Associations between oxidative balance scores and heart failure among americans: NHANES (2007–2018)

Abstract

Background

The relationship between oxidative balance score (OBS) and heart failure (HF) is controversial. The OBS was used to assess systemic oxidative stress status, with higher OBS scores implying exposure to more antioxidants. This study aimed to explore whether OBS is associated with heart failure in US adults.

Methods

A cross-sectional investigation was carried out using information from the National Health and Nutrition Examination Survey 2007–2018. The linear link between OBS and HF in adults aged ≥ 45 years was investigated using multivariate linear regression models. Interaction tests and subgroup analysis were also conducted.

Results

The prevalence of HF was 3.84%. There was a significant negative relationship between OBS (OR: 0.96 ,95%CI: 0.95–0.98, P < 0.0001) and HF. In the fully adjusted model, compared to the lowest quartile of OBS, subjects in the highest quartile had a 45% lower likelihood of developing HF (OR: 0.55, 95% CI: 0.41–0.74, p < 0.0001). In stratified analysis, OBS and HF showed no obvious negative correlation.

Conclusion

OBS was strongly negatively associated with heart failure. The findings underline the significance of adhering to an antioxidant diet and lifestyle, which helps prevent heart failure.

Introduction

Heart failure (HF), the terminal status of many cardiovascular diseases, is closely related to hospitalizations and mortality [1]. Owing to an aging society, the prevalence increases from 1% for those aged < 55 years to > 10% in those aged 70 years or over, and the overall incidence of HF is increasing with a dismal prognosis [2]. Because unidentified HF patients are neglected, the prevalence can be higher. The decreased cardiac output and accelerated ventricular remodeling caused by HF may contribute to the deterioration of the impaired heart.

In recent years, researchers have become particularly interested in the impact of oxidative stress levels on HF. A major contributing factor to HF is oxidative stress, which is an imbalance between the antioxidant defense system’s generation and clearance of ROS [3]. The Oxidative Balance Score (OBS) is a novel construct that originates from diverse dietary factors, including both pro-oxidant and antioxidant nutrients, as well as lifestyle variables. It encompasses parameters such as smoking, alcohol consumption, obesity, and physical activity (PA). It serves as a valuable instrument for assessing the oxidative stress status of an individual. The antioxidant qualities of certain food ingredients play a crucial role in preventing heart disease. Numerous clinical studies have explored the association between vitamin C supplementation and the prevalence of cardiovascular diseases (CVD), heart failure (HF), and coronary heart disease (CHD), with mixed results reported [4]. A prospective study investigated that every 20 µmol/L increase in plasma vitamin C concentration was associated with a 9% reduced likelihood of HF in 20,299 healthy adults [5, 6]. Additionally, a prospective cohort study identified a positive association between vitamin C supplementation (≥ 300 mg/day) and mortality from CHD among diabetic postmenopausal women, using data from food-frequency questionnaires [7]. Luteolin, an antioxidant supplement, could enhance cardiac function by regulating myocardial contractility, promoting myocardial autophagy, and reversing ventricular remodeling [8]. Magnesium deficiency could exacerbate oxidative stress in the body, particularly in patients with HF [9]. Conversely, a large trial involving 14,641 male participants found that vitamin C supplementation (500 mg/day) over approximately 8 years of follow-up had no significant effect on cardiovascular mortality [10]. Similarly, a meta-analysis found inconsistent or low-quality (downgraded) evidence for a correlation between vitamin C supplementation and major cardiovascular events or cardiovascular mortality [11]. The impact of lifestyle on HF should not be overlooked. For instance, research has shown that individuals who are overweight or obese, based on body mass index (BMI), tend to experience more severe HF compared to those who are underweight or of normal weight [12]. Antioxidant-rich diets and lifestyles are especially important for lowering the occurrence of HF. We were compelled to delve more into their connection as a result.

The Oxidative Balance Score (OBS) was established by calculating the pro- and antioxidant components of dietary and lifestyle determinants, in order to evaluate a person’s oxidative/antioxidant status [13]. OBS was very useful in epidemiological investigations, especially those involving chronic illnesses, since it could evaluate lifestyle choices and diets that might have a negative impact on health [14]. According to a prospective community-based cohort research conducted in Korea, individuals with higher OBS were less likely to get new-onset hypertension [15]. Previous study demonstrated that higher OBS was linked to a reduced prevalence of lumbar spine osteoporosis in postmenopausal Iranian women [16]. However, the relationship between OBS and HF remains a mystery. On the contrary, the review by Aimo et al. discovered that antioxidant treatments were effective in vitro and in animal models of HF but failed to improve outcomes in human studies of HF [17]. Notably, the effects of antioxidant medications in patients with non-ischemic HF are still not well understood.

