Diurnal rhythm of circulating nicotinamide phosphoribosyltransferase (Nampt/visfatin/PBEF): impact of sleep loss and relation to glucose metabolism.

What Was Tested

This randomized controlled trial looks at NAD+.

Their objective was to examine the 24-h profile of serum Nampt in humans under conditions of sleep and sleep deprivation and relate the Nampt pattern to morning postprandial glucose metabolism.

Why It Was Studied

Animal studies indicate that nicotinamide phosphoribosyltransferase [Nampt/visfatin/pre-B-cell colony-enhancing factor (PBEF)] contributes to the circadian fine-tuning of metabolic turnover.

However, it is unknown whether circulating Nampt concentrations, which are elevated in type 2 diabetes and obesity, display a diurnal rhythm in humans.

Who Took Part

The age groups tagged for this paper are young adults and adults, men only.

Fourteen healthy men participated in two 24-h sessions starting at 1800 h, including either regular 8-h-night sleep or continuous wakefulness.

How the Study Was Run

In design terms this was a randomized and crossover study.

Because people in this NAD+ study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

In the crossover set-up each of the participants took both NAD+ and the comparison in turn, acting as their own control.

Serum Nampt and leptin were measured in 1.5- to 3-h intervals.

In the morning, plasma glucose and serum insulin responses to standardized breakfast intake were determined.

What Was Measured

Topics PubMed links to this paper include Blood Glucose, Circadian Rhythm, Cytokines, Glucose, Leptin, Metabolome and Nicotinamide Phosphoribosyltransferase.

What This Means in Plain Language

The paper is a randomized and crossover study of NAD+.

The abstract goes on to report its results in about 6 sentences; this page does not restate them, so read the paper for the findings and their limits.

The publication is from 2012 (The Journal of clinical endocrinology and metabolism), a journal based in United States.

More context: the NAD+ compound page, all human trials.