Aging, Obesity
Conditions
Keywords
Adipose tissue, Overfeeding
Brief summary
The purpose of this pilot study is to determine whether adipose tissue loses some of its ability to expand in response to overfeeding in older compared to younger men. The investigators hypothesize that the adipose tissue response to overfeeding may be weakened in older when compared to younger men, thereby leading to worsened ectopic storage depots for older men.
Detailed description
This pilot study will begin to address whether adipose tissue biology changes with advancing age. Specifically, we will test whether adipose tissue loses some of its ability to expand in response to overfeeding in older compared to younger men. To test this possibility the Investigators will recruit overweight and mildly obese older (age 55-75y) and younger (age 25-40y) men and collect adipose tissue biopsies before and after 7 days of overfeeding. The investigators will test how well the cells in adipose tissue expand in response to overfeeding and whether this differs between younger and older men.
Interventions
OTHEROverfeeding
Consumption of 40% excess calories for 7 consecutive days
Sponsors
Colorado State University
University of Colorado, Denver
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
25 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* Men * Aged 25-40y OR 55-75y * BMI 28-35 kg/m2 * Weight stable (±2kg over past 3 mo) * Sedentary to moderately active (\<3 d/wk of exercise lasting \>20min) * Non-smokers (never used or quit \>7yrs prior)
Exclusion criteria
* Women * Currently using hormones, glucose or lipid lowering medication * Engaged in exercise or diet program * Currently gaining or losing weight or using weight loss drugs * Diabetes mellitus (diagnosis, treatment, FBG ≥126 mg/dL) * Uncontrolled metabolic disorders (e.g., thyroid)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in adipose-derived stem cell (ASC) differentiation (Delta%oil red O+) | 1 wk of overfeeding | age-related difference in the ASC differentiation response to overfeeding |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in ASC proliferation (Delta rate of cell growth) | 1 wk of overfeeding | age-related difference in the ASC proliferative response to overfeeding |
| Change in expression of C/EBPalpha, C/EBPbeta, PPARgamma2, SREBP1c, SREBf1a, and Wnt10b (fold-changes in mRNA expression) | 1 wk overfeeding | age-related difference in the pro-adipogenic response to overfeeding |
| Change in intramyocellular (IMCL) di-saturated diacylglycerol (DAG) localization (Delta %membrane:cytosol) | 1 week overfeeding | age-related difference in the IMCL DAG response to overfeeding |
Countries
United States
Outcome results
None listed