Research supports the significance of ꞵ-hydroxy-ꞵ-methylbutyrate (HMB) for muscle health for those ages 18-40 and 65+, and TSI Group reports that a new human clinical study, published in Nutrients, bridges the gap by assessing the impact of the company's patented HMB + vitamin D3 formula in middle-aged women (ages 45-60). The study has implications for a consumer segment that is often overlooked, the company added.

The results showed decreased intermuscular adipose tissue (IMAT) independent of exercise. TSI Group explained that even lean people have small amounts of intermuscular fat (adipose tissue). “As we age, we exercise less or store more fat, and the concentration of intermuscular fat increases,” said principal investigator and TSI Group Director of Clinical Research John A. Rathmacher, Ph.D. “Increased IMAT can have a detrimental effect on metabolism, as well as muscle quality and function as we age.”

Muscle mass begins to decline around age 30, yet people don't always notice the changing ratio between muscle and fat. Dr. Rathmache cautioned: “Whether our body weight goes up, down or stays the same, it’s inevitable that our body composition is changing with an increase in fat mass at a rather remarkable rate, and that can be concerning."

HMB + D’s muscle health benefits for older adults

HMB both stimulates protein synthesis and reduces muscle breakdown, TSI Group reports, noting that multiple clinical studies have shown that HMB supplementation helps improve lean body mass, muscle strength, and physical function in older adults. The effects are optimized when combined with vitamin D, the company added, pointing to a year-long randomized, double-blind, placebo-controlled study indicating that the combination of calcium HMB + vitamin D improved muscle function in older adults, even without exercise. The study was supported by a grant from the National Institutes of Health (NIH)  and published in The Journals of Gerontology.

HMB + D’s benefits on the middle-age adults

Taking steps to preserve muscle mass and function in middle age may have the greatest impact on quality of life, Dr. Rathmacher said, because it gives adults more time to take steps to maintain their muscle health (as opposed to trying to regain muscle that’s already lost later in life). In this most recent double-blind, randomized, placebo-controlled, 43 healthy women ages 45-60 years were randomly assigned to one of four groups: placebo or calcium HMB + D supplementation during 12 weeks of non-exercise sedentary control or a progressive resistance exercise training program.

The research findings:

HMB + D appears to maintain muscle size in sedentary conditions, and to decrease IMAT in middle-aged women with vitamin D3 sufficiency, independent of exercise, TSI Group reported. “In essence, because we looked at middle-aged adults, this study was like a prequel to the work already done on HMB on older adults,” said TSI Group Vice President of Business Development Shawn Baier. “This age group and gender have greater purchasing power than older adults. And this study helps to explain why—on a global scale—we see middle-aged women buying HMB + D for themselves and their spouses as well as their older parents.”

The researchers said the results of this small-scale study lend support to conduct a longer-duration study with greater sample size to determine the validity of the observed positive effects of HMB + D on IMAT and skeletal muscle in a small cohort of middle-aged women.