Postprandial hypertension, an overlooked risk marker for arteriosclerosis

Arterial hypertension and antihypertensive therapy in older patients. The agreed opinion of experts from the Russian Association of Gerontologists and Geriatricians, the Antihypertensive League, the National Society for Preventive Cardiology

High blood pressure is a risk factor for cardiovascular morbidity and mortality, as well as cognitive decline and loss of autonomy in the elderly and old age. Randomized clinical trials (RCTs) in populations of older patients living at home with low comorbidity and preserved autonomy indicate the benefit of lowering elevated blood pressure in patients over 80 years of age. Older patients with senile asthenia, loss of autonomy and other geriatric problems were excluded from RCTs, and observational studies in these groups of patients indicate an increase in morbidity and mortality with lower blood pressure and antihypertensive therapy. Obviously, in very elderly patients, a universal strategy for the treatment of arterial hypertension cannot be applied due to the significant heterogeneity of their functional status. The geriatric approach to the management of arterial hypertension in older patients involves an assessment of the functional status, the presence of senile asthenia, and the degree of autonomy for the choice of antihypertensive therapy tactics.

Strawberry Consumption, Cardiometabolic Risk Factors, and Vascular Function: A Randomized Controlled Trial in Adults with Moderate Hypercholesterolemia

BACKGROUND

Certain fruits, such as strawberries, may impart cardiometabolic benefits due to their phytochemical content.

OBJECTIVES

Study aims were to assess the effects of strawberry intake on cardiometabolic risk factors and vascular endothelial function in adults with moderate hypercholesterolemia.

METHODS

This study was a randomized, controlled, double-blinded, 2-arm, 2-period (4-wk/period) crossover trial. Adults (n = 34; male/female 1:1; mean ± SEM age, 53 ± 1 y; BMI, 31 ± 1 kg/m2;  LDL cholesterol, 133 ± 3 mg/dL) were randomly allocated to 1 of 2 study sequences in a 1:1 ratio. Participants drank study beverages twice daily containing freeze-dried strawberry powder (2 × 25 g) or energy-, volume-matched control powder for 4 wk separated by a 4-wk washout. The primary outcome variable was the difference in fasting LDL cholesterol after 4-wk interventions. Secondary outcomes were metabolic markers, inflammation, quantitative (poly)phenolic metabolomics, flow-mediated dilation (FMD), and blood pressure (BP), with the latter (FMD, BP) also assessed acutely at 1 h and 2 h after a 50-g bolus strawberry or control beverage. Mixed-model analysis of repeated measures via PROC MIXED, PC-SAS was performed on primary and secondary outcome variables.

RESULTS

LDL cholesterol did not differ after the 4-wk interventions (P > 0.05), nor did fasting total cholesterol, triglycerides, glucose, insulin, high-sensitivity C-reactive protein, FMD, or BP (all P > 0.05). Significant intervention-by-hour interaction for FMD (P = 0.03) and BP (P = 0.05) revealed increased FMD at 1 h after strawberry compared with control by 1.5 ± 0.38% (P = 0.0008) and attenuated systolic BP at 2 h by 3.1 ± 0.99 mmHg (P = 0.02). Select phenolic metabolites increased significantly (P < 0.05) in blood following strawberry consumption while others decreased, including 3-(4-methoxyphenyl)propanoic acid-3-O-glucuronide, which was significantly correlated with increased FMD (P < 0.05).

CONCLUSION

Strawberries may improve vascular health, independent of other metabolic changes. The effect may be related to changes in microbial-derived phenolic metabolites after strawberry consumption influencing endothelial function. Data support inclusion of strawberries in a heart-healthy diet in adults with moderate hypercholesterolemia.This trial was registered at clinicaltrials.gov as NCT02612090.

