Simultaneous determination of serum tryptophan metabolites in an older Chinese population.

Tryptophan (TRP) and its metabolites exhibit significant biological effects and are strongly associated with age-related disease and mortality. However, reports on quantitatively analyzing these metabolites in older individuals are not available. We used ultra-high-performance liquid chromatography-tandem mass spectrometry to optimize and validate a method for isotope dilution analysis of TRP metabolites in older individuals. The targeted analytes are TRP, serotonin or 5-hydroxytryptamine, kynurenine, kynurenic acid, xanthurenic acid, indole-3-acetic acid, indole-3-propionic acid, and tryptamine. The serum sample was purified using solid-phase extraction and was separated on a Waters HSS T3 column (100 mm × 2.1 mm, 1.8 µm). The analytes were detected in the multiple reaction monitoring mode under positive ionization. TRP was confirmed and measured after being diluted 100 times. This method exhibited satisfactory linearity (r > 0.99). The intrabatch and interbatch accuracies (85.7-114%) and precisions (<15%) were acceptable. The standard-normalized matrix effects ranged from 51.6 to 145%. This method was successfully applied to a cohort of 1021 older Chinese individuals, and this study may enable further understanding of the metabolic phenotypes associated with TRP in other populations.

Chronic inflammation as a potential mediator between phthalate exposure and depressive symptoms.

BACKGROUND: A few studies have reported phthalate exposure as a risk factor for depressive symptoms, but the results have been inconsistent. Whether chronic inflammation mediates the relationship between phthalates (PAEs) and depressive symptoms remains unclear. In this study, we establish mediating models of inflammatory factors and explore the mediating role of chronic inflammation in the association between PAEs exposure and depressive symptoms. METHODS: The sample included 989 participants from the Study on Health and Environment of the Elderly in Lu'an City, Anhui Province. Geriatric depression scale (GDS-30) was used to screen depressive symptoms of the elderly. The levels of seven kinds of PAEs in urine samples and four inflammatory factors in serum of the elderly were measured. To establish the mediating effect of inflammatory factors to explore the potential effect of PAEs exposure on the increased odds of depressive symptoms. RESULTS: Adjusted for multiple variables, the highest tertiles of Mono (2-ethylhexyl) phthalate (MEHP) (95%CI = 1.051-2.112), Mono benzyl phthalate (MBzP) (95%CI = 1.016-2.082) and Mono butyl phthalate (MBP) (95%CI = 1.102-2.262) were positively correlated with depressive symptoms. The mediating effect of IL-6 and generalized inflammation factor between MEHP exposure and depressive symptoms were 15.96% (95%CI=0.0288-0.1971) and 14.25% (95%CI = 0.0167-0.1899). CONCLUSIONS: High levels of MEHP, MBzP and MBP increased the odds of depressive symptoms in the elderly, and chronic inflammation had a partial mediating effect on the increased odds of depressive symptoms due to MEHP exposure.

Urban-rural differences in the effect of empty-nest on mental health and behaviors of Chinese older population.

This study aimed to comprehensively analyze the effect of empty-nest on mental health and behaviors of the older population and explore the urban-rural differences. Data from the Cohort of Older People Health and Environment Controllable Factors were used, including 1071 older people aged 60 or over from a rural and an urban. Mental health, daily life behaviors, chronic physical diseases, and activities of daily living were evaluated. Logistic regression was used. The prevalence of empty-nest in older people was 55.0% in urban and 58.7% in rural. The empty-nest older people in urban were more likely to participate in physical exercise (OR[95%CI]: 1.55[1.03-2.31]), while the empty-nest older people in rural had lower rate of smoking (OR[95%CI]: 0.46[0.28-0.76]) and religious belief (OR[95%CI]: 1.61[1.01-2.58]), and higher prevalence of depression (OR[95%CI]: 1.55[1.03-2.35]) and higher level of total cholesterol (OR[95%CI]: 1.51[1.03-2.19]) compared with the non-empty-nest older people. In conclusion, the prevalence of empty-nest in older people was high both in rural and urban in China. Empty-nest exerts greater influences on the older people in rural than in urban, which should be given more attention, especially the depression and high total cholesterol.

