Platelet activation in obese women: role of inflammation and oxidant stress.
BACKGROUND
Obesity, in particular abdominal adiposity, is associated with increased cardiovascular morbidity and mortality through mechanisms possibly linking the metabolic disorder to platelet and vascular abnormalities.


OBJECTIVE
To investigate the clinical and biochemical determinants of lipid peroxidation and platelet activation in obese women.


METHODS
Cross-sectional comparison, conducted between September 1999 and September 2001, of urinary 8-iso prostaglandin F(2alpha) (8-iso PGF(2alpha)) and 11-dehydrothromboxane B2 (11-dehyhdro-TxB2) excretion levels in 93 women: 44 with a body mass index (BMI) higher than 28 and a waist-to-hip ratio (WHR) of 0.86 or higher, android obesity; 25 with a BMI higher than 28 and a WHR lower than 0.86, gynoid obesity; and 24 nonobese women with a BMI lower than 25. An additional study was conducted to determine the short-term effects of weight loss in 20 of the 44 women with android obesity.


METHODS
During a 12-week period, 20 women with android obesity followed a weight loss program to reduce caloric intake to about 1200 kcal/d.


METHODS
Plasma C-reactive protein, insulin and leptin levels, and urinary 8-iso PGF(2alpha) (marker of in vivo lipid peroxidation) and 11-dehyhdro-TxB2 (marker of in vivo platelet activation) excretion. Weight loss was defined as successful when the initial body weight decreased by at least 5 kg after a 12-week period of caloric restriction.


RESULTS
Women with android obesity had higher levels of 8-iso PGF(2alpha )(median [interquartile range [IQR]] 523 [393-685] vs 187 [140-225] pg/mg creatinine) and 11-dehyhdro-TxB2 (median [IQR], 948 [729-1296] vs 215 [184-253] pg/mg creatinine) than nonobese women (P<.001). Both 8-iso PGF(2alpha)and 11-dehyhdro-TxB2 were higher in women with android obesity than women with gynoid obesity (P<.001). Based on multiple regression analysis, C-reactive protein levels and WHRs of 0.86 or higher predicted the rate of 8-iso PGF(2alpha) excretion independently of insulin and leptin levels. Of 20 women with android obesity, 11 achieved successful weight loss, which was associated with statistically significant reductions in C-reactive protein (median change, 23%; P<.05), 8-iso PGF(2alpha) (median change, 32%; P =.04) and 11-dehydro-TxB2 (median change, 54%; P =.005).


CONCLUSIONS
Android obesity is associated with enhanced lipid peroxidation and persistent platelet activation. These abnormalities are driven by inflammatory triggers related to the degree of abdominal adiposity and are, at least in part, reversible with a successful weight-loss program.
Davì
Giovanni
G
Center of Excellence on Aging, G. D'Annunzio University Schools of Medicine and Pharmacy, Chieti, Italy.
Guagnano
Maria Teresa
MT
Ciabattoni
Giovanni
G
Basili
Stefania
S
Falco
Angela
A
Marinopiccoli
Marina
M
Nutini
Michele
M
Sensi
Sergio
S
Patrono
Carlo
C
D000328:Adult; D001786:Blood Glucose; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology; D003430:Cross-Sectional Studies; D004038:Diet, Reducing; D015237:Dinoprost / Q000031:analogs & derivatives*; D028441:F2-Isoprostanes / Q000652:urine; D005260:Female; D006801:Humans; D007249:Inflammation; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood; D016014:Linear Models; D015227:Lipid Peroxidation; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000150:complications / Q000178:diet therapy / Q000378:metabolism*; D018384:Oxidative Stress; D010974:Platelet Aggregation / Q000276:immunology / Q000502:physiology; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013929:Thromboxane B2 / Q000031:analogs & derivatives* / Q000652:urine; D015431:Weight Loss
D001786:Blood Glucose; D028441:F2-Isoprostanes; D007328:Insulin; D020738:Leptin; C075750:8-epi-prostaglandin F2alpha; D013929:Thromboxane B2; C049235:11-dehydro-thromboxane B2; D002097:C-Reactive Protein; D015237:Dinoprost