Effects of Low Intensity Therapeutic Ultrasound on Endothelial Function
Condition: Diabetes Mellitus, Type 2
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 2
Study type: Interventional

Summary: 
      Endothelium is a cell layer that interposes blood and smooth muscle of vessels. This
      biological sensor reacts to physical and chemical stimuli by synthesis and/or liberation of
      regulatory substances like nitric oxide (NO), which acts on vascular tone, growth of muscle
      cells and platelet aggregation and leukocyte. Clinically, endothelial function measured by
      technique flow-mediated dilation (FMD) is a strong predictor of cardiovascular events and
      all-cause mortality. Previo study demonstrated that continuous and pulsed therapeutic 1-MHz
      ultrasound waveforms improved endothelial function in health volunteers and this vasodilation
      persisted for 20 min, which provided them with anti-inflammatory vascular effects. In
      subjects with type 2 diabetes (DM2) the chronical hyperglycemia and dyslipidemia reduce NO
      bioavailability causing endothelial dysfunction. Low intensity therapeutic ultrasound is an
      electrotherapeutic instrument employed in musculoskeletal injuries that promotes
      endothelium-dependent vasodilation, and its mechanism of action has not been studied on DM2.
      The aim of our study is evaluate endothelial function of patients with DM2 after different
      waveforms (placebo, continuous and pulsed) of therapeutic ultrasound. Therapeutic ultrasound
      is a electrotherapeutic instrument that can changes arterial endothelial function of subjects
      with DM2 because of NO bioavailability increasing, which implies anti-inflammatory and
      vasodilatory beneficial alterations for diabetic patients.
    

Detailed description: 
      Evaluation of endothelial function will be made by flow-mediated dilation (FMD). The
      therapeutic ultrasound will applied over brachial artery using continuous (CUT: 0,4W/cm2),
      pulsed (PUT: 20% duty cycle, 0,08W/cm2SATA) and Placebo (equipment off) waveforms during 5min
      in 3 intercalated days.
    

Intervention name(s): Low intensity therapeutic ultrasound
Intervention type(s): Other
Intervention description(s): The ultrasound equipment (Sonopulse III, 1 MHz, IBRAMED, Brazil) was calibrated with the radiation force method. In study, the head of the transducer will be positioned and applied for 5 min over the brachial artery at the same point that will be evaluated the endothelium function (Cruz et al., 2016). Continuous waveforms of ultrasound therapy (CWUT) are applied in the stationary mode for 5 minutes at a spatial averaged temporal intensity (SATA) of 0.4 W/cm2 using a transducer 1-MHz. A pulsed waveform of ultrasound therapy (PWUT) are applied (5 minutes) with a 20% duty cycle (2 ms on, 8 ms off), which represents a constant intensity of 0.08 W/cm2 SATA. In the placebo intervention, all of the procedures above are repeated, but with the ultrasound equipment powered off (Cruz et al., 2016).
Other intervention name(s): Ultrasonic therapy, Ultrasound
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Basic Science
Keywords: Endothelial function; Ultrasonic Therapy; Vascular endothelium; Nitric oxide; Ultrasound