Counteracting Age-related Loss of Skeletal Muscle Mass: a clinical and ethnological trial on the role of protein supplementation and training load (CALM Intervention Study): study protocol for a randomized controlled trial

Abstract

Background: Aging is associated with decreased muscle mass and functional capacity, which in turn decrease quality of life. The number of citizens over the age of 65 years in the Western world will increase by 50 % over the next four decades, and this demographic shift brings forth new challenges at both societal and individual levels. Only a few longitudinal studies have been reported, but whey protein supplementation seems to improve muscle mass and function, and its combination with heavy strength training appears even more effective. However, heavy resistance training may reduce adherence to training, thereby attenuating the overall benefits of training. We hypothesize that light load resistance training is more efficient when both adherence and physical improvement are considered longitudinally. We launched the interdisciplinary project on Counteracting Age-related Loss of Skeletal Muscle Mass (CALM) to investigate the impact of lifestyle changes on physical and functional outcomes as well as everyday practices and habits in a qualitative context.

Methods: We will randomize 205 participants older than 65 years to be given 1 year of two daily nutrient supplements with 10 g of sucrose and 20 g of either collagen protein, carbohydrates, or whey. Further, two groups will perform either heavy progressive resistance training or light load training on top of the whey supplement.

Discussion: The primary outcome of the CALM Intervention Study is the change in thigh cross-sectional area. Moreover, we will evaluate changes in physical performance, muscle fiber type and acute anabolic response to whey protein ingestion, sensory adaptation, gut microbiome, and a range of other measures, combined with questionnaires on life quality and qualitative interviews with selected subjects. The CALM Intervention Study will generate scientific evidence and recommendations to counteract age-related loss of skeletal muscle mass in elderly individuals.

Trial registration: ClinicalTrials.gov NCT02034760 . Registered on 10 January 2014. ClinicalTrials.gov NCT02115698 . Registered on 14 April 2014. Danish regional committee of the Capital Region H-4-2013-070. Registered on 4 July 2013. Danish Data Protection Agency 2012-58-0004 - BBH-2015-001 I-Suite 03432. Registered on 9 January 2015.

Keywords: Elderly; Gut microbiome; Muscle; Plasma metabolome; Protein; Strength training; Whey.

Fig. 1

Hypothesized improvements over time with different interventions. Black lines mark the expected effect of per-protocol analysis: HRTW (solid line), LITW (long-dashed line), WHEY (short-dashed line), COLL (dashed-dotted line), and CARB (dotted line) interventions when analyzed per protocol. The gray line marks the expected effect intention-to-treat analysis of HRTW. CARB carbohydrate supplementation group, COLL collagen supplementation group, HRTW heavy resistance training with whey supplementation, LITW light-intensity training with whey supplementation, WHEY whey supplementation

Fig. 2

Spectrum of outcome variables. In the interdisciplinary Counteracting Age-related Loss of Skeletal Muscle Mass Intervention Study, we are investigating the entire spectrum of possible impacts of the intervention by applying objective, quantitative measures of the body and subjective, qualitative investigations of the participants

Fig. 3

Participant flow. N_total represents the expected number of inclusions in each group. N_acute represents the expected number of participants who will complete the measurements of fractional synthesis rate at 0 and 12 months. COLL Collagen supplementation, CARB Carbohydrate supplementation, WHEY Whey supplementation, LITW Light intensity resistance training and whey supplementation, HRTW Heavy resistance training and whey supplementation

Fig. 4

Magnetic resonance imaging analysis. We place slices as shown for analysis of cross-sectional area of the m. quadriceps femoris muscle and analyze slices 3 (counting in distal to proximal direction) and 4 for all subjects, and we use slice 4 for primary outcome evaluation. We fix the placement of slices in absolute distances, but we measure the femur length on dual-energy X-ray absorptiometric scans from the lateral tibial plateau (0 %) to the top of the greater trochanter (100 %) to report the relative placement of slices. Currently, placement of slice 3 ranges from 27 % to 36 % and slice 4 from 40 % to 54 % of the femoral length, depending on the height of the participant