2 diabetes mellitus (T2DM).

Methods: This observational, multicenter, cross sectional study was based on a sample of patients with T2DM from seven European countries who added sulfonylurea or thiazolidinedione to metformin monotherapy between January 2001 and January 2006. Included patients were required to have at least one hemoglobin A1c (HbA1c) measurement in the 12 months before enrollment and to not be receiving insulin. Demographic and clinical data from medical records were collected using case report forms. Questionnaires measured patient-reported hypoglycemic symptoms, health-related quality of life (EuroQol visual analogue scale, EQ-5D VAS), and treatment-related adverse events.

Results: A total of 1,709 patients were included in the study. Mean patient age was 63 years, 45% were female, mean HbA1c was 7.06%, and 28% were at HbA1c goal (HbA1c < 6.5%). Hypoglycemic symptoms during the 12 months before enrollment were reported by 38% of patients; among whom 68% reported their most severe symptoms were mild, 27% moderate, and 5% severe. Adjusted linear regression analyses revealed that patients reporting hypoglycemic symptoms had significantly lower EQ-5D VAS scores indicating worse patient-reported quality of life (mean difference -4.33, p < 0.0001). Relative to those not reporting symptoms, the adjusted decrement to quality of life increased with greater hypoglycemic symptom severity (mild: -2.68, p = 0.0039; moderate: -6.42, p < 0.0001; severe: -16.09, p < 0.0001). Patients with hypoglycemia reported significantly higher rates of shakiness, sweating, excessive fatigue, drowsiness, inability to concentrate, dizziness, hunger, asthenia, and headache (p < 0.0001 for each comparison).

Conclusions: Hypoglycemic symptoms and symptom severity have an adverse effect on patients' rating of their health related quality of life state. Hypoglycemic symptoms are correlated with treatment-related adverse effects. Minimizing the risk and severity of hypoglycemia may improve patients' quality of life and clinical outcomes. Results are subject to limitations associated with observational studies including the potential biases due to unobserved patient heterogeneity and the use of a convenience sample of patients.

Figure 1

Prevalence of patient-reported experience of hypoglycemic symptoms* and symptom severity^† during the 12 months prior to the patient enrollment date. * Hypoglycemic symptoms are based on the response to the question: "Have you ever felt symptoms of hypoglycemia (low blood sugar) in the last year?". † Hypoglycemic symptom severity is based on the most severe form reported by a patient, i.e. if a patient reports both 'mild' and 'moderate' symptoms, the patient is listed only under the 'moderate' symptoms group. Mild symptoms were defined as: Little or no interruption of your activities, and you didn't feel you needed assistance to manage symptoms. Moderate symptoms were defined as: Some interruption of your activities, but you didn't feel you needed assistance to manage symptoms. The severe symptoms group is a consolidation of the 'severe' and 'very severe' symptoms that were respectively defined as: Felt that you needed assistance of others to manage symptoms (for example, to bring you food or drink), and needed medical attention (for example, called an ambulance, visited an emergency room or hospital, or saw a doctor or nurse).

Figure 2

Patient-reported experience of treatment-related adverse events and experience of hypoglycemic symptoms. Points (filled boxes) signify odds ratios; error bars signify 95% confidence intervals.