Acute glucose influx-induced mitochondrial hyperpolarization inactivates myosin phosphatase as a novel mechanism of vascular smooth muscle contraction

It is well-established that long-term exposure of the vasculature to metabolic disturbances leads to abnormal vascular tone, while the physiological regulation of vascular tone upon acute metabolic challenge remains unknown. Here, we found that acute glucose challenge induced transient increases in blood pressure and vascular constriction in humans and mice. Ex vivo study in isolated thoracic aortas from mice showed that glucose-induced vascular constriction is dependent on glucose oxidation in vascular smooth muscle cells. Specifically, mitochondrial membrane potential (ΔΨm), an essential component in glucose oxidation, was increased along with glucose influx and positively regulated vascular smooth muscle tone. Mechanistically, mitochondrial hyperpolarization inhibited the activity of myosin light chain phosphatase (MLCP) in a Ca2+-independent manner through activation of Rho-associated kinase, leading to cell contraction. However, ΔΨm regulated smooth muscle tone independently of the small G protein RhoA, a major regulator of Rho-associated kinase signaling. Furthermore, myosin phosphatase target subunit 1 (MYPT1) was found to be a key molecule in mediating MLCP activity regulated by ΔΨm. ΔΨm positively phosphorylated MYPT1, and either knockdown or knockout of MYPT1 abolished the effects of glucose in stimulating smooth muscle contraction. In addition, smooth muscle-specific Mypt1 knockout mice displayed blunted response to glucose challenge in blood pressure and vascular constriction and impaired clearance rate of circulating metabolites. These results suggested that glucose influx stimulates vascular smooth muscle contraction via mitochondrial hyperpolarization-inactivated myosin phosphatase, which represents a novel mechanism underlying vascular constriction and circulating metabolite clearance.

Plasma brain-derived neurotrophic factor and dynamic cerebral autoregulation in acute response to glycemic control following breakfast in young men

We examined the acute impact of both low- and high-glycemic index (GI) breakfasts on plasma brain-derived neurotrophic factor (BDNF) and dynamic cerebral autoregulation (dCA) compared with breakfast omission. Ten healthy men (age 24 ± 1 yr) performed three trials in a randomized crossover order; omission and Low-GI (GI = 40) and High-GI (GI = 71) breakfast conditions. Middle cerebral artery velocity (transcranial Doppler ultrasonography) and arterial pressure (finger photoplethysmography) were continuously measured for 5 min before and 120 min following breakfast consumption to determine dCA using transfer function analysis. After these measurements of dCA, venous blood samples for the assessment of plasma BDNF were obtained. Moreover, blood glucose was measured before breakfast and every 30 min thereafter. The area under the curve of 2 h postprandial blood glucose in the High-GI trial was higher than the Low-GI trial (P < 0.01). The GI of the breakfast did not affect BDNF. In addition, both very-low (VLF) and low-frequency (LF) transfer function phase or gains were not changed during the omission trial. In contrast, LF gain (High-GI P < 0.05) and normalized gain (Low-GI P < 0.05) were decreased by both GI trials, while a decrease in VLF phase was observed in only the High-GI trial (P < 0.05). These findings indicate that breakfast consumption augmented dCA in the LF range but High-GI breakfast attenuated cerebral blood flow regulation against slow change (i.e., the VLF range) in arterial pressure. Thus we propose that breakfast and glycemic control may be an important strategy to optimize cerebrovascular health.

Longitudinal Changes in the Blood Pressure Responses to, and Gastric Emptying of, an Oral Glucose Load in Healthy Older Subjects

The rate of gastric emptying is a major determinant of the hypotensive response to a meal. Cross-sectional studies suggest that healthy aging is associated with a modest slowing of gastric emptying. We aimed to determine longitudinal changes in the blood pressure (BP) response to, and gastric emptying of, glucose in healthy older people. Thirty-three participants (77.0 ± 0.7 years) had baseline and follow-up measurements after 5.8 ± 0.1 years. Participants consumed a 300-mL drink containing 75 g glucose and 150 mg C13-acetate. BP and heart rate (HR) were measured at 5-minute intervals for 120 minutes after the drink. Exhaled breath was collected to calculate the gastric 50% emptying time. The prevalence of postprandial hypotension (PPH) doubled from 9.1% to 18.2%. Gastric emptying was slower at follow-up (p = .04). The fall in systolic BP (SBP) was related directly to the rate of gastric emptying at both the initial study (r = .54, p = .005) and at follow-up (r = .41, p = .04). The change in the maximum fall in SBP was related to the increase in baseline SBP (r = -.63, p < .001). In conclusion, in healthy older people over a period of ~5.8 years, there was an increased prevalence of PPH and a modest slowing of gastric emptying. The latter was related directly to a greater hypotensive response.

