Second NMN clinical trial: Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women

Findings analysis

 

In previous studies, NMN was effectively used in increasing the NAD+ levels in the body, increasing mitochondrial function, decreasing the aging process, improving age-related conditions, and increasing the cognitive functions in aging mice. What is more interesting is how NMN can influence muscle insulin sensitivity. 

 

Insulin resistance is a metabolic disorder that is characterized by an inadequate response of cells to the action of insulin. As insulin is a hormone that allows glucose to enter the cells, as well as its further processing, inadequate or absent response to its action leads to an increase in blood glucose levels, and a constant tendency to regulate high glucose levels by increased insulin secretion.

 

In this case, insulin receptors become resistant and lead to insulin resistance. People with obesity and diabetes type 2 are more likely to develop this condition during life. That’s why in this trial was observed how quickly and efficiently the glucose will be taken into the cells as a response to the insulin.  

 

The new clinical trial is focused on how NMN can help in preventing and managing diabetes in postmenopausal women who are obese. NMN can help in glucose metabolism and increase insulin sensitivity. To find out if this is true, a 10-week study was conducted on twenty-five postmenopausal, overweight women with prediabetes. In the study, 13 women were taking NMN supplementation and 12 were taking placebo.

 

The results from the study were observed in muscle. NMN supplementation was showing greater metabolic benefits when done in female mice with induced diet, compared to male mice. After completing the treatment, peripheral blood was taken 4 hours after placebo or NMN ingestion.

 

Results show increased NAD+ levels in the blood in those participants who were taking NMN supplementation, unlike those that took a placebo. Also, there were no side effects reported or abnormalities in the blood test results in either group.

 

NMN draws attention for its metabolic effects in diabetic management. Recent studies claim its influence on muscle sensitivity in prediabetic women. For the first time, researchers discovered that NMN improves muscle sensitivity in women with prediabetes, by enhancing insulin’s ability for glucose intake. There is a gap in how NMN can affect and manage diabetes in people, therefore studies are still going on.

 

However, NMN supplementation prolongs the health span in mice. After 12 months of treating healthy mice with NMN, the signs of aging were significantly reduced. The energy production and its usage, decrease with age, and we must replenish it by taking NMN supplementation. Acting as a great NAD+ booster, NMN can decrease the signs of aging in mice, and thus extend healthspan.

 

Limitations

 

Aging is the natural process of our lives, which means there is a decrease in energy production and weight. NAD+ is the molecule that keeps us alive and healthy. Besides the fact that NMN is the perfect solution for increasing NAD+ levels, in the first trial NMN show positive results in improving the insulin potential to process glucose in skeletal muscle. 

 

It also shows improvement in the genes that are involved in the muscle structure in prediabetic women. Although the potential NMN effects were found in muscles, there are still some limitations.

 

For example, after 10-week of treatment, there were no changes in muscle NAD+ and strength in both groups. Furthermore, body composition (body fat), blood pressure, blood glucose, lipids, remained unchanged in both groups, the one with taking NMN supplement every day, and the one that received an inactive placebo.

 

Also, after the treatment with whether NMN or placebo, hepatic insulin sensitivity, and adipose tissue insulin sensitivity were the same as they were before the treatment.

 

NMN vs NR

 

Nicotinamide riboside is a perfect NAD+ booster, which the body needs for various functions. For example, scientific studies have shown that nicotinamide riboside improves mitochondrial function by activating the sirtuins genes, responsible for regulating oxidative metabolism in the body. Studies have investigated how NR impacts muscle insulin sensitivity.

 

Although NR is a potential precursor for increasing NAD+ levels, it doesn’t impact insulin sensitivity in random treatment done in middle-aged and older adult men. While NMN has the ability to impact muscle insulin sensitivity, nicotinamide riboside (NR) doesn’t impact the whole body. Also, no changes were found in blood pressure, blood glucose, body weight, mitochondrial function, energy metabolism, and lipid profile.

 

Some preclinical studies found the potential metabolic benefits after NR supplementation. For this study, 13 healthy obese participants were treated with NR and placebo supplementation. NR can increase body fat-free mass, while NMN can’t do so. Still, there is a lack of trials about treating metabolic disorders with NR supplementation, and further research is needed.

 

To sum up

 

Taking NMN supplementation is a great solution for treating prediabetic women who are overweight or obese. NMN shows great results in glucose metabolism and thus in insulin sensitivity.

 

But, NMN can increase muscle insulin sensitivity without changes in the muscle NAD+. These findings are specific to the NMN effects of insulin sensitivity, and no other improvements were found in other conditions associated with insulin resistance such as liver insulin sensitivity, fasting plasma glucose, and abdominal adipose tissue mass. Because NMN may play a role in diabetes management, it means that also can prolong the healthspan.

 

To determine whether NMN has the same effects in different groups of patients with similar or other conditions, further studies need to be explored.

 

References

Mihoko Yoshino, Jun Yoshino, Brandon D. Kayser et al. (2021) Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021 Jun 11; 372(6547): 1224–1229. doi: 10.1126/science.abe9985

 

IMPORTANT: This infomation is not intended to diagnose, treat, cure, or prevent any disease, and it should not be used by anyone who is pregnant or under the care of a medical practitioner. Please consult your physician about which supplements may or may not be right for you.