Interactions between ghrelin, leptin and IGF-I affect metabolic syndrome and early atherosclerosis

Abstract

Background. High leptin and low ghrelin are associated with the metabolic syndrome (MS).

Aims and methods. Ghrelin, leptin (RIA kits), and insulin-like growth factor I (IGF-I) (ELISA kit) concentrations of the population-based cohort of 1045 subjects and their interactions with metabolic parameters were analysed. Intima-media thickness (IMT) was measured with carotid ultrasound.

Results. The interaction between leptin and ghrelin on the MS was significant (P=0.011). An additive effect of high leptin and low ghrelin on metabolic disturbances was observed: low ghrelin concentration (adjusted for age and sex) (P<0.001) was associated with the MS and type 2 diabetes in the highest but not in the lower leptin quartiles. In the highest leptin quartile, ghrelin concentrations decreased linearly when the number of International Diabetes Federation MS criteria met (P<0.01) increased. Ghrelin-leptin relation was independently associated with carotid IMT (P<0.005). The independent positive association (P<0.01) between the plasma ghrelin quartile and the carotid IMT was evident in the lowest IGF-I quartile.

Conclusions. Low ghrelin is associated with MS and type 2 diabetes in the presence of insulin and leptin resistance. Ghrelin-leptin relation is associated with early atherosclerosis. The interaction between IGF-I and ghrelin modifies the association of ghrelin with early atherosclerosis.

• Ghrelin
• IGF-I
• insulin resistance
• leptin
• type 2 diabetes

Acknowledgements

This work was supported by The Research Council for Health of the Academy of Finland and The Finnish Foundation for Cardiovascular Research. The technical assistance of Ms. Saija Kortetjärvi, Ms. Liisa Mannermaa, and Ms. Leena Ukkola is greatly appreciated.