Levels and determinants of urinary phthalate metabolites in Chinese community-dwelling older adults.

BACKGROUND: Biomonitoring studies have demonstrated extensive exposure of infants, children, and pregnant women to phthalates, but data on phthalate exposure and their determinants in Chinese older adults remain insufficient. This study aims to assess urinary phthalate metabolite levels, individual and cumulative exposure risk, and their determinants in Chinese community-dwelling older adults. METHODS: A total of 987 individuals aged 60 years or over were included in this study. The urinary levels of seven phthalate metabolites were measured using high-performance liquid chromatography-tandem mass spectrometry. The estimated daily intake (EDI), hazard quotient (HQ), and hazard index (HI) of phthalates were calculated based on urinary metabolite levels. The associations between phthalate metabolite levels and potential determinants were examined using multiple linear regressions. RESULTS: Detection rates of seven phthalate metabolites from the study population ranged from 63.83% to 99.39%. The highest median concentration was 43.64 µg/L (42.59 µg/g creatinine) for mono-butyl phthalate (MBP). The highest median EDI was 1.55 µg/kg-bw/day for diethyl phthalate (DBP). Nearly 5% of participants had high HI values exceeding 1, mainly attributed to DBP and di-2-ethylhexyl phthalate (DEHP). Furthermore, we found that females, higher body mass index (BMI), smoking, having two or more chronic diseases, and vegetable-based diets were significantly associated with higher levels of parts of phthalate metabolites. More interestingly, higher urine levels of high-molecular-weight (HMW) phthalate metabolites and lower urine levels of low-molecular-weight (LMW) phthalate metabolites were found in rural older adults than in urban older adults. CONCLUSIONS: Chinese community-dwelling older adults are extensively exposed to phthalates, especially to DBP and DEHP. More attention should be paid to urban-rural differences in exposure to HMW and LMW phthalates and to phthalate exposure among older adults with overweight/obesity, females, and individuals who are current heavy smokers, have two or more chronic diseases, and consume vegetable-based diets.

The association of marital status with cognitive function and the role of gender in Chinese community-dwelling older adults: a cross-sectional study.

BACKGROUND: Evidence of the association between marital status and cognitive function in Chinese older adults is limited. AIMS: To examine the relationship between marital status and cognitive function and to explore the role of gender amongst older adults from three Chinese communities. METHODS: A total of 1376 participants aged 60 years or over were included in this cross-sectional study. Cognitive function was assessed using the Chinese version of the mini-mental state examination (MMSE). Marital status and other variables were collected using a standardized questionnaire. Multiple linear regression models were used to examine associations between marital statuses and cognitive function amongst the target population. The moderating role of gender in these potential associations has also been explored. RESULTS: In univariate linear regression models, compared to being married, both being widowed (ß [95% CI]: -1.46[-2.78 to - 0.13]) and being single (ß [95% CI]: - 4.88[-6.43 to - 3.38]) were associated with lower MMSE scores. After adjustment for confounding factors, the significant association of being widowed with MMSE scores disappeared (ß [95% CI: - 0.08[- 1.04 to 0.86]), but the association of being single with MMSE scores still existed (ß [95% CI]: - 1.87[- 3.17 to - 0.58]). Furthermore, the association of being single with MMSE scores was statistically significant in men (ß [95% CI]: - 5.25[- 7.17 to - 3.33]) but not in women (ß [95% CI: 0.88[- 0.87 to 2.64]). DISCUSSION AND CONCLUSIONS: Being single was associated with poorer cognitive function compared with their married counterparts in older Chinese men but not in women. More preventive measurements should be implemented for single men to reduce or delay cognitive decline. This is particularly important in the context of an aging population in China.

