Hypoglycemia in Type 2 Diabetes--More Common Than You Think: A Continuous Glucose Monitoring Study

J Diabetes Sci Technol. 2015 Apr 27;9(5):999-1005. doi: 10.1177/1932296815581052.


Background: Hypoglycemia is often the limiting factor for intensive glucose control in diabetes management, however its actual prevalence in type 2 diabetes (T2DM) is not well documented.

Methodology: A total of 108 patients with T2DM wore a continuous glucose monitoring system (CGMS) for 5 days. Rates and patterns of hypoglycemia and glycemic variability (GV) were calculated. Patient and medication factors were correlated with rates, timing, and severity of hypoglycemia.

Results: Of the patients, 49.1% had at least 1 hypoglycemic episode (mean 1.74 episodes/patient/ 5 days of CGMS) and 75% of those patients experienced at least 1 asymptomatic hypoglycemic episode. There was no significant difference in the frequency of daytime versus nocturnal hypoglycemia. Hypoglycemia was more frequent in individuals on insulin (alone or in combination) (P = .02) and those on oral hypoglycemic agents (P < .001) compared to noninsulin secretagogues. CGMS analysis resulted in treatment modifications in 64% of the patients. T2DM patients on insulin exhibited higher glycemic variability (GV) scores (2.3 ± 0.6) as compared to those on oral medications (1.8 ± 0.7, P = .017).

Conclusions: CGMS can provide rich data that show glucose excursions in diabetes patients throughout the day. Consequently, unwarranted onset of hypo- and hyperglycemic events can be detected, intervened, and prevented by using CGMS. Hypoglycemia was frequently unrecognized by the patients in this study (75%), which increases their potential risk of significant adverse events. Incorporation of CGMS into the routine management of T2DM would increase the detection and self-awareness of hypoglycemia resulting in safer and potentially better overall control.

Keywords: continuous glucose monitoring system; glycemic variability; hypoglycemia; hypoglycemia unawareness; self-glucose monitoring; type 2 diabetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biosensing Techniques
  • Blood Glucose / analysis*
  • Blood Glucose Self-Monitoring
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / drug therapy
  • Female
  • Glycated Hemoglobin
  • Humans
  • Hypoglycemia / blood*
  • Hypoglycemia / chemically induced
  • Hypoglycemic Agents / adverse effects*
  • Hypoglycemic Agents / therapeutic use
  • Insulin / adverse effects*
  • Insulin / therapeutic use
  • Middle Aged
  • Prospective Studies


  • Blood Glucose
  • Glycated Hemoglobin A
  • Hypoglycemic Agents
  • Insulin