Serum chymase levels in obese individuals: the relationship with inflammation and hypertension

Background: Inflammation related hypertension is reported in obesity due to synthesis of angiotensinII (Ang-II) and proinflammatory compounds in obese adipose tissue. Mast cell chymase (MC) also stimulate Ang-II synthesis, and activate transforming growth factor beta-1 (TGF-beta 1) and matrix metalloproteinase-9 (MMP-9). The aim of our study is to evaluate the relation of serum chymase levels, a serine protease enzyme secreted from mast cells, in obese patients with hypertension and cytokines that lead to cell damage. Materials and methods: Three study groups are composed of individuals aged between 19 and 63 with following characteristics; (1) control (n=30): healthy subjects with body mass index (BMI) <25; (2) obese (n=30): patients with BMI >30; (3) obese+ HT (n=20): patients BMI >30 and hypertension. Serum Ang-II, MC, TGF-beta 1 and MMP-9 are determined by commercial ELISA. Angiotensin converting enzyme (ACE) activity is determined with enzymatic colorimetric assay. Results: Serum chymase levels did not vary between groups. Chymase levels showed significant negative correlation with ACE activity (r = -0.278, p= 0.013) and positive correlation with Ang-II levels (r=0.251, p=0.024). No correlation was evident between chymase levels and hsCRP, TGF-beta 1 and MMP-9. Conclusion: Serum chymase, Ang-II, TGF-beta 1 and MMP-9 levels did not change in obese and hypertensive-obese patients despite evident hyperinsulinemia, increased insulin resistance and elevated hsCRP levels.