The levels of phthalate exposure and associations with obesity in an elderly population in China.

BACKGROUND: Few epidemiological studies on the correlation between phthalate exposure and elderly obesity in China are available. The purpose of the present study is to assess phthalate exposure levels and explore the connections between exposure to phthalates and obesity using a sample of Chinese community-dwelling elderly individuals. METHODS: Data were acquired from the baseline survey of the Cohort of Health of Elderly and Controllable Factors of Environment, which was established in Lu'an, Anhui province, China, from June to September in 2016. Urine samples were obtained to analyze the concentrations of seven phthalate metabolites, utilizing a high-performance liquid chromatography-tandem mass spectrometry method. General obesity was determined based on body mass index, and abdominal obesity based on waist circumference. Binary logistic regression models were utilized to analyze the associations of creatinine-corrected phthalate metabolite concentrations (categorized into quartiles) with general and abdominal obesity in elderly people. Moreover, a stratified analysis was performed to explore the difference between genders. RESULTS: Of 942 elderly individuals, 52.9% were defined as generally obese and 75.5% as abdominally obese. The detection rates of seven phthalate metabolites ranged from 90.07% to 99.80%. The highest median concentration was 44.08 µg/l (for MBP), and the lowest was 0.55 µg/l (for MEHP). The level of exposure to LMW(low-molecular-weight) PAEs is higher than that to HMW(high-molecular-weight) PAEs. After adjustment for confounding variables, we found a significant association between urinary MEOHP (mono-2-ethyl-5-oxohexyl phthalate), MEHP (mono-2-ethylhexyl phthalate), MBP (mono-n-butyl phthalate), MEP (mono-ethyl phthalate), and MMP (mono-methyl phthalate) levels and general obesity. MBP levels were also correlated with abdominal obesity. When stratified by gender, higher urinary levels of MEOHP, MBP, MEP, and MMP were associated with general obesity in males, whereas MBP and MMP levels were eminently correlated with general obesity in females. Higher urinary MBP levels were associated with increased abdominal obesity rates in males, but not in females. CONCLUSIONS: In conclusion, higher phthalate metabolite concentrations were correlated with obesity in the elderly. Moreover, a gender difference was observed in these associations.

Persistently Upregulated Hippocampal mTOR Signals Mediated by Fecal SCFAs Impair Memory in Male Pups with SMM Exposure in Utero.

OBJECTIVE: To investigate the molecular mechanisms of the adverse effects of exposure to sulfamonomethoxin (SMM) in pregnancy on the neurobehavioral development of male offspring. METHODS: Pregnant mice were randomly divided into four groups: control- (normal saline), low- [10 mg/(kg•day)], middle- [50 mg/(kg•day)], and high-dose [200 mg/(kg•day)] groups, which received SMM by gavage daily during gestational days 1-18. We measured the levels of short-chain fatty acids (SCFAs) in feces from dams and male pups. Furthermore, we analyzed the mRNA and protein levels of genes involved in the mammalian target of rapamycin (mTOR) pathway in the hippocampus of male pups by RT-PCR or Western blotting. RESULTS: Fecal SCFA concentrations were significantly decreased in dams. Moreover, the production of individual fecal SCFAs was unbalanced, with a tendency for an increased level of total fecal SCFAs in male pups on postnatal day (PND) 22 and 56. Furthermore, the phosphatidylinositol 3-kinase (PI3k)/protein kinase B (AKT)/mTOR or mTOR/ribosomal protein S6 kinase 1 (S6K1)/4EBP1 signaling pathway was continuously upregulated until PND 56 in male offspring. In addition, the expression of Sepiapterin Reductase (SPR), a potential target of mTOR, was inhibited. CONCLUSION: In utero exposure to SMM, persistent upregulation of the hippocampal mTOR pathway related to dysfunction of the gut (SCFA)-brain axis may contribute to cognitive deficits in male offspring.

