Yoko Noda

Alogliptin ameliorates postprandial lipemia and postprandial endothelial dysfunction in non- diabetic subjects: a preliminary report

BackgroundPostprandial hyperlipidemia impairs endothelial function and participates in the development of atherosclerosis. We investigated the postprandial effects of a dipeptidyl peptidase IV inhibitor, alogliptin, on endothelial dysfunction and the lipid profile.MethodsA randomized cross-over trial design in 10 healthy volunteers (8 males and 2 females, 35 ± 10 years) was performed. The postprandial effects before and after a 1-week treatment of 25 mg/day alogliptin on endothelial function were assessed with brachial artery flow-mediated dilation (FMD) and changing levels of lipids, apolipoprotein B48 (apoB-48), glucose, glucagon, insulin, and glucagon-like peptide-1 (GLP-1) during fasting and at 2, 4, 6, and 8 h after a standard meal loading test.ResultsAlogliptin treatment significantly suppressed the postprandial elevation in serum triglyceride (incremental area under the curve [AUC]; 279 ± 31 vs. 182 ± 32 mg h/dl, p = 0.01), apoB-48 (incremental AUC; 15.4 ± 1.7 vs. 11.7 ± 1.1 μg h/ml, p = 0.04), and remnant lipoprotein cholesterol (RLP-C) (incremental AUC: 29.3 ± 3.2 vs. 17.6 ± 3.3 mg h/dl, p = 0.01). GLP-1 secretion was significantly increased after alogliptin treatment. Postprandial endothelial dysfunction (maximum decrease in%FMD, from −4.2 ± 0.5% to −2.6 ± 0.4%, p = 0.03) was significantly associated with the maximum change in apoB-48 (r = −0.46, p = 0.03) and RLP-C (r = −0.45, p = 0.04).ConclusionAlogliptin significantly improved postprandial endothelial dysfunction and postprandial lipemia, suggesting that alogliptin may be a promising anti-atherogenic agent.

Omega-3 fatty acids improve postprandial lipemia and associated endothelial dysfunction in healthy individuals – a randomized cross-over trial

BACKGROUND Postprandial elevation of triglycerides impairs endothelial function and contributes to the development of atherosclerosis. We investigated the effects of omega-3 fatty acids on postprandial endothelial function and lipid profiles. METHODS Healthy volunteers [10] were given supplementation at 4g/day omega-3 fatty acids (or were not treated) for 4 weeks in a randomised crossover study. Postprandial levels of various lipids were monitored and endothelial function assessed by brachial artery flow-mediated dilation during fasting and after a standard cookie test. RESULTS Omega-3 fatty acids reduced postprandial endothelial dysfunction compared with the control diet (flow-mediated dilation at 4h=-0.5±1.2 vs. -2.0±1.6%, P=0.03). Postprandial levels of triglycerides, apolipoprotein B-48, and remnant lipoprotein-cholesterol increased in untreated subjects, peaked at 2-4h, and returned to baseline at 8h, whereas low-density lipoprotein-cholesterol levels did not change. Supplementation with omega-3 fatty acids significantly suppressed postprandial elevation of triglycerides (incremental area under the curve=220±209 vs. 374±216mg/h/dL, P=0.04) and remnant lipoprotein-cholesterol (incremental area under the curve=21.7±13.8 vs. 13.3±12.9mg/h/dL, P=0.04). Supplementation with omega-3 fatty acids significantly suppressed the increase in triglyceride content in chylomicrons as well as in very-low-density lipoproteins from baseline to 4h after the cookie test. CONCLUSION Omega-3 fatty acids significantly decreased postprandial triglyceride elevation and postprandial endothelial dysfunction, suggesting that omega-3 fatty acids may have vascular protective effects in postprandial state.