Positive Effects of Tomato Paste on Vascular Function After a Fat Meal in Male Healthy Subjects

Tomato consumption has been recently associated with a reduced incidence of cardiovascular disease (CVD). The aim of this study was to test whether a seven-day period of tomato paste purèe (tomato paste, TP) supplementation could improve some haemodynamic parameters in healthy volunteers before and after a standardized fat meal (FM).

METHODS AND RESULTS

Nineteen healthy male volunteers participated in a randomized, single-blind (operator) crossover study. Participants maintained low fiber diets (LFD) during the study periods. They were randomized either to a LFD and TP arm (80 g of TP/day) for seven-days, or to a control arm (LFD-only) with a two-week washout period. Flow Mediated Dilatation and other morpho-functional vascular indices were measured by ultrasound. Stiffness Index and Reflection Index were estimated by digital photo-plethysmography. All these parameters were measured one h before and two and 3.5 h after the FM. The difference in Stiffness Index was increased in the LFD and TP + FM-arm, as compared to the LFD-only + FM arm at both two and 3.5 h points. After the FM, in both arms, at two h, we observed a reduction in the Reflection Index and an increase in heart rate. Interestingly, only in the LFD and TP + FM-arm, some haemodynamic changes were detectable at two h; notably, there was an increase in brachial artery diameter and a reduction in diastolic blood pressure (BP).

CONCLUSIONS

TP has no effect on Flow Mediated Dilatation but acutely modifies some haemodynamic parameters triggered by FM, suggesting possible haemodynamic beneficial effects in people consuming tomatoes.

Lixisenatide Versus Insulin Glulisine on Fasting and Postbreakfast Systemic Hemodynamics in Type 2 Diabetes Mellitus Patients

The prolonged treatment effects of a short-acting GLP-1RA (glucagon-like peptide-1 receptor agonist), such as lixisenatide, on fasting and postprandial systemic hemodynamics in type 2 diabetes mellitus patients are unknown. In this secondary analysis, we included 34 overweight insulin glargine-treated type 2 diabetes mellitus patients (mean±SD age, 62±7 years; HbA_1c, 8.0±0.9%; systolic blood pressure [BP], 133.9±16.1 mm Hg; diastolic BP, 75.4±8.39 mm Hg) that were randomized to once-daily lixisenatide 20 μg or once-daily titrated insulin glulisine for 8 weeks. Systemic hemodynamics (oscillometric device and finger photoplethysmography), arterial stiffness (applanation tonometry), and cardiac sympathovagal balance (heart rate variability) were measured in the fasting state and repetitively (up to minute 175) after a standardized mixed breakfast. Acetaminophen was given orally to estimate gastric emptying rate. Lixisenatide did not affect fasting systemic hemodynamics compared with insulin glulisine from baseline to week 8. Postbreakfast overall, lixisenatide compared with insulin glulisine tended to increase systolic BP by 5.2±2.9 mm Hg (P=0.087) and increased diastolic BP by 5.4±1.4 mm Hg (P<0.001), with respective maximal differences of +10.2±3.7 mm Hg (P=0.007) and +7.2±1.5 mm Hg (P<0.001). Lixisenatide increased systemic vascular resistance (P<0.001) and arterial stiffness (P=0.007). No between-group differences in overall postbreakfast heart rate, cardiac output, or cardiac sympathovagal balance, and circulating catecholamines, angiotensin II, or aldosterone were observed. Both treatments lowered HbA_1c similarly, whereas lixisenatide achieved greater reductions in postbreakfast plasma glucose excursions. Lixisenatide slowed gastric emptying rate, which statistically explained changes in postbreakfast BP. Lixisenatide compared with once-daily titrated insulin glulisine for 8 weeks does not affect fasting but increases postbreakfast BP in insulin glargine-treated type 2 diabetes mellitus patients. This effect could, at least in part, be explained by reduced passage rate of nutrients and water and activation of the gastrovascular reflex.

The association between brain-derived neurotrophic factor and central pulse pressure after an oral glucose tolerance test

BACKGROUND

Arterial stiffening blunts postprandial vasodilatation. We hypothesized that brain-derived neurotrophic factor (BDNF) may modulate postprandial central pulse pressure, a surrogate marker for arterial stiffening.

