Strategies targeting the NO pathway to counteract extra-pulmonary manifestations of COPD: A systematic review and meta-analysis

Effects of sildenafil on gas exchange, ventilatory, and sensory responses to exercise in subjects with mild-to-moderate COPD: a randomized cross-over trial

Excess exercise ventilation (high ventilation (V̇E)/carbon dioxide output (V̇CO2)) contributes significantly to dyspnea and exercise intolerance since the earlier stages of chronic obstructive pulmonary disease (COPD). A selective pulmonary vasodilator (inhaled nitric oxide) has shown to increase exercise tolerance secondary to lower V̇E/V̇CO2 and dyspnea in patients with early COPD. We aimed to assess whether a clinically more practical option - oral sildenafil - would be associated with similar beneficial effects. In a randomized, placebo-controlled study, twenty-four patients with mild-to-moderate COPD completed, on different days, two incremental cardiopulmonary exercise tests (CPET) one hour after sildenafil or placebo. Eleven healthy participants performed a CPET in a non-interventional visit for comparative purposes with patients when receiving placebo. Patients (FEV1= 69.4 ± 13.5% predicted) showed higher ventilatory demands (V̇E/V̇CO2), worse pulmonary gas exchange, and higher dyspnea during exercise compared to controls (FEV1= 98.3 ±11.6% predicted). Contrary to our expectations, however, sildenafil (50mg; N= 15) did not change exertional V̇E/V̇CO2, dead space/tidal volume ratio, operating lung volumes, dyspnea, or exercise tolerance compared to placebo (P>0.05). Due to the lack of significant beneficial effects, nine additional patients were trialed with a higher dose (100mg). Similarly, active intervention was not associated with positive physiological or sensory effects. In conclusion, acute oral sildenafil (50 or 100mg) failed to improve gas exchange efficiency or excess exercise ventilation in patients with predominantly moderate COPD. The current study does not endorse a therapeutic role for sildenafil to mitigate exertional dyspnea in this specific patient subpopulation. Clinical trial registry: https://ensaiosclinicos.gov.br/rg/RBR-4qhkf4 Web of Science Researcher ID: O-7665-2019.

Effects of Nitric Oxide Supplementation on the Levels of Interleukin-6 in Saliva after Dental Implant Placement - A Prospective Study

Introduction

The purpose of the study was to evaluate and compare the levels of salivary Interleukin-6 (IL-6) before and after the placement of dental implants in patients who are supplemented with nitric oxide (NO).

Materials and Methods

The study comprised 34 patients, divided into control and study groups (17 in each group). The control group was given a placebo and in the study group, nitric oxide supplement was prescribed, whereas the control group received a placebo. Saliva samples were taken before placement of dental implants, first and third day after the implant placement. The levels of salivary IL-6 were assessed using an enzyme-linked immunosorbent assay test.

Results

Statistical analysis showed a significant P value (<0.05) with respect to IL-6 levels on first and third days after placement of dental implants. Salivary IL-6 levels in the study group declined significantly. On day three, the IL-6 values for the control and study groups were 0.0639 and 0.0443, respectively. Within the groups, it was observed that there was a significant decrease in IL-6 values from day one to day three.

Discussion

The levels of salivary IL-6 reduced from day one to day three more significantly and consistently in patients prescribed with NO supplements post-dental implant placement, suggesting better resolution of inflammation.