Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women

Yoshino M, Yoshino J, Kayser BD, et al. · Science

Insulin-stimulated glucose disposal per kg of fat-free mass was 25 plus or minus 7 percent greater after ten weeks of NMN than before it (p<0.01) and unchanged after placebo, and the between-group evidence is a three-way mixed model interaction of time, condition and group at p=0.022. Muscle insulin signalling rose with it. Nothing else moved: body composition, intra-abdominal fat, intrahepatic triglyceride, blood pressure, plasma glucose, insulin, lipids, adiponectin and leptin were unchanged in both arms, as were hepatic and adipose insulin sensitivity. Muscle NAD+ itself did not rise, though NMN metabolites in muscle did, which the authors read as faster NAD+ turnover rather than a larger pool. No joint or cartilage outcome was measured.

Population

Postmenopausal women with prediabetes and overweight/obesity

Intervention

NMN 250 mg/day for 10 weeks

Comparator

Placebo

Limitations

Twenty-five participants, one metabolic population, ten weeks, and never replicated. Randomisation left the arms apart on the variable the mechanism runs through: baseline intrahepatic triglyceride content was 6.3 plus or minus 1.2 percent in the thirteen women given NMN and 14.8 plus or minus 2.0 percent in the twelve given placebo, a group difference the trial's own Table 1 puts at p=0.003. Nothing was measured in joints. NIH-funded.