Effects of different degrees of insulin sensitivity on endothelial function in obese patients.
BACKGROUND
Obesity derived from intra-abdominal fat deposition tends to increase hormonal and cytokine production, thus worsening insulin sensitivity and leading to endothelial dysfunction. Hyperinsulinemia is considered an independent risk factor for ischemic heart disease and cause of endothelial dysfunction in healthy individuals.


OBJECTIVE
To assess the impact of different degrees of insulin resistance, measured by HOMA-IR (Homeostasis Model Assessment of Insulin Resistance), on endothelial function in obese, non-diabetic patients without prior history of cardiovascular events and different metabolic syndrome components.


METHODS
Forty obese individuals were submitted to anthropometric measurements, BP measurements at office and ABPM and laboratory tests, in addition to non-invasive ultrasound assessment of endothelial function. Patients were divided into 3 groups according to the level of insulin resistance: patients with HOMA-IR values from 0.590 to 1.082 were assigned to Group 1 (n=13), from 1.083 to 1.410 to Group 2 (n=14) and from 1.610 to 2.510 to Group 3 (n=13).


RESULTS
We found a significant difference in flow-mediated dilation in group 3 compared to group 1 (9.2 ± 7.0 vs 18.0 ± 7.5 %, p=0.006). There was a negative correlation between endothelial function and insulin, HOMA-IR and triglycerides.


CONCLUSIONS
Our data suggest that mild changes in insulin resistance levels assessed by HOMA-IR may have an impact on vasodilatatory endothelial function in uncomplicated obese individuals with different cardiovascular risk factors.
Universidade Federal de São Paulo/EPM, Brazil. roberto.nefro@uol.com.br
Roberto
R
Galvão
Frida Liane
FL
Plavnik
Fernando Flexa
FF
Ribeiro
Sérgio Aron
SA
Ajzen
Dejaldo M de J
DM
Christofalo
Osvaldo
O
Kohlmann
D000328:Adult; D000368:Aged; D000886:Anthropometry; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000209:etiology; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000503:physiopathology*; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000503:physiopathology*; D012016:Reference Values; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D014463:Ultrasonography; D055815:Young Adult
D014280:Triglycerides