Mesenteric blood flow is related to disease activity and risk of relapse in ulcerative colitis: a prospective follow up study.
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BACKGROUND: The diagnostic significance of increased splanchnic blood flow in ulcerative colitis is unclear. This prospective study was therefore undertaken to define the role of Doppler sonography in the assessment of disease activity and in the prediction of early relapse. SUBJECTS/METHODS: Splanchnic flowmetry was performed in 76 patients with ulcerative colitis (47 with active disease and 29 in remission), six with infectious colitis, and 13 healthy controls during fasting and 30 minutes after ingestion of a standardised meal. Twenty seven of the patients with ulcerative colitis and all patients with infectious colitis were investigated during the active state as well as in clinical remission and followed up for six months. Flow velocity and pulsatility index (PI) of the superior (SMA) and inferior (IMA) mesenteric arteries and the portal vein were related to clinical (Truelove index), laboratory (C-reactive protein), and endoscopic (Sutherland index) parameters of disease activity. RESULTS: The mean flow velocity of the IMA correlated closest with clinical activity (Truelove, r = 0.41, p<0.005), the PI with C-reactive protein (r = 0.30, p<0.05), and endoscopic activity (r = 0.45, p<0.001). All patients in remission after six months (14/14) or with infectious colitis (6/6) showed an increase in PI of the IMA compared with the initial measurement during active disease (mean increase for ulcerative colitis +36% and for infectious colitis +77%). In contrast, most patients with later relapse or surgery (11/13) had decreased PI during initial remission (mean decrease -12%). The positive predictive value of this index for maintenance of remission was 0.77. Flow variables of the SMA and portal vein displayed weaker correlations. CONCLUSIONS: Flow measurements in the IMA are closely related to clinical and endoscopic disease activity in patients with ulcerative colitis. Repeated measurement of the PI allows estimation of the risk of recurrence. (+info)
Local regulation of postprandial motor responses in ileal pouches.
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BACKGROUND: Local mechanisms are involved in the postprandial regulation of ileal tone in healthy subjects, but whether these mechanisms affect the postprandial tonic response of ileal pouches has not yet been investigated. AIMS: To study the effect of a meal on pouch tone and phasic motor activity in patients with gut continuity or ileostomy and, in the latter group, the effect of a pouch perfusion with chyme or saline. PATIENTS: Twenty patients with ileal pouches: 10 with gut continuity and 10 with ileostomy. METHODS: Pouch tone and the frequency of phasic volume events were recorded with a barostat under fasting and postprandial conditions and after perfusion of the isolated pouch with chyme or saline. RESULTS: The meal increased pouch tone and the frequency of phasic volume events in the patients with gut continuity, but not in those with ileostomy. Pouch perfusion with chyme induced a greater increase in pouch tone than saline. CONCLUSIONS: The meal stimulated pouch tone and phasic motor activity. These effects were at least partially related to local pouch stimulation by intraluminal contents. (+info)
Postprandial response of activated factor VII in elderly women depends on the R353Q polymorphism.
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BACKGROUND: Activated factor VII (FVIIa) is a very potent coagulant and may be a key determinant of the outcome of a cardiovascular event. The main determinants of FVIIa are the R353Q polymorphism and dietary fat intake, which may have an interactive effect. OBJECTIVE: The objective was to investigate whether the response of FVIIa to a fat-rich breakfast varies across genotypes of the R353Q polymorphism. DESIGN: Ninety-one apparently healthy elderly women (>60 y of age), 56 with the RR genotype and 35 with the RQ or QQ genotype, participated in a randomized, controlled crossover study. Subjects received 5 breakfasts, each on a separate day: 1 low-fat control breakfast and 4 high-fat test breakfasts. Blood samples were taken for measurement of FVIIa at 0800 before each breakfast (fasting) and at 1300 and 1500. RESULTS: The mean (+/-SD) fasting FVIIa concentration was 93.3 +/- 26.7 U/L in women with the RR genotype, 49.3 +/- 19.1 U/L in those with the RQ genotype and 39.5 +/- 17.2 U/L in those with the QQ genotype. The mean absolute response to all 4 test breakfasts was 37.0 U/L in those with the RR genotype and 16. 1 U/L in those carrying the Q allele (P < 0.001 for difference). Likewise, the FVIIa response relative to fasting FVIIa was significantly higher in women homozygous for the R allele. CONCLUSION: This observation may indicate a considerable difference in cardiovascular risk between genotype groups as a result of an increase in FVIIa after a fat-rich diet. (+info)
Gender difference in postprandial lipemia : importance of visceral adipose tissue accumulation.
