Severe Hypoglycemia Identifies Vulnerable Patients With Type 2 Diabetes at Risk for Premature Death and All-Site Cancer: The Hong Kong Diabetes Registry

Abstract

OBJECTIVE We examined the associations of clinical profiles in type 2 diabetic patients who developed severe hypoglycemia and their clinical outcomes, including death and all-site cancer. RESEARCH DESIGN AND METHODS A consecutive cohort of 8,767 type 2 diabetic patients with and without severe hypoglycemia in the 12 months before enrollment were recruited between 1995 and 2007, with follow-up until 2009. Severe hypoglycemia was defined by ICD-9 codes as hospitalizations resulting from hypoglycemia. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and 95% CIs of clinical factors collected at enrollment for severe hypoglycemia. RESULTS In this cohort, mean age was 57.4 (SD 13.2) years and median disease duration of diabetes was 5 (interquartile range [IQR] 1–11) years. During a median follow-up of 6.71 (IQR 3.47–10.38) years, 235 patients had severe hypoglycemia (incidence 3.96 [95% CI 3.45–4.46] per 1,000 patient-years). At enrollment, patients with and without severe hypoglycemia had similar cancer rates. During follow-up, patients with severe hypoglycemia had a higher incidence of all-site cancer (13.4 vs. 6.4%, P < 0.0001) and mortality (32.8 vs. 11.2%, P < 0.0001) than those without severe hypoglycemia. After adjusting for confounders, old age, low BMI, high glycated hemoglobin, low triglyceride (TG), low LDL cholesterol (LDL-C), albuminuria, and chronic kidney disease were independent predictors for severe hypoglycemia. CONCLUSIONS In type 2 diabetes, severe hypoglycemia is associated with advanced age, renal dysfunction, poor glycemic control, and cancer subphenotypes (low BMI, low LDL-C, and low TG).