The research team from the Medical University of Bialystok published the article „Serum secreted frizzled-related protein 5 in relation to insulin sensitivity and its regulation by insulin and free fatty acids” in Endocrine journal.
The worldwide epidemic of overweight and obesity is expanding and has become an alarming problem as well as a major health challenge. Obesity is linked to insulin resistance, which is a major risk factor for type 2 diabetes as well as cardiovascular disease. In addition, people with obesity develop a chronic state of low-grade systemic inflammation in white adipose tissue.
Secreted frizzled-related protein 5 (SFRP5) is an adipokine, which acts as an inhibitor of noncanonical WNT signaling pathway associated with glucose and lipid metabolism as well as adipogenesis (a complex multi-step process of adipocyte development). The distinctive marker of mature adipocytes is adiponectin, which has insulin-sensitizing and anti-inflammatory properties. SFRP5 has been suggested to exert anti-inflammatory and insulin-sensitizing effects as well, however, contradictory data has also been reported.
The aim of this study was to assess serum SFRP5 concentration in a young healthy population in relation to insulin sensitivity and its regulation by hyperinsulinemia and/or serum free fatty acids (FFA) elevation.
Baseline SFRP5 was lower in the overweight/obese group and was positively associated with insulin sensitivity and serum adiponectin and negatively with body mass index (BMI). In multiple regression analysis, adiponectin was independently associated with SFRP5. Insulin decreased circulating SFRP5, and this effect was abolished by the concurrent Intralipid/heparin infusion (Figure 2). Intralipid/heparin alone or saline infusion did not affect SFRP5 (Figure 1).
Our data indicate that the relation between SFRP5 and insulin sensitivity is mainly dependent on adiponectin. Moreover, FFA abolish an insulin-caused decrease in circulating SFRP5, but Intralipid/heparin infusion alone does not regulate SFRP5 concentration. To sum up, insulin seems to be a more important factor regulating circulating SFRP5 levels than FFA.
Link to the paper: https://link.springer.com/article/10.1007%2Fs12020-021-02793-z