Insulin Resistance in Nondiabetic Peritoneal Dialysis Patients: Associations with Body Composition, Peritoneal Transport, and Peritoneal Glucose Absorption.
OBJECTIVE
Insulin resistance has been associated with cardiovascular disease in peritoneal dialysis patients. Few studies have addressed the impact of fast transport status or dialysis prescription on insulin resistance. The aim of this study was to test whether insulin resistance is associated with obesity parameters, peritoneal transport rate, and glucose absorption.


METHODS
Insulin resistance was evaluated with homeostasis model assessment method (HOMA-IR), additionally corrected by adiponectin (HOMA-AD). Enrolled patients were prevalent nondiabetics attending at Santo António Hospital Peritoneal Dialysis Unit, who were free of hospitalization or infectious events in the previous 3 months (51 patients aged 50.4 ± 15.9 years, 59% women). Leptin, adiponectin, insulin-like growth factor-binding protein 1 (IGFBP-1), and daily glucose absorption were also measured. Lean tissue index, fat tissue index (FTI), and relative fat mass (rel.FM) were assessed using multifrequency bioimpedance. Patients were categorized according to dialysate to plasma creatinine ratio at 4 hours, 3.86% peritoneal equilibration test, and obesity parameters.


RESULTS
Obesity was present in 49% of patients according to rel.FM. HOMA-IR correlated better with FTI than with body mass index. Significant correlations were found in obese, but not in nonobese patients, between HOMA-IR and leptin, leptin/adiponectin ratio (LAR), and IGFBP-1. HOMA-IR correlated with HOMA-AD, but did not correlate with glucose absorption or transport rate. There were no significant differences in insulin resistance indices, glucose absorption, and body composition parameters between fast and nonfast transporters. A total of 18 patients (35.3%) who had insulin resistance presented with higher LAR and rel.FM (7.3 [12.3, interquartile range] versus 0.7 [1.4, interquartile range], P<0.001, and 39.4 ± 10.1% versus 27.2 ± 11.5%, P=0.002, respectively), lower IGFBP-1 (8.2 ± 7.2 versus 21.0 ± 16.3 ng/ml, P=0.002), but similar glucose absorption and small-solute transport compared with patients without insulin resistance. FTI and LAR were independent correlates of HOMA-IR in multivariate analysis adjusted for glucose absorption and small-solute transport (r=0.82, P<0.001).


CONCLUSIONS
Insulin resistance in nondiabetic peritoneal dialysis patients is associated with obesity and LAR independent of glucose absorption and small-solute transport status. Fast transport status was not associated with higher likelihood of obesity or insulin resistance.
Department of Nephrology and Unit for Multidisciplinary Research in Biomedicine, Abel Salazar Biomedical Sciences Institute, University of Porto, Porto, Portugal anabernardo@portugalmail.pt.
Ana Paula
AP
Bernardo
Department of Clinical Pathology, Santo António General Hospital(Hospital Center of Porto, EPE), Porto, Portugal; and.
Jose C
JC
Oliveira
Department of Nephrology and.
Olivia
O
Santos
Department of Nephrology and.
Maria J
MJ
Carvalho
Department of Nephrology and.
Antonio
A
Cabrita
Department of Nephrology and Unit for Multidisciplinary Research in Biomedicine, Abel Salazar Biomedical Sciences Institute, University of Porto, Porto, Portugal.
Anabela
A
Rodrigues
D052242:Adiponectin / Q000097:blood; D000328:Adult; D000368:Aged; D001692:Biological Transport; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D001823:Body Composition; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood; D007674:Kidney Diseases / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D020738:Leptin / Q000097:blood; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D065629:Peritoneal Absorption; D010530:Peritoneal Dialysis; D010537:Peritoneum / Q000473:pathology*; D011174:Portugal / Q000453:epidemiology; D012307:Risk Factors
C499918:ADIPOQ protein, human; D052242:Adiponectin; D015415:Biomarkers; D001786:Blood Glucose; C032231:IGFBP1 protein, human; D007328:Insulin; D018970:Insulin-Like Growth Factor Binding Protein 1; D020738:Leptin
Adiponectin; Body Mass Index; Insulin-Like Growth Factor Binding Protein 1 Leptin obesity peritoneal dialysis; diabetes mellitus; insulin resistance; nutrition; peritoneal glucose absorption