title: Characteristics in the beat-to-beat laser-Doppler waveform indices in subjects with diabetes.
abstract: BACKGROUND
  The present study performed laser-Doppler flowmetry (LDF) measurements on the skin surface around the ankle with the aim of verifying if beat-to-beat analysis of the LDF waveform can help to discriminate the microcirculatory-blood-flow (MBF) characteristics between diabetic, prediabetic, and healthy subjects.
  
  
  METHODS
  84 subjects were assigned to three groups (diabetic, prediabetic, and normal) according to the results of oral glucose tolerance tests. Beat-to-beat analysis was performed on the pulsatile LDF waveform to obtain foot delay time (FDT), flow rise time (FRT), and the corresponding MBF-variability parameters (FDTCV and FRTCV).
  
  
  RESULTS
  Relative to the control group, FDT and FRT were significantly shorter in prediabetic subjects, FDT was significantly shorter in diabetic subjects, and FRTCV and FDTCV were significantly larger in prediabetic and diabetic subjects. There were no significant associations for FRT after adjustment for age and gender.
  
  
  CONCLUSIONS
  The present results indicate that FRT may help to discriminate differences in the elastic properties of local vascular beds during diabetes or even during prediabetic stages. The proposed blood-filling-volume model can help to explain the underlying mechanism. The present findings may aid the noninvasive early detection of diabetes-associated vascular damage, and could be used in the development of home-care and telemedicine applications.
authors.affiliation: Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
authors.forename: Hsin
authors.initials: H
authors.lastname: Hsiu
authors.affiliation: Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, Taiwan Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Hsiao-Feng
authors.initials: HF
authors.lastname: Hu
authors.affiliation: Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
authors.forename: Guan-Shian
authors.initials: GS
authors.lastname: Wu
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Fone-Ching
authors.initials: FC
authors.lastname: Hsiao
mesh_terms: D000328:Adult; D001794:Blood Pressure; D048909:Diabetes Complications / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D042241:Early Diagnosis; D005951:Glucose Tolerance Test; D006439:Hemodynamics; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D012867:Skin / Q000098:blood supply; D014652:Vascular Diseases / Q000150:complications / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology
keywords: Diabetes; beat-to-beat waveform; laser Doppler; microcirculatory blood flow variability