This clinical research study will investigate the effects of 6 weeks of inspiratory muscle strength training on metabolic and cardiovascular outcomes in adults with recent-onset type 2 diabetes.
Type 2 diabetes mellitus (T2DM) is at epidemic proportions in the United States and worldwide. It is a chronic obesity-associated metabolic disorder characterized by glucose dysregulation combined with insulin resistance and beta-cell defects. First-line T2DM treatments include lifestyle remedies, such as dietary modifications and exercise. Exercise, whether aerobic and/or resistance training, increases whole-body insulin sensitivity and stimulates muscle glucose uptake independent of insulin. The acute effects of exercise on muscle in patients with abnormal glucose regulation produce immediate improvements in blood glucose levels. In addition, when exercise is repeated over time, adaptations occur that include more long-lasting increases in insulin sensitivity. The effects of traditional exercise on glycemic control and insulin sensitivity in patients with T2DM are well established. However, adherence to traditional exercise programs is low, in part, due to lack of time and physical discomfort, and new regimens for T2DM treatment are needed. Recently, a novel time-efficient respiratory exercise called Inspiratory Muscle Strength Training (IMST) was developed. IMST is distinct from other traditional forms of exercise as it is only 5 minutes per session and performed on a hand-held device during stationary sitting or standing. Typically, IMST comprises 5 sets of 6 inspiratory maneuvers with 1-minute rests between sets. Previous studies demonstrate that 6 weeks of IMST improve systolic blood pressure (SBP), sympathetic nervous system activity, and endothelial function in healthy individuals, middle-aged and older people, and adults with obstructive sleep apnea. These BP-lowering effects of IMST are significant for reducing the risks of cardiovascular disease (CVD), the number one cause of death in people living with diabetes. IMST is safe and tolerable, with adherence rates \>90% in diverse populations, and presents a manageable program for improving metabolic health in T2DM patients who have difficulty maintaining a traditional exercise program requiring a large amount of time and physical exertion. It is unknown if IMST, a highly-abbreviated respiratory exercise that is not physically demanding, has beneficial effects on glycemic control and insulin sensitivity, in combination with its improvements on BP measures, in patients with T2DM. The potential for IMST to exert metabolic benefits in diabetic patients warrants assessment
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
11
30 breaths/day, 5 days/week, 6 weeks
Arizona Respiratory and Neurophysiology Laboratory
Tucson, Arizona, United States
Change from baseline fasting blood plasma glucose after 6 weeks of IMST
A blood sample will be collected after 12 hours of fasting. Blood and plasma will be separated and plasma glucose levels will be quantified.
Time frame: Blood plasma collected and analyzed at baseline and after 6 weeks of training
Change from baseline fasting blood plasma Insulin after 6 weeks of IMST
A blood sample will be collected after 12 hours of fasting. Blood and plasma will be separated and plasma insulin levels will be quantified.
Time frame: Blood plasma collected and analyzed at baseline and after 6 weeks of training
Change from baseline insulin sensitivity after 6 weeks of IMST
A blood sample will be collected after 12 hours of fasting. Insulin sensitivity will be calculated using the homeostatic model assessment of insulin resistance (HOMA-IR): (fasting serum insulin (mU/L) × fasting plasma glucose (mmol/L) × 22.5).
Time frame: Blood plasma collected and analyzed at baseline and after 6 weeks of training
Change from baseline systolic blood pressure after 6 weeks of IMST
Change in systolic blood pressure (SBP) will be measured by both relative and absolute changes from baseline. SBP will be assessed in accordance with American College of Cardiology/American Heart Association guidelines. Measurements will be taken using an automated oscillometric sphygmomanometer and will be performed in triplicate over the brachial artery of the left arm after 5 minutes of quiet rest, with 1 minute of recovery between measures. SBP will be defined as the average of the 3 pressures.
Time frame: Blood pressure will be assessed at baseline and after 6 weeks of training
Change from baseline Nitric Oxide-mediated Endothelial Dependent Dilation (EDD)
Brachial artery Flow Mediated Dilation (BA-FMD), a well-established measure of NO-mediated endothelial function, will be measured by both relative and absolute changes from baseline. BA-FMD will be determined using high-resolution ultrasonography and analyzed with a commercially available software package. An ultrasound probe will be placed 3-6 cm proximal to the antecubital crease on the right arm and a baseline image of the right brachial artery will be obtained. Following baseline, reactive hyperemia will be produced by inflating a rapid-inflating blood pressure cuff. Brachial artery diameter change will be measured for 2 minutes following 5-min of forearm blood flow occlusion.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: EDD will be assessed at baseline and after 6 weeks of training