Free fatty acids are associated with obesity, insulin resistance, and atherosclerosis in renal transplant recipients.
BACKGROUND
Insulin resistance (IR) may be implicated in the pathogenesis of atherosclerosis in renal transplant recipients (RTRs) and be contributed to, in part, by free fatty acids (FFAs), produced in excess in centrally obese individuals. The aim of this study was to determine the prevalence of IR and the relationships between FFAs, central obesity, and atherosclerosis in a cohort of prevalent RTRs.


METHODS
Observational data were collected on 85 RTRs (mean age 54 years; 49% male, 87% Caucasian). Fasting serum was analyzed for FFAs, glucose, and insulin; IR was calculated using the homeostasis model assessment (HOMA-IR) score. Vascular structure was assessed by carotid intima-media thickness (IMT) measurement. Linear regression analyses were performed to determine the factors associated with IR and atherosclerosis.


RESULTS
IR occurred in 75% of RTRs, and FFA levels were independently associated with its occurrence (beta: -0.55, 95% CI: -1.02 to -0.07, P = 0.02). Other variables independently associated with IR were male sex, body mass index, central obesity, diabetes, systolic blood pressure and corticosteroid use. There was a significant correlation between FFA levels and IMT (r = 0.3, P=0.01). On multivariate analysis, IMT correlated with elevated FFA (beta: 0.07, 95% CI: 0.02-0.12, P = 0.007), diabetes mellitus (P = 0.05), older age (P < 0.002), and a body mass index >25 kg/m (P = 0.002).


CONCLUSIONS
FFAs are associated with the development of IR and may be involved in the pathogenesis of atherosclerosis in RTRs. Additional studies are required to explore these associations further before considering whether an interventional trial aimed at lowering FFA would be a worthwhile undertaking.
Armstrong
Kirsten A
KA
Department of Renal Medicine, University of Queensland at Princess Alexandra Hospital, Brisbane, Queensland, Australia. kirsty@ascom.net
Hiremagalur
Balaji
B
Haluska
Brian A
BA
Campbell
Scott B
SB
Hawley
Carmel M
CM
Marks
Lisa
L
Prins
Johannes
J
Johnson
David W
DW
Isbel
Nicole M
NM
D050197:Atherosclerosis / Q000175:diagnosis / Q000453:epidemiology*; D015331:Cohort Studies; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D012737:Sex Factors; D017539:Tunica Intima / Q000473:pathology
D005230:Fatty Acids, Nonesterified