Abstract-We tested whether trans fatty acids and saturated fatty acids had different effects on flow-mediated vasodilation (FMD), a risk marker of coronary heart disease (CHD). Consumption of trans fatty acids is related to increased risk of CHD, probably through effects on lipoproteins. Trans fatty acids differ from most saturated fatty acids because they decrease serum high-density lipoprotein (HDL) cholesterol, and this may increase the risk of CHD. We fed 29 volunteers 2 controlled diets in a 2ϫ4-week randomized crossover design. The "Trans-diet" contained 9.2 energy percent of trans fatty acids; these were replaced by saturated fatty acids in the "Sat-diet." Mean serum HDL cholesterol after the 3 trans fatty acids (TFAs) constitute 4% to 7% of dietary fat intake. A high intake of TFAs is associated with an increased risk of coronary heart disease (CHD). 4 -6 One probable cause is the effect of TFAs on serum lipoproteins. Like saturated fatty acids, TFAs increase the concentration of serum LDL cholesterol. 7,8 Moreover, and unlike saturated fatty acids, TFAs decrease serum HDL cholesterol (HDL-C). [7][8][9][10][11] This might be harmful, inasmuch as there is increasing evidence that HDL-C is inversely related to CHD. 12,13 We investigated whether the intake of trans fat would indeed increase the risk of CHD more than the intake of saturated fat by comparing the effects of these fats on endothelial function, a surrogate cardiovascular end point. 14 -16 We assessed endothelial function as flow-mediated vasodilation (FMD) of the brachial artery, because this is a noninvasive measurement that correlates well with known risk factors [17][18][19][20][21][22] and other markers of CHD. [23][24][25] Moreover, 2 longitudinal studies show an association between FMD in the past with future CHD events. 26,27 The diets were given for a minimum of 3 weeks, a time period long enough to establish changes in serum lipids 28 and FMD. 21 We hypothesized that FMD would be lower after the diet rich in trans fat than after the diet rich in saturated fat because of the expected difference in serum HDL-C. Methods SubjectsThe Medical Ethical Committee of Wageningen University approved the study aim and design. Each volunteer signed an informed consent form. We recruited 39 nonsmoking men and women and assessed their health by using a questionnaire; we eliminated 1 person because of use of medication, 2 because of missing information, and 1 because of poor veins for venipuncture. All subjects had normal concentrations of serum cholesterol and triglycerides and normal amounts of protein and glucose in their urine. We excluded 2 subjects because we could not obtain clear ultrasound images of their brachial arteries. One other subject withdrew before the start of the study; in the end, 32 subjects were enrolled. They all completed the study. Study DesignWe provided 2 controlled diets for 4 weeks, each in a randomized crossover design. The diets consisted of conventional food items supplemented with special margarines and were given i...

Previous studies have established a seasonal variation in stroke occurrence, but none have assessed the influence of inclement weather conditions on stroke incidence in a general population of Russia. We performed a stroke population-based study in the Oktiabrsky District of Novosibirsk, Siberia, Russia. Included in the analysis were 1929 patients with their first occurrence of ischemic stroke (IS), 215 patients with their first occurrence of intracerebral hemorrhage (ICH) and 64 patients with their first occurrence of subarachnoid hemorrhage (SAH): all patients were aged between 25 and 74 years. The cumulative daily occurrence of total strokes and stroke subtypes was evaluated in relation to aggregated daily mean values of ambient temperature, relative humidity and air pressure by means of Poisson regression analysis to estimate the rate ratio (RR) with corresponding confidence interval (CI) and to identify the weather parameters of most importance. In a multivariate analysis, with adjustment for the effects of season, solar and geomagnetic activity, and age of the patients, low ambient temperature (RR 1.32; 95% CI 1.05-1.66) and mean value of air pressure (RR 0.986; 95% CI 0.972-0.999) were important predictors of IS occurrence, while mild ambient temperature (RR 1.52; 95% CI 1. 04-2.22) was an important predictor of ICH occurrence. No relationship between SAH occurrence and any one of the weather parameters studied was revealed. There was no interaction between any meteorological variables that was statistically significant. Inclement weather conditions are associated with the occurrence of IS and ICH in Siberia, Russia. Among the meteorological parameters studied, low ambient temperature and mean air pressure are the most important predictors of IS occurrence, whereas the occurrence of ICH is associated with mild ambient temperature. There is no association between any one of the weather parameters studied and the occurrence of SAH.

The patterns of FDG uptake for uninfected vascular grafts largely overlap with those of infected vascular grafts. This questions the value of these individual FDG-PET-CT parameters in identifying infected grafts.