Abstract MP011: Effect of a Low-Carbohydrate Versus a Low-Fat Weight Loss Program on Endothelial Function

Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Kerry J Stewart ◽  
Pamela Ouyang ◽  
Harry A Silber ◽  
Sammy Zakaria ◽  
Dipan Desai ◽  
...  

Background: A concern about low-carbohydrate (CHO) diets is that a higher fat intake may adversely affect vascular health. We hypothesized that the effect of two weight loss programs on endothelial function would be similar. Each program included exercise but differed in that one included a low-CHO diet whereas the other a low-fat diet. Methods: Overweight or obese but otherwise healthy persons (n=77), 30–65 years old, were randomly assigned to 6-months of an isocaloric low-CHO or low-fat diet, plus 3 times per week supervised aerobic and resistance exercise training. Endothelial function was assessed with non-invasive peripheral arterial tonometry using the Endopat device. Reactive hyperemia was induced after 5 minutes of upper arm occlusion of SBP. The reactive hyperemia peripheral arterial tonometry index (RH-PAT), the ratio between the digital pulse volume during reactive hyperemia and at rest was measured at baseline and after 6 months, as were body weight, BMI, waist circumference, total body fat and trunk fat percent, and BP. Results: Sixty subjects (low-CHO group: n=31,74% women; low-fat group, n=29, 72% women) completed the study. At baseline, there were no group differences in the following variables and the combined values are: age, 50.0±8.7 years; weight, 215.4±32.7 lbs; BMI, 34.2±3.8 kg/m 2 ; waist circumference, 103.1±8.7 cm; total body fat, 43.3±7.2%; trunk fat, 46.4±5.7%; SBP, 124.7±13.5 mm Hg; DBP, 74.2±9.5, RH-PAT, 2.32±0.44%. After 6 months, low-CHO versus low-fat subjects had a greater reduction in weight, −28.9±11.0 versus −18.7± 2.0 lbs, p<0.001; BMI, −4.7±2.0 versus −2.9±1.7, p<0.001; waist circumference, −12.1±6.0 versus −6.2±7.8 cm, p<0.01; body fat, −6.8±4.5 versus −4.0±3.9%, p>0.02. The groups did not differ in reduction of trunk fat percent, with an overall loss of − 5.5±5.7%, p<0.001, or BP, overall reduction −10.7±12.1/−8.6±8.2 mm Hg, p<0.001. After 6 months, there was no overall change in RH-PAT, p=0.64. By regression analysis, 6-month RH-PAT, adjusted for the baseline value, did not differ by group. However, an absolute 1% drop in trunk fat percent was associated with an absolute 0.29% (or relative 12.5%) increase in RH-PAT, p=0.05. Conclusions: A key finding was the lack of an adverse effect on a marker of endothelial function in the low-CHO group. Successful weight loss and reductions in total and abdominal fat, and BP were achieved with both programs. Greater reductions in weight, BMI, waist circumference, and body fat occurred in the low-CHO group. Though overall endothelial function did not change in either group, when individual variations were examined, a greater percent loss in trunk fat was associated with enhanced endothelial function. These data suggest that loss of central fat is associated with improved vascular health, independent of the dietary content of the weight loss program.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Naohiro Komura ◽  
Kenichi Tsujita ◽  
Kenshi Yamanaga ◽  
Kenji Sakamoto ◽  
Takashi Miyazaki ◽  
...  

