Potato Preload Mitigated Postprandial Glycemic Excursion in Healthy Subjects: An Acute Randomized Trial.

This study investigated the preload effect of the medium and high glycemic index (GI) potato, as well as the combination of partially hydrolyzed guar gum (HG) and potato, when ingested prior to a rice meal, on the iso-carbohydrate basis. In a randomized crossover trial, 17 healthy female subjects consumed (1) rice; (2) co-ingestion of highly cooked potato (HP), and rice (HP + R); (3) co-ingestion of minimally cooked potato (MP) and rice (MP + R); (4) preload HP prior to rice meal (PHP + R); (5) preload MP prior to rice meal (PMP + R); (6) co-ingestion of partially hydrolyzed guar gum (HG), HP and rice (HG + HP + R); (7) preload HG prior to co-ingestion of HP and rice (PHG + HP + R); (8) co-preload of HG and HP prior to rice (PHG + PHP + R); and (9) preload of HP prior to co-ingestion of HG and rice (PHP + HG + R). Postprandial glycemic response (GR) tests and subjective satiety tests were conducted for each test food. Cooked potato as a preload to a rice meal could significantly cut the acute postprandial glycemic excursion by around 1.0 mmol/L, irrespective of the GI of the preload. Co-preload of partial hydrolyzed guar gum and highly cooked potato (PHG + PHP + R) resulted in improved acute GR in terms of peak glucose value and glycemic excursion compared with either HG preload or HP preload. All the meals with preload showed comparable or improved self-reported satiety. Within an equicarbohydrate exchange framework, both high-GI and medium-GI potato preload decreased the postprandial glycemic excursion in young healthy female subjects. The combination of HG and HP as double preload resulted in better GR than both single HG or HP preload did.

The Global End-Diastolic Volume (GEDV) Could Be More Appropiate to Fluid Management Than Central Venous Pressure (CVP) During Closed Hyperthermic Intrabdominal Chemotherapy with CO2 Circulation.

BACKGROUND: Closed hyperthermic intraperitoneal chemotherapy (HIPEC) may increase abdominal pressure and effects of hemodynamic changes due to maintenance hyperthermia. Our aim was to analyze the safety and effectiveness of our closed technique with CO2 circulation in management fluid status and hemodynamic parameters by means of cardiac preload control measured by Global End Diastolic Values (GEDV) and a gas exchanger. MATERIAL AND METHODS: A Pilot Clinical Study that included 18 advanced ovarian cancer patients undergoing citoreductive surgery and HIPEC. We used a closed-perfusion system (PRS Combat®) that includes CO2 circulation and a gas exchanger. Transpulmonary thermodilutions and hemodynamic measurements (PiCCO2®) were performed after citoreductive surgery (Pre-HIPEC); At half time of the HIPEC (Intra-HIPEC); After HIPEC (Post-HIPEC). RESULTS: No significant hemodynamic measurements changes in the three thermodilutions values of Cardiac Index (CI) (p = 0.227), Global End Diastolic Values (GEVD) (p = 0.966), Stroke Volume Variation (SVV) (p = 0,884) and Systemic Vascular Resistance Index (SVRI) (p = 0.082). No correlation between central venous pressure (CVP) and GEDV (Pre-HIPEC: r = 0.164, p = 0.211; Intra-HIPEC: r = 0.015, p = 0.900; Post-HIPEC: r = 0.018, p = 0.890). There was better correlation between GEDV and CI (Pre-HIPEC: r = 0.432, p = 0.071; Intra-HIPEC: r = 0.418, p = 0.074; Post-HIPEC: r = 0.411, p = 0.080). CONCLUSIONS: Closed intrabdominal chemotherapy with CO2 circulation model may be a safe model for HIPEC by means of a gas exchanger. GEDV and its changes significantly correlated to CI, and not observed for CVP. GEDV values may be more appropriate for monitoring cardiac preload, blood loss limitation and to predict changes in intravascular volume status during intraperitoneal chemotherapy.

'Snack' versus 'meal': The impact of label and place on food intake.

Eating behaviour is influenced by both cognitions and triggers in the environment. The potential difference between a 'snack' and a 'meal' illustrates these factors and the way in which they interact, particularly in terms of the label used to describe food and the way it is presented. To date no research has specifically explored the independent and combined impact of label and presentation on eating behaviour. Using a preload/taste test design this experimental study evaluated the impact of label ('snack' vs. 'meal') and place ('snack' vs. 'meal') of a preload on changes in desire to eat and subsequent food intake. Eighty female participants consumed a pasta preload which labelled as either a 'snack' or a 'meal' and presented as either a 'snack' (standing and eating from a container) or a 'meal' (eating at a table from a plate), generating four conditions. The results showed main effects of label and place with participants consuming significantly more sweet mass (specifically chocolate) at the taste test when the preload had been labelled a 'snack' and more total mass and calories when the preload had been presented as a 'snack'. No label by place interactions were found. The results also showed a combined effect of both label and place with those who had eaten the preload both labelled and presented as a 'snack' consuming significantly more in terms of nearly all measures of food intake than those in the other conditions. To conclude, label and presentation influence subsequent food intake both independently and combined which is pertinent given the increase in 'snacking' in contemporary culture.

