Visfatin (NAMPT)
Visfatin, also called NAMPT, is a protein made by fat tissue and other cells that was once thought to act like insulin; levels are often higher in obesity and insulin resistance, but it remains a research marker rather than a clinical test.
Plain English
Patient-Friendly Explanation
Visfatin is one of the many signalling proteins released by body fat. It was discovered in the 1990s under a different name - pre-B-cell colony-enhancing factor - and then, in the 2000s, was reported to be produced in large amounts by fat around the abdominal organs and to behave like insulin, lowering blood sugar. That first insulin-mimicking claim has not stood up well, and it turned out that the same protein is an enzyme, NAMPT, that cells use to make a molecule called NAD, which is essential for turning food into energy. Visfatin is made not just by fat cells but also by liver, muscle and immune cells, and it can act as an inflammatory signal. In many studies, blood levels are higher in people with obesity, type 2 diabetes, abnormal cholesterol and fatty liver, and they tend to track with waist size and insulin resistance, though findings are not consistent enough for it to be a useful test. Its real value is in research: it is part of the evidence that fat tissue is an active organ that constantly talks to the liver, muscles and immune system through dozens of proteins - which is why losing fat changes far more than the number on the scale. There is no test to ask for and no treatment to take; the practical levers remain food quality, activity, sleep and, where appropriate, medication.
Medical
Clinical Definition
Visfatin is the protein originally described as pre-B-cell colony-enhancing factor and later identified as nicotinamide phosphoribosyltransferase, the rate-limiting enzyme of the mammalian NAD salvage pathway. It exists in two functional compartments: intracellular NAMPT, which supports NAD-dependent processes including sirtuin activity, DNA repair and circadian metabolism, and extracellular NAMPT, which is secreted by adipose tissue, hepatocytes, skeletal muscle and monocytes and behaves as a pro-inflammatory cytokine and damage-associated molecular pattern acting at least partly through toll-like receptor 4, with downstream effects on endothelial function, vascular smooth muscle and innate immunity. The 2005 report that visfatin is enriched in visceral fat and exerts insulin-mimetic effects by binding the insulin receptor was widely cited and subsequently challenged on methodological grounds - enzymatic NAD generation, contaminating nucleotides and reagent artefacts account for much of the apparent insulin-like activity - and current evidence places its metabolic actions in NAD biology and innate immune signalling rather than at the insulin receptor. Circulating concentrations are reported as elevated in obesity, insulin resistance, type 2 diabetes, dyslipidaemia and steatotic liver disease in most but not all studies, correlating with body mass index, waist circumference and homeostatic model assessment of insulin resistance, and decreasing after weight loss and metabolic surgery in some cohorts; specificity is limited because values also rise in acute inflammation and sepsis. Preclinical work includes extracellular NAMPT neutralising antibodies, NAMPT inhibitors and extracellular vesicle studies linking NAMPT to hypothalamic function and age-related metabolic decline, and the NAD field more broadly has raised interest in NAD precursors, none of which is established therapy for weight management. Visfatin has no clinical role as a screening or monitoring test; its importance is mechanistic and it belongs to the same family of adipose-secreted signals as adiponectin, leptin, resistin, omentin, vaspin, chemerin and retinol-binding protein 4.
Key Insight
Why It Matters
You cannot test visfatin in a clinic and you do not need to - it matters mainly as proof that fat tissue is a busy signalling organ rather than an inert store, which is why losing fat changes inflammation, blood sugar and blood pressure as well as your waistline.
Sources
Reviewed against standard medical references.
Medically reviewed by
Family Physician & Registered Acupuncturist, Accord Medical Clinic. MBBS (NUS), Graduate Diploma in Family Medicine (NUS), Graduate Diploma in Acupuncture (Singapore College of TCM).
Last reviewed: September 2026
This page is general health education, not medical advice. Whether any treatment is appropriate for you is a decision made in consultation after assessment.
