Dietary fiber intake is positively associated with health-related quality of life in patients with hypertension: The mediating role of anxiety in mental component summary

Few studies have focused on the exploration of the relationship between dietary fiber intake (DFI) and health-related quality of life (HRQoL) and its mediators in hypertensive patients. This study is a cross-sectional survey and the data were obtained from hypertensive patients from Suzhou, China. The DFI, office systolic blood pressure and diastolic blood pressure, anxiety and depression, and HRQoL were investigated. We hypothesized that blood pressure, anxiety, and depression mediated the association between DFI and HRQoL, and used Pearson correlations, linear regression, and bootstrap tests to validate this relationship. A total of 211 hypertensive patients aged 20 to 64 years were included in this study. The average DFI was 12.4 ± 5.2 g/d, and the scores of physical component summary and mental component summary (MCS) were 46.5 ± 6.1 and 46.4 ± 6.4, respectively. DFI was positively correlated with physical component summary (r = 0.17, p = 0.014) and MCS (r = 0.27, P < .001). After controlling for sociodemographic and clinical characteristics, neither systolic blood pressure nor diastolic blood pressure showed mediating effects in the mediated model of DFI on MCS, whereas anxiety (b = -0.30; 95% confidence interval, -0.41 to -0.18) fully mediated the improvement in MCS by DFI (F = 11.14, P < .001). Because the MCS of HRQoL encompassed the assessment of depression, we did not analyze the mediating effect of depression in this model in order to avoid variable duplication. The decreased DFI is a risk factor for lower HRQoL, and anxiety mediated the relationship between DFI and MCS. Further research should focus on increasing DFI and reducing anxiety levels in hypertensive patients to improve their quality of life.