In our investigation, considering the contentious nature of these findings, we aim to examine the correlation between the OBS and Heart HF within a nationally representative cohort of U.S. adults. The presence of this link suggests that modifying dietary/lifestyle OBS might potentially ameliorate HF in the key population. Therefore, the findings of this study might have significant ramifications for improving HF management and enhancing the quality of life for Americans.

Methods

Study population

The NHANES survey, administered by the nationwide Center for Health Statistics (NCHS), is a nationwide population-based cross-sectional study that examines the nutritional and health status of Americans [18]. NHANES is a cross-sectional survey that follows a two-year cycle and employs standard samples and intricate multi-stage stratified random sampling. This study included data from six NHANES cycles: 2007–2008 to 2017–2018, with information on HF patients and complete variables used to calculate OBS. We used the “MCQ160B” variable in the questionnaire, ‘Has a doctor or other health professional ever told you that you have congestive heart failure?’ for the diagnose HF, and participants who answered “yes” to this question were defined as having HF. Of the 20,302 participants aged 45 and older in the NHANES 2007–2018, the following were excluded if they were present: (1) participants missing data on HF (n = 87), (2) participants lost data for any of the OBS components (n = 8,828), (3) participants were missing covariates (n = 1065) and energy intake was unbelievable (male: <800 kcal/d or > 4200 kcal/d, female: <500 kcal/d or > 3500 kcal/d) (n = 514)¹⁹. After the exclusions, overall 9,808 individuals were included in the study (Fig. 1).

Fig. 1

The participant selection flowchart

Assessment of OBS

The research used pre-Defined Oxidative Balance Scores to estimate OBS, which included 16 nutrients and 4 lifestyle variables [14, 19]. A higher OBS value indicates a greater level of antioxidant exposure. Dietary components of OBS include dietary fiber, carotenoids, riboflavin, niacin, calcium, magnesium, zinc, total folate, vitamins (B6, B12, C and E), copper, selenium, total fat and iron. The lifestyle components of OBS include physical activity (PA), alcohol consumption, body mass index, and smoking, with PA expressed as metabolic equivalent (MET) score × frequency of each PA per week × duration of each PA, and smoking reflected by serum cotinine (the major metabolite of nicotine). The individual OBS score is the sum of the corresponding values for each component of the nutrient and lifestyle components, which are scored based on attributes (antioxidant or pro-oxidant) and gender (male or female) (Table 1). Alcohol drinkers were categorised as non-drinkers, non-heavy drinkers (0–15 g/day for females and 0–30 g/day for males) and heavy drinkers (≥ 15 g/day for females and ≥ 30 g/day for males) and were given a score of 2, 1 and 0 respectively [19]. The other ingredients were divided into three groups according to tertiles and grouped by gender, antioxidants were assigned a score of 0 to 2 in groups 1 to 3, respectively, and the opposite was true for pro-oxidants [14].

Table 1 Oxidative balance score assignment scheme

Selection of covariates

The covariates associated with OBS or HF from the previous research have been included, and collinearity issues have been eliminated. These covariates include age (years), sex (male/female), race (Mexican American/other Hispanic/non-Hispanic White/non-Hispanic Black/Other race), education level (below high school/high school/above high school), marital status (cohabitation (Married/Living with someone), solitude (widowed/divorced/separated/unmarried), PIR (Poverty-income ratio) (≤ 1: below the poverty line, > 1: above the poverty line) [20], and diabetes (yes/no). Standardized questioning, physical examinations, laboratory testing, and questionnaires from medical professionals with the necessary training were used to gather all of the data. Since this research is a retrospective study without clinical trials, there is no clinical trial number.