Introduction: Drug-eluting stents (DESs) are replacing bare-metal stents (BMSs), but in-stent restenosis (ISR) remains a problem. Impaired endothelial function is a key event in the atherosclerosis process and a predictor of future cardiovascular events. Reactive hyperemia index (RHI) assessed by peripheral arterial tonometry (PAT) evaluates endothelial function noninvasively. Hypothesis: We prospectively assessed the prognostic value of RHI in predicting ISR after percutaneous coronary intervention (PCI). Methods: RHI was measured using Endo-PAT 2000 before PCI (initial RHI) and at follow-up angiography (F/U RHI) in 249 consecutive patients who had successful PCI. F/U angiography was performed at six and nine months after PCI with BMS and DES, respectively. ISR was defined as percent diameter stenosis >50% at F/U angiography assessed by quantitative coronary angiography. Results: At F/U, ISR was seen in 68 patients (27.3%). F/U ln(RHI) was significantly lower in patients with ISR than in those without (0.52 ± 0.23 vs. 0.65 ± 0.27, p < 0.01); no between-group difference in initial ln(RHI) was seen (0.60 ± 0.26 vs. 0.62 ± 0.25, p = 0.56). By multivariate logistic regression analysis, even after adjusting for other significant parameters in univariate analysis (BMS use, total stent length, HDL-Cholesterol, HbA1c, calcium antagonist use, and post-PCI minimum lumen diameter), F/U ln(RHI) independently predicted ISR (odds ratio: 0.13; 95% confidence interval [CI]: 0.04-0.48; p = 0.002). In receiver operating-characteristic analysis, F/U RHI was the strongest predictor of ISR (area under the curve [AUC]: 0.67; 95% CI: 0.60-0.75; p < 0.01; RHI < 1.73 had 67.6% sensitivity, 64.1% specificity); AUC significantly improved from 0.62 to 0.70 when RHI was added to traditional ISR risk factors (diabetes mellitus, total stent length, minimum stent diameter) (p = 0.02). Net reclassification index was significant after addition of RHI (26.5%, p = 0.002). Conclusions: To our knowledge, this is the first study indicating that impaired RHI at F/U angiography independently predicts occurrence of ISR. The simple and noninvasive assessment of endothelial function by RH-PAT adds incremental prognostic value to ISR-risk stratification following PCI.


2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Andrew J. Degnan ◽  
Nandini Shah ◽  
David M. Carty ◽  
John R. Petrie ◽  
Christian Delles ◽  
...  

Background. Peripheral arterial tonometry (PAT) is a novel, non-invasive and operator-independent method for simultaneous assessment of endothelial function and arterial stiffness. We examined the repeatability of PAT in females and the influence of the estrous cycle. Methods. In 14 healthy female and five healthy male control subjects, PAT was performed on three separate occasions with 10 days between visits. Reactive hyperemia index (RHI), a measure of endothelial function, and peripheral augmentation index (AIx), a measure of arterial stiffness, were determined with the EndoPAT-2000 system. Intraclass correlation coefficient (ICC) was calculated as a measure of repeatability. Results. In both female and male groups, RHI and AIx did not differ between the three measurements (all n.s. by 1-way ANOVA). In females, reanalyzing the data after taking phase of estrous cycle into account had no effect on the results. Repeatability for RHI and AIx in females (ICC for RHI = 0.43, ICC for AIx = 0.78) was similar to that in male subjects (ICC for RHI = 0.42, ICC for AIx = 0.63). Conclusions. PAT measurements were not affected by the estrous cycle in females, and repeatability was comparable to that in males. This should facilitate inclusion of female subjects into vascular function studies using PAT.


Author(s):  
Hisanori Kanazawa ◽  
Koichi Kaikita ◽  
Miwa Ito ◽  
Yusei Kawahara ◽  
Tadashi Hoshiyama ◽  
...  

Background The clinical implication of vascular endothelial dysfunction in patients with atrial fibrillation (AF) remains unclear. This study aimed to elucidate the correlation between changes in vascular endothelial function assessed by reactive hyperemia‐peripheral arterial tonometry and the effect of sinus rhythm restoration after catheter ablation (CA) for AF. Methods and Results Consecutive 214 patients who underwent CA for AF were included in this single center, retrospective study. The natural logarithmic transformed reactive hyperemia‐peripheral arterial tonometry index (LnRHI) of all patients was measured before CA as well as 3 and 6 months after CA. LnRHI in sinus rhythm was significantly higher than that in AF before CA. Multivariate logistic regression analysis revealed that the presence of AF was an independent risk factor for lowering of LnRHI (odds ratio, 4.092; P =0.002) before CA. The LnRHI was significantly improved 3 and 6 months after CA in patients without AF recurrence. Multivariate Cox hazard analysis revealed that changes in LnRHI from before to 3 months after CA independently correlated with recurrence of AF (hazard ratio, 0.106; P =0.001). Receiver operating characteristic analysis showed the decrease in LnRHI levels from before to 3 months after CA as a significant marker that suspects AF recurrence (area under the curve, 0.792; log‐rank test, P <0.001). Conclusions The presence of AF was independently correlated with the impaired vascular endothelial function assessed by the reactive hyperemia‐peripheral arterial tonometry. Long‐term sinus rhythm restoration after CA for AF might contribute to the improvement of vascular endothelial function, which may reflect the nonrecurrence of AF.


