Association between serum zinc levels and suicidal ideation in US adults: A population-based cross-sectional study

Association between suicidal ideation and oxidative balance score (OBS): National Health and Nutrition Examination Survey (NHANES) 2005-2018

BACKGROUND

The oxidative balance score (OBS) serves as an indicator of systemic oxidative stress status, where a higher OBS indicates significant exposure to antioxidants through dietary and lifestyle choices. Studies exploring the relationship between OBS and suicidal ideation are limited. Therefore, this study aimed to examine the association between OBS and suicidal ideation.

METHODS

This cross-sectional study selected 28,598 individuals aged ≥20 years from the 2005-2018 National Health and Nutrition Examination Survey dataset. The OBS was determined using 16 dietary components and 4 lifestyle components. Item 9 of the Patient Health Questionnaire-9 was used to evaluate suicidal ideation. The association between suicidal ideation and OBS, dietary OBS, and lifestyle OBS was examined using weighted logistic regression and restricted cubic spline. The subgroup analyses and interaction tests were further conducted to assess the robustness of these associations across different populations.

RESULTS

The prevalence of suicidal ideation was 3.35 %. OBS, dietary OBS, and lifestyle OBS were substantially and inversely linked with suicidal ideation in Models 1, 2, and 3 (p < 0.05). The odds ratio for the highest quartile (Q4) of these variables and suicidal ideation in Model 3 was 0.44 [95 % confidence interval (CI): 0.30-0.65], 0.54 (95 % CI: 0.37-0.78), and 0.50 (95 % CI, 0.34-0.74), respectively, compared with the lowest quartile (Q1). The subgroup analyses revealed consistent connections between the three oxidative stress indices and suicidal ideation. The lifestyle OBS was negatively correlated with suicidal ideation, especially in women (p for interaction < 0.05).

CONCLUSIONS

The dietary and lifestyle OBSs may influence suicidal ideation by modulating oxidative balance. An antioxidant diet and lifestyle are crucial in mitigating suicidal ideation. These findings suggest a potential sex-specific suicide ideation risk, which significantly correlates with suicidal ideation in women but not in men.

Vitamin C and suicidal ideation: A cross-sectional and Mendelian randomization study

BACKGROUND

Studies have shown that a history of suicide attempts is associated with low levels of antioxidant vitamins. However, the specific relationship between vitamin C and suicidal ideation remains poorly understood. The purpose of this study is to investigate the effect of vitamin C on the development of suicidal ideation and to explore further the causal relationship using Mendelian randomization (MR).

METHODS

Using the 2005-2018 National Health and Nutrition Examination Survey (NHANES) dataset, a comprehensive, cross-sectional, stratified survey of 28,623 participants aged 20 years and older was conducted. Suicidal ideation was assessed using item 9 of the Patient Health Questionnaire-9 (PHQ-9) item. The relationship between vitamin C and suicidal ideation was revealed by weighted multiple linear regression, smooth curve fitting, hierarchical analysis, and interaction test. To determine causality, MR was performed on vitamin C and suicidal ideation.

RESULTS

In cross-sectional studies, all models showed a negative association between vitamin C and suicidal ideation, with a 37 % reduction in the risk of suicidal ideation for each unit increase in vitamin C in the highest quartile in the fully adjusted model. The results of the subgroup analysis showed that the association between vitamin C and suicidal ideation was stable across gender, age, education, smoking status, and marital status. In the MR study, our bivariate model showed no significant causal relationship between vitamin C and the development of suicidal ideation.

CONCLUSIONS

Dietary vitamin C intake was negatively associated with the development of suicidal ideation. However, genetic evidence does not support causation of these associations.

The link between endocrine parameters, serum lithium concentrations, and cognitive functions among individuals with affective disorders at risk of suicidal behavior. A study protocol

INTRODUCTION

Suicidal behavior is prevalent among individuals with mental disorders and constitutes a major global, clinical, and public health concern. It is generally accepted that the majority of persons who die by suicide are suffering from psychiatric disorders in most cases and that affective disorders make up the single commonest group. Suicide risk is highest during the years immediately following the onset of affective disorders; therefore, identifying risk factors and successful treatment of initially non-suicidal individuals with affective disorders can prevent developing suicidal behavior, help detecting, and predict it. Clarifying risk factors for individual types of major affective disorders could enhance earlier identification of suicidal risk, support preventive interventions and improve the treatment and prognosis of individuals at risk. We have developed a study protocol with the aim to address the complex interaction of endocrine parameters, lithium trace concentrations and cognitive functions with affective disorders and risk of suicidal behavior.

