Sedentary Behavior in Older Women With and Without Type 2 Diabetes
Sedentary Behavior in Older Women With and Without Type 2 Diabetes
Sedentary behavior has been linked to cardiovascular morbidity and mortality, and is
 particularly common in older adults with type 2 diabetes. The purpose of this observational,
 mixed-methods study is to better understand the relationship between prolonged sedentary
 behavior and cardiovascular and metabolic health in older women.
The investigators will recruit 20 women age 60-75 years, n=10 with uncomplicated type 2
 diabetes (T2D) and n=10 healthy controls. Participants will wear two accelerometers and a
 continuous glucose monitor (CGM) for two different periods of 7 days for objective assessment
 of physical activity, sedentary behavior, and blood glucose, respectively, and complete a
 graded exercise test (cardiorespiratory fitness), assessment of insulin sensitivity
 (hyperinsulinemic-euglycemic clamp) and single leg exercise using near-infrared spectroscopy
 (microvascular function). Participants will also complete a semi-structured qualitative
 interview to understand knowledge and attitudes toward sedentary behavior and questionnaires
 to assess the relationship between modifiable psychological and behavioral factors and
 sedentary behavior.

 The aims of the study are to:

 1. Compare objectively-measured, free-living physical activity and sedentary behavior
 between older women with and without T2D.

 2. Evaluate the relationship between prolonged bouts of sedentary behavior,
 cardiorespiratory fitness, glucose control, insulin sensitivity, and skeletal muscle
 microvascular function in older women with and without T2D.

 3. Assess knowledge and attitudes toward sedentary behavior and characterize the
 relationship between knowledge and attitudes toward sedentary behavior and modifiable
 psychological and behavioral factors in older women with T2D.

 4. Evaluate the relationship between sedentary behavior, mood states, and meaning salience
 during "normal" life and the period of confinement imposed by the COVID-19 epidemic.
Inclusion Criteria:

 -  Female

 -  Age 60-75 years

 -  Postmenopausal (self-reported)

 -  BMI between 25-40 kg/m2

 -  Participants with T2D:

 -  T2D confirmed via chart review

 -  T2D diet controlled or treated with the following acceptable medication treatments:
 metformin, sulfonylureas, glinides, or glucose absorption blockers

 Exclusion Criteria:

 -  Male

 -  Age <60 or >75 years

 -  Type 1 diabetes

 -  Control participants only - HbA1C ≥ 5.7%

 -  Use of beta blockers or centrally-acting calcium channel blockers (i.e., diltiazem,
 verapamil) due to potential blunting of cardiorespiratory fitness assessments

 -  Use of hormone replacement therapy (e.g., estrogen, progesterone, testosterone)
 (within the past 5 years)

 -  Taking insulin, thiazolidinediones (e.g., rosiglitazone), glucagon-like peptide-1
 (GLP1) agonists (e.g., exenatide), dipeptidyl peptidase-4 (DPP4) inhibitors (e.g.,
 sitagliptin) or any medication for the treatment of T2D other than those listed above
 in the inclusion criteria

 -  Uncontrolled hypertension at rest (systolic >160 or diastolic >110 mmHg)

 -  Obstructive pulmonary disease or asthma with a forced expiratory volume in 1 second
 (FEV1)/forced vital capacity (FVC) ratio <70% of predicted

 -  Any of the following conditions:

 -  Uncontrolled T2D (HbA1C >9.0%)

 -  Unstable angina

 -  Recent myocardial infarction, cardiac surgery, or vascular surgery (<3 months)

 -  Heart failure

 -  Peripheral artery disease (based on report of symptomatic claudication or ankle
 brachial index testing)

 -  Anemia (tHb <10 mg/dL)

 -  Hepatic or renal disease

 -  Severe arthritis or mobility impairment that would interfere with exercise testing

 -  Current tobacco or marijuana use or nicotine use within the last year

 -  Dementia or evidence of cognitive impairment (Mini-Cog score < 3)

 -  Engaging in >150 minutes/week of moderate to vigorous physical activity (assessed via
 Low-Level Physical Activity Recall questionnaire)