title: The association between glycemic variability and diabetic cardiovascular autonomic neuropathy in patients with type 2 diabetes.
abstract: BACKGROUND
  It is presently unclear whether glycemic variability is associated with diabetic cardiovascular autonomic neuropathy (CAN). The aim of this study was to examine whether short- and/or long-term glycemic variability (GV) contribute to CAN.
  
  
  METHODS
  A total of 110 patients with type 2 diabetes who underwent three-day continuous glucose monitoring (CGM) completed five standardized autonomic neuropathy tests. Short-term GV was measured by the standard deviation (SD), coefficient of variation (CV) of glucose, and the mean amplitude of glycemic excursions (MAGE) in CGM. HbA1c variability was calculated from the intrapersonal SD, adjusted SD, and CV of serial HbA1c over 2-year period. CAN was defined as the presence of at least two abnormal parasympathetic function tests. The severity of CAN was evaluated by total scores of five autonomic function tests.
  
  
  RESULTS
  In univariate analysis, not only SD and CV in CGM but also all parameters of HbA1c variability were significantly higher in the patients with CAN (n = 47, 42.7 %) than in those without CAN. In multivariate analysis, CV (Odds ratio [OR] 1.07, 95 % confidence interval [CI] 1.01-1.13; p = 0.033), but neither SD nor MAGE in CGM, independently correlated with the presence of CAN. All parameters of HbA1c variability, such as SD of HbA1c (OR 12.10 [95 % CI 2.29-63.94], p = 0.003), adjusted SD of HbA1c (OR 17.02 [95 % CI 2.66-108.86], p = 0.003), and log CV of HbA1c (OR 24.00 [95 % CI 3.09-186.48], p = 0.002), were significantly associated with the presence of CAN. The patients with higher HbA1c variability had an increased risk of advanced CAN.
  
  
  CONCLUSIONS
  CV in CGM and all parameters of HbA1c variability were independently associated with the presence of CAN in patients with inadequately controlled type 2 diabetes requiring CGM.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-Gu, Seoul, 135-710, Republic of Korea. jieun77.jun@samsung.com.
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Jun
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-Gu, Seoul, 135-710, Republic of Korea. sjin772@gmail.com.
authors.forename: Sang-Man
authors.initials: SM
authors.lastname: Jin
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Republic of Korea. Jongha100@gmail.com.
authors.forename: Jongha
authors.initials: J
authors.lastname: Baek
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-Gu, Seoul, 135-710, Republic of Korea. dhtdnjs@hanmail.com.
authors.forename: Sewon
authors.initials: S
authors.lastname: Oh
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-Gu, Seoul, 135-710, Republic of Korea. hurky73@gmail.com.
authors.forename: Kyu Yeon
authors.initials: KY
authors.lastname: Hur
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-Gu, Seoul, 135-710, Republic of Korea. ms0923.lee@samsung.com.
authors.forename: Myung-Shik
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-Gu, Seoul, 135-710, Republic of Korea. mk4132.lee@samsung.com.
authors.forename: Moon-Kyu
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-Gu, Seoul, 135-710, Republic of Korea. jaehyeon@skku.edu.
authors.forename: Jae Hyeon
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000209:etiology / Q000503:physiopathology*; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000209:etiology / Q000503:physiopathology*; D002319:Cardiovascular System / Q000294:innervation*; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism*; D003929:Diabetic Neuropathies / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D014636:Valsalva Maneuver
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human