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Insulin resistance, hyperinsulinemia, hypertriglyceridemia, and low HDL-cholesterol concentrations are common features of a plurimetabolic syndrome, which increases the risk of coronary artery disease. Although it has been proposed that the development of atherosclerosis through alterations in plasma lipid levels could be a postprandial phenomenon, most studies on gender differences in plasma lipoprotein-lipid concentrations have reported fasting levels. Therefore, the aim of our study was to examine the response of postprandial triglyceride-rich lipoproteins to a standardized meal in 63 men and 25 women. In addition to the measurement of fasting and postprandial plasma lipid levels, numerous physical and metabolic variables were assessed, including body composition by underwater weighing and body fat distribution by computed tomography. Although no gender difference was noted in total body fat mass, men were characterized by a preferential accumulation of abdominal adipose tissue as revealed by an increased waist circumference and a greater visceral adipose tissue accumulation (50% difference) compared with women (P<0.001). Men also showed a greater plasma triglyceride response (P<0.005) as well as increased postprandial insulin and free fatty acid levels compared with women (P<0.01). Visceral adipose tissue was significantly associated with the postprandial triglyceride response in both genders (men: r=0.49, P<0. 0001; women: r=0.43, P<0.05). Finally, when men and women were matched for visceral adipose tissue accumulation, the gender difference in postprandial plasma triglyceride response was eliminated. Thus results of the present study suggest that the well known gender difference in visceral adipose tissue accumulation is an important contributing factor involved in the exaggerated postprandial triglyceride-rich lipoprotein response noted in men compared with women. (+info)
Independent effects of Apo E phenotype and plasma triglyceride on lipoprotein particle sizes in the fasting and postprandial states.
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LDL particle sizes and Apo E phenotypes were determined in 212 subjects of whom 51 had angina. LDL diameter was significantly less in subjects with an epsilon2 allele (24.76+/-0.08 vs 24.94+/-0.02 nm, P=0.02), and this was evident for both E2/E3 (24.77+/-0.09 nm) and E2/E4 (24.69+/-0.08 nm) phenotypes. Although there was a negative relation between LDL diameter and plasma triglyceride, the effect of apo E2 was still evident with adjustment for triglyceride. In multiple regression analysis, the significant determinants of LDL diameter were gender (with females having larger particles than males), body mass index, and the presence (or absence) of E2. HDL particle sizes and compositions were determined on fasting samples and, additionally, 5 and 8 hours after a fat-rich meal for 48 coronary heart disease cases and 49 control subjects. Fasting HDL particle sizes were not related to the presence of E2 but were significantly smaller for subjects possessing an epsilon4 allele (8. 09+/-0.08 vs 8.39+/-0.05 nm, P=0.003) and were negatively related to plasma triglyceride. However, the effect of E4 persisted after adjustment for triglyceride. In a multiple regression analysis, the only significant determinant of fasting HDL diameter was the presence (or absence) of E4 with fasting plasma triglyceride just failing to reach significance (P=0.06). There was a postprandial increase in HDL diameter that was less marked in subjects with coronary heart disease. The postprandial increase in HDL diameter was of sufficient magnitude to result in size reclassification of HDL particles. The influence of E4 was also evident at both postprandial time points. Compositional analysis demonstrated that the increase in HDL diameters postprandially could be attributed to triglyceride enrichment, with an accompanying fall in cholesterol ester content. Phospholipid changes postprandially were biphasic with an initial fall followed by a rise in concentration. The increase in triglyceride content was significantly less in those subjects with angina despite an equivalent rise in plasma triglyceride. The present study demonstrates significant, but different, effects of variation in apo E phenotype on the particle sizes of both HDL and LDL. Such effects were still evident with adjustment for differences in plasma triglyceride and suggests that variation in apo E phenotype exerts effects on lipoprotein particle sizes by mechanisms additional to those dependent on change in plasma triglyceride. (+info)
Pre- and postprandial expression of the leptin receptor splice variants OB-Ra and OB-Rb in murine peripheral tissues.
