Suche
Mein Konto
This article is part of our May 2022 Healthy Aging special issue. Download the full issue here.
Relation
Dos Santos EEP, de Araújo RC, Candow DG, et al. Effectiveness of creatine supplementation combined with resistance training on muscle strength and muscle mass in older women: a systematic review and meta-analysis.Nutrients.2021;13(11):3757.
Study objective
To determine the influence of creatine and resistance training on muscle strength and mass in older women through systemic review and meta-analysis
Key to take away
Creatine supplementation is a promising and safe intervention to support resistance training in older women to reduce dynapenia.
Draft
Systematic review and meta-analysis
Participant
The investigators included 10 randomized controlled trials in the systematic review. The total number of participants was 211. Investigators initially identified a total of 543 studies and 2 additional studies from gray literature, but only 12 met eligibility criteria after screening.
Studies met criteria if they compared creatine alone (as opposed to a combination of ingredients) and resistance training with placebo in older women (over 60 years of age) and used the outcome measures of muscle strength and/or muscle mass.
Studies that did not include a placebo control group were excluded, as was one study that recruited patients with neurodegenerative diseases. Two further studies were not evaluated in the meta-analysis due to lack of access to the raw data.
Study parameters assessed
Regarding the quality of evidence, researchers assigned a PEDro score to each study included in the analysis. Scores ranged from 6 to 9 with an average PEDro score of 7.7. PEDro scores refer to the Physiotherapy Evidence Database and are rated between 0 and 11, with 11 representing the highest quality of evidence. The meta-analysis found high imprecision and the quality of evidence according to GRADE (Grading of Recommendations, Assessment, Development and Evaluation) was low, indicating limited confidence in the effect size. Wide confidence intervals and sample sizes less than 300 contributed to this quality assessment.
The risk of bias was minimized because studies with low PEDro scores were not used, and publication bias due to the use of fewer than 10 studies was not seen in this analysis.
Key insights
Overall, creatine significantly increased upper body strength (7 studies with 142 participants [P=0.04]), but had no effect on lower body strength or upper or lower body muscle mass. However, when studies lasted longer than 24 weeks, both upper body strength (P=0.05) and lower body strength (P=0.03) increased in the creatine groups, again without significant changes in muscle mass.
transparency
As disclosed by the authors: "DGC has conducted industry-sponsored research on creatine supplementation, received donations of creatine for scientific studies, and received travel support for presentations on creatine supplementation at scientific conferences. In addition, DGC serves on the scientific advisory board of Alzchem (a company that produces creatine). SCF previously served as a scientific advisor for a company that produces creatine sold.”
Effects and limitations of practice
Increased risks of disability, frailty, and falls are relevant to aging patients, in part due to the physiological and functional deteriorations associated with sarcopenia, which include loss of muscle mass and strength.1 Dynapenia is specifically the loss of muscle strength.
Improving strength and increasing muscle mass also have metabolic benefits, including combating insulin resistance. These 2 benefits alone support the recommendation of resistance training in aging patients.2Another promising benefit of resistance training is supporting mitochondrial function within muscle cells, which also declines with age.3
Physical activity and exercise are established countermeasures against muscle aging and the consequences of age-related decreases in muscle mass, strength and ability to regenerate as well as impairments in muscle metabolism.4Maximizing this effect through additional diet, lifestyle, or additional support is often a strategy used by integrative medicine clinicians. Creatine (creatine monohydrate) is an intervention worth considering.
In both primary care and specialized settings, the use of creatine often raises debates about safety, particularly in relation to renal and liver function. However, in a statement from the International Society of Sports Nutrition, a review of the available evidence suggests that both short-term and long-term supplementation is safe and well tolerated by healthy individuals.5This review also concluded that older adults tolerate creatine supplementation well.
Dynapenia is specifically the loss of muscle strength.”
Most studies evaluating creatine supplementation report no adverse events, even when renal and liver function were evaluated.6,7,8
A previous systemic review and meta-analysis concluded that postmenopausal women can safely use supplemental creatine.9Aware of his own responsibility towards the individual patient, the doctor can maintain his confidence in safety by monitoring with liver function tests (ALT [alanine aminotransferase], AST [aspartate aminotransferase]) and kidney function tests (BUN [blood urea nitrogen], creatinine). Individualizing patient management requires physician judgment.
For older women, recommending resistance exercises 2 to 3 times per week with compound or multi-joint movements such as chest press, bench press, leg press, and hack squat is a relevant intervention. Statistical significance for strength was achieved in this meta-analysis of creatine plus resistance training, but the effect size has limited confidence. Therefore, it is somewhat difficult to help a patient understand how much adding creatine can help and whether it is worth the cost and effort of developing a new habit.
In the studies included in this review, the dosage of creatine ranged from 5 g daily (typical maintenance dose) to 20 g daily for 5 to 7 days, followed by 5 g daily or a weight-based dosage of 0.1 g per kg daily (for a 150-pound person, this is 6.8 g). Optimal or preferred dosage has not been determined.
From this review, the greatest muscle strength benefit occurs with training durations longer than 24 weeks, but some upper body strength benefits can be achieved in as little as 12 weeks. Perhaps the most relevant clinical implication from this systematic review and meta-analysis is that monitoring the progress of resistance training and creatine regimens in older women should focus on muscle strength rather than muscle mass. Improvements in upper body strength are likely to be noticed sooner than lower body strength. Similar research in older adults previously suggested improvements in both muscle strength and muscle mass, but these studies included both men and women.8The addition of creatine to resistance training recommendations in older women is promising, but is still largely based on patient preference and individualization of care.