Impact of dietary nitrate supplementation on exercise capacity and cardiovascular parameters in chronic respiratory disease: a systematic review and meta-analysis

Outcomes of Surgery for Patients With Coexisting Heart and Lung Disease: A Retrospective Study

INTRODUCTION

The optimal surgical approach and the associated adverse outcomes in patients with lung cancer and heart disease remain unknown. This study was designed to explore the potential influence of simultaneous or staged surgery on the perioperative and oncological outcomes of these patients.

MATERIALS AND METHODS

This retrospective study analyzed 158 patients who underwent cardiac and thoracic surgery between January 2016 and December 2021. The patients were divided into two groups according to the timing of surgery: simultaneous and staged. Perioperative and oncologic outcomes between the two groups were compared using 1:1 propensity score matching analysis and Kaplan-Meier analysis.

RESULTS

In the 50 patients (72% male, mean age 60.9 ± 11.7 y) of the simultaneous surgery group, 10 (20%) developed tumor metastasis or recurrence and 6 (12%) died from tumor metastasis. In the staged surgery group, with 108 patients (75% male, mean age 66.1 ± 8.4 y), 18 (16.7%) developed tumor metastasis or recurrence, and 8 (7.4%) died. There was no significant difference in overall survival or progression-free survival between the groups. Compared with the staged surgery group, the simultaneous surgery group had a higher incidence of pulmonary infection (3.7% versus 18.0%; P = 0.002), longer operative time (173.9 ± 104.4 versus 295.6 ± 77.1 min; P < 0.001), increased intraoperative blood loss (89.2 ± 53.1 versus 386.0 ± 207.0 mL; P < 0.001), and a prolonged hospital stay (7.0 ± 3.1 versus 16.5 ± 6.1 d; P < 0.001).

CONCLUSIONS

For patients with concurrent lung cancer and heart disease, staged surgery holds certain advantages when it comes to postoperative complications. Further researches are still needed to verify these findings.

Dietary nitrate supplementation enhances exercise capacity in WHO Group 3 pulmonary hypertension: a double-blind, placebo-controlled, randomised crossover study (EDEN-OX2)

Dietary nitrate supplementation, which improves skeletal muscle oxygen utilisation, vascular endothelial function and exercise capacity in people with chronic obstructive pulmonary disease, may benefit other lung conditions. In a double-blind, placebo-controlled, crossover study, in 19 adults with Group 3 pulmonary hypertension who desaturated during exercise, 140 mL of nitrate-rich beetroot juice improved endurance shuttle walk time compared with nitrate-depleted beetroot juice placebo (median (IQR) ESWT NR-BRJ 197 (140-273) s vs PL-BRJ 174 (107-229) s; median difference (MD) (95% CI) 30 (6.19 to 91.07) s, p=0.0281), endothelial function, flow-mediated dilatation (+3.40±5.47% vs -1.33±4.78; MD (95% CI) 4.73 (1.44 to 8.02), p=0.007) and lowered mean arterial blood pressure (-3.9 (-7.4 to -0.4) mm Hg, p=0.028).

Acute effects of a chewable beetroot-based supplement on cognitive performance: a double-blind randomized placebo-controlled crossover clinical trial

BACKGROUND

Dietary nitrate (NO3-) has been shown to be useful as an ergogenic aid with potential applications in health and disease (e.g., blood pressure control). However, there is no consensus about the effects of dietary NO3- or beetroot (BR) juice supplementation on cognitive function.

OBJECTIVE

The aim of this study was to evaluate the effects of a single dose of a chewable BR-based supplement on cognitive performance.

METHODS

A double-blind randomized placebo-controlled two-period crossover clinical trial was carried out based on the extension of the CONSORT guidelines for randomized crossover trials. A total of 44 participants (24 F; 20 M; 32.7 [12.5] years; 66.3 [9.0] kg; 170 [9.2] cm; 22.8 [1.4] kg/m2) were randomly allocated to receive first either four BR-based chewable tablets (BR-CT) containing 3 g of a Beta vulgaris extract (RedNite®) or four tablets of a placebo (maltodextrin). A 4-day washout period was used before crossover. Ninety minutes after ingestion of the treatments, a neuropsychological testing battery was administered in each period. The trial was registered at clinicaltrials.gov NCT05509075.