2012 ◽  
Vol 39 (2) ◽  
pp. 277-284
Author(s):  
Ryotaro Takahashi ◽  
Kenji Okumura ◽  
Chisuzu Ohyama ◽  
Akiko Ogawa ◽  
Masahiro Ohno ◽  
...  

2017 ◽  
Vol 313 (5) ◽  
pp. R518-R525 ◽  
Author(s):  
Dominique Mannaerts ◽  
Ellen Faes ◽  
Inge Goovaerts ◽  
Tibor Stoop ◽  
Jerome Cornette ◽  
...  

Endothelial function and arterial stiffness are known to be altered in preeclamptic pregnancies. Previous studies have shown conflicting results regarding the best technique for assessing vascular function in pregnancy. In this study, we made a comprehensive evaluation of in vivo vascular function [including flow-mediated dilatation (FMD), peripheral arterial tonometry (PAT), and arterial stiffness] in preeclamptic patients and compared them with normal pregnancies. In addition, we assessed the relation between vascular function and systemic inflammation. Fourteen patients with preeclampsia (PE) and 14 healthy pregnant controls were included. Endothelial function was determined by FMD and PAT and arterial stiffness by carotid-femoral pulse-wave velocity and augmentation index. Systemic inflammation was assessed using mean platelet volume (MPV) and neutrophil-lymphocyte ratio (NLR). The reactive hyperemia index, assessed using PAT, is decreased at the third trimester compared with the first trimester in a normal, uncomplicated pregnancy ( P = 0.001). Arterial stiffness is significantly higher in PE versus normal pregnancy ( P < 0.001). Endothelial function, obtained by FMD, is deteriorated in PE versus normal pregnancy ( P = 0.015), whereas endothelial function assessment by PAT is improved in PE versus normal pregnancy ( P = 0.001). Systemic inflammation (MPV and NLR) increases during normal pregnancy. FMD and PAT are disturbed in PE. Endothelial function, assessed by FMD and PAT, shows distinct results. This may indicate that measurements with FMD and PAT reflect different aspects of endothelial function and that PAT should not be used as a substitute for FMD as a measure of endothelial function in pregnancy.


2021 ◽  
Author(s):  
A Garu ◽  
Eri Nitta ◽  
Yuri Yoshida ◽  
Erika Yata ◽  
Akari Tsunematsu ◽  
...  

Abstract Background The reactive hyperemia index (RHI), which is obtained from the measurement of peripheral arterial tonometry (PAT), is highly associated with the percentage change in the end-diastolic arterial diameter (%flow-mediated dilatation) at reactive hyperemia. Low RHI is reported to be a mortality risk in patients with a high risk of cardiovascular (CV) disease. CV events are thought to be induced by physical and mental stress, including long-term fatigue and lack of sleep. However, the relationship between fatigue, lack of sleep, and endothelial function has not yet been established. MethodsHealthy hospital workers (n=13, 6 men and 7 women) with an average age of 31.6 years were assigned to this study after they provided written informed consent. During the study period, we conducted 72 measurements of reactive hyperemia-peripheral arterial tonometry (RH-PAT) in the morning before or after their duty. At each measurement of the RH-PAT, we recorded the participants’ hours of sleep and evaluated their degree of fatigue using a visual analog scale (VAS).ResultsAlthough the VAS was significantly less (36±16% and 64±12%, p<0.001) and the hours of sleep were longer (6.0±1.1 h and 2.3±1.0 h, p<0.001) before duty compared to those after duty, the RHI was comparable between them (2.12±0.53 vs. 1.97±0.50, p=0.21). The VAS score was significantly higher in participants with low RHI (<1.67) than in those with normal RHI (≥2.07) (59±13% and 46±21%, respectively, p<0.05). However, binary logistic regression showed no significant association between low RHI and the VAS when adjusted for systemic blood pressure (SBP) and heart rate variability (HRV). In a simple regression analysis, the RHI was significantly correlated with the VAS score (r=-0.287, p<0.05), while no significant correlation was found between the RHI and sleep duration (r=0.045, p=0.71). A multiple linear regression analysis also showed no significant association between the RHI and VAS scores after adjustment for SBP and HRV.ConclusionsVascular endothelial function was not associated with overnight duty, hours of sleep, or degree of fatigue in healthy young adults. Since the RHI may be decreased in severe fatigue conditions through autonomic nerve activity, one should consider the physical and mental conditions of the examinee when evaluating the RH-PAT results.


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