Association of Ghrelin and Resistin With Body Fat Composition and Insulin Resistance in Chronic Renal Failure

Document Type : Original Article

Authors

1 Department of Medical Biochemistry, Faculty of Medicine, Cairo University

2 Department of Internal Medicine, Faculty of Medicine, Cairo University

3 Department of Radiology, Faculty of Medicine, Cairo University

Abstract

The metabolic role of the energy modulating hormone ghrelin and the adipocytokine
resistin is perturbed in uremia and could contribute to nutritional abnormalities.
Malnutrition is an important risk factor for mortality in uremic patients. The present
study aimed to clarify the possible role of ghrelin and resistin in malnutrition
observed in patients with chronic renal failure and to study their interrelationship, as
well as, their correlation with body fat composition and insulin resistance. The study
was performed on sixty patients and twenty control subjects matched for age, sex, and
body mass index (BMI). The patients were classified into two groups: 30 patients with
end-stage renal failure on chronic hemodialysis; and 30 pre-dialysis chronic renal
failure patients on conservative treatment. All patients and control subjects were
subjected to a thorough clinical assessment, and estimation of fasting plasma levels of
lipid profile, creatinine, glucose, insulin, ghrelin and resistin. Insulin resistance was
assessed using the homeostatic assessment model for insulin resistance (HOMAIR
).
Body fat composition was measured in all subjects by means of dual-energy X- ray
absorptiometry (DEXA). Plasma ghrelin and resistin levels were significantly higher
in both hemodialysis and pre-dialysis groups compared to control subjects.
Furthermore, plasma ghrelinand resistin levels weresignificantly higher in
hemodialysis group compared to pre-dialysis group. In hemodialysis group, a
significant negative correlation was found between plasma ghrelin and each of
resistin, BMI, insulin, HOMAIR
, and truncal fat mass, while a significant positive
correlation between plasma ghrelin and creatinine was found. In pre-dialysis group,
plasma ghrelin was inversely correlated significantly with BMI, insulin, HOMAIR
, and
truncal fat mass, but positively correlated significantly with creatinine and lean body
mass. As regards plasma resistin, no correlation was found between resistin and any
of the studied parameters in that group. In control subjects, plasma ghrelin showed
significant negative correlation with BMI, and both truncal fat mass and body fat
mass, but a significant positive correlation was detected between plasma ghrelin and
lean body mass. However, plasma resistinwas negatively correlated significantly
with truncal fat mass, body fat mass, and positively correlated significantly with lean
body mass. Multiple regression analysis showed that plasma ghrelin was dependent
on BMI in both hemodialysis and predialysis subjects and on truncal fat mass in
control subjects
In conclusion, plasma ghrelin and resistin concentration were markedly elevated in
patients with end-stage renal failure, which might be caused by decreased metabolism
or excretion in renal failure. The negative correlation between plasma ghrelin and fat
composition and insulin suggest that anorexia causes increase in ghrelin secretion in
dialysis patients, which might be a compensatory mechanism rather than a causative
factor. However, the lack of association between the increased plasma resistin and fat
composition and insulin resistance suggest that resistin is not likely a mediator of
nutritional status and insulin resistance in patients with end-stage renal failure.

Keywords