METHOD

A cross-sectional study will be done among individuals hospitalized after a suicidal attempt for treatment of affective disorders (group 1), hospitalized for the treatment of affective disorders without life time history of suicidal behavior (group 2), and control group individuals without life time history of mental disorders or suicidal behavior (group 3). Based on this study design we calculated the appropriate study sample size (N = 210). Venous blood samples of study participants will be collected for the evaluation of endocrine parameters, serum lithium concentrations, liver and kidney function. Data on sociodemographic factors, cognitive functions, history of mental disorders, and suicidality risk will be evaluated using validated questionnaires and instruments. Associations of endocrine parameters, serum lithium concentrations, cognitive functions, and suicidality risk will be analyzed using descriptive and inferential statistics, including linear and logistic regression. Based on this study design we calculated the appropriate study sample size (N = 210). Power analysis has shown that this sample size is appropriate for detection of significant differences between the groups.

CONCLUSION

The findings of the potential influence of the associations between serum lithium trace concentrations, endocrine parameters, and cognitive functions on suicidality risk in individuals with affective disorders may help clinicians effectively plan suicide prevention and timely implement actions for treatment.

The association between triglyceride glucose index and suicidal ideation in American adults: Results from NHANES 2005 to 2018

Previous studies have shown a significant association between the triglyceride glucose index (TyG) and suicidal ideation in Korean women. However, this association has not yet been examined among American adults. This study aims to investigate the association between TyG and suicidal ideation using data from the National Health and Nutrition Examination Survey. The National Health and Nutrition Examination Survey database from 2005 to 2018 was used, including samples ≥20 years old. Suicidal ideation was assessed through questionnaires, and the TyG was derived from fasting triglyceride and glucose measurements. Weighted logistic regression models were used to analyze the relationship between the TyG and suicidal ideation. Generalized additive model curves explored the nonlinear relationship, while stratified and sensitivity analyses assessed potential interactions and the robustness of the findings. A significance level of P < .05 was considered statistically significant. A total of 15,694 participants were enrolled, of whom 3.67% participants showed suicidal ideation. The mean TyG index for participants with or without suicidal ideation was 8.82 ± 0.76, 8.65 ± 0.68, respectively (P < .001). Multivariable logistic regression showed that a higher level of TyG were associated with a higher likelihood of suicidal ideation (OR = 1.20; 95% CI, 1.05-1.38) after full adjustment. Subgroup analysis and interaction tests showed no significant correlation between gender, age, race, marital status, education, body mass index, poverty income ratio, smoking status, drinking status, diabetes, hypertension, stroke, and cancer (P > .05 for all interactions). Our findings confirm a significant and positive association between the TyG and suicidal ideation among American adults. Further large-scale prospective studies are needed to analyze the role of TyG in suicidal ideation.

Associations of composite dietary antioxidant index with suicidal ideation incidence and mortality among the U.S. population

Background

The relationship between CDAI and suicidal ideation is unclear. This study investigates the relationship between CDAI and suicidal ideation and examines the association between CDAI and all-cause mortality (ACM) or cardiovascular disease mortality (CVM) among participants with and without suicidal ideation.

Methods

Data from seven NHANES cycles (2005-2018) were analyzed using cross-sectional and prospective cohort studies. Weighted multivariable logistic regression models, restricted cubic spline (RCS) plots, and subgroup analyses explored the association between CDAI and suicidal ideation. Kaplan-Meier (KM) curves, weighted multivariable Cox proportional hazards models, and RCS assessed the relationship between CDAI and CVM or ACM.

Results

Among 30,976 participants aged over 20, 1,154 (3.72%) had suicidal ideation. Higher CDAI levels (Quartile 4) were associated with a 28% reduction in suicidal ideation compared to lower levels (Quartile 1). Over an average follow-up of 89 months, 3,267 participants (7.6%) died, including 808 (1.8%) from cardiovascular causes. Higher CDAI levels were linked to a 30, 68, and 28% reduction in ACM in the total population, those with suicidal ideation, and those without, respectively. CVM was reduced by 40% in the total population and by 41% in those without suicidal ideation.

