Association of dietary total antioxidant capacity with all-cause and cardiovascular mortality in patients with chronic kidney disease: based on two retrospective cohort studies of NHANES

Association between dietary antioxidant levels and chronic obstructive pulmonary disease: a mediation analysis of inflammatory factors

Introduction

The development of chronic obstructive pulmonary disease (COPD) is strongly associated with oxidative stress, but it is unclear whether increasing dietary antioxidant intake reduces the risk of COPD. Therefore, this study assessed the association between antioxidant intake and COPD in US adults aged ≥ 40 years and further examined the correlation using the Composite Dietary Antioxidant Index (CDAI).

Methods

The study included 8,257 US adults aged ≥ 40 years using data from the National Health and Nutrition Examination Survey (NHANES) for three cycles from 2007-2012. Multivariate logistic regression models were used to calculate the correlation between antioxidant intake and CDAI with COPD. Restricted cubic spline was further used to explore the exposure-response relationship. Mediation analysis was used to explore the role of inflammatory factors in the association between CDAI and COPD.

Results

This study included 8257 participants (4111 women [weighted, 50.7%]; mean [SD] age, 58.8 [11.2] years). In a multivariable-adjusted model of single antioxidant intake, a linear downward association between carotenoid intake and the incidence of COPD (P for trend = 0.052; Pnon- linear = 0.961). In a multivariable adjusted model for CDAI, this association is similarly present (P for trend = 0.018; Pnon-linear = 0.360). Multiple linear regression modeling showed that leukocytes (P = 0.002), alkaline phosphatase (P< 0.001), and c-reactive protein (P< 0.001) were negatively associated with CDAI levels. Meanwhile, mediation analysis revealed that alkaline phosphatase and c-reactive protein partially influenced the association between CDAI and COPD prevalence, with mediation ratios of 6.4% (P< 0.01) and 4.68% (P = 0.04), respectively.

Conclusion

The risk of COPD decreased with increased carotenoid intake and CDAI. In addition, CDAI has been found to be strongly associated with inflammatory factors and can reduce the incidence of COPD by mediating inflammatory factors.

Physical activity modifies the association of the composite dietary antioxidant index with all-cause mortality in the US osteoarthritis population

Background

It remains unclear how antioxidant intake affects all-cause mortality in osteoarthritis (OA) patients. In this prospective cohort study, we aim to explore the association of the Composite Dietary Antioxidant Index (CDAI) with all-cause mortality and investigate the interaction of physical activity (PA) and CDAI on all-cause mortality in OA populations.

Methods

A total of 3,197 adults with OA in the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2018 were included in this study. Death outcomes were obtained from National Death Index (NDI) records. Multivariable Cox regression analyses with cubic spines were applied to estimate the association of CDAI with all-cause mortality. The interaction between CDAI and PA on all-cause mortality was further assessed in stratified analysis and interaction tests.

Results

The hazard ratios for all-cause mortality were 0.95 (0.77-1.17) for Q2, 0.75 (0.59-0.97) for Q3, and 0.71 (0.55-0.92) for Q4 (P for trend <0.001), compared with the lowest quartile of CDAI. A negative linear association was found between CDAI and all-cause mortality. In the stratified analyses, CDAI was negatively associated with all-cause mortality in the insufficient PA group. While in the low and sufficient PA group, there were nonlinear relationships of CDAI with all-cause mortality.

Conclusion

A negative linear relationship was observed between CDAI and all-cause mortality in OA patients, and this association was significantly modified by PA. Higher intake of dietary antioxidants might be the interventional objective to reduce the risk of all-cause mortality in the US OA population.