The escalating public health problem represented by obesity has spurred multidisciplinary research into adipose tissue and importantly, the molecular biology of the adipocyte. Recent studies suggest that obesity related metabolic disorders are characterised by chronic mild inflammation as a result of adipocytokine production from fat tissue leading to dysregulation in the pro/anti-inflammatory systemic balance. Adipokines and pro-inflammatory markers are implicated in insulin insensitivity, blood glucose dysregulation, inflammation and atherosclerosis. As a result, circulating levels of adipokines and pro-inflammatory markers may be valuable biomarkers in identifying future risk of disease states associated with obesity. Whilst there is a considerable amount of research into the characterisation of adipokines and pro-inflammatory cytokines, the anti-inflammatory adipocytokines warrant further exploration.
AnxA1, is an endogenous glucocorticoid regulated protein, which mediates systemic anti-inflammatory processess. The expression of AnxA1 with increased adiposity has not been investigated to date. However, given the balance that exists between pro and anti-inflammatory substances, it seems plausable that AnxA1 may be altered in individuals with increasing adiposity.
We recruited 94 healthy males for an in vivo study measuring both metabolic and anthropometric parameters. Plasma AnxA1 levels were correlated with levels of adiposity and distribution of fat, body mass index (BMI), waist to hip ratio, adipocytokines, blood cholesterol, glucose and blood pressure. AnxA1 was measured using an in-house sandwich ELISA. Ethical approval was granted by the University of Westminster (08/09/22).
Our results show that plasma AnxA1 protein is significantly inversely correlated with waist to hip ratio (P=0.03) in healthy male subjects suggesting that as central fat mass increases the concentration of plasma AnxA1 decreases.
AnxA1 could potentially represent a (fat) depot specific biomarker whose decline with increasing central adiposity may relate to the phenomena of increasing systemic inflammation and associated disease risk.