Conclusion

CDAI is negatively associated with suicidal ideation and correlated with reduced ACM and CVM among participants with and without suicidal ideation.

Dysregulated zinc homeostasis and microadenomas in the anterior pituitary: pathological insights into suicide risk

Background

Suicide is a significant public health problem influenced by various risk factors, including dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis. Zinc (Zn), essential for pituitary function in hormone synthesis and release, has been linked to suicide, with studies noting reduced serum levels and altered brain transport mechanisms. Despite Zn's crucial role in pituitary function and its involvement in suicidal behavior, information on pituitary Zn in suicide is scarce. Tumor cells modify Zn dynamics in tissues, and a previous report suggests microadenomas in the anterior pituitary as a risk factor for suicide.

Methods

Histopathological analysis with hematoxylin-eosin stain and histochemical techniques to assess Zn homeostasis were carried out on anterior pituitary postmortem samples from 14 suicide completers and 9 non-suicidal cases.

Results

Pituitary microadenomas were identified in 35% of suicide cases and none in the non-suicidal cases. Furthermore, compartmentalized Zn (detected via dithizone reactivity), but not free Zn levels (detected via zinquin reactivity), was lower in the suicide cases compared to the non-suicidal group.

Conclusion

This is the first report of a potential association between disrupted Zn homeostasis and microadenomas in the anterior pituitary as a feature in suicide and provides critical insights for future neuroendocrine Zn-related research.

Association between exposure to organophosphorus pesticide and suicidal ideation among U.S. adults: A population-based study

OBJECTIVE

This study aims to investigate the potential link between exposure to organophosphorus pesticides (OPPs) and suicidal ideation (SI) among adults.

METHODS

This study encompassed four cycles of the National Health and Nutrition Examination Survey (NHANES), involving 5244 participants aged 20 and above. SI was assessed using the Patient Health Questionnaire-9. The levels of exposure to OPPs were estimated by analyzing concentrations of OPP metabolites in urine samples. Multivariate logistic regression models were used to explore the association between exposure to each OPP and SI. Stratified analyses and interaction tests were conducted across various groups, including pairwise combinations of gender and age, as well as body mass index, smoking status, hypertension, and diabetes. Weighted Quantile Sum (WQS) regression and Bayesian Kernel Machine Regression (BKMR) models were applied to assess the cumulative impact of exposure to the four OPPs on SI, along with their respective contributions. Additionally, the potential interactions among these four OPPs were evaluated.

RESULTS

Multivariate logistic regression revealed that only dimethylthiophosphate (DMTP) among OPPs demonstrated a statistically significant positive association with SI [OR: 1.18; 95 % CI: 1.02-1.37]. Stratified analyses indicated that the influence of OPPs on SI was particularly pronounced in young and older men. The WQS regression analysis revealed a statistically significant association between the mixed metabolites of OPPs and SI [OR = 1.10, 95 % CI: 1.04-1.16], with DMTP (weighted 0.63) contributing the most. Furthermore, the BKMR model supported a positive trend in the overall impact of these OPP metabolites on SI, displaying notable individual exposure-response relationships for DMTP (PIP: 0.77).

CONCLUSIONS

Our study suggests an association between exposure to DMTP and an increased risk of SI. Specifically, young adult males and older males appear particularly susceptible to the effects of OPP exposure.

Association between weight-adjusted waist index and risk of diabetes mellitus type 2 in United States adults and the predictive value of obesity indicators

BACKGROUND

The weight-adjusted waist index (WWI) is a quantitative anthropometric index that can be applied to evaluate obesity. This study examined the relationship between adult United States (US) residents' risk of diabetes mellitus type 2 (T2DM) and WWI.

METHODS

The NHANES (National Health and Nutrition Examination Survey) 2001-2018 provided the data for this investigation. This study used multifactorial logistic regression analysis, smoothed curve fitting, subgroup analysis, and interaction tests to assess the association between WWI and T2DM. Additionally, threshold effects were calculated using a two-stage linear regression model. The receiver operating characteristic(ROC) curves evaluated the diagnostic ability of the WWI and commonly used obesity indicators.

