Insulin sensitivity and related cytokines, chemokines, and adipokines in polymyalgia rheumatica

Abstract

Objectives: To evaluate the insulin sensitivity (IS) and levels of peptides with impact on IS in polymyalgia rheumatica (PMR) before and after prednisolone treatment.

Methods: Fifteen PMR patients and 15 controls were included. Subjects were studied before and after treatment with prednisolone for 14 days (20 mg/day). Composite IS indices were calculated from glucose and insulin concentrations during an oral glucose tolerance test (OGTT). Plasma concentrations of tumour necrosis factor alpha (TNF), interleukin (IL)-6, IL-8, monocyte chemoattractant protein 1 (MCP-1), resistin, leptin, and adiponectin were measured.

Results: Prednisolone abolished symptoms and increased physical activity within 1–2 days; erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were normalized at day 14. Before treatment, IS was lower in patients vs. controls (p < 0.001). Following treatment, IS was restored in patients (p < 0.01) but not changed in controls (p > 0.05). IL-6, TNF, and IL-8 were higher in patients vs. controls before treatment (p < 0.05–0.001), and decreased after treatment in patients (p < 0.001) but did not change in controls. Before treatment, adiponectin was lower in patients vs. controls (p < 0.05). During treatment, adiponectin increased in both groups (p < 0.05). Leptin did not differ between untreated patients and controls but increased in both groups (p < 0.05). MCP-1 and resistin did not differ (p > 0.05).

Conclusion: IS is decreased in PMR, probably reflecting abnormal cytokine and adipokine levels. Treatment with prednisolone improves IS along with normalization of cytokine and adipokine levels and physical activity.

Acknowledgements

This work was supported by the Danish Rheumatism Association and by the Danish Medical Research Council.