The association between 2,4-D and serum testosterone levels: NHANES 2013-2014

The relationship between klotho, testosterone, and sexual health parameters among US adult men

BACKGROUND

Klotho is a pleotropic hormone involved in a multitude of biological processes necessary for healthy aging, and affords protection from adverse events such as cardiovascular disease, inflammation, and various cancers. Emerging evidence suggests that klotho is also an important component of biochemical pathways that regulate hormone balance, which may include those pathways governing testosterone production and men's sexual health, though data are limited and results are mixed.

OBJECTIVE

Using a cohort of 767 men from the NHANES 2015-2016 survey cycle, we set out to quantify the association between serum klotho levels and serum testosterone levels, as well as clinical markers of men's sexual health (e.g., testosterone:estrogen ratio, bioavailable testosterone, and free testosterone).

METHODS

Multivariable linear and logistic regression models while controlling for potential confounders were constructed to quantify the relationship between serum klotho and testosterone, as well as between serum klotho and odds of low testosterone (serum testosterone < 300 ng/dL).

RESULTS

A positive association was observed between serum klotho and testosterone (β = 0.18, p = 0.04). Serum klotho levels were also stratified into quartiles, and we observed statistically significant increases in testosterone for increasing quartile level of klotho using the first quartile as the reference group (β = 90.51, p = 0.001, β = 106.93, p = 0.002, β = 95.33, p = 0.03 for quartiles 2, 3, and 4, respectively). The average testosterone values by quartiles of klotho were 306.9 ng/dL, 390 ng/dL, 409.3 ng/dL, and 436.6 ng/dL, respectively. We modeled important proxies for sexual health including bioavailable and free testosterone, the testosterone:estradiol ratio, and C-reactive protein. Men in the second quartile of klotho had a significantly lower odds of an abnormal testosterone:estradiol ratio compared to the first quartile [OR = 0.18, 95% CI = (0.03, 0.98)].We observed null associations between continuous serum klotho and odds of low testosterone [OR = 1.0, 95% CI = (1.0, 1.0)], and when stratified by quartile, we observed a significant decrease in the odds of low testosterone for individuals in the second quartile of klotho compared to the first quartile [OR = 0.21, 95% CI = (0.05, 0.91)]. In addition, C-reactive protein was inversely associated with testosterone in men (β = - 4.65, p = 0.001), and inversely associated with quartiles of klotho (β = - 2.28, p = 0.04, β = - 2.22, p = 0.04, β = - 2.28, p = 0.03, for quartiles 2, 3, and 4, respectively).

CONCLUSION

Our findings support previous studies suggesting a role for klotho in testosterone levels and sexual function among men. Future studies are warranted to corroborate these findings, determine clinical significance, and elucidate potential mechanisms underlying these associations.

Associations of maternal exposure to 2,4-dichlorophenoxyacetic acid during early pregnancy with steroid hormones among one-month-old infants

BACKGROUND

Exposure to 2,4-dichlorophenoxyacetic acid (2,4-D), a widely used hormonal herbicide, may disrupt steroid hormone homeostasis. However, evidence from population-based studies is limited, especially for one-month-old infants whose steroid hormones are in a state of adjustment to extrauterine life and can be important indicators of endocrine development. This study aimed to explore the associations between maternal 2,4-D exposure during early pregnancy and infant steroid hormone levels.

METHODS

The 885 mother-infant pairs were from a birth cohort in Wuhan, China. Maternal exposure to 2,4-D was determined in urine samples from early pregnancy, and nine steroid hormones were determined in infant urine. The associations of maternal 2,4-D exposure with infant steroid hormones and their product-to-precursor ratios were estimated based on generalized linear models, and bioinformatic analysis was conducted with public databases to explore the potential mechanisms involved.

