Despoina Kyriaki

Eating Slowly Increases the Postprandial Response of the Anorexigenic Gut Hormones, Peptide YY and Glucagon-Like Peptide-1

CONTEXT The rate at which people eat has been suggested to be positively associated with obesity, although appetite and related gut hormones have not been measured. The objective of the study was to determine whether eating the same meal at varying speeds elicits different postprandial gut peptide responses. DESIGN AND SETTING This was a crossover study at a clinical research facility. STUDY PARTICIPANTS Seventeen healthy adult male volunteers participated in the study. INTERVENTION A test meal consisting of 300 ml ice cream (675 kcal) was consumed in random order on two different sessions by each subject: meal duration took either 5 or 30 min. MAIN OUTCOME MEASURES The postprandial response of the orexigenic hormone ghrelin and the anorexigenic peptides peptide YY and glucagon-like peptide-1 over 210 min was assessed. Visual analog scales for the subjective feelings of hunger and fullness were completed throughout each session. RESULTS Peptide YY area under the curve (AUC) was higher after the 30-min meal than after the 5-min meal (mean +/- sem AUC 5 min meal: 4133 +/- 324, AUC 30 min meal: 5250 +/- 330 pmol/liter . min, P = 0.004), as was glucagon-like peptide-1 AUC (mean +/- sem AUC 5 min meal: 6219 +/- 256, AUC 30 min meal: 8794 +/- 656 pmol/liter . min, P = 0.001). There was a trend for higher visual analog scale fullness ratings immediately after the end of the 30-min meal compared with immediately after the 5-min meal. There were no differences in ghrelin response. CONCLUSIONS Eating at a physiologically moderate pace leads to a more pronounced anorexigenic gut peptide response than eating very fast.

Differential effects of high-fat and high-carbohydrate isoenergetic meals on cardiac autonomic nervous system activity in lean and obese women.

Food ingestion can influence autonomic nervous system activity. This study compares the effects of 2 different isoenergetic meals on sympathetic nervous system (SNS) activity, assessed by heart rate variability (HRV) and plasma norepinephrine (NE) levels, in lean and obese women. Fifteen lean and 15 obese healthy women were examined on 2 occasions: after a carbohydrate (CHO)-rich and after a fat-rich test meal. Measurements of blood pressure, heart rate, resting energy expenditure, plasma glucose, lipids, insulin, leptin, and NE, as well as spectral analysis of the HRV, were performed at baseline and every 1 hour for 3 hours after meals. At baseline, obese women had higher SNS activity than lean controls (higher values of low-to-high frequency ratio [LF/HF], 1.52 +/- 0.31 v 0.78 +/- 0.13, P=.04; and plasma NE levels, 405.6 +/- 197.9 v 240.5 +/- 95.8 pg/mL, P<.0001). After the CHO-rich meal a greater increase in LF/HF and in plasma NE levels was observed in lean, compared to obese women (1.21 +/- 0.6 v 0.32 +/- 0.06, P=.04; and 102.9 +/- 35.4 v 38.7 +/- 12.3 pg/mL, P=.01, respectively), while no differences were observed after the fat-rich meal. Meal-induced thermogenesis was higher after the CHO-rich as compared to the fat-rich meal and was comparable between lean and obese women. Changes in HRV were not associated with the thermogenic response to the test meals. In conclusion, consumption of a CHO-rich meal causes greater cardiac SNS activation in lean than in obese women, while fat ingestion does not result in any appreciable change in either group. SNS activation does not appear to influence the thermic effect of the food in either lean or obese women.

High postprandial triglyceridemia in patients with type 2 diabetes and microalbuminuria

Microalbuminuria (MA) is an independent risk factor for atherosclerosis in patients with type 2 diabetes mellitus (T2DM). Postprandial lipemia is also associated with excess cardiovascular risk. However, the association between MA and postprandial lipemia in diabetes has not been investigated. A total of 64 patients with T2DM, 30 with and 34 without MA, were examined. Plasma total triglycerides (TGs), triglycerides contained in chylomicrons (CM-TG), and TGs in CM-deficient plasma were measured at baseline and every 2 h for 6 h after a mixed meal. Postheparin LPL and HL activities were also determined. Plasma levels of apolipoprotein A-V (apoA-V), apoC-II, and apoC-III were measured in the fasting state and 2 h postprandially. Patients with MA had higher postprandial total TG levels than those without MA (P < 0.001); this increase been attributed mainly to CM-TG. LPL activity and fasting concentrations of the measured apolipoproteins were not different between the studied groups, whereas HL activity was higher in the patients with MA. ApoC-II and apoC-III levels did not change postprandially in either study group, whereas apoA-V increased more in the patients with MA. These data demonstrate for the first time that MA is characterized by increased postprandial lipemia in patients with T2DM and may explain in part the excess cardiovascular risk in these patients.

The impact of metabolic syndrome on left ventricular myocardial performance

Metabolic syndrome (MetS) is common and is associated with increased cardiovascular morbidity and mortality. Recent prospective studies suggested that MetS is associated with increased risk of heart failure. In the present cross‐sectional study, we examined the association between left ventricular myocardial performance with MetS.

Differential effects of two isoenergetic meals rich in saturated or monounsaturated fat on endothelial function in subjects with type 2 diabetes.

