Adipokines such as
leptin and
adiponectin are involved in the regulation of
inflammation.
Ghrelin, a gastric
peptide playing a role in the appetite regulation, possesses anti-inflammatory properties. In this study, we evaluated the circulating levels of
adipokines (
leptin as potential proinflammatory and
adiponectin as anti-inflammatory marker) and
ghrelin and the fat mass in patients with
ankylosing spondylitis (AS). Serum
leptin,
adiponectin, and
ghrelin were evaluated in 53 AS patients with active disease (mean Bath
Ankylosing Spondylitis Disease Activity Index >40) and 35 controls. Fat and lean masses were determined using dual-energy x-ray absorptiometry. Fat and lean masses did not differ between patients and controls.
Ankylosing spondylitis patients had lower
leptin levels compared with controls, even after adjustment for fat mass (AS vs controls:
leptin, 7.6 +/- 1.3 ng/mL vs 10.3 +/- 1.5 ng/mL;
leptin [in nanograms per milliliter]/fat mass [in kilograms], 0.28 +/- 0.04 vs 0.44 +/- 0.04; P = .006 and P = .0003, respectively). Serum
adiponectin did not differ between patients and controls, whereas circulating
ghrelin was higher in AS patients (1354.6 +/- 70.5 pg/mL vs 1008.0 +/- 82.5 pg/mL; P = .001). However, all these results were significant only for male patients. No correlation was found between
leptin and
adiponectin, and erythrocyte sedimentation rate,
C-reactive protein levels,
tumor necrosis factor alpha, or Bath
Ankylosing Spondylitis Disease Activity Index.
Ankylosing spondylitis patients had no changes in fat mass.
Leptin production was reduced in contrast with normal levels of
adiponectin. These
adipokine results, together with high serum
ghrelin levels, may influence the inflammatory response in AS.