A study on the carotid artery intima-media thickness and its association with lipid peroxidation.

High resolution B-mode ultrasonography of the carotid arteries has been used to investigate the signs of early atherosclerotic vessel wall disease by measuring the intima-media thickness (IMT). We examined the association between IMT and lipid peroxidation and found IMT to be increased in a group of patients with respect to controls (1.430+/-0.341 mm versus 0.703+/-0.201 mm, P < 0.001). Plasma and erythrocyte malondialdehyde (MDA) levels were also significantly higher (P<0.001) and the erythrocyte reduced glutathione (GSH) levels were significantly lower (P <0.001) in the patients with respect to the controls. In the groups of patients there was no significant correlation between the mean IMT and the plasma and erythrocyte MDA levels or the erythrocyte GSH levels. In conclusion determination of lipid peroxides would be especially important and advisable in patients with increased carotid IMT. Type II diabetes and hypertension were also associated with increased IMT.

Plasma leptin levels in obese and non-obese postmenopausal women before and after hormone replacement therapy.

OBJECTIVE: the aim of this study was to investigate the effect of hormone replacement therapy (HRT) on plasma leptin levels in postmenopausal women, and the relationship between the plasma leptin levels and obesity. METHODS: premenopausal women with normal cycles (n=30; mean ages, 35.4+/-8.3 years) and postmenopausal women (n=45; mean ages, 49.5+/-4.7 years) were randomly selected. Women were classified as obese (BMI>27 kg/m(2)) and as non-obese (BMI<27 kg/m(2)). Blood samples were obtained from the premenopausal women at the beginning of cycle, and from the postmenopausal women before and 6 months after HRT. Plasma leptin levels were measured by radioimmunassay. RESULTS: plasma leptin levels were significantly higher in premenopausal women than in postmenopausal women (18. 60+/-5.0; 3.67+/-2.44 ng/ml, respectively, P<0.001). Obese premenopausal women (n=15) had significantly higher plasma leptin levels (24. 60+/-7.81 ng/ml) in comparison with the levels of the non-obese premenopausal women (n=15; 12.50+/-4. 63 ng/ml) (P<0.001). Although there was no significant difference in the plasma leptin levels between obese (n=25) and non-obese (n=20) postmenopausal women before HRT, plasma leptin levels were significantly elevated in both obese and non-obese postmenopausal women after HRT (P<0.001), and the obese women had significantly higher plasma leptin levels than the non-obese (29.05+/-10.53; 14.78+/-6.76 ng/ml, respectively, P<0.001). CONCLUSION: HRT is effective in the elevation of the plasma leptin levels in postmenopausal women, and in obese women the increase of the plasma leptin levels are more marked than the non-obese women after HRT.

Effects of hormone replacement therapy on plasma nitric oxide and total thiol levels in postmenopausal women.

Improvement in endothelial function may be an important mechanism by which hormone replacement therapy (HRT) protects postmenopausal women against coronary artery disease. Our aim was to assess the effects of HRT on plasma nitric oxide (NOx) (nitrate plus nitrite) and total thiols in postmenopausal women, as these parameters are associated with enhanced endothelial functions. Thirty-five healthy postmenopausal volunteers (mean age 50.5 +/- 4.7 yr) in an academic and hospital research environment were involved in the study. Blood samples were collected, one at baseline and the second after 6 mo of HRT. Plasma NOx and total thiol levels were significantly elevated in the subjects after HRT. NOx may be of importance in the protective effects of HRT. Further, the increase of plasma antioxidant thiol levels might also contribute to the beneficial effects of HRT.

The relationship between plasma viscosity and cholesterol in postmenopausal women on hormone replacement therapy.

In women, cardiovascular morbidity and mortality sharply increase after the onset of menopause. There is substantial evidence that hormone replacement therapy (HRT) may decrease the risk of coronary heart disease; however the mechanism is unclear. We investigated the relationship between HRT and plasma viscosity as well as cholesterol levels in postmenopausal women. 30 women were using HRT (HRT users), and 30 women were not using HRT (non-users). According to the classification of their plasma cholesterol levels, 30 women were hypercholesterolemic levels (hypercholesterolemic users n = 15, and hypercholesterolemic non-users n = 15), and the others were normocholesterolemic levels. While the highest plasma viscosity was measured in hypercholesterolemic users (1.291 +/- 0.053 cP), the lowest plasma viscosity was measured in normocholesterolemic users (1.127 +/- 0.056 cP). There was a significant correlation between plasma viscosity and cholesterol levels in the women on HRT (r = 0.76, p < 0.001). We have not found a difference neither in fibrinogen levels nor in triglycerides between users and non-users. These data demonstrated that HRT has beneficial effect on plasma viscosity; mainly in normocholesterolemic post menopausal women.

Serum oxidized low density lipoprotein, paraoxonase 1 and lipid peroxidation levels during oral glucose tolerance test.

Increasing evidence suggests that the postprandial state is a contributing factor to the development of atherosclerosis. To evaluate the effects of acute hyperglycemia on the oxidative stress, concentrations of serum-oxidized low density lipoprotein (oxLDL), paraoxonase 1 (PON1), and thiobarbituric acid reactive substances (TBARS) were measured in subjects with normal glucose tolerance (NGT) (n=35), impaired glucose tolerance (IGT) (n=25), and diabetic glucose tolerance (DGT) (n=20). In NGT group, the 2 hours' TBARS and oxLDL levels were not statistically different when compared to baseline, and 2 hours' PON1 activities were higher when compared to baseline (p<0.01). Subjects with IGT and DGT have higher 2 hours' serum TBARS and oxLDL levels than their baseline levels (p<0.01, for each). Baseline oxLDL levels of both IGT and DGT groups were higher than NGT group (p<0.01 and p<0.01, respectively). While there were not any significant differences in 2 hours' versus baseline PON1 activities in the IGT group, the 2 hours' versus baseline PON1 activities in the DGT group were significantly lower (p<0.01). The postchallenge 2 hours' PON1 activities of both IGT and DGT groups were lower than NGT group (p<0.01 and p<0.01, respectively). Baseline oxLDL was positively correlated with 2 hours' glucose (r=0.613, p<0.01) in IGT and DGT groups. PON1 activities were correlated with HDL-cholesterol, total cholesterol, and fasting glucose (r=0.680, r=0.698 and r=0.431, respectively, for each p<0.01) in NGT. In conclusion, oxidative stress occurs at an early stage in diabetes, and protective effects of HDL against atherosclerosis may be dependent on the PON1 activities.

Copy management in a shared care environment using the Internet.

A new approach to sharing medical records using a demand-based database replication method and the Internet e-mail facility is proposed. The underlying model allows subscribed physicians to collect patient records from distant nodes and have local access to these records when needed. A system called the Internet-Based Distributed Medical Information System has been developed and implemented in a shared care environment comprising outpatient clinics, independent practitioners, and diagnostic laboratories. This tool may be highly beneficial in improving coordination among health care professionals and reducing unnecessary repeat investigations.