Writing in Nutrients, researchers wrote that supplementation with high-protein HMB, alongside an exercise regimen, has significantly improved chair rise repetitions and the six-minute walk test at six months post-operation in sarcopenic patients who have undergone gastrointestinal surgery.
Anthropometric measurements such as mid-arm muscle circumference, mid-arm muscle area, weight and body mass index, also increased significantly at six months post-operation.
However, the regimen did not lead to significant improvements in muscle quality.
Study method
A total of 36 sarcopenic patients between 40 and 90 years old took part in the study, where they consumed the high-protein HMB supplement for two weeks and did resistance exercises daily.
The supplement used was Ensure Plus Advance, a high-protein oral nutritional supplement that contains 20g of protein per 220ml. Manufactured by Abbott Nutrition, the supplement is marketed to build muscle and improve the nutritional status of older adults.
Abbott Nutrition also funded this pilot study together with Singapore’s National Medical Research Council Clinical Trial Grant—Industry Collaborative Trials.
After the two weeks of supplementation, these patients underwent gastrointestinal surgery, which they were already scheduled for.
Following the surgery, they continued to consume the supplement for another two months.
To assess the effects of the supplement and the pre-surgery regimen, researchers followed up on the patients for another four months, during which the patients did not have to take the supplement or exercise. During this period, researchers measured their muscle quality in terms of intramuscular adipose tissue (IMAT%), IMAT index (ratio of IMAT% to muscle area), surface area of the rectus femoris (RFSA) and thickness of the rectus femoris (RFT).
Researchers also assessed their functional outcomes, including handgrip strength, 30 seconds chair rise, functional reach test, 6-min-walk test (6MWT) and gait speed.
Significant changes
The findings revealed significant improvements in functional outcomes as well as anthropometric measurements.
For example, the number of chair rise repetitions completed in 30 seconds has significantly increased from 11 at baseline, to 15 at six months post operation.
Results of the 6MWT also significantly increased from 349m at baseline to 387m at six months post operation. However, there were no significant changes in other areas such as handgrip strength, functional reach test and gait speed.
On the other hand, significant increases were seen in mid-arm muscle circumference, mid-arm muscle area, weight and BMI from baseline to six months post operation.
In fact, the effects of the pre-surgery supplementation and exercise regimen were seen to be long-lasting and sustained to six months post-operatively, despite the rehabilitation phase being stopped two months post-surgery.
“The magnitude of increase in BMI and muscle volume in terms of mid-arm muscle circumference and mid-arm muscle area was greater between post-Op six months and week zero than between week two and week zero,” researchers wrote. “This suggested that not only was the gain in muscle volume and weight achieved from prehabilitation preserved over the six months, but the gain was compounded over time. HMB may possibly provide the protective effect of exercise and nutrition-focused prehabilitation against sarcopenic decline following significant surgical stress.”
Researchers added: “Our findings suggest that improvements in anthropometric and functional outcomes from prehabilitation may persist beyond the acute recovery period. If supported by future works, multimodal prehabilitation has the potential to optimise postoperative recovery amongst sarcopenic older adult surgical patients.”
Muscle quality
Notably, there was a significant decrease in muscle quality as compared to baseline, as assessed by the IMAT index.
The IMAT index, which measures absolute fat relative to body or muscle size, went up from 4.9 %/cm2 at baseline to 6.0%/cm2 six months post operation. The higher the index, the poorer the muscle quality.
The increase suggests no improvement or even a deterioration in muscle quality.
Researchers also reported a significant decrease in rectus femoris surface area (RFSA) from 304 cm2 at baseline to 227 cm2 at post-op 6 months.
Similarly, rectus femoris thickness (RFT) significantly reduced from 13 cm2 at baseline to 11 cm2 at post-op 6 months.
Still, researchers noted no apparent functional loss despite a decrease in muscle quality.
“In fact, certain functional outcomes appear to improve from baseline,” researchers wrote. “This suggests that muscle loss and deterioration post-operatively may not be global. The lack of functional decline indicates that prehabilitation intervention likely improved the recovery outcomes amongst these sarcopenic surgical patients in spite of muscle loss.”
HMB impact
Derived from the amino acid leucine, HMB is an active metabolite in regulating muscle protein synthesis. It works by slowing down muscle breakdown, instead of building new muscle. This is important in situations like ageing or surgery, where the body tends to lose muscle faster than it can rebuild it.
When participants undergo surgery, their body induces acute metabolic stress, increasing stress hormones and inflammatory cytokines.
HMB has been shown to lower the levels of inflammatory cytokines like TNF-α and IL-6, which play a role in preventing muscle degradation.
Findings of this pilot study may have a widespread impact for the approximately 16% of the global older adult population with sarcopenia, a progressive, age-related loss of muscle mass and function that cannot be reversed.
However, researchers cautioned against attributing the changes in muscle quality and function to HMB supplementation alone. They suggest isolating the prehabilitation components, such as nutrition-only versus exercise-only protocols, to study the potential effects of such intervention.
“There is a potential that multimodal prehabilitation programmes centred on exercise and nutrition can be used to optimise postoperative recovery trajectories towards regaining function amongst sarcopenic older adults undergoing surgery,” they wrote.
Source: Nutrients, 18(4), 703. doi: 10.3390/nu18040703. “Long-Term Outcomes of Multimodal Prehabilitation with High Protein Oral and HMB Supplementation in Sarcopenic Surgical Patients: The HEROS Study.” Authors: Shua, I. Y. L. et al