Background/Objectives: The hemoglobin-to-red blood cell distribution width (RDW) ratio (HRR) reflects the status of inflammation and oxidative stress size. Previously, it has been suggested that HRR is associated with cardiovascular diseases (CVD). However, evidence has been limited for examining the association between HRR and the incidence of specific cardiovascular events (e.g., cardiovascular disease, stroke, congestive heart failure) and all-cause cardiovascular death and non-cardiovascular death, adjusting for known confounders. Methods: Data from the National Health and Nutrition Examination Survey (NHANES) in the year cycle of 1999–2018 were collected. HRR was calculated as the ratio of hemoglobin divided by the RDW. The outcomes were CVD, including stroke, congestive heart failure, atherosclerotic cardiovascular diseases (ASCVD), coronary artery disease as well as all-cause death including cardiovascular death and non-cardiovascular death. Univariate and multivariate analyses were performed to explore the association between HRR and outcomes. Restricted cubic spline curves were delineated. Results: In total, 47,719 participants were eligible for further analysis. In multivariate analysis adjusting for all confounding factors, higher HRR levels were significantly associated with a decreased risk of CVD. Compared to Q1 (<9.86), the odds ratio (OR) and 95% confidence intervals (95% CI) in Q2 (9.86–10.96), Q3 (10.96–11.97), and Q4 (≥11.97) were 0.79 (0.66, 0.94), 0.59 (0.48, 0.73), and 0.53, (0.42, 0.67), respectively, for predicting CVD. Similar results were observed for different subtypes of CVD, including stroke, congestive heart failure, and ASCVD. Notably, for predicting coronary heart disease, only Q3 was significant compared to Q1 (0.70, [0.54, 0.92], p = 0.010). HRR was significant for predicting all-cause death, cardiovascular death, and non-cardiovascular death. Additionally, HRR had the highest discriminative ability for predicting all-cause death compared with that of hemoglobin and RDW. Conclusions: A higher HRR was associated with a lower risk of CVD and death. Moderate levels of HRR were associated with the lowest risk for coronary heart disease. HRR had better discriminative ability than hemoglobin and RDW.

Background: Most studies on improvements in respiratory muscle strength, activities of daily living (ADL) and quality of life (QoL) in stroke patients receiving threshold respiratory muscle training (TRMT) have small sample sizes, and some studies have contradictory results. Objectives: To evaluate the effectiveness of TRMT on respiratory muscle strength, pulmonary function and exercise endurance in stroke patients. Materials and Methods: PubMed, Cochrane Library, Physical Therapy Evidence Database (PEDro), Embase (via OVID) and Web of Science databases were searched for randomized controlled trial (RCT) from inception to January 17, 2024. The primary outcome was maximum inspiratory pressure (MIP) or maximum expiratory pressure (MEP). Secondary outcomes included pulmonary function measured by forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and peak expiratory flow (PEF), and exercise endurance measured by 6-minute walk test (6MWT). Results: A total of eight randomized controlled trials(RCTs), including 305 persons, were included in this study. The training time ranged from 3 weeks to 10 weeks. Among them, the intervention group in 4 studies used inspiratory muscle training, and the other 4 studies used inspiratory muscle training and expiratory muscle training. For the primary outcome, TRMT significantly improved MIP (mean=14.68 cmH(2)O, 95 %CI=2.28 to 27.09 cmH(2)O, P=0.02) and MEP (mean=9.37 cmH(2)O, 95 %CI=2.89 to 15.84 cmH(2)O, P=0.005) in stroke patients. Regarding the secondary outcomes, TRMT improved FVC, FEV1 and 6MWT (P<0.05) but did not significantly improve PEF. Conclusion: TRMT improved inspiratory muscle strength and expiratory muscle strength, improved exercise endurance, and improved FVC and FEV1 of pulmonary function but did not significantly improve PEF.