1: Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women.
Science of the Month - June 2021
Epub 2021 Apr 22.
Mihoko Yoshino, Jun Yoshino, Brandon D. Kayser, Gary Patti, Michael P. Franczyk,Kathryn F. Mills, Miriam Sindelar, Terri Pietka, Bruce W. Patterson, Shin-Ichiro Imai, Samuel Klein
At the Center for Human Nutrition, Department of Medicine, Washington University School of Medicine, where I work, pioneering clinical metabolic research is being conducted under the leadership of Professor Samuel Klein, who also serves as a Guest Professor at the Juku School of Medicine. In this study, we investigated the metabolic effects of nicotinamide mononucleotide (NMN), a metabolite of NAD (nicotinamide adenine dinucleotide) that has been gaining attention, in a placebo-controlled, double-blind comparative study. Groups led by co-investigators of this study, including Associate Professor Jun Yoshino (currently of the Department of Nephrology, Endocrinology and Metabolism, Juku School of Medicine) and Professor Shin-Ichiro Imai (Department of Developmental Biology, Washington University School of Medicine), have reported that NMN administration in rodents activates NAD synthesis in major metabolic organs and improves insulin resistance and other metabolic abnormalities associated with obesity and aging. Therefore, in this clinical study, we examined the effects of 10 weeks of oral administration of NMN (250 mg/day) or a placebo in postmenopausal women with prediabetes and obesity. The results, obtained using the hyperinsulinemic-euglycemic clamp procedure with non-radioactive isotopes, showed that NMN significantly increased glucose uptake capacity in skeletal muscle compared to the placebo (see figure), revealing that NMN also improves insulin resistance in humans. Consistent with these results, NMN enhanced the phosphorylation of AKT and mTOR, which regulate insulin signaling in skeletal muscle, and increased the expression of genes related to remodeling. Further studies are anticipated to investigate the detailed mechanisms of action and to examine its effects in other cohorts. Finally, I would like to take this opportunity to express my sincere gratitude to Professor Hiroshi Ito (Department of Nephrology, Endocrinology and Metabolism) for his guidance from my time as a student to the present.
(Mihoko Yoshino, Center for Human Nutrition, Department of Medicine, Washington University School of Medicine, Class of 1979 equivalent)