Effect modification by aging on the associations of nicotine exposure with cognitive impairment among Chinese elderly.

Active and passive exposure to tobacco smoke may increase risk of cognitive decline. However, effects of enhanced the aging process on the association of urinary nicotine metabolites with cognitive impairment remain unclear. In this study, 6657 Chinese older adults completed the physical examinations and cognitive tests. We measured urinary nicotine metabolite levels, mitochondrial DNA copy number (mtDNA-CN), and relative telomere length (RTL) and analyzed effects of urinary nicotine metabolites and their interaction with mtDNA-CN or RTL on cognitive impairment by generalized linear models and qg-computation, respectively. Each 1-unit increase in urinary 3-OHCot, 3-OHCotGluc, CotGluc, or NicGluc levels corresponded to a 1.05-, 1.09-, 1.04-, and 0.90-fold increased risk of cognitive impairment. Each 1-quantile increment in the mixture level of 8 nicotine metabolites corresponded to an increment of 1.40- and 1.34-fold risk of cognitive impairment in individuals with longer RTL or low mtDNA-CN. Urinary 3-OHCotGluc and RTL or mtDNA-CN exhibited an additive effect on cognitive impairment in addition to the mixture of 8 nicotine metabolites and mtDNA-CN. The findings suggested that aging process may increase the risk of tobacco-related cognitive impairment.

Non-linear dose-response relation between urinary levels of nicotine and its metabolites and cognitive impairment among an elderly population in China.

BACKGROUND: Active smoking and exposure to environmental tobacco smoke may be related to cognitive function decline. We assessed the associations of urinary levels of nicotine and its metabolites with cognitive function. METHODS: A total of 553 elder adults at high risk of cognitive impairment and 2212 gender- and age-matched individuals at low risk of cognitive impairment were selected at a ratio of 1: 4 from the remained individuals (n = 6771) who completed the baseline survey of the Shenzhen Ageing-Related Disorder Cohort, after excluding those with either Alzheimer's disease, Parkinson's syndrome or stroke as well as those with missing data on variables (including active and passive smoking status, Mini-Cog score). Urinary levels of nicotine and its metabolites and cognitive function for all individuals were measured by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) and assessed using the Mini-Cog test, respectively. Associations of urinary levels of nicotine and its metabolites with cognitive function were analyzed by conditional logistic regression models. RESULTS: Individuals in the highest tertile of urinary OHCotGluc (OR: 1.52, 95%CI: 1.19-1.93) or NNO (OR: 1.50, 95%CI: 1.16-1.93) levels as well as in the second tertile of urinary ∑Nic level (OR: 1.43, 95%CI: 1.13-1.82) were at higher risk of cognitive impairment compared with those in the corresponding lowest tertile. Restricted cubic spline models revealed the non-linear dose-response relationships between urinary levels of OHCotGluc, NNO or ∑Nic and the risk of cognitive impairment. CONCLUSIONS: Urinary levels of OHCotGluc, NNO or ∑Nic exhibited a non-linear dose-response relationship with cognitive function in the urban elderly.

A model for phenotyping crop fractional vegetation cover using imagery from unmanned aerial vehicles.

Fractional vegetation cover (FVC) is the key trait of interest for characterizing crop growth status in crop breeding and precision management. Accurate quantification of FVC among different breeding lines, cultivars, and growth environments is challenging, especially because of the large spatiotemporal variability in complex field conditions. This study presents an ensemble modeling strategy for phenotyping crop FVC from unmanned aerial vehicle (UAV)-based multispectral images by coupling the PROSAIL model with a gap probability model (PROSAIL-GP). Seven field experiments for four main crops were conducted, and canopy images were acquired using a UAV platform equipped with RGB and multispectral cameras. The PROSAIL-GP model successfully retrieved FVC in oilseed rape (Brassica napus L.) with coefficient of determination, root mean square error (RMSE), and relative RMSE (rRMSE) of 0.79, 0.09, and 18%, respectively. The robustness of the proposed method was further examined in rice (Oryza sativa L.), wheat (Triticum aestivum L.), and cotton (Gossypium hirsutum L.), and a high accuracy of FVC retrieval was obtained, with rRMSEs of 12%, 6%, and 6%, respectively. Our findings suggest that the proposed method can efficiently retrieve crop FVC from UAV images at a high spatiotemporal domain, which should be a promising tool for precision crop breeding.

Spatiotemporal Heterogeneity of Chlorophyll Content and Fluorescence Response Within Rice (Oryza sativa L.) Canopies Under Different Nitrogen Treatments.