METHODS

A total of 82 non-diabetic subjects received a 75-g oral glucose tolerance test (OGTT) after overnight fasting. Serum BDNF concentrations were determined at 0, 30, and 120min to calculate the area under the curve (AUC). Brachial and central blood pressures were measured using a noninvasive central blood pressure monitor before blood withdrawals at 0 and 120min.

RESULTS

With the median AUC of BDNF of 45(ng/ml)∗h as the cutoff value, the central pulse pressure after glucose intake was significantly higher in the subjects with a low BDNF than in those with a high BDNF (63±16 vs. 53±11mmHg, P=0.003), while the brachial pulse pressure was not significantly different between the 2 groups (P=0.099). In a multivariate linear regression model, a lower AUC of BDNF was an independent predictor of a higher central pulse pressure after oral glucose intake (linear regression coefficient-0.202, 95% confidence interval-0.340 to -0.065, P=0.004).

CONCLUSION

After oral glucose challenge, a lower serum BDNF response is significantly associated with a higher central pulse pressure.

Predictors of postprandial hypotension in elderly patients with de novo Parkinson's disease

Postprandial hypotension is one of the most important autonomic disorders in Parkinson's disease. However, its predictors remain unclear. We investigated which variable(s) predict the presence of postprandial hypotension in elderly patients with Parkinson's disease. The subjects were 64 patients with de novo Parkinson's disease who were 70 years or older. Postprandial hypotension was evaluated on a 75-g oral glucose tolerance test. Olfactory function, constipation, cardiac sympathetic or parasympathetic denervation, orthostatic intolerance on head-up tilt table testing, and other baseline characteristics were evaluated. The results showed the presence of postprandial hypotension was associated with severe dysosmia, constipation, orthostatic hypotension (a decrease in systolic blood pressure ≥30 mmHg) and preprandial hypertension at rest. On multiple logistic regression analyses adjusted for age, sex, symptom duration, disease severity, and motor subtype, the odds ratio was 4.02 for severe dysosmia (p = 0.027), 9.99 for constipation (p = 0.006), 6.42 for orthostatic hypotension with alternative definition (p = 0.004) and 7.90 for preprandial hypertension at rest (p = 0.001). Each multiple logistic regression analysis revealed that female sex was also a risk factor for postprandial hypotension. The variables with the highest sensitivity and specificity for postprandial hypotension were constipation (89.6 %) and preprandial hypertension at rest or orthostatic hypotension with alternative definition (both 77.1 %), respectively. Our results suggest that these variables predict the presence of postprandial hypotension in elderly patients with Parkinson's disease, suggesting that postprandial hypotension shares etiologic factors with these potential predictors.

Heart rate, blood pressure and repolarization effects of an energy drink as compared to coffee

The goal of this study was to investigate the impact of energy drinks on haemodynamic and cardiac physiology. Comparisons were made to coffee as well as water consumption. In Protocol #1 the caffeine content was normalized to body weight to represent a controlled environment. Heart rate, blood pressure and cardiac QTc interval were assessed in 15 participants, on 4 days, prior to and for 6·5 h postconsumption of (i) energy drink (2 mg caffeine per kg body weight; low dose), (ii) energy drink (3 mg caffeine per kg body weight; medium dose), (iii) coffee (2 mg caffeine per kg body weight) and (iv) 250 ml water. In Protocol #2, the beverages were consumed in volumes that they are purchased to represent real-life conditions. The aforementioned measurements were repeated in 15 participants following (i) 1 16 oz can of energy drink (16 oz Monster), (ii) 1 24 oz can of energy drink (24 oz Monster), (iii) 1 packet of Keurig K-Cup Starbucks coffee (coffee) and (iv) 250 ml water. The order of the beverages was performed in a randomized double-blinded fashion. For both protocols, QTc interval, heart rate and systolic blood pressure were unchanged in any condition (P>0·05). Diastolic blood pressure and mean blood pressure were slightly elevated in Protocol #1 (P<0·05, main effect of time) with no difference between beverages (P<0·05, interaction of beverage × time); however, they were unaffected in Protocol #2 (P>0·05). These findings suggest that acute consumption of these commonly consumed beverages has no negative effect on cardiac QTc interval.

Accumulating exercise and postprandial health in adolescents

PURPOSE

To examine the influence of exercise intensity on postprandial health outcomes in adolescents when exercise is accumulated throughout the day.