RESULTS

20,477 participants were enrolled in the analysis, and patients with greater levels of WWI had a higher prevalence of T2DM. WWI and T2DM have a non-linear relationship, with a positive association found on the left side of the breakpoint (WWI = 12.35) (OR = 1.82, 95%CI:1.64-2.02), whereas, on the right side, no such relationship was found (OR = 0.9, 95%CI:0.61-1.34). For every unit rise in WWI, the probability of having T2DM increased by 67% after controlling for all other variables (OR:1.67,95%CI:1.53-1.83). Based on subgroup analyses, individuals under 40 had a higher correlation between WWI and T2DM (P < 0.001).ROC analyses showed that WWI had the best discrimination and accuracy in predicting T2DM compared to other obesity indicators (WC, BMI, and Weight).

CONCLUSION

Higher WWI values had a higher prevalence of T2DM in US individuals, especially in adults under 40. WWI has the strongest ability to predict T2DM. Therefore, the importance of WWI in the early identification of T2DM in US adults should be emphasized.

Association between depression and diabetes mellitus and the impact of their comorbidity on mortality: Evidence from a nationally representative study

BACKGROUND

Depression and diabetes mellitus (DM) are major chronic noncommunicable diseases that impair one's mental and physical well-being and impose substantial burdens on the health system. Depressed individuals have an increased risk of impaired blood glucose, weight gain and dyslipidemia which could induce poorer long-term survival.

METHODS

37,040 individuals from the National Health and Nutrition Examination Survey (NHANES) were included. Depressive symptoms were assessed by the Patient Health Questionnaire (PHQ-9) and classified by the total scores as no (0-4), mild (5-9), moderate (10-14), and severe (15-27). DM was determined based on self-reported medical history, clinical test results, and medication use. Logistic and Cox regression were the main statistical models. All analyses were based on weighted data from complex sampling.

RESULTS

The prevalence of DM was higher in depressed than non-depressed individuals (21.26 % vs. 13.75 %). The adjusted odds ratio (OR) (95 % CI) of comorbid DM increased with depression severity, from 1.00 (reference) for no depression, to 1.22 (1.09,1.36) for mild, 1.62 (1.37,1.92) for moderate, and 1.52(1.28,1.82) for severe depression. Comorbidity of DM and depression significantly associated with a higher risk of all-cause mortality, with a hazard ratio (HR) (95 % CI) = 2.09 (1.64,2.66).

LIMITATIONS

Dynamic demographic and metabolic data were not available.

CONCLUSION

Depression is associated with a higher risk of DM, which may be related to biological, socioeconomic, and medication-related factors. Comorbidity of the two worsens long-term survival. Therefore, blood glucose management and prevention of DM should be emphasized in depressed patients.

Sex differences in serum trace elements and minerals levels in unmedicated patients with major depressive episode: The role of suicidal ideation

BACKGROUND

We aimed to examine the influence of gender on serum trace elements and minerals levels in depression, as well as the impact of suicidal ideation (SI) on these gender dimorphisms.

METHODS

A total of 260 unmedicated patients with a current major depressive episode were enrolled. The Beck Scale for Suicide Ideation was utilized to evaluate SI. The serum levels of copper, zinc, iron, calcium, phosphorus, and magnesium were quantified.

RESULTS

Within the non-SI (NSI) group, females exhibited higher levels of copper (p = 0.001) and phosphorus (p = 0.008), and lower levels of zinc (p = 0.022) and calcium (p = 0.008) compared to males. Conversely, no discernible gender disparities were observed in the SI group (all p > 0.05). Also, no group differences in these trace elements/minerals were observed between the SI and NSI groups (all p > 0.05). Notably, serum iron levels exhibited a significant group-by-sex interaction effect (p = 0.024). Further analysis revealed that iron levels were higher in the SI group than in the NSI group among females (p = 0.048), but lower in females than in males within the NSI group (p < 0.001). Moreover, a positive association between the fourth quantile of serum iron and SI was detected in females (odds ratio [OR] = 2.88, 95 % confidence interval [CI]: 1.08-8.11).

CONCLUSIONS

Gender effects on serum trace element/mineral levels were different in depressed patients with and without SI. Female patients were susceptible to SI when serum iron was at the upper end of normal.