Effect of Consuming Oat Bran Mixed in Water before a Meal on Glycemic Responses in Healthy Humans-A Pilot Study.

BACKGROUND: Viscous dietary fibers including oat ß-glucan are one of the most effective classes of functional food ingredients for reducing postprandial blood glucose. The mechanism of action is thought to be via an increase in viscosity of the stomach contents that delays gastric emptying and reduces mixing of food with digestive enzymes, which, in turn, retards glucose absorption. Previous studies suggest that taking viscous fibers separate from a meal may not be effective in reducing postprandial glycemia. METHODS: We aimed to re-assess the effect of consuming a preload of a commercially available oat-bran (4.5, 13.6 or 27.3 g) containing 22% of high molecular weight oat ß-glucan (O22 (OatWell(®)22)) mixed in water before a test-meal of white bread on glycemic responses in 10 healthy humans. RESULTS: We found a significant effect of dose on blood glucose area under the curve (AUC) (p = 0.006) with AUC after 27.3 g of O22 being significantly lower than white bread only. Linear regression analysis showed that each gram of oat ß-glucan reduced glucose AUC by 4.35% ± 1.20% (r = 0.507, p = 0.0008, n = 40) and peak rise by 6.57% ± 1.49% (r = 0.582, p < 0.0001). CONCLUSION: These data suggest the use of oat bran as nutritional preload strategy in the management of postprandial glycemia.

The Effect of Preload Reduction on a New Parameter to Evaluate Left Ventricular Diastolic Function

BACKGROUND AND OBJECTIVES: The time interval between the onset of the mitral inflow and the mitral annulus velocity (TE'-E) has been proposed as a new index for representing the left ventricular (LV) relaxation and this is related to the LV filling pressure. This index has been reported to be a preload independent parameter in an experimental canine model. However, the impact of the preload on this index has not been studied in humans. SUBJECTS AND METHODS: Forty-five patients (29 men, mean age: 51+/-14 years old) who had end-stage renal disease underwent echocardiography immediately before and after hemodialysis (HD). The two-dimensional and Doppler parameters were measured, including the peak early (E) and late (A) transmitral inflow velocity. The mitral annulus velocity (E') at the septal, lateral, anterior and inferior corners of the mitral annulus, as accessed by Doppler tissue imaging (DTI), and the flow propagation velocity (Vp), as accessed by color M-mode, were also measured. The time intervals between the peak of the R wave and the onset of the mitral E velocity and also between the peak R wave and the onset of E' at the four corners of the mitral annulus were measured. RESULTS: The mean ejection fraction was 62+/-16%. The average weight reduction by the HD was 2.9+/-1.1 kg. The dimensions of the LV end-diastole, left atrium and inferior vena cava were significantly reduced. After the HD, the peak E, A and E/A ratio, the average peak E' and the Vp were significantly decreased. The TE'-E did not change significantly after the HD regardless of the LV systolic function. CONCLUSION: A new parameter for the diastolic function, i.e., the time interval between the onset of mitral inflow and the mitral annulus velocity, appears to be preload-independent in the patients with a normal or decreased LV systolic function.

The Influence of Changes in Preload on Tei index

BACKGROUND: Tei index is a Doppler-derived index of combined systolic and diastolic myocardial performance proposed to be a promising noninvasive measurement of overall cardiac function, calculated as the sum of isovolumic contraction (ICT) and isovolumic relaxation times (IRT) divided by ejection time (ET). This study aimed to investigate the effect of changes in preload on Tei index. SUBJECTS AND METHOD: The study population was 10 patients with chronic renal failure who are on regular hemodialysis (HD). They were 3 men and 7 women with a mean age of 45.3+/-12.4 years old. The complete 2-dimensional and Doppler echocardiography including recordings of mitral inflow and left ventricular outflow were performed using HP SONOS 1500 equipment before and after HD. Body weight was measured using electric scale before and after HD. Blood pressure and pulse rate were measured by an automated cuff measurement every 1 hour throughout HD. Hematocrit was monitored noninvasively and continuously using the Crit-Line instrument (In-Line Diagnostics, Riverdale, UT, USA) during HD. RESULTS: There were no significant changes in systolic and diastolic blood pressure, RR interval, left ventricular end-diastolic and end-systolic dimension, left atrial dimension, and left ventricular ejection fraction during HD. The mean body weight loss during HD was 2.1+/-0.65 kg. The percentage of reduction of body weight was 4.1+/-1.56%. Changes in total blood volume at the end of HD were compared with that of baseline -11.79+/-5.51%. The percent change in total blood volume during the HD correlated significantly with the amount of change in body weight (r=0.678, p<0.05) and percent change in body weight (r=0.835, p<0.01), respectively. ICT before HD and at the end of HD were 39+/-13.0, 42+/-24.1 msec (p=NS). IRT before HD and at the end of HD were 76+/-29.1, 95+/-28.5 msec (p<0.01) and , ET before HD and at the end of HD were 317+/-18.1, 289+/-9.0 msec (p<0.01), respectively. Tei index before HD was 0.36+/-0.10, and the index at the end of HD were 0.47+/-0.13 (p<0.001). CONCLUSION: When there is a change in preload during a short period, it seems that the effect of change in preload should be considered when using Tei index to assess ventricular function.

