Blood Pressure

Background & aims
Many experimental and clinical trials suggested that flaxseed might be a potent antihypertensive, but the evidences concerning the effects of flaxseed supplements on blood pressure (BP) has not been fully conclusive. We aimed to assess the impact of the effects of flaxseed supplements on blood pressure through systematic review of literature and meta-analysis of available randomized controlled trials (RCTs).

Methods
The literature search included PUBMED, Cochrane Library, Scopus, and EMBASE up to February 2015 to identify RCTs investigating the effect of flaxseed supplements on plasma blood pressure. Effect size was expressed as weighed mean difference (WMD) and 95% confidence interval (CI).

Results
15 trials (comprising 19 treatment arms) with 1302 participants were included in this meta-analysis. Random-effects meta-analysis suggested significant reductions in both systolic BP (SBP) (WMD: −2.85 mmHg, 95%CI: −5.37 to −0.33, p = 0.027) and diastolic BP (DBP) (WMD: −2.39 mmHg, 95%CI: −3.78 to −0.99, p = 0.001) following supplementation with flaxseed products. When the studies were stratified according to their duration, there was a greater effect on both SBP and DBP in the subset of trials with ≥12 weeks of duration (WMD: −3.10 mmHg, 95%CI: −6.46 to 0.27, p = 0.072 and −2.62 mmHg, 95%CI: −4.39 to −0.86, p = 0.003, respectively) vs the subset lasting <12 weeks (WMD: −1.60 mmHg, 95%CI: −5.44 to 2.24, p = 0.413, and −1.74 mmHg, 95%CI: −4.41 to 0.93, p = 0.202, respectively). Another subgroup analysis was performed to assess the impact of flaxseed supplement type on BP. Reduction of SBP was significant with flaxseed powder (WMD: −1.81 mmHg, 95% CI: −2.03 to −1.59, p < 0.001) but not oil (WMD: −4.62 mmHg, 95%CI: −11.86 to 2.62, p = 0.211) and lignan extract (WMD: 0.28 mmHg, 95% CI: −3.49 to 4.04, p = 0.885). However, DBP was significantly reduced with powder and oil preparations (WMD: −1.28 mmHg, 95% CI: −2.44 to −0.11, p = 0.031, and −4.10 mmHg, 95%CI: −6.81 to −1.39, p = 0.003, respectively), but not with lignan extract (WMD: −1.78 mmHg, 95% CI: −4.28 to 0.72, p = 0.162).

Conclusions
This meta-analysis of RCTs showed significant reductions in both SBP and DBP following supplementation with various flaxseed products.

Gouania longipetala is commonly used in Cameroonian traditional medicine to manage women fertility and menopausal complaints. However, despite this use, the estrogenic properties of Gouania longipetala (G. longipetala) have not been studied until now. The present study was aimed to assess estrogenic activities of the stem bark aqueous (GLA) and ethanolic (GLE) extracts of G. longipetala in post menopause-like model of ovariectomized (Ovx) Wistar rats. Animals were either sham-operated or Ovx. 84 days after ovariectomy, animals were divided into seven groups of five animals and were daily treated for 28 days with distilled water (10mL/kg) for group 1, 2% solution of Tween 80 (10mL/kg) for group 2, estradiol valerate (1mg/kg) for group 3, GLA (45 or 180mg/kg) and GLE (40 or 160mg/kg) for groups 4 to 7 respectively. Sham-operated animals daily received distilled water (10mL/kg). During the experimental period, the body weight was registered every week. At the day 29, blood pressure was registered by invasive method while uterine and vagina morphometry as well as body, uterine and abdominal fat weights changes were analyzed. Serum levels of total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol were determined. Moreover, oxidative stress markers such as nitrites, reduced glutathione (GSH) and malondialdehyde (MDA) were measured in homogenized liver and aorta. Compared with the sham control, vagina and uterine dystrophy and elevated blood pressure were observed in Ovx rats treated with vehicles. Biochemical parameters showed a significant increase of total cholesterol, triglycerides, LDL-cholesterol and MDA as well as a significant decrease of nitrites and GSH in Ovx animals treated with vehicle as compared to sham group. GLA and GLE displayed estrogen-like effects on vagina and did not affect uterine wet weight and epithelial height compared with vehicle groups. Both extracts displayed anti-atherogenic properties by reducing AI, AIP and LDL-cholesterol level as compared to vehicles groups. GLA and GLE significantly prevented the increase of MDA induced by ovariectomy as compared to rats treated with vehicles. This study showed that GLA and GLE exhibited estrogenic effects by providing vaginal lubrication, by modulating blood pressure and improving lipid profile, oxidative status and endothelial function and may not have an undesirable influence on the endometrium in ovariectomized rats.

Electrocardiogram, cardiac output, and blood lactate accumulation were recorded in three elite breath-hold divers diving to 40-55 m in a pressure chamber in thermoneutral (35 degrees C) or cool (25 degrees C) water. In two of the divers, invasive recordings of arterial blood pressure were also obtained during dives to 50 m in cool water. Bradycardia during the dives was more pronounced and developed more rapidly in the cool water, with heart rates dropping to 20-30 beats/min. Arrhythmias occurred, particularly during the dives in cool water, when they were often more frequent than sinus beats. Because of bradycardia, cardiac output decreased during the dives, especially in cool water (to &lt;3 l/min in 2 of the divers). Arterial blood pressure increased dramatically, reaching values as high as 280/200 and 290/150 mmHg in the two divers, respectively. This hypertension was secondary to peripheral vasoconstriction, which also led to anaerobic metabolism, reflected in increased blood l...

Objective: To verify if acute intake of beetroot juice potentiates post-exercise hypotension (PEH) in hypertensive postmenopausal women. Methods: Thirteen hypertensive postmenopausal women (58.1 ± 4.62 years and 27.4 ± 4.25 kg/m 2) were recruited to participate in three experimental sessions, taking three different beverages: Beetroot juice (BJ), placebo nitrate-depleted BJ (PLA), and orange flavored non-caloric drink (OFD). The participants performed moderate aerobic exercise training on a treadmill, at 65-70% of heart rate reserve (HRR), for 40 min. After an overnight fast, the protocol started at 07h when the first resting blood pressure (BP) was measured. The beverage was ingested at 07h30 and BP was monitored until the exercise training started, at 09h30. After the end of the exercise session, BP was measured every 15 min over a 90-min period. Saliva samples were collected at rest, immediately before and after exercise, and 90 min after exercise for nitrite (NO 2 −) analysis. Results: There was an increase in salivary NO 2 − with BJ intake when compared to OFD and PLA. A slight increase in salivary NO 2 − was observed with PLA when compared to OFD (p < 0.05), however, PLA resulted in lower salivary NO 2 − when compared to BJ (p < 0.001). There were no changes in salivary NO 2 − with the OFD. Systolic and diastolic BP decreased (p < 0.001) on all post exercise time points after all interventions, with no difference between the three beverages. Conclusion: Acute BJ intake does not change PEH responses in hypertensive postmenopausal women, even though there is an increase in salivary NO 2 − .