Accurate acquisition of plant phenotypic information has raised long-standing concerns in support of crop breeding programs. Different methods have been developed for high throughput plant phenotyping, while they mainly focused on the canopy level without considering the spatiotemporal heterogeneity at different canopy layers and growth stages. This study aims to phenotype spatiotemporal heterogeneity of chlorophyll (Chl) content and fluorescence response within rice leaves and canopies. Multipoint Chl content and high time-resolved Chl a fluorescence (ChlF) transient (OJIP transient) of rice plants were measured at different nitrogen levels and growth stages. Results showed that the Chl content within the upper leaves exhibited an increasing trend from the basal to the top portions but a decreasing pattern within the lower leaves at the most growth stages. Leaf Chl content within the rice canopy was higher in the lower leaves in the vegetative phase, while from the initial heading stage the pattern gradually reversed with the highest Chl content appearing in the upper leaves. Nitrogen supply mainly affects the occurrence time of the reverse vertical pattern. This could be the result of different nutritional demands of leaves transforming from sinks to sources, and it was further confirmed by the fall of the JI phase of OJIP transient in the vegetative phase and the rise in the reproductive phase. We further deduced that the vertical distribution of Chl content could have a defined pattern at a specific growth stage. Furthermore, the reduction of end acceptors at photosystem I (PSI) electron acceptor side per cross section (RE0/CS) was found to be a potential sensitive predictor for identifying the vertical heterogeneity of leaf Chl content. These findings provide prior knowledge on the vertical profiles of crop physiological traits, which explore the opportunity to develop more efficient plant phenotyping tools for crop breeding.

Mediation effect of platelet indices on the association of daytime nap duration with 10-year ASCVD risk.

Daytime nap is associated with the risk of atherosclerotic cardiovascular disease (ASCVD). However, the contribution of platelet to the association of daytime nap with ASCVD remains unclear. We analyzed the mediation effect of abnormal platelet indices on the association between daytime nap and 10-year ASCVD risk. The participants of this study were 2445 adults aged 30 to 74 years without ASCVD from the baseline Wuhan residents (n = 3053) of the Wuhan-Zhuhai (WHZH) Cohort Study. Participants completed the questionnaire and physical examination (including blood pressure, height, weight, and blood biochemical indicators). We assessed the association of daytime nap or nocturnal sleep duration with 10-year ASCVD risk and mediation effects of platelet indices on the associations using generalized linear models (GLM). Individuals with daytime nap duration of 30 or 60 min had a 1.37- (95%CI: 1.05, 1.78) or 1.44- (95%CI: 1.17, 1.78) fold increased risk of 10-year ASCVD compared with non-nappers. As compared with non-nappers, MPV values or MPV/PLT ratio mediated 15.29% or 6.18% of the association of daytime nap duration of 30 min with 10-year ADCVD risk as well as 19.21% or 7.61% of the association of daytime nap duration of 60 min with 10-year ADCVD risk (all p < .05). Platelet might partially contribute to increased 10-year ASCVD risk in individuals with daytime nap duration of 30 or 60 min.

Study design and baseline characteristics of Shenzhen ageing-related disorder cohort in China.

PURPOSE: The Shenzhen ageing-related disorder cohort was designed to detect the associations of lifestyle, environmental and genetic factors with major ageing-related disorders, especially neurological and mental disorders. PARTICIPANTS: The cohort was a community-dwelling prospective study of 9411 elderly adults aged 60 to 92 years from 51 community health service centres in Luohu district of Shenzhen, China. The baseline data were collected between 2017 and 2018, including demographics and socioeconomics, lifestyles, medical history, family history of major non-communicable chronic disease, environmental exposures, clinical analysis of blood and urine, clinical imaging measurements, anthropometric measures and neurological function and mental health assessments. Blood and urinary samples were collected at baseline. All participants will be followed for physiological and psychological disorders and updated lifestyle and environmental exposures every 5 years. FINDINGS TO DATE: The mean age of the participants was 67.73 years at baseline, and 42.74% were males. The prevalences of individuals with unhealthy conditions were as follows: overweight/obesity (54.38%), hypertension (58.24%), diabetes mellitus (22.30%), dyslipidaemia (75.69%), chronic bronchitis (1.45%), myocardial infarction (0.55%), coronary heart disease (5.69%), stroke (1.10%), cancer (2.18%), arthritis (5.04%), Alzheimer's disease (0.18%), Parkinson's disease (0.23%), brain injury (5.75%), cognitive impairment (5.39%) and depression status (3.28%). The mean scores for the Lawton-Brody Activities of Daily Living Scale and the Social Support Rate Scale were 14.15 and 39.54, respectively. FUTURE PLANS: 2000 new entrants from Luohu district will be recruited every year until 2028. The data collection is expected to be ended at the end of 2030. The data will be used to assess the causality of ageing-related disorders, especially neurological and mental disorders through integrating environmental, genetic and lifestyle factors. The data sets generated and/or analysed during the current study are not publicly available at this stage, but are available from the corresponding author on reasonable request.

