None listed
Conditions
Brief summary
Diabetes mellitus is a significant health issue in New Zealand, with a high prevalence reported in adults aged 50 years and over (older adults) and in Maori and Pacific people. Cardiovascular disease is the leading cause of mortality in adults with type 2 diabetes mellitus (T2D). Human aging and T2D are associated with a diminished exercise capacity, which is strongly associated with the development and progression of many chronic diseases (cardiovascular disease, obesity, some types of cancers) and a higher risk of cardiovascular-related and all-cause mortality. There is substantial evidence to support the hypothesis that structural adaptations including the accumulation of collagen, advanced glycation end products (AGE’s) and triglycerides contribute to the stiffening and dysfunction of the aged heart and blood vessels. Stiffening of the cardiovascular system is believed to play a key role in the pathophysiology of several cardiovascular conditions (systolic hypertension, stroke, atrial fibrillation, congestive heart failure) that affect older adults. People with T2D experience a greater accumulation of these toxic metabolites and thus T2D may accelerate the cardiovascular aging process. Indeed, abnormalities in measures of left ventricular diastolic function are more prevalent in humans with T2D compared to healthy controls. Moreover, a smaller left ventricular stroke volume and end-diastolic volume during exercise in people with T2D suggest that the reduction in exercise capacity in people with T2D may be primarily related to a smaller exercise stroke volume secondary to impaired diastolic function. Regular physical exercise training increases exercise capacity in previously sedentary older adults with T2D; however, no studies have assessed changes in exercise stroke volume before and after training. Therefore, it remains unclear whether increases in exercise capacity with regular and sustained exercise training in older adults with T2D are associated with improved left ventricular function. The aim of this project is to examine the consequences of T2D on cardiovascular function in adults aged 35-80 years. Adults aged 50 years and older with and without T2D will perform a 12 week exercise training programme to examine the effect of exercise training on maximal exercise capacity and left ventricular function during exercise. A comprehensive set of baseline testing and follow-up testing will take place to assess the effects of a 12 week exercise-based intervention. This testing will include submaximal and maximal exercise testing and non-invasive imaging (MRI) of cardiac structure and function at rest and during exercise. We hypothesize that aging will result in a reduction in exercise capacity and left ventricular function during exercise, which will be further reduced in people with T2D. 12 weeks of exercise training will improve exercise capacity and left ventricular function during exercise in older adults with T2D.
Interventions
Adults aged 50 years and older with and without type 2 diabetes will perform a 12 week supervised, group-based aerobic exercise programme that includes cycle, rowing and walking/running exercise. For the entire 12 week intervention, exercise prescription will be 4 weekly exercise sessions for 45-60 minutes. Initial exercise prescription includes 3 moderate-intensity (50-75% of VO2peak), continuous exercise sessions and 1 interval type exercise session (75-95% of VO2peak). At the 4 week period,
Adults aged 50 years and older with and without type 2 diabetes will perform a 12 week supervised, group-based aerobic exercise programme that includes cycle, rowing and walking/running exercise. For the entire 12 week intervention, exercise prescription will be 4 weekly exercise sessions for 45-60 minutes. Initial exercise prescription includes 3 moderate-intensity (50-75% of VO2peak), continuous exercise sessions and 1 interval type exercise session (75-95% of VO2peak). At the 4 week period, a moderate-intensity continuous training session will be substituted for another interval-type exercise session for the remainder of the exercise intervention. Exercise sessions will be supervised by exercise physiologists. Adults aged 35-49 years will not perform the exercise intervention and serve as an age comparator to baseline data (prior to exercise training) of adults aged 50 years and older.
Sponsors
The Univeristy of Auckland
Study design
Allocation
Non-randomised trial
Intervention model
Parallel
Primary purpose
Treatment
Eligibility
Sex/Gender
All
Age
35 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
Type 2 diabetes group: Diagnosed for at least 6 months but not longer 10 years Aged 35-80 years Performing less than 150 minutes per week of moderate intensity aerobic exercise over the prior 6 months. Healthy control group (without Type 2 Diabetes): Aged 35-80 years Performing less than 150 minutes per week of moderate intensity aerobic exercise over the prior 6 months.
Exclusion criteria
Diagnosed type 2 diabetes for less than 6 months or longer than 10 years Hypertension Heart failure Chronic obstructive pulmonary disease Coronary artery disease (as evidenced by angina or prior myocardial infarction) Cerebrovascular disease (as evidenced by prior transient ischemic attack or stroke) Renal disease
Outcome results
None listed