METHODS

19 adolescents (9 male, 13.7±0.4 years old) completed three 1-day trials in a randomised order: (1) rest (CON); or four bouts of (2) 2×1 min cycling at 90% peak power with 75 s recovery (high-intensity interval exercise; HIIE); or (3) cycling at 90% of the gas exchange threshold (moderate-intensity exercise; MIE), which was work-matched to HIIE. Each bout was separated by 2 hours. Participants consumed a high fat milkshake for breakfast and lunch. Postprandial triacylglycerol (TAG), glucose, systolic blood pressure (SBP) and fat oxidation were assessed throughout the day.

RESULTS

There was no effect of trial on total area under the curve (TAUC) for TAG (P=0.87). TAUC-glucose was lower in HIIE compared to CON (P=0.03, ES=0.42) and MIE (P=0.04, ES=0.41), with no difference between MIE and CON (P=0.89, ES=0.04). Postprandial SBP was lower in HIIE compared to CON (P=0.04, ES=0.50) and MIE (P=0.04, ES=0.40), but not different between MIE and CON (P=0.52, ES=0.11). Resting fat oxidation was increased in HIIE compared to CON (P=0.01, ES=0.74) and MIE (P=0.05, ES=0.51), with no difference between MIE and CON (P=0.37, ES=0.24).

CONCLUSION

Neither exercise trial attenuated postprandial lipaemia. However, accumulating brief bouts of HIIE, but not MIE, reduced postprandial plasma glucose and SBP, and increased resting fat oxidation in adolescent boys and girls. The intensity of accumulated exercise may therefore have important implications for health outcomes in youth.

Postprandial hypotension as a risk marker for asymptomatic lacunar infarction

OBJECTIVE

Increasing blood pressure (BP) variability is reported to be a cardiovascular risk factor. However, the clinical implications of postprandial hypotension (PHYPO), a commonly observed BP variability in elderly persons, are poorly understood. Here, we investigated the possible associations between postprandial BP decline and asymptomatic cerebral damage in community residents.

METHODS

Study participants consisted of 1308 general community residents (65 ± 9 years old). Postprandial BP change was calculated from SBP measured just before and 30 min after lunch. PHYPO was defined as a decline in SBP of more than 20 mmHg. The presence of asymptomatic cerebrovascular damage was evaluated by brain MRI.

RESULTS

Prevalence of lacunar infarction was significantly higher in participants with PHYPO (P = 0.004). A postprandial decline in SBP was linearly increased with the number of lacunar lesions (none, n = 1200, -3.4± 11.3 mmHg; one lesion, n = 82, -5.2 ± 11.8; two lesions, n = 18, -6.9 ± 11.5; three lesions, n = 7, -13.4 ± 11.3; and four lesions, n = 1, -27; P = 0.012). Although participants with PHYPO were older (P < 0.001) and had higher preprandial BP (P < 0.001) and faster pulse wave velocity (P = 0.001), multivariate analysis adjusted for these covariates indicated that postprandial BP decline was an independent determinant for the number of lacunar infarctions (P = 0.004). No significant associations were observed with grade of periventricular hyperintensity or frequency of microbleeds. These relationships were also found in an analysis based on central BP, whereas no superiority was seen in the analysis based on central BP.

CONCLUSION

Postprandial BP decline is an overlooked risk marker for asymptomatic lacunar infarction in community residents.

Postprandial hypotension: a systematic review

BACKGROUND

Postprandial hypotension (PPH) is an important clinical problem, which has received inappropriately little attention.

METHODS

A systematic search of the databases PubMed, Embase, Cochrane Library, and Web of Knowledge, from their inception to the present time, was conducted to identify studies relevant to the epidemiology, pathophysiology, and/or management of PPH.

RESULTS

A total of 417 full-text papers were retrieved from database searching and, following screening, 248 were retained. Of these, 167 papers were considered eligible for inclusion.

CONCLUSIONS

PPH occurs commonly in older people and represents a major cause of morbidity. Although the pathophysiology of PPH remains poorly defined, diverse factors, including impairments in sympathetic and baroreflex function, release of vasodilatory peptides, the rate of small intestinal nutrient delivery, gastric distension, and splanchnic blood pooling, appear important. Current pharmacologic and nonpharmacologic management is suboptimal. Research into the pathophysiology of PPH represents a priority so that management can be targeted more effectively.