Seasonal modification of the associations of exposure to polycyclic aromatic hydrocarbons or phthalates of cellular aging.

Exposure to polycyclic aromatic hydrocarbons (PAHs) and phthalates link to oxidative stress and inflammatory response, which exert cellular aging. However, modification effect of seasonal factor on the association of PAHs or phthalates exposure with relative telomere length (RTL) or mitochondrial DNA copy number (mtDNA-CN) has remained unclear. In this pilot study, 106 subjects were from an urban population (n = 1240) who lived in the two districts in Wuhan city, China. Participants completed physical examinations and provided 191 blood samples for RTL and mtDNA-CN analysis and 627 urine samples for monohydroxylated-PAHs (OH-PAHs) and phthalate metabolites measurements in the winter and summer seasons. We assessed the associations of urinary OH-PAHs or phthalates metabolites with RTL or mtDNA-CN by linear regression analysis and linear mixed-effect models. We found that urinary OH-PAHs were positively associated with mtDNA-CN at lag 2 day and 3-day moving average, but negatively related to RTL at lag 0, lag 1 and lag 2 day and 3-day moving average (p < 0.05). Urinary phthalate metabolites were negatively associated with mtDNA lag 0, lag 1 and lag 2 day and 3-day moving average, but positively related to RTL at lag 0 day (p < 0.05). Seasonal factor modified the association of urinary OH-PAHs with mtDNA-CN as well as urinary phthalate metabolites with RTL. In vitro experiment showed that under certain conditions, benzo[a]pyrene increased mtDNA-CN at 48 h and di (2-ethylhexyl) phthalate did RTL at 24 h in HepG2 cells. Seasonal variations in the metabolisms of PAHs or phthalates in human body may affect the relation of PAHs or phthalates exposure with cellular aging.

Long-term iron exposure causes widespread molecular alterations associated with memory impairment in mice.

Limited literature available indicates the neurotoxic effects of excessive iron, however, a deep understanding of iron neurotoxicity needs to be developed. In this study, we evaluated the toxic effects of excessive iron on learning and cognitive function in long-term iron exposure (oral, 10 mg/L, 6 months) of mice by behavioral tests including novel object recognition test, step-down passive avoidance test and Morris water maze test, and further analyzed differential expression of hippocampal proteins. The behavioral tests consistently showed that iron treatment caused cognitive defects of the mice. Proteomic analysis revealed 66 differentially expressed hippocampal proteins (30 increased and 36 decreased) in iron-treated mice as compared with the control ones. Bioinformatics analysis showed that the dysregulated proteins mainly included: synapse-associated proteins (i.e. synaptosomal-associated protein 25 (SNAP25), complexin-1 (CPLX1), vesicle-associated membrane protein 2 (VAMP2), neurochondrin (NCDN)); mitochondria-related proteins (i.e. ADP/ATP translocase 1 (SLC25A4), 14-3-3 protein zeta/delta (YWHAZ)); cytoskeleton proteins (i.e. neurofilament light polypeptide (NEFL), tubulin beta-2B chain (TUBB2B), tubulin alpha-4A chain (TUBA4A)). The findings suggest that the dysregulations of synaptic, mitochondrial, and cytoskeletal proteins may be involved in iron-triggered memory impairment. This study provides new insights into the molecular mechanisms of iron neurotoxicity.

Interaction between diet- and exercise-lifestyle and phthalates exposure on sex hormone levels.

Phthalate can affect sex hormones secretion. Exercise and diet habits affect sex hormones levels. However, interaction of phthalates exposure and diet or exercise habits with sex hormones is unclear. We enrolled 106 residents aged 11-88 years (48 males and 58 females) from two communities, Wuhan city, China during the winter of 2014 and summer of 2015. Data were collected on socio-demographic characteristics and lifestyle by a questionnaire in two seasons. Participants provided the blood and urine samples over 3 consecutive days for measuring sex hormones and urinary phthalate metabolites. We assessed the associations of urinary phthalate metabolites levels, lifestyle with hormones levels, the interaction of phthalate exposure and lifestyle with hormones levels using multivariate binary logistic regression models. High urinary mono-(2-ethyl-5-oxyhexyl) phthalate (MEOHP) levels and no exercise had an additive interaction on abnormal serum progesterone (PROG) levels in winter as well as on abnormal serum follicle-stimulating hormone (FSH) or luteinizing hormone (LH) levels in summer. High urinary MEOHP levels and red meat intake (>1 time/day) had an additive interaction with abnormal levels of serum FSH only in the winter. Phthalates exposure may confer differential susceptibility to abnormal hormones levels in individuals with no exercise or eating meat >1 time/day.