OBJECTIVE—To examine the acute effects of consumption of monounsaturated (MUFAs) and saturated fatty acids (SAFAs) on endothelial function in subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS—A total of 33 participants were examined after consumption of two different isocaloric meals: one rich in MUFA and one rich in SAFA, in the form of extra-virgin olive oil and butter, respectively. Endothelial function was assessed by determination of flow-mediated dilatation (FMD). RESULTS—FMD did not change significantly after the MUFA-rich meal but declined after the SAFA-rich meal. The FMD during the experiment, expressed as incremental area under the curve, increased after the MUFA-rich meal by 5.2 ± 2.5% and decreased after the SAFA-rich meal by 16.7 ± 6.0% (Δ = −11.5 ± 6.4%; P = 0.008). CONCLUSIONS—Consumption of an SAFA-rich meal is harmful for the endothelium, while a MUFA-rich meal does not impair endothelial function in subjects with type 2 diabetes.

The association between the spatial QRS-T angle with cardiac autonomic neuropathy in subjects with Type 2 diabetes mellitus

Diabet. Med. 27, 1420–1429 (2010)

Meal-induced thermogenesis and macronutrient oxidation in lean and obese women after consumption of carbohydrate-rich and fat-rich meals

OBJECTIVE To examine differences in meal-induced thermogenesis and macronutrient oxidation between lean and obese women after consumption of two different isocaloric meals, one rich in carbohydrate (CHO) and one rich in fat. METHODS A total of 19 lean and 22 obese women were studied on two occasions, 1 wk apart. In one visit they consumed a CHO-rich meal and in the other visit a fat-rich meal. The two meals were isocaloric and were given in random order. Resting energy expenditure and macronutrient oxidation rates were measured and calculated in the fasting state and every hour for 3 h after meal consumption. RESULTS Meal-induced thermogenesis was not different between lean and obese subjects after the CHO-rich (P = 0.89) or fat-rich (P = 0.32) meal, but it was significantly higher after the CHO-rich compared with the fat-rich meal in the lean and the obese individuals (P < 0.05). Protein oxidation rate increased slightly but significantly after the test meals in both groups (P < 0.01). Fat oxidation rate decreased after consumption of the CHO-rich meal (P < 0.001), whereas it increased after consumption of the fat-rich meal in both groups (P < 0.01). CHO oxidation rate increased in both groups after consumption of the CHO-rich meal (P < 0.001). Oxidation rates of protein, fat, and CHO during the experiment were not significantly different between lean and obese participants. CONCLUSION Meal-induced thermogenesis and macronutrient oxidation rates were not significantly different between lean and obese women after consumption of a CHO-rich or a fat-rich meal.

Increased left ventricular arrhythmogenicity in metabolic syndrome and relationship with myocardial performance, risk factors for atherosclerosis, and low-grade inflammation.

Metabolic syndrome (MetS) is a clustering of cardiovascular risk factors recently associated with left ventricular dysfunction. Limited data exist on the association between MetS and ventricular arrhythmogenicity. This study examined differences in ventricular arrhythmogenicity assessed by classic (QT interval) and newer (spatial QRS-T angle [spQRS-Ta]) electrocardiographic markers in subjects with and without MetS. A total of 306 subjects, 153 with and 153 without MetS, matched for sex and age were examined. The spQRS-Ta, which vectorcardiographically quantifies the deviation between the directions of ventricular depolarization and repolarization, was measured using a computer-based electrocardiograph. Left ventricular mass index and myocardial performance were evaluated echocardiographically. The spQRS-Ta was significantly higher in subjects with in comparison with those without MetS. Left ventricular mass index, QT interval, and its dispersion were not different between the 2 groups. Left ventricular myocardial performance was worse in subjects with MetS and was associated with higher values of the spQRS-Ta. Multivariate linear regression analysis demonstrated MetS status as the strongest predictor of ventricular arrhythmogenicity. Addition of the high-sensitivity C-reactive protein in the model increased the explained variance of the spQRS-Ta by 11%. In conclusion, ventricular arrhythmogenicity is present in MetS and is associated with myocardial dysfunction, risk factors for atherosclerosis, and low-grade inflammation. The independent association between the spQRS-Ta and MetS implies that the clustering of the metabolic disturbances has additional prognostic information than its individual components in terms of ventricular arrhythmogenicity and may explain in part the excess cardiovascular risk in subjects with MetS.

Arterial Stiffness Is Inversely Related to Plasma Adiponectin Levels in Young Normotensive Patients With Type 1 Diabetes

OBJECTIVE This study investigated the association between arterial stiffness and plasma adiponectin in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS Participants were normotensive patients with type 1 diabetes who were up to age 40 years. Subjects on statins with macrovascular disease or overt nephropathy were excluded. Large artery stiffness was assessed by measurement of carotid-femoral pulse wave velocity (PWV), whereas plasma adiponectin was measured by radioimmunoassay. RESULTS Data from 80 patients (age 27.1 ± 6.1 years, BMI 24.2 ± 3.1 kg/m2, HbA1c 7.5 ± 1.6%, 39 men, adiponectin 13.9 ± 6.7 μg/mL, and PWV 5.6 ± 0.9 m/s) were analyzed. Log adiponectin inversely correlated with age-adjusted PWV (r = −0.291, P = 0.009) and waist circumference (r = −0.427, P < 0.001). In a fully adjusted model, age, expiration/inspiration index, and log adiponectin were independently associated with PWV, explaining 39.6% of its variance. CONCLUSIONS Arterial stiffness is inversely related to adiponectin concentration in young patients with type 1 diabetes without major complications.