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Leptin receptors (OB-R) are widely distributed in peripheral tissues. However, the RT-PCR data published on the distribution of OB-R are not always consistent. The present study was undertaken in order to test whether the different muscle fiber type profile or the acute nutritional status in which tissue samples were excised from animals may influence OB-R expression. Six 12-week-old male Swiss-Webster mice were killed by decapitation either 1 h after feeding or after a 16-h fast, and the kidneys, testes, brown adipose tissue, gastrocnemius (G), soleus (SOL) and extensor digitorum longus (EDL) muscles were dissected out. In parallel, muscle fibers obtained from other animals were classified on the basis of differences in the staining intensity for myofibrillar adenosinetriphosphatase. The expression of OB-R isoforms was assessed by RT-PCR and ethidium bromide staining. The signal for OB-Ra and OB-Rb was detected in all tissues examined. No differences were observed in samples obtained from either fed or fasted mice. G, SOL and EDL muscles showed the same pattern of OB-R expression. Neither the short-term nutritional changes of the animal as regards to the pre- versus the postprandial-state nor differences in muscle fiber type had any influence on the qualitative expression of the OB-R splice variants a and b in the murine tissues studied. However, quantitative differences cannot be ruled out. (+info)
Nutritional value of [15N]-soy protein isolate assessed from ileal digestibility and postprandial protein utilization in humans.
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The purpose of this work was to assess the true oro-ileal digestibility, and to concurrently quantify the deamination of absorbed dietary nitrogen to examine the postprandial nutritional value of a soy protein isolate (SPI) in humans. To assess bioavailability and bioutilization of SPI, 10 healthy volunteers ingested 30 g of SPI, intrinsically and uniformly [15N]-labeled, added with 100 g of sucrose and water up to a final volume of 500 mL. True ileal digestibility was assessed by the [15N]-dilution method for 8 h by means of a naso-intestinal intubation technique. To describe and quantify exogenous nitrogen deamination for the same time period, urine and plasma samples were collected. True oro-ileal digestibility of SPI nitrogen was 91%. The amount of absorbed SPI amino acids used for nonoxidative disposal, i.e., postprandial biological value, was 86% 8 h after meal ingestion. Hence, net postprandial protein utilization of SPI was 78%. Compared to previous data that were assessed under the same condition in humans, the nutritional value of SPI is 92% of that in milk protein concentrate. (+info)
Menopause is associated with reduced protection from postprandial lipemia.
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Deficiency of endogenous estrogens has been associated with a higher incidence of coronary heart disease (CHD) in women. We investigated whether natural menopause is associated with reduced protection from postprandial lipemia, which represents a risk indicator of CHD. Twenty-three postmenopausal women (mean age, 50+/-1 [SD] years; body mass index, 24.6+/-2.8 kg/m(2)) and 21 premenopausal women matched for age and body mass index (age, 49+/-1 years; body mass index, 24. 1+/-2.6 kg/m(2)) underwent an oral vitamin A fat-loading test. Vitamin A is a marker of the metabolism of chylomicrons and chylomicron remnants. All women were normolipidemic, were in good health, were nonsmokers, and used no medication. Postprandial lipids and vitamin A were measured at hourly intervals up to 12 hours. In postmenopausal women, plasma total cholesterol and LDL cholesterol concentrations were significantly higher. Fasting plasma triglyceride (TG) concentrations were 1.14+/-0.57 mmol/L in postmenopausal women and 0.88+/-0.33 mmol/L in premenopausal women (P=NS). In the postprandial phase, postmenopausal women had higher plasma TG (13.0+/-6.1 versus 9.5+/-3.3 mmol x L(-1) x h(-1); P=0.024) and vitamin A (54.1+/-22.9 versus 35.9+/-9.6 mg x L(-1) x h(-1); P=0. 001) responses. To correct for the possible confounding effect of fasting TG, 13 postmenopausal women were carefully matched with 19 premenopausal women. Although fasting TG levels were identical (0. 72+/-0.20 versus 0.73+/-0.21 mmol/L), differences in postprandial vitamin A (45.3+/-14.5 versus 33.0+/-7.7 mg x L(-1) x h(-1); P=0.006) and incremental TG (ie, after subtraction of baseline TG) (3.2+/-1.8 versus 2.3+/-1.0 mmol x L(-1) x h(-1); P=0.023) persisted between postmenopausal and premenopausal women. Natural menopause is associated with aggravated postprandial lipemia in women matched for age and body mass index. Higher postprandial lipemia potentially explains the relation of TGs and CHD mortality risk in postmenopausal women. (+info)