Mediating factors explaining the associations between polycyclic aromatic hydrocarbons exposure, low socioeconomic status and diabetes: A structural equation modeling approach.

Exposure to polycyclic aromatic hydrocarbons (PAHs) is linked with increased risk of diabetes, whereas socioeconomic status (SES) may contribute to the development of diabetes. However, the mechanisms underlying the relationships between them are unclear. We used structural equation modeling (SEM) to identify mediating factors in the associations of PAHs exposure, low SES with diabetes risk. Data were collected from 2751 Wuhan participants at baseline from the Wuhan-Zhuhai Cohort Study (n = 3053). They answered the questionnaires regarding socio-demographic, participated physical examinations and provided urine samples for measurements of urinary monohydroxy-polycyclic aromatic hydrocarbons (OH-PAHs) levels. SEM was used to identify the mediating factors (such as hypertension, body mass index (BMI), triglycerides (TG) and total cholesterol (TCHO)) in the associations of low SES or PAHs exposure with diabetes risk. We observed that partial effect of PAHs exposure (ß = 0.281, p = 0.034), BMI (ß = 0.182, p = 0.000), TG (ß = 0.358, p = 0.000), TCHO (ß = 0.203, p = 0.009) or hypertension (ß = 0.385, p = 0.000) on diabetes was directive. Moreover, low SES also exhibited a directive effect on PAHs exposure (ß = -0.084, p = 0.000), BMI (ß = 0.301, p = 0.000), hypertension (ß = 0.134, p = 0.003) and TG (ß = 0.087, p = 0.001). PAHs exposure directly affected TCHO levels (ß = 0.080, p = 0.002) and TG (ß = 0.076, p = 0.017). The proportion of the effect of PAHs exposure on diabetes mediated by TG and TCHO was 15.6%. The proportion of the effect of low SES on diabetes mediated by BMI, hypertension and TG was 89.1%. The results suggested that low SES increased diabetes risk, which may be partially explained by BMI, hypertension and triglycerides, and exposure to high levels of PAHs may have indirect contribution to increased risk for diabetes with dyslipidemia.

Dose-response relationships between urinary phthalate metabolites and serum thyroid hormones among waste plastic recycling workers in China.

BACKGROUND: Exposure to phthalates may affect thyroid hormone status. However, there were inconsistent observations for the associations of phthalates exposure with altered thyroid hormones. OBJECTIVES: The aim of this study was to investigate effects of urinary excretion of phthalate metabolites on the levels of thyroid hormones among workers engaged in waste plastic recycling in China. METHODS: We measured serum levels of thyroid hormones and urinary levels of eight phthalate metabolites among 317 participants (165 workers engaged in waste plastic recycling and 152 farmers), analyzed relationships between urinary phthalate metabolites and thyroid function parameters by multivariate linear regression analysis and structural equation modelling as well as assessed the dose-response relationships between them by restricted cubic spline functions. RESULTS: Maximum urinary values of eight phthalate metabolites in the occupational exposed workers were higher than the controls. Compared with the controls, the workers had higher levels of urinary monobenzyl phthalate (MBzP, 1.12 vs. 0.92 µg/g creatinine), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP, 38.84 vs. 32.55 µg/g creatinine), mono-n-octyl phthalate (MOP, .11 vs. 0.09 µg/g creatinine), serum total triiodothyronine (T3, 1.04 vs. 0.92 ng/mL) and the T3 to thyroxine (T4) ratio (1.44 vs. 1.09) (all P < 0.05). The results from structural equation modelling analysis showed that phthalates metabolites were positively associated with total T3 (ß = 0.044, SE = 0.021, P < 0.05) or the T3/T4 ratio (ß = 0.053, SE = 0.022, P < 0.05) among all participants. Among the workers, there were the non-monotonic dose-response associations between urinary monomethyl phthalate (MMP) and serum total T3 or the T3/T4 ratio, as well as between urinary monoethyl phthalate (MEP) and the T3/T4 ratio (all P < 0.05). CONCLUSIONS: The dose-response relationships between urinary phthalate metabolites and thyroid hormone parameters may be non-monotonic among the workers. Further investigations are needed to corroborate these findings.