RESULTS

The detection frequency of 2,4-D was 99.32 %, and the detection frequency of steroid hormones ranged from 98.42 % to 100.00 %. After adjusting for covariates, an interquartile range increase in 2,4-D concentrations was associated with a 7.84 % decrease in 11-deoxycortisol (95 % confidence interval, CI: -14.12 %, -1.10 %), an 8.09 % decrease in corticosterone (95 % CI: -14.56 %, -1.14 %), an 8.67 % decrease in cortisol (95 % CI: -14.43 %, -2.52 %), a 13.00 % decrease in cortisone (95 % CI: -20.64 %, -4.62 %), and an 11.17 % decrease in aldosterone (95 % CI: -19.62 %, -1.83 %). Maternal 2,4-D was also associated with lower infant cortisol/17α-OH-progesterone, cortisol/pregnenolone, and aldosterone/pregnenolone ratios. In bioinformatic analysis, pathways/biological processes related to steroid hormone synthesis and secretion were enriched from target genes of 2,4-D exposure.

CONCLUSIONS

Maternal urinary 2,4-D during early pregnancy was associated with lower infant urinary 11-deoxycortisol, corticosterone, cortisol, cortisone, and aldosterone, reflecting that 2,4-D exposure may interfere with infant steroid hormone homeostasis. Further efforts are still needed to study the relevant health effects of exposure to 2,4-D, particularly for vulnerable populations.

Mechanism of 2,4-Dichlorophenoxyacetic acid-induced damage to rat testis via Fas/FasL pathway and the protective effect of Lycium barbarum polysaccharides

The herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D) is widely used to control broadleaved weeds and has been associated with male infertility. We studied the molecular mechanisms of 2,4-D induced male reproductive system damage and the protective effects of Lycium barbarum polysaccharides (LBP) using Sprague Dawley rats and TM4 cells. Treatment with 2,4-D caused architectural and functional changes in the testis, including collapsed and atrophied seminiferous tubules with reduced number of spermatozoa, scarce sperm in the epididymal duct, low levels of serum testosterone, decreased superoxide dismutase and glutathione peroxidase activity, high malondialdehyde content, and increased apoptosis in the testis and epididymis. The expression of Fas, FasL, FADD, Pro-caspase-8, Cleaved-Caspase-8, Pro-Caspase-3, and Cleaved-Caspase-3 were significantly increased in the testicular tissue of 2,4-D-treated rats. The proliferative activity of TM4 cells decreased with an increase in dose and time of 2,4-D exposure, along with enhanced Fas/Fas ligand expression and a decreased concentration of inhibin B in TM4 cell culture medium. Depletion of Fas by specific shRNA transfection reversed the effects of 2,4-D in TM4 cells, further confirming the involvement of death receptor pathway in 2,4-D-mediated apoptosis of sertoli cells. Treatment with LBP also reversed the effects of 2,4-D in testicular cells, resulting in improved cell architecture along with enhanced proliferative capacity. Moreover, in response to LBP treatment of Sertoli cells, the content of inhibin B increased, the level of reactive oxygen species and malondialdehyde decreased, the activities of superoxide dismutase and glutathione peroxidase increased, and the rate of apoptosis as well as the expression of Fas/Fas ligand signaling pathway proteins decreased.

Correlation between dietary score and depression in cancer patients: Data from the 2005–2018 National Health and Nutrition Examination Surveys

Aim

To investigate the correlation between dietary score and depression in patients with cancer.

Methods

In this cross-sectional study, data were collected from the National Health and Nutrition Examination Survey (NHANES) 2005–2018, a cross-sectional and nationally representative database, to compare 322 patients with depression to 2,868 with no depression. Mediterranean (MEDS) diet, Dietary Approaches to Stop Hypertension (DASH) diet, and the Healthy Eating Index 2015 (HEI-2015) score were calculated. Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9). Weighted logistic regression models were used to explore the relationship between dietary scores and depression in patients with cancer. Subgroup analysis was performed by sleep disorders, sex, cancer type, number of tumors, and pain relief prescription treatment.

Results

The final study sample included 3,190 adults, with 56.94% of them being women, representing 2,177 (86.51%) non-Hispanic white adults. After multivariable adjustment, the MEDS score was correlated with a reduced risk of depression in patients with cancer [odds ratio (OR): 0.90, 95% confidence interval (CI): 0.82–0.97, p = 0.010]. Moreover, the MEDS score was correlated with depression in cancer patients with sleep disorders (OR: 0.84, 95% CI: 0.76–0.93, p = 0.001), in female patients with cancer (OR: 0.83, 95% CI: 0.74–0.92, p &lt; 0.001), particularly in female cancer reproductive system patients (OR: 0.69, 95% CI: 0.57–0.82, p &lt; 0.001). MEDS score also showed a decreased risk of depression in patients with 1 cancer (OR: 0.90, 95% CI: 0.82–0.98, p = 0.019). MEDS score (OR: 0.86, 95% CI: 0.86–0.98, p = 0.024) and DASH (OR: 0.91, 95% CI: 0.84–0.98, p = 0.015) score were related to a decreased risk of depression in patients with cancer using pain relief prescription.

