Resistance-type Exercise Training in the Older Population (RETO)

Background: Aging is associated with muscle mass and strength loss and "oldest" old people (≥85 y) are at a far greater risk of developing sarcopenia. Training increases muscle mass and strength in a variety of populations, yet the efficacy has not been clearly defined for individuals in the fourth age (≥80 y). A better understanding of the skeletal muscle adaptive response to resistance-type exercise training with advanced age will provide a strong basis to develop and implement care programs within our rapidly aging population, in which the "oldest" old represent the fastest growing group.

Hypothesis: The following hypotheses will be investigated:

• Twelve weeks of progressive resistance-type exercise training increases muscle mass and strength in young old (65-75 y) and oldest old (85 y and over) subjects.
• The training-induced increase in muscle mass and strength is relatively greater in young old subjects when compared to oldest old subjects.

Goals: The primary aim of this study is to compare the effect of resistance-type exercise training on skeletal muscle mass (i.e. quadriceps cross-sectional area and whole body lean mass) in young old and oldest old subjects.

Specific goals

• Determine whether resistance-type exercise training can increase muscle mass and muscle strength in young old and oldest old subjects.
• Determine whether resistance-type exercise training can improve physical performance in young old and oldest old subjects.
• Identify whether inflammatory markers (i.e., TNFα, IL-4, IL-6, IL-10, IL-13) are up- or down-regulated in young old and oldest old subjects before and after resistance-type exercise training.

Methodology:

Study design Sixty older females and males (young old group: n=30, 65-75 y; oldest old group: n=30, 85 y and over) will be included in this prospective clinical trial. All volunteers will be subjected to 12 weeks of whole-body resistance-type exercise training (3x/wk). Before, and after 6 and 12 weeks of training, a computed tomography (CT) scan of the upper leg will be performed to assess quadriceps cross sectional area. On those days, fasting blood samples will be obtained and whole-body dual energy x-ray absorptiometry (DEXA) scan will also be performed. Maximal strength will be determined by 1-repetition maximum (1RM) and physical functioning by the short physical performance battery (SPPB) at the same time points.

Study parameters/endpoints

• The main study endpoint is the increase in quadriceps cross-sectional area as assessed via CT scan.
• Secondary endpoints include: Whole-body and segmental body composition (i.e., lean mass, fat mass, bone mineral content; DEXA scan); Maximal strength assessment (1RM); Hand grip strength; Short physical performance battery (SPPB); Inflammatory and molecular markers (blood samples analysis).
• Other study parameters include: Age, body weight, body height, body mass index (BMI), lipid profile, glucose, and insulin.

Expected results:

The impact of resistance-type exercise training to increase muscle mass and strength in the oldest old population remains unclear. With the proposed project, we expect that resistance-type exercise training will increase muscle mass and strength, although the impact will be relatively lower in the oldest old group when compared with a group of young old individuals. The potential findings will define the efficacy of resistance-type exercise training to increase muscle mass and strength in individuals with advancing age. Better maintenance, or even an increase in muscle mass and strength increases independence, prolonging good health, recovery from disease and illness, and ultimately decreases burden on healthcare systems. This information will have a beneficial impact in the exercise physiology and aging areas for future interventions at the local, regional, national and international levels.