Single administration of vildagliptin attenuates postprandial hypertriglyceridemia and endothelial dysfunction in normoglycemic individuals

Postprandial hypertriglyceridemia impairs endothelial function and plays an important role in the development of atherosclerosis. The aim of the present study was to examine the postprandial effects of the dipeptidyl peptidase-4 inhibitor vildagliptin and the α-glucosidase inhibitor voglibose on endothelial dysfunction and lipid profiles following a single administration. A randomized cross-over trial using 11 normoglycemic individuals was performed. The postprandial effects of a single administration of vildagliptin (50 mg) or voglibose (0.3 mg) on endothelial function were analyzed using brachial artery flow-mediated dilation (FMD) and lipid profiles during fasting and 1.5 and 3 h after an oral cookie-loading test. Compared with voglibose, vildagliptin significantly suppressed postprandial endothelial dysfunction, (%FMD, −1.6±0.9 vildagliptin vs. −4.0±0.7 voglibose; P=0.01) and the postprandial incremental increase in the triglyceride level (28±18 vildagliptin vs. 51±26 mg/dl voglibose; P=0.01) 3 h after a cookie-loading test. In addition, vildagliptin significantly increased the levels of glucagon-like peptide-1 compared with voglibose 3 h after a loading cookie test (4.4±0.6 vs. 2.9±0.7 pmol/l, respectively; P=0.04). No significant differences in the levels of glucose, apolipoprotein B-48, glucagon or insulin were observed between vildagliptin and voglibose treatments. In conclusion, a single administration of vildagliptin attenuated postprandial endothelial dysfunction and postprandial hypertriglyceridemia, suggesting that vildagliptin may be a promising antiatherogenic agent.

Arterial stiffness determined according to the cardio-ankle vascular index is associated with paroxysmal atrial fibrillation: a cross-sectional study

Background Several lines of evidence suggest that atrial fibrillation (AF) may be a consequence of vascular disease. We investigated the relationship between cardio-ankle vascular index (CAVI), a new index of arterial stiffness, and the presence of paroxysmal AF (PAF). Methods and results 181 outpatients (91 patients with PAF and 90 age- and gender-matched subjects without PAF) were analysed for their sinus rhythm. The CAVI was significantly higher in patients with PAF than in subjects without PAF (9.0±1.0 vs 8.7±0.8, p<0.01). In all subjects, the CAVI was significantly correlated with the left ventricular mass index (r=0.30, p<0.01), left atrial diameter (r=0.22, p<0.01), and augmentation index, a parameter of wave reflection (r=0.32, p<0.01), in addition to age, systolic blood pressure and pulse pressure. Logistic analysis demonstrated that the CAVI was independently associated with PAF even after adjustment for confounding factors. The adjusted OR of PAF was 1.8 for each unit increase in the CAVI (p=0.01). Conclusions Our finding suggests that increased arterial stiffness may be involved in the maintenance of AF.

Pioglitazone prevents the endothelial dysfunction induced by ischemia and reperfusion in healthy subjects

Background: No study has investigated whether pioglitazone (an agonist of peroxisome proliferator-activated receptor gamma) protects against ischemia and reperfusion (IR)–induced endothelial dysfunction in humans. Methods and Results: In the first crossover study, 20 volunteers were randomized to 1 week of pioglitazone (30 mg/d, postoperatively) or control (no treatment). In the second single-arm study, 15 volunteers received pioglitazone and the cyclooxygenase-2 inhibitor meloxicam for 1 week. On day 7, endothelium-dependent flow-mediated dilation (FMD) of the distal brachial artery was measured before and after IR (15 minutes of ischemia followed by 15 minutes of reperfusion in the proximal upper arm). Pre-IR brachial-artery diameter and FMD were similar across the 2 sessions (control, pioglitazone) in protocol 1 and between the 2 protocols. IR significantly blunted FMD after no treatment (pre-IR FMD: 10.2% ± 2.6%; post-IR FMD: 3.5% ± 1.9%, P < 0.01) but not after pioglitazone administration (pre-IR FMD: 9.7% ± 2.5%; post-IR FMD: 8.8% ± 2.9%, P = 0.11). This protective effect was accompanied by an increase in serum levels of the antioxidant enzyme extracellular superoxide dismutase and was not affected by concomitant administration of the cyclooxygenase-2 inhibitor meloxicam (P = 0.10). Conclusions: In humans, pioglitazone provides potent protection against IR-induced endothelial dysfunction.