Serum concentrations of adiponectin and resistin and their relationship to hypertension in patients with end-stage renal failure

Abstract EN

Background : Patients with end-stage renal disease (ESRD) are at high risk of developing devastating cardiovascular squelae due to unique clustering of risk factors, particularly atherosclerosis and hypertension.

Adipocyte hormones, adiponectin (ADPN) and resistin are implicated in insulin resistance and atherosclerosis however, few studies in literature address the role of these adipocyte hormones in chronic kidney disease (CKD) and their relationship to cardiovascular events which are high in those patients.

Objective : The aim of this study was to evaluate the levels of adiponectin and resistin, and to investigate their possible relation to hypertension in patients with ESRD on regular hemodialysis.

Study Design : Both serum adiponectin and resistin were estimated by ELISA technique in thirty five patients with ESRD on regular hemodialysis (HD) selected from hemodialysis unit, Ain Shams University Hospitals.

They were 18 males and 17 females with mean age of (46.4 + 6.5 years).

The mean duration of dialysis therapy was (49.0 + 23.2 months).

The patients were further classified into hypertensive and normotensive.

All patients underwent carotid duplex for measurement of right common carotid artery intimal medial thickness (cIMT).

The patients were compared to twenty age and sex matched healthy subjects.

Results : The mean serum adiponectin and resistin levels were significantly higher in all ESRD patients (18.91 + 5.34 μg / mL) and (20.73 + 3.09 ng / mL), respectively compared to healthy subjects (8.38 + 1.44 μg / mL) and (9.05 + 3.13 ng / mL), respectively, p < 0.001.

There was no significant change in mean serum ADPN and resistin before dialysis session (16.83 + 4.47 μg / mL) and (21.22 + 3.05 ng / mL), respectively than after the session (14.78 + 4.71 μg / mL) and (19.32 + 4.46 ng/ mL), respectively, p > 0.05.

The mean serum ADPN level was significantly lower in hypertensive patients (16.83 + 4.47 μg / mL) compared to normotensives (21.98 + 6.11 μg / mL), p < 0.001, while there was no statistically significant difference in serum resistin levels on comparing hypertensive group (21.22 + 3.05 ng / mL) and normotensive (20.15 + 3.4 ng / mL).

Serum HDL-C levels were directly related to serum ADPN levels (r = 0.63, p < 0.01), while serum LDL-C, systolic blood pressure (SBP) and cIMT showed an inverse significant correlation with serum ADPN (r = -0.41, p < 0.05, r = -0.56, p < 0.01, r = -0.52, p < 0.01, respectively).

Resistin only showed a significant positive correlation with serum creatinine (r = 0.37, p < 0.05).

Stepwise multiregression analysis showed that the best predictors for positivity of cIMT were ADPN, LDL-C, SBP and HDL-C (F-ratio = 22.3, p < 0.01).

Conclusion : Serum adiponectin levels are increased in hemodialysis patients.

The pattern of ADPN relation to HDL-C, LDL-C, IMT and blood pressure might suggest the relatively low ADPN concentrations as cardiovascular risk factor and indicates a cardiovascular protective role for this important protein.

It also reflects the inhibitory effect of hypertension on this protective mechanism.

Resistin serum concentrations are also increased in HD patients which implicate a role of the kidney in resistin elimination.

The insignificant change in resistin level with hypertension or IMT suggest that there is no association between resistin and atherosclerotic vascular disease in ESRD patients, yet, resistin may play a role in subclinical inflammation associated with CKD.

Finally, hemodialysis didn’t remove excess ADPN or resistin in these patients.