Conclusion

Good diet quality is significantly correlated with decreased risk of depression in patients with cancer. Aligning with the Dietary Guidelines, such as the MEDS diet, may be beneficial to the reduced risk of depression in patients with cancer.

Association of urinary metabolites of non-persistent pesticides with serum sex hormones among the US females: NHANES 2013-2014

BACKGROUND

Evidence indicated the possibility of non-persistent pesticides disrupting the homeostasis of sex hormones. However, few studies have focused on this relationship in females. We aimed to explore the relationship between non-persistent pesticide exposure and sex hormones among the US females from the National Health and Nutrition Examination Survey 2013-2014.

METHODS

A total of 790 females, including girls (6-11 years), female adolescents (12-19 years), and adult females (>19 years), were enrolled in this study. Age stratified associations of individual non-persistent pesticide metabolites and their mixtures with sex hormones were analyzed by weighted multiple linear regression and Bayesian kernel machine regression (BKMR) using spot urinary non-persistent pesticide measurement, including 2,4-dichlorophenoxyacetic acid (2,4-D), 3,5,6-trichloropyridinol (TCPY), para-nitrophenol (PNP) and 3-phenoxybenzoic acid (3-PBA), and three serum sex hormones [total testosterone (TT), estradiol (E2) and sex hormone binding globulin (SHBG)].

RESULTS

In girls, weighted multivariate linear regression indicated that both 2,4-D and PNP were negatively associated with TT, and TCPY was inversely associated with SHBG. In female adolescents, TCPY was negatively associated with TT and E2, and 3-PBA was negatively associated with SHBG; positive associations were detected both in 2,4-D with SHBG, and in PNP with TT. In adult females, a higher concentration of 3-PBA was associated with higher levels of TT. The BKMR model showed that in female adolescents, the concentrations of pesticide metabolite mixtures at or above the 55th percentile were negatively related to the levels of E2 compared with their mixtures at 50th percentile, and an inverse U-shaped exposure-response function between PNP and E2 was found.

CONCLUSIONS

Associations between the four non-persistent pesticide metabolites and serum sex hormones were identified in the US females from NHANES 2013-2014 and these associations were age dependent, especially in adolescents. Large-scale cohort studies are needed to confirm these findings and elucidate the potential biological mechanisms.

The Association Between 2, 4-Dichlorophenoxyacetic Acid and Erectile Dysfunction

Background

2, 4-dichlorophenoxyacetic acid (2,4-D) is one of the most frequently used herbicides in the world, and it has been linked with low testosterone; however, studies regarding its effect on erectile function are limited. The current study aimed to determine the association between the 2,4-D exposure and erectile dysfunction (ED) in men from the National Health and Nutrition Examination Survey (NHANES).

Methods

We analyzed data for urinary 2,4-D levels from 1,311 men (>20 years of age) in the NHANES 2001–2004. ED was assessed by a single, validated survey question. Multivariable logistic regression analysis utilizing sampling weights was performed to determine the relationship between 2,4-D exposure and ED.

Results

Multivariable logistic regression models demonstrated no statistically significant association between 2,4-D exposure and ED after full adjustment [odds ratio (OR) 1.02; 95% CI 0.77–1.36; P = 0.882)]. Men in the 2,4-D quartile 4 groups were not associated with an increased risk of ED (OR 1.13; 95% CI 0.74–1.75; P for trend = 0.481). Furthermore, the association between urinary 2,4-D level and ED was not significant in the subgroup analysis stratified by age, BMI, cardiovascular disease, hypertension, diabetes, and high cholesterol.

Conclusion

We demonstrated that there was no association between 2,4-D exposure and ED. Further studies are warranted to corroborate our results.