title: Impaired diurnal cardiac autonomic function in subjects with type 2 diabetes.
abstract: OBJECTIVE
  To assess diurnal cardiac sympathetic and parasympathetic nerve functions in diabetic subjects with variable diabetic neuropathy.
  
  
  METHODS
  Frequency domain analysis of 24-h Holter ECG was done for 132 diabetic subjects (84 without any symptomatic neuropathy; 37 with only symptomatic peripheral neuropathy; 11 with symptomatic autonomic neuropathy) and 57 normal volunteers to calculate the low frequency (LF) component representing the beta-adrenoceptor function and the high frequency (HF) component representing the cardiac parasympathetic nerve function.
  
  
  RESULTS
  Cardiac LF and HF components in diabetic subjects without peripheral neuropathy showed values comparable to those of normal volunteers and a similar circadian rhythm. Diabetic subjects with peripheral neuropathy or autonomic neuropathy showed significantly depressed LF and HF components and loss of the circadian rhythm of LF and HF components compared with diabetic subjects without neuropathy. Impairment of the LF component in the afternoon could be accounted for by the duration of diabetes and elevated HbA1c level. Impairment of the HF component at night could be accounted for by the duration of diabetes but not an elevated HbA1c level.
  
  
  CONCLUSIONS
  These data indicated that diabetic subjects with peripheral neuropathy and diabetic subjects with symptomatic autonomic neuropathy, but not diabetic subjects without neuropathy, showed a marked decrease in cardiac sympathetic and parasympathetic nerve functions and loss of circadian rhythm.
authors.affiliation: First Department of Medicine, Osaka University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Yamasaki
authors.forename: M
authors.initials: M
authors.lastname: Kodama
authors.forename: M
authors.initials: M
authors.lastname: Matsuhisa
authors.forename: M
authors.initials: M
authors.lastname: Kishimoto
authors.forename: H
authors.initials: H
authors.lastname: Ozaki
authors.forename: A
authors.initials: A
authors.lastname: Tani
authors.forename: N
authors.initials: N
authors.lastname: Ueda
authors.forename: M
authors.initials: M
authors.lastname: Iwasaki
authors.forename: M
authors.initials: M
authors.lastname: Hori
mesh_terms: D000328:Adult; D000368:Aged; D002940:Circadian Rhythm; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000503:physiopathology; D015716:Electrocardiography, Ambulatory; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010275:Parasympathetic Nervous System / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*