Statistical analysis

The statistical analysis was conducted in accordance with CDC recommendations, using appropriate NHANES sample weights and accounting for complex multi-stage cluster surveys. In the baseline characteristics table, Standard deviations (SDs) are used to describe continuous data, and proportions are used for depicting categorical parameters. To test for differences between the HF patient group and the non-HF patient group, the weighted Student’s t-test was used for continuous variables and the weighted Chi-Square test was used for categorical variables. We analyzed the linear connection between OBS and HF using multivariate logistic regression methodology, and three models were in place for the evaluation of the relationship. In Model 1, no adjustment for covariates was made. Age, sex and race were adjusted for in Model 2. Model 3 was adjusted for sex, age, race, education level, marital status, PIR, hypertension and diabetes. We further analyzed OBS, dietary OBS components and lifestyle OBS components after dividing it into quartiles to evaluate the robustness of the correlations. Subgroup analysis of the correlation between OBS and HF was conducted to assess the stability of the correlation. All findings from multiple logistic regression analyses and subgroup analyses were interpreted using the results from model 3. The statistical software packages R (The R Foundation; http://www.r-project.org; version 4.1.3) and EmpowerStats (www.empowerstats.com; X&Y Solutions Inc.) were used for all analyses. Statistical significance was deemed to be p < 0.05.

Results

Baseline characteristics of participants

Our research covered 5119 males and 4689 females in NHANES (2007–2018). The average age of all those participating was 61.06 ± 10.42 years and the average OBS was 19.17 ± 6.78. And 3.84% of the participants were patients with HF. The socio-demographic information of the respondents was classified and described according to age, sex, race, educational level, marital status, PIR, hypertension and diabetes. There were no significant differences between HF patients and non-HF patients in terms of age, gender, race, ethnicity, education, marital status, PIR, hypertension, and diabetes mellitus, whereas there were significant differences in terms of dietary OBS components, lifestyle OBS components, and OBS. Patients with HF had lower scores on dietary OBS components, lifestyle OBS components and OBS compared to non-HF patients, suggesting less significant antioxidant exposure. Detailed data are shown in Table 2.

Table 2 NHANES 2007–2018 study population characteristics (N = 9808)

Association between OBS and HF

Table 3 shows the correlation between OBS and HF, with the prevalence of HF decreasing with increasing OBS. In model 3, there was a negative association between OBS (OR: 0.96 ,95%CI: 0.95–0.98, P < 0.0001) (both dietary OBS (OR: 0.97 ,95%CI: 0.96–0.99, P = 0.0004) and lifestyle OBS (OR:0.76, 95%CI: 0.71–0.82, P < 0.0001)) and HF. T OBS was further converted to categorical variables (quartiles) and used to judge the robustness of the association. In all models, the prevalence of HF decreased progressively with increasing quartiles (p for-trend < 0.0001). And in model 3, subjects in Q4 compared with Q1 had 45% (OR:0.55, 95% CI: ,0.41–0.74, P < 0.0001) decreased prevalence of HF. Similarly, compared with Q1, dietary OBS and lifestyle OBS in Q4 reduced the prevalence of HF by 46% and 67% in model 3, respectively (all p for-trend < 0.0001). The results demonstrated a clear linear association between OBS and HF, as shown in Fig. 2; Table 4.

Table 3 The associations between OBS with HF

Table 4 Threshold effect analysis for correlations between OBS and HF

Fig. 2

Smooth curve fitting for OBS and HF. Notes: The smoothed curve fit between the variables is shown by the red solid line. The area between the blue dashed lines indicates the fitted 95% confidence interval

Subgroup analysis

To evaluate the stability of the correlation between OBS and HF, we performed subgroup analyses and interaction tests stratified by age, sex, race, educational level, marital status, PIR, hypertension and diabetes (Fig. 3). No interaction was found in the relationship between OBS and HF (p > 0.05 for all interactions).

Fig. 3

Subgroup analysis of associations between OBS and HF. OR: Odds ratio; 95% CI: 95% confidence interval

Discussion

To elucidate the relationship between HF and the OBS, we conducted a cross-sectional study involving 9,808 participants from the NHANES cohort. Our findings revealed that total OBS, dietary OBS, and lifestyle OBS were inversely associated with HF prevalence, highlighting the importance of antioxidant-rich diets and lifestyles for cardiovascular health. Collectively, individuals with higher OBS scores exhibited a significantly lower prevalence of HF.

