Perivascular Adipose Tissue
Perivascular adipose tissue is the fat wrapped around blood vessels; far from inert padding, it releases signals that affect how arteries relax, stiffen and become inflamed.
Plain English
Patient-Friendly Explanation
Perivascular adipose tissue is the fat that sits in and around the outer wall of arteries and veins - a sleeve that follows the vessels almost everywhere in the body. For a long time it was assumed to be no more than packing material that held vessels in place. It is not: healthy perivascular fat releases substances that help arteries relax and damp down inflammation, which supports normal blood flow and blood pressure. When weight increases, this fat changes character - it becomes thicker, more inflamed and less able to release the protective signals, and instead produces molecules that promote vessel stiffness, plaque formation and high blood pressure. Because it lies directly against the vessel wall, what it releases reaches the artery itself rather than being diluted in the general circulation, so it can influence blood pressure and cardiovascular risk out of proportion to its size. This is also why modern cardiac CT scans can examine the fat around the heart's own arteries and use its appearance as a marker of inflammation in those vessels - an approach that is beginning to be used in clinical practice.
Medical
Clinical Definition
Perivascular adipose tissue is a distinct depot that surrounds most systemic arteries and veins, extending from the adventitia into the vessel wall and sharing the vasa vasorum of the vessel it envelops; its proximity means its secretions act on adjacent smooth muscle and endothelium at concentrations far above circulating levels, an outside-to-inside paracrine signalling axis. In health, perivascular adipose tissue is anti-contractile: it releases adipocyte-derived relaxing factors including hydrogen sulfide, nitric oxide, angiotensin 1-7 and adiponectin, which counteract vasoconstrictor tone, and it buffers the vessel wall against mechanical and inflammatory stress. Its phenotype is depot-specific and influenced by the underlying vessel - perivascular fat around the thoracic aorta has brown and beige-like characteristics, whereas coronary and abdominal aortic perivascular fat is predominantly white - and it is remodelled by obesity, ageing, hypertension and diabetes into an inflamed, oxidative phenotype characterised by macrophage infiltration, reduced adiponectin, increased tumour necrosis factor alpha, interleukin-6, leptin and superoxide generation, mineralocorticoid receptor-driven signalling, loss of the anti-contractile effect, and increased vasoconstriction, endothelial dysfunction and arterial stiffness. Perivascular adipose tissue also contributes to adventitial fibrosis and to the local inflammatory environment that promotes atherosclerosis, and its aldosterone and leptin signalling has been implicated in obesity-related hypertension. This biology now has an imaging corollary: coronary computed tomography angiography allows quantification of perivascular fat attenuation around the epicardial coronary arteries, and a high pericoronary fat attenuation index identifies coronary inflammation and predicts cardiac events independently of stenosis severity and conventional risk scores. In weight-management practice, perivascular adipose tissue explains part of the mechanistic link between excess adiposity, hypertension, arterial stiffness and cardiovascular disease, and supports the clinical observation that blood pressure and vascular function often improve early in weight loss, before plaque burden changes.
Key Insight
Why It Matters
Fat around the arteries is not just padding - it talks directly to the vessel wall, and when it becomes inflamed it helps drive up blood pressure and stiffen arteries. It is one reason blood pressure often falls within weeks of starting effective weight treatment, well before the weight loss itself looks dramatic.
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.
