Aug 2026· Substance Use & Misuse· pp.
1-9
· 0 citations· 15 references
Medicine
TL;DR
Findings suggest a potential link between nicotine exposure and depression and underscore the importance of further investigating the relationship between tobacco exposure and mental health.
Abstract
Background: Evidence on the association between objective measures of tobacco exposure and depression remains limited. This study examined the relationship between serum cotinine and depression in a nationally representative U.S. population. Methods: Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Serum cotinine was analyzed as a biomarker of nicotine exposure. Depression was defined as a Patient Health Questionnaire-9 (PHQ-9) score ≥10. Weighted logistic regression and restricted cubic spline models were used to assess linear and nonlinear associations. Subgroup and sensitivity analyses were also performed. Results: A total of 29,514 participants were included. Serum cotinine concentrations were positively associated with depression. Each one-unit increase in log-transformed cotinine was associated with higher odds of depression (OR = 1.07, 95% CI: 1.06-1.09). Compared with the lowest tertile, participants in the highest tertile had increased odds of depression (OR = 1.72, 95% CI: 1.45-2.04). Restricted cubic spline analysis indicated a linear association between log-transformed serum cotinine concentrations and depression after excluding participants with serum cotinine concentrations at the lower limit of detection. The association remained robust after additional adjustment for smoking status (OR = 1.05, 95% CI: 1.03-1.07) and subgroup analyses. Conclusions: Serum cotinine concentrations were positively associated with depression in a nationally representative U.S. population. These findings suggest a potential link between nicotine exposure and depression and underscore the importance of further investigating the relationship between tobacco exposure and mental health.
BACKGROUND
Previous studies on folate and cancer-related outcomes have reported inconsistent findings. This study examined the association between serum folate levels and mortality among cancer survivors using National Health and Nutrition Examination Survey (NHANES) 1999-2018 data.
METHODS
We included 3524 cancer survivors aged ≥20 years with available serum folate and mortality data. Because of its right-skewed distribution, serum folate was log2-transformed and analyzed as both a continuous variable and quartiles. Quartiles were generated based on the distribution of log2-transformed serum folate in the final analytic sample. Cox proportional hazards models were used to estimate associations with all-cause, cancer-specific, and cardiovascular disease (CVD) mortality, adjusting for demographic, socioeconomic, lifestyle, and clinical covariates.
RESULTS
In the fully adjusted model, log2-transformed serum folate was inversely associated with all-cause mortality during follow-up (HR = 0.89, 95% CI: 0.83-0.96, P < 0.01). Compared with Q3, participants in the lowest quartile had higher risks of all-cause mortality (HR = 1.52, 95% CI: 1.26-1.83, P < 0.001), cancer-specific mortality (HR = 2.03, 95% CI: 1.44-2.87, P < 0.001), and CVD mortality (HR = 1.60, 95% CI: 1.04-2.44, P = 0.03). The highest quartile showed a higher crude mortality proportion than Q3 and was not associated with lower mortality after full adjustment.
CONCLUSIONS
Lower serum folate levels were associated with increased mortality among cancer survivors. The findings suggest a non-linear pattern, with more favorable outcomes at intermediate folate levels and no additional benefit at higher levels. Further prospective studies are needed to confirm these associations.
Yang Qu, Juan Sun, Lu Gao et al.· Cancer Treatment and Researc...· 0 citations
Depression has been associated with cardiovascular disorders, including stroke. Although, the graded association and the role of antidepressant medication use continue to be uncertain. To examine the link between depression severity (PHQ-9) and stroke, comprising nonlinear effects and interaction with the use of antidepressant. In this study, data was analysed from NHANES 2007–2018 (n = 35,162), of whom 32,040 participants with complete data were incorporated in the final analysis. Severity of depression was evaluated by using PHQ-9. Self-reported prevalent stroke was the outcome. Odds ratios (ORs) were estimated by survey weighted logistic regression models. Nonlinear associations were evaluated by using natural cubic splines. Greater PHQ-9 scores were significantly linked with augmented odds of self-reported stroke (OR 1.07, 95% CI 1.05–1.09, p < 0.001). Use of antidepressant was independently linked with self-reported stroke (OR 1.74, 95% CI 1.27–2.39). No statistically significant interaction was observed between PHQ-9 score and antidepressant use (p = 0.061). Natural cubic spline analysis demonstrated a significant overall association between PHQ-9 score and self-reported stroke, with no statistically significant evidence of nonlinearity. Both hypertension and diabetes were strong independent predictors of self-reported stroke, while higher income (PIR) was protective. Severity of depression was independently associated with higher odds of self-reported stroke. These findings highlight an association between depression severity and self-reported stroke history.
Himanshu Sharma, K. Reeta· Discover Public Health· 0 citations
Higher SIRI levels were associated with higher odds of clinically relevant depressive symptoms among adults from the National Health and Nutrition Examination Survey 2005 to 2016, with a nonlinear dose-response pattern.