The Effect of Ultrafiltration and Hemodialysis on Doppler Myocardial Performance Index in Patients with End-stage Renal Disease and Normal Left Ventricular Function

BACKGROUND: Doppler myocardial performance index (DMPI), defined as the sum of isovolumetric contraction time (IVCT) and isovolumetric relaxation time (IVRT) divided by ejection time (ET), is an easily measurable index which has been shown to reflect the severity of the disease. It has been known each component of DMPI, as IVCT, IVRT and ET, was affected by the change of preload. Therefore, the objective of this study was to estimate the changes of DMPI during intravascular volume reduction in patients with end-stage renal disease and to determine which components of DMPI contribute to DMPI alteration during intravacular volume reduction. METHODS: We measured blood pressure, heart rate, M-mode echocardiographic and Doppler parameters within 10 minutes before and after hemodialysis and ultrafitration with amount of average 2 L. RESULTS: We studied 40 end-stage renal disease patients (22 men and 18 women, mean age of 52 years) who had left ventricular hypertrophy 39 (97.5%) and normal left ventricular systolic function (diastolic interventricular septal thickness, 13.8+/-2 mm; diastolic left ventricular posterior wall thickness, 12.6+/-2 mm; Ejection fraction, 63.1+/-0.1%). Peak E-wave velocity was significantly decreased after hemodialysis and ultrafiltration (84.85+/-25 cm/s vs 72.89+/-23 cm/s, p<0.05), but other Doppler parameters such as peak A-wave velocity and E deceleration time were not changed. E/A ratio showed decreased tendency which was not significant statistically (p<0.097). DMPI was significantly increased after hemodialysis and ultrafiltration (0.41+/-0.14 vs 0.45+/-0.15, p<0.001). The increase of DMPI was mainly affected by prolongation of IVRT/ET which was due to prolonged IVRT, but IVCT/ET was not changed. The changes of DMPI was little with hemodialysis and ultrafiltration of about 2 L. CONCLUSION: We could prove that DMPI was preload dependent parameter of myocardial function. We suggest the change of preload should be considered as an important factor which may alter the DMPI.

Effect of Changes in Pulmonary Venous Flow Pattern by Preload Reduction on Distinguishing Pseudonormal Pattern from Normal

BACKGROUND AND OBJECTIVES: The degree of diastolic dysfunction may explain the difference in clinical symptoms between patients with similar degrees of systolic dysfunction. Pseudonormal mitral filling pattern with increased left ventricular filling pressure is a transitional stage of diastolic dysfunction and is difficult to distinguish from normal. Preload is one of factors affecting the diastolic filling patterns and mitral flow patterns may be influenced by changes in preload in the absence of changes in the left ventricular pressure-volume curve. The changes in the mitral flow velocities caused by preload reduction may be useful in distinguishing patients with a pseudonormal pattern from those with normal. The aim of this study was to establish whether the effect of changes in pulmonary venous flow pattern by preload reduction may be useful in distinguishing pseudonormal pattern from normal. MATERIALS AND METHODS: This study included 40 patients (men 25, female 15, average age 51.0+/-11.2 years) underwent left side cardiac catheterization among patients with normal or pseudonormal patterns. All patients with pseudonormal group had increased LVEDPr (>15 mmHg). The Doppler mitral inflow & pulmonary venous flow parameters at baseline and during reduction of preload using Valsalva maneuver were recorded. RESULTS: 1) There were no difference in sex, diabetes mellitus, hypertension and lipid profiles between both groups. The left ventricular systolic function was better and mean age was younger in normal than pseudonormal group (p 1.0 during Valsalva maneuver in normal group (p<0.05). In pseudonormal group, E velocity was significantly decreased but A velocity was not significantly changed and the E/A ratio was <1.0 during Valsalva (p<0.05). Therefore the change revealed masked LV relaxation abnormality pattern. 3) S and D velocities of pulmonary venous flow were significantly decreased and S/D ratio was significantly increased in both groups (p<0.05). The % changes before and after Valsalva maneuver showed that S velocity was less decreased, D velocity was more decreased and S/D ratio was more significantly increased in pseudonormal than normal group (p<0.05). That revealed masked LV relaxation abnormality pattern. CONCLUSIONS: The Valsalva maneuver for preload reduction is a relatively simple, easily applicable, safe and reproducible method of acutely reducing venous return. The assessment of changes in pulmonary venous flow pattern by preload reduction may be helpful in distinguishing pseudonormal and normal diastolic function in addition to changes in mitral inflow pattern.