NMN administration in overweight or obese, middle-aged and older adults safely increased circulating NAD levels, and significantly reduced total LDL and non-HDL cholesterol, body weight, and diastolic blood pressure.

Glyoxolase 1 (GLO1) [a rate-limiting enzyme for detoxification of methylglyoxal, which has been implicated in Type 2 diabetes (T2D) and other age-related disorders] is decreased in muscle from individuals with obesity prior to the development of T2D. In vitro modeling of this molecular milieu via GLO1 KD in human immortalized myotubes suggest that muscle lacking GLO1 is characterized by inflammation, stress, fibrosis, and muscle dysfunction. Mechanistic experiments in human myotubes and implicate SIRT2, NAMPT, and NAD+ as potential regulators of GLO1 protein and activity and suggest that NR or other NAD precursors may be able to augment GLO1....The findings presented here demonstrating that nicotinamide riboside NR can promote GLO1 transcripts, and activity, as well as NRF2 are perhaps the most exciting data which warrant further exploration of NR as a potential therapy for the prevention and treatment of metabolic dysfunction.

Supplementation with a metabolic cocktail including nicotinamide riboside promotes the amelioration of adipose tissue dysfunction observed in the diet-induced obese mouse model...Altogether, this study suggests that the supplements ameliorate adipose tissue dysfunction acting in different pathways affected by obesity, and can be an effective treatment for reducing the incidence of obesity-related metabolic disorders.

...We found that NR supplementation could ameliorate high-fructose-induced lipid metabolism disorder by improving FGF21 resistance in the liver and WAT, which may be related to the regulation of inflammation mediated by the SIRT1/NF-κB signaling pathway.

...We previously reported that NR supplementation prevented the development of liver fibrosis in male mice. However, whether NR exerts a similar effect in females is unknown. Therefore, we determined whether NR supplementation can prevent obesity-induced inflammation and fibrosis in the liver and white adipose tissue (WAT) by providing NAD+ in obese female mice...Our results indicated that NR supplementation exerted an anti-obesity effect and prevented the development of inflammation and fibrosis in the white adipose tissue of old, but not young, female mice with diet-induced obesity.

We aimed to determine whether long-term nicotinamide riboside (NR) supplementation boosts mitochondrial biogenesis and metabolic health in humans. Twins from 22 BMI-discordant monozygotic pairs were supplemented with an escalating dose of NR (250-1000 mg/day) for 5 months (clinicaltrials.gov entry NCT03951285). NR improved blood and tissue NAD+ metabolism, muscle mitochondrial number, myoblast differentiation and gut microbiota composition independent of BMI. NR also showed a capacity to modulate epigenetic control of gene expression in muscle and adipose tissue. However, NR did not ameliorate adiposity or metabolic health. Overall, our results suggest that NR acts as a potent modifier of NAD+ metabolism, muscle mitochondrial biogenesis and stem cell function, gut microbiota, and DNA methylation in humans irrespective of BMI.

We found that the supplement of NAD+ precursors seems to have little effect on healthy people, but it has a significant beneficial effect on patients with cardiovascular disease and dyslipidemia. Due to the limitation of the number and quality of included studies, the above conclusions need to be verified by more high-quality studies.

...It is unknown how dietary supplementation of NR alters the microbiome and if those alterations contribute to deflection of weight gain. In this study, we fed C57BL/6J male mice a high-fat diet (HFD) supplemented with or without NR and performed a fecal material transfer (FMT) to establish a link between NR-conditioned microbiota and NR-induced deflection of weight gain...We also investigated the effects of NR on the microbiome by using metagenomics sequencing. We found that NR-treated mice displayed an altered gut microbial composition relative to controls and that fecal transplant resulted in a distinct functional metabolic profile characterized by enrichment of butyrate-producing Firmicutes...These findings suggest that microbial factors contribute to the beneficial effects of dietary NR supplementation, which may be useful to enhance the therapeutic effects of NR...

...This investigation examined the impact of nicotinamide riboside supplementation on whole body energy homeostasis, skeletal muscle mitochondrial function, and corresponding shifts in the acetyl-lysine proteome, in the context of diet-induced obesity using C57BL/6NJ mice. The study also included a genetically modified mouse model that imposes greater demand on sirtuin flux and associated NAD+ consumption, specifically within muscle tissues. In general, whole body glucose control was marginally improved by nicotinamide riboside supplementation when administered at the midpoint of a chronic high-fat diet, but not when given as a preventative therapy upon initiation of the diet. Contrary to anticipated outcomes, the study produced little evidence that NRS increases tissue NAD+ levels, augments mitochondrial function, and/or mitigates diet-induced hyperacetylation of the skeletal muscle proteome.