Qiongqiong Zhan, Yu Wu, Jiaojiao Sun et al.· Medicine· 0 citations
Depressive symptoms represent a prevalent and burdensome comorbidity among adults with a history of cancer, yet the relationship between routinely available inflammatory markers and depression in this population remains insufficiently characterized, particularly regarding potential nonlinear patterns. This cross-sectional study analyzed data from 4,175 adults with a history of cancer in the National Health and Nutrition Examination Survey (NHANES) to examine the association between neutrophil percentage and clinically significant depressive symptoms, defined as a Patient Health Questionnaire-9 (PHQ-9) score ≥ 10, using multivariable logistic regression, restricted cubic spline (RCS) regression, and piecewise threshold analyses with sequential covariate adjustment. When neutrophil percentage was categorized into quartiles, participants in the third quartile (Q3) exhibited significantly higher odds of depressive symptoms compared with the lowest quartile (adjusted OR = 1.91, 95% CI: 1.11–3.29). RCS regression revealed a significant nonlinear association, with inflection points identified at 50.15% and 64.42%. Within this intermediate range, each 1% increment in neutrophil percentage was associated with a 16.4% increase in depression odds (OR = 1.164, 95% CI: 1.090–1.242, P < 0.001), whereas no significant associations were observed outside this interval. These findings indicate that in adults with a history of cancer, the segmented neutrophil percentage is non-linearly associated with depressive symptoms, and the higher odds of clinically significant depressive symptoms is confined to a specific intermediate range. The identified inflection point should be regarded as an exploratory, study-derived threshold for stratification, and further prospective validation is required.
BACKGROUND
Klotho, an anti-aging protein with anti-inflammatory and antioxidant properties, plays a role in asthma pathophysiology. This study investigated whether serum Klotho concentrations are associated with asthma prevalence among middle-aged and elderly Americans.
METHODS
This cross-sectional study included 12,442 participants from the National Health and Nutrition Examination Survey (2007-2016). Serum Klotho was measured by ELISA and asthma was self-reported. Weighted multivariable logistic regression adjusting for demographic and clinical confounders was performed to evaluate associations. Smoothed curve fitting assessed potential nonlinear relationships.
RESULTS
After adjustment for confounding variables, a significant inverse association was found between serum Klotho concentration and asthma incidence. Specifically, each unit increase in log-transformed Klotho was associated with a 48% reduction in asthma risk (odds ratio: 0.52; 95% confidence interval: 0.38-0.69). Participants in the lowest Klotho quartile had a higher prevalence of asthma than those in the highest quartile (odds ratio, 0.58; 95% confidence interval: 0.45-0.76). Subgroup analyses revealed associations between a history of cardiovascular disease and drinking status. Notably, smoothing curve analysis did not reveal a nonlinear association between Klotho levels and asthma prevalence.
CONCLUSIONS
Lower serum Klotho levels are significantly associated with higher asthma prevalence in middle-aged and elderly Americans. Klotho may serve as a potential biomarker for asthma risk assessment, though prospective cohort studies are needed to establish causality.
Jie Wang, Yunzhe Li, Hailong Zhong et al.· Journal of Asthma· 0 citations
This study examined the association between serum cotinine, an objective biomarker of tobacco exposure, and prostate-related clinical endpoints in men participating in the National Health and Nutrition Examination Survey. Cross-sectional data from five NHANES cycles between 2001 and 2010 were analyzed. Eligible participants were men with available serum cotinine, total prostate-specific antigen (PSA), and free PSA measurements. The free-to-total PSA ratio was calculated from measured free and total PSA. Multivariable linear regression was used to examine associations of serum cotinine with total PSA and PSA ratio. To address the concern that a single cotinine measurement mainly reflects recent exposure, cumulative smoking exposure was estimated from self-reported cigarette history as pack-years. Correlation analyses and sensitivity models were then performed to compare serum cotinine with pack-years. The final analytic population included 7,174 men. Pack-years were available for 6,132 participants, including 3,433 current or former smokers. Serum cotinine was positively but modestly correlated with pack-years (Pearson r = 0.209; Spearman r = 0.270), and the correlation between log-transformed cotinine and log-transformed pack-years was stronger (Pearson r = 0.337). In fully adjusted models, serum cotinine was not associated with total PSA (β=-0.00006, 95% CI: -0.00054 to 0.00042; P = 0.801), but was independently associated with a lower PSA ratio (β=-0.00494, 95% CI: -0.00705 to -0.00283; P = 0.000005). Pack-years was not significantly associated with PSA ratio after adjustment (β=-0.00750, 95% CI: -0.02010 to 0.00509; P = 0.243). Serum cotinine was associated with a lower free-to-total PSA ratio in this nationally representative sample. The pack-years analysis supported partial agreement between recent biomarker exposure and cumulative smoking history, but also showed that cotinine and pack-years capture different exposure dimensions. Longitudinal studies with repeated exposure assessment and detailed prostate disease history are warranted.