RESULTS

Significant improvements with moderate effect size were found on memory consolidation at the short and long term only after BR-CT supplementation via the Rey Auditory Verbal Learning Test immediate (+ 20.69%) and delayed (+ 12.34%) recalls. Likewise, enhancement on both frontal lobe functions (+ 2.57%) and cognitive flexibility (+ 11.16%) were detected after BR-CT. There was no significant change (p < 0.05) on verbal memory of short-term digits, working memory and information processing speed. Mixed results were found on mood and anxiety through the Beck Depression Inventory-II (BDI-II) and the State-Trait Anxiety Inventory (STAI-Y1 and STAI-Y2); however, sequence and period effects were seen on STAI-Y2.

CONCLUSIONS

The acute administration of a chewable BR-based supplement improves certain aspects of cognitive function in healthy females and males, particularly memory capacity and frontal skills.

Oral nitrate supplementation improves cardiovascular risk markers in COPD: ON-BC, a randomised controlled trial

BACKGROUND

Short-term studies suggest that dietary nitrate (NO3 -) supplementation may improve the cardiovascular risk profile, lowering blood pressure (BP) and enhancing endothelial function. It is not clear if these beneficial effects are sustained and whether they apply in people with COPD, who have a worse cardiovascular profile than those without COPD. Nitrate-rich beetroot juice (NR-BRJ) is a convenient dietary source of nitrate.

METHODS

The ON-BC trial was a randomised, double-blind, placebo-controlled parallel group study in stable COPD patients with home systolic BP (SBP) measurement ≥130 mmHg. Participants were randomly allocated (1:1) using computer-generated, block randomisation to either 70 mL NR-BRJ (400 mg NO3 -) (n=40) or an otherwise identical nitrate-depleted placebo juice (0 mg NO3 -) (n=41), once daily for 12 weeks. The primary end-point was between-group change in home SBP measurement. Secondary outcomes included change in 6-min walk distance (6MWD) and measures of endothelial function (reactive hyperaemia index (RHI) and augmentation index normalised to a heart rate of 75 beats·min-1 (AIx75)) using an EndoPAT device. Plasma nitrate and platelet function were also measured.

RESULTS

Compared with placebo, active treatment lowered SBP (Hodges-Lehmann treatment effect -4.5 (95% CI -5.9- -3.0) mmHg), and improved 6MWD (30.0 (95% CI 15.7-44.2) m; p<0.001), RHI (0.34 (95% CI 0.03-0.63); p=0.03) and AIx75 (-7.61% (95% CI -14.3- -0.95%); p=0.026).

CONCLUSIONS

In people with COPD, prolonged dietary nitrate supplementation in the form of beetroot juice produces a sustained reduction in BP, associated with an improvement in endothelial function and exercise capacity.

Dietary nitrate supplementation to enhance exercise capacity in hypoxic COPD: EDEN-OX, a double-blind, placebo-controlled, randomised cross-over study

RATIONALE

Dietary nitrate supplementation improves skeletal muscle oxygen utilisation and vascular endothelial function. We hypothesised that these effects might be sufficient to improve exercise performance in patients with COPD and hypoxia severe enough to require supplemental oxygen.

METHODS

We conducted a single-centre, double-blind, placebo-controlled, cross-over study, enrolling adults with COPD who were established users of long-term oxygen therapy. Participants performed an endurance shuttle walk test, using their prescribed oxygen, 3 hours after consuming either 140 mL of nitrate-rich beetroot juice (BRJ) (12.9 mmol nitrate) or placebo (nitrate-depleted BRJ). Treatment order was allocated (1:1) by computer-generated block randomisation.

MEASUREMENTS

The primary outcome was endurance shuttle walk test time. The secondary outcomes included area under the curve to isotime for fingertip oxygen saturation and heart rate parameters during the test, blood pressure, and endothelial function assessed using flow-mediated dilatation. Plasma nitrate and nitrite levels as well as FE_NO were also measured.

MAIN RESULTS

20 participants were recruited and all completed the study. Nitrate-rich BRJ supplementation prolonged exercise endurance time in all participants as compared with placebo: median (IQR) 194.6 (147.5-411.7) s vs 159.1 (121.9-298.5) s, estimated treatment effect 62 (33-106) s (p<0.0001). Supplementation also improved endothelial function: NR-BRJ group +4.1% (-1.1% to 14.8%) vs placebo BRJ group -5.0% (-10.6% to -0.6%) (p=0.0003).

CONCLUSION

Acute dietary nitrate supplementation increases exercise endurance in patients with COPD who require supplemental oxygen.Trial registration number ISRCTN14888729.