Cardiovascular autonomic dysfunction predicts severe hypoglycemia in patients with type 2 diabetes: a 10-year follow-up study

Diabetes Care. 2014;37(1):235-41. doi: 10.2337/dc13-1164. Epub 2013 Aug 19.

Abstract

OBJECTIVE The aim of this study was to investigate the development of severe hypoglycemia (SH) in the presence of cardiovascular autonomic neuropathy (CAN) in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS From January 2001 to December 2002, a total of 894 patients with type 2 diabetes were enrolled. A cardiovascular autonomic function test (AFT) was performed using the following heart rate variability parameters: expiration-to-inspiration ratio, response to Valsalva maneuver, and standing. From the results for each of the three tests (0 for normal, 1 for abnormal), a total AFT score of 1 was defined as early CAN, and an AFT score of ≥2 was defined as definite CAN. RESULTS The median follow-up time was 9.5 years. The mean age was 54.5 ± 10.1 years, and the mean duration of diabetes was 8.9 ± 6.3 years. One hundred ninety-six patients (31.4%) showed an abnormal cardiovascular AFT score at baseline. Sixty-two patients (9.9%) experienced 77 episodes of SH (1.33 per 100 patient-years). The number of SH events increased as the CAN score increased (23 patients [5.4%] with normal score; 17 patients [17.2%] with early CAN; and 22 patients [22.7%] with definite CAN; P for trends < 0.001). Cox proportional hazards regression analysis revealed that SH was associated with definite CAN (normal vs. definite CAN: hazard ratio 2.43 [95% CI 1.21-4.84]; P = 0.012). CONCLUSIONS Definite CAN was an independent prognostic factor for the development of SH in patients with type 2 diabetes.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Aged
  • Autonomic Nervous System / physiopathology*
  • Cardiovascular System / physiopathology*
  • Cohort Studies
  • Diabetes Mellitus, Type 2 / complications*
  • Diabetes Mellitus, Type 2 / physiopathology*
  • Female
  • Follow-Up Studies
  • Heart Rate / physiology
  • Humans
  • Hypoglycemia / epidemiology*
  • Hypoglycemia / physiopathology
  • Incidence
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Posture / physiology
  • Predictive Value of Tests
  • Prospective Studies
  • Regression Analysis
  • Risk Factors
  • Valsalva Maneuver / physiology