Serum RBP4 and CKD: Association with insulin resistance and lipids.

OBJECTIVE

Serum RBP4 is new adipokine and it has been related to insulin resistance and diabetes risk in animal and clinical studies. However, there is controversy on this relationship among CKD patients. In this study, we evaluated the association of serum RBP4 with insulin resistance and cardiovascular risk factors in CKD.

METHODS

Baseline data from the PROGREDIR Study (Sao Paulo, Brazil) comprising 454 participants (mainly stages 3 and 4) was analyzed.

RESULTS

In univariable analysis, RBP4 was inversely related to renal function, age and HDL, and positively related to other lipids, insulinemia, HOMA, glycemia, albumin, phosphorus and right hepatic lobe diameter. After adjustment for sex, age and eGFR, HOMA and lipids remained associated to RBP4. In multivariable analysis, eGFR and triglyceride remained significantly associated with RBP4, while HOMA showed no longer a significant positive association. An interaction term between RBP4 and eGFR was significantly related to HOMA.

CONCLUSIONS

Renal function is inversely related to serum RBP4. As GFR decreases, the relationship between RBP4 and HOMA is attenuated. On the other hand, triglycerides remained strongly related to RBP4 and this was not affected by eGFR, suggesting that in the CKD population triglycerides may be a better marker of RBP4-associated metabolic effects.