Obesity treatments, such as calorie restriction (CR), eventually lead to muscle wasting and higher rates of neuroinflammation, whereas hypothalamic inflammatory conditions impair body weight (BW) control. Nicotinamide riboside (NR) has been proposed against obesity but with little evidence on skeletal muscle tissue (SMT) and neuroinflammation...NR supplementation, in all groups, enhanced weight loss and increased relative weight of the skeletal muscle tissue. Furthermore, in animals under calorie restriction, NR reversed increases TNF-α levels in the hypothalamus...NR emerges as a potential adjuvant for preventing muscle mass loss in the weight loss processes.

Nicotinamide (NAM) influences whole-body energy expenditure by driving changes in the adipose phenotype. Thus, NAM is an attractive potential treatment for preventing obesity and associated complications.

This is the first study to report effects of nicotinamide riboside on cardiac oxidative stress in an obesity model. Nicotinamide riboside, a natural dietary compound, presented antiobesity effects and cardiometabolic benefits, in addition to positively modulating oxidative stress in the heart, in a state-dependent manner.

NR supplementation of 1000 mg/d for 6 wk in healthy overweight or obese men and women increased skeletal muscle NAD+ metabolites, affected skeletal muscle acetylcarnitine metabolism, and induced minor changes in body composition and sleeping metabolic rate. However, no other metabolic health effects were observed.

We suggest that NR initially mobilizes fat from the liver and, as the liver clears steatosis, glycemic control improves through a mechanism that does not involve direct insulin sensitization

Resveratrol and nicotinamide riboside supplementations in early postnatal life affect white adipose tissue's thermogenic/oxidative transcriptional phenotype and metabolic responses in adulthood, with upregulatory and beneficial effects evidenced in male animals.

...NR supplementation during 12 weeks did not affect fasting or postglucose challenge concentrations of glucose, insulin, C-peptide, glucagon, GLP-1, or GIP, and β-cell function did not respond to the intervention. Additionally, no changes in circulating adipsin or bile acids were observed following NR supplementation. The current study does not provide evidence to support that dietary supplementation with the NAD+ precursor NR serves to impact glucose tolerance, β-cell secretory capacity, α-cell function, and incretin hormone secretion in nondiabetic males with obesity. Moreover, bile acid levels in plasma did not change in response to NR supplementation.

Modulation of the browning potential of adipose tissues through the intake of food bioactives in early life is a potential, yet still largely unexplored, strategy to enhance metabolic health in later life...Our studies are first to examine nutritional programming of adipose tissue metabolic features by NR and RSV supplements given directly to the lactating pups. ...The fate of preadipocytes resident in WAT of young animals toward the beige adipogenesis transcriptional program can be modulated by specific food bioactives/micronutrients [resveratrol and nicotinamide riboside] received in early postnatal life.

This study demonstrated the oral NR supplementation was sufficient to induce the thermogenic response in lean mice changing the Brown Adipose Tissue (BAT) metabolism.

...The aim of this study was to test the safety of dietary NR supplementation over a 12-wk period and potential to improve insulin sensitivity and other metabolic parameters in obese, insulin-resistant men...Insulin sensitivity, endogenous glucose production, and glucose disposal and oxidation were not improved by NR supplementation. Similarly, NR supplementation had no effect on resting energy expenditure, lipolysis, oxidation of lipids, or body composition. No serious adverse events due to NR supplementation were observed and safety blood tests were normal. 12 wk of NR supplementation in doses of 2000 mg/d appears safe, but does not improve insulin sensitivity and whole-body glucose metabolism in obese, insulin-resistant men.

Elevated low-density lipoprotein cholesterol (LDL-C) has been the main target of lipid-altering therapy to reduce cardiovascular risk associated with dyslipidemia...This review is designed to assist healthcare professionals in evaluating the form(s) of niacin best suited for a particular therapeutic goal. Further, it provides a literature-based evaluation of risk for NA, extended-release NA, inositol hexanicotinate, and nicotinamide.