The OBS, as an integrative metric of pro-oxidant and antioxidant factors, evaluates oxidative stress status. Components such as dietary antioxidants (e.g., vitamins C and E, carotenoids) and lifestyle factors (e.g., smoking, alcohol use, and physical activity) are closely linked to cardiovascular outcomes. Higher OBS levels, indicative of greater antioxidant exposure, are associated with a reduced prevalence of HF and other cardiovascular diseases [21, 22]. For instance, individuals in the highest OBS quartile show a 30% reduction in all-cause and cardiovascular mortality after adjusting for confounders [22]. Among populations at high prevalence for HF, such as those with type 2 diabetes, elevated OBS levels improve insulin sensitivity and lower systemic inflammation [22]. Research further highlights the pathogenic role of oxidative imbalances in HF. Patients with HF consistently exhibit reduced dietary antioxidant intake and higher pro-oxidant exposure, correlating with elevated systemic inflammation [23]. Markers such as the Systemic Immune-Inflammation Index indicate that oxidative and inflammatory pathways are central to cardiovascular health [21]. A higher OBS is significantly associated with lower levels of systemic inflammation, suggesting a protective role against HF [21]. Research comparing HF and non-HF populations reveals that HF patients consistently have lower dietary antioxidant intake, which correlates with increased oxidative stress. Additionally, these patients exhibit higher levels of pro-oxidants such as smoking and alcohol consumption. This elevated oxidative stress in HF patients is associated with increased systemic inflammation markers, reinforcing the pathogenic role of oxidative imbalances. As research into the pathogenesis of heart failure deepens, oxidative stress has been found to play a critical role in its development and prognosis. The excessive production of reactive oxygen species induced by oxidative stress can trigger the opening of mitochondrial transition pores and overexpression of transcription factors, thereby impairing mitochondrial function [24]. Additionally, a higher OBS reduces the prevalence of hypertension and hyperlipidemia—key prevalence factors for HF [15]. Studies show that antioxidants improve vascular function and lipid metabolism, reducing the prevalence of hypertension by 31% and hyperlipidemia by 36% among individuals in the highest OBS quartile [25]. These findings underscore the potential of oxidative balance in mitigating metabolic risk factors and systemic inflammation, thereby preventing HF.

In summary, OBS serves as a comprehensive tool for assessing HF prevalence, offering predictive value through its integration of oxidative and inflammatory factors. While these associations are largely supported by observational studies, further clinical trials are essential to confirm these findings [26]. As a low-cost, adaptable index, OBS holds promise for guiding personalized prevention strategies and public health policies. Future research should focus on validating its utility across diverse populations and integrating it with traditional predictive models to enhance its clinical applicability.

The present study has several strengths. First, our research focused on the OBS as a composite indicator, rather than a single component. This approach allowed us to get a full understanding of the intricate interactions among the components and conduct a deeper inquiry into the desired results. Second, in order to guarantee the excellent quality of the NHANES data, a representative sample of the civilian noninstitutionalized resident population was chosen using a complicated, multi-stage probability sampling technique. When applied to the whole noninstitutionalized civilian population in the US, the findings are therefore quite trustworthy. Third, a number of confounding variables, such as sociodemographic traits, diabetes, and hypertension, were taken into account in this investigation. Furthermore, we examined the independent effects on HF dietary OBS and lifestyle OBS. We conducted distinct subgroup analyses for every one of these three attributes, since it was crucial to consider the potential impacts of age, gender, and educational attainment on the results. Consequently, the results have further ramifications for public health in terms of HF prevention.

Our research did have several shortcomings. First, since the research is cross-sectional, it is challenging to determine a causal association between OBS and HF. Therefore, more prospectively oriented research is required to prove that OBS is effective. Second, owing to database constraints, it was challenging to include all OS-related dietary and lifestyle exposures in OBS; flavonoids, for example, were one of the components with restricted availability in the database. Third, individuals’ N-terminal pro brain natriuretic peptide (NT-proBNP) and echocardiography data are not gathered by the NHANES. Individuals with self-reported physician-diagnosed HF were considered to be participants with HF. In the meanwhile, it was unable to determine if OBS alongside various types of HF had a distinct association since it could not differentiate between the different kinds of HF that participants had.

Conclusion

To sum up, findings from a nationally representative sample of adult US citizens indicated a substantial negative correlation between OBS and HF. It shown a correlation between a lower incidence of HF and higher OBS, which indicates more exposure to antioxidants than prooxidants via diet and lifestyle choices. According to this research, adopting an antioxidant-rich diet and lifestyle may improve cardiovascular health. Further investigation is needed to understand the causal link and the mechanisms behind the correlation between OBS and HF in the future.