Perinatal sulfamonomethoxine exposure influences physiological and behavioral responses and the brain mTOR pathway in mouse offspring.

Sulfamonomethoxine (SMM) is widely used in the veterinary field in China. Although some clinical surveys have revealed that sulfonamide antibiotics cause adverse nervous system symptoms, the related mechanisms of maternal SMM exposure on the neurobehavioral development of offspring remain unclear. Here, we investigated the effects of perinatal SMM exposure on the physiological and behavioral responses of pubertal offspring mice and the underlying mechanisms. We randomly allocated pregnant mice into the groups treated with SMM at different doses and the saline-treated groups. Maternal mice were orally administered SMM daily from gestational day 1 to postpartum day 21. On postnatal day (PND) 22, the parameters of growth, endocrine hormones, and brain amino acid composition were assessed, as well as the brain transcript levels of key genes involved in the mammalian target of rapamycin (mTOR) signaling pathway. From PND 50 to 55, a battery of behavioral tests relevant to anxiety and memory were then administered. Analysis of the results indicated that the pups, particularly the pubertal female offspring, showed anxiety-like behavior. Moreover, the pubertal offspring showed cognitive impairments and fat accumulation. Furthermore, the relative mRNA expression of genes involved in the mTOR signaling pathway in females on PND 22 was elevated, whereas the expression of N-methyl-d-aspartate receptor 2B (NR2B) was reduced. Together, the results showed that perinatal SMM exposure perturbs neuroendocrine functions, and further alters gene expression in the mTOR pathway and NR2B gene expression early in life, which may contribute to brain dysfunction in pubertal life.

Gender difference in the association of hyperuricemia with hypertension in a middle-aged Chinese population.

In this study, we report the relationship between hyperuricemia and hypertension in a middle-aged Chinese population, emphasizing the difference of gender. The cross-sectional study was conducted among 1776 adults aged 45-60 years, who participated in the Hefei Nutrition and Health Study (2012). Hyperuricemia was defined as serum uric acid (SUA)> 420 µmol/l for men, and > 360 µmol/l for women. Hypertension was defined as systolic blood pressure (SBP) ≥ 140 mmHg or diastolic blood pressure (DBP) ≥ 90 mmHg. Anthropometric measurements and biochemical data were collected using standardized procedures. Multivariate logistic regression analysis was performed to determine the relationship between hyperuricemia and hypertension with adjustment of potential confounding factors. Body mass index (BMI), waist circumference (WC), SBP, DBP, fasting glucose, SUA and the prevalence of hyperuricemia and hypertension were significantly higher in male than in female (p < 0.001). Females had significantly higher levels of triglycerides (TG) and high-density lipoprotein (HDL)-cholesterol (5.23 ± 0.87 vs 5.12 ± 1.01, p < 0.05, 1.50 ± 0.37 vs 1.28 ± 0.41, respectively.) than males. Simple correlation analysis showed that SUA was positively associated with WC and TG. In addition, after adjusting for potential confounders, hyperuricemia was associated with increased risk of hypertension in both males and females, with odds ratios (95% CI) of 1.680 (1.110-2.543) and 1.065 (1.012-1.118), respectively. Conclusions: The association of hyperuricemia with hypertension was stronger in males than in females, and middle-aged men with hyperuricemia had greater association with hypertension. Our findings remain to be confirmed in future prospective studies.

Dietary patterns are associated with body mass index and bone mineral density in Chinese freshmen.

OBJECTIVE: Our objective was to examine associations between dietary patterns and body mass index (BMI) and bone mineral density (BMD) in Chinese freshmen. METHODS: A cross-sectional study was done in 1319 college freshmen (aged 18.1 ± 1.2 years old). Diet was assessed by using a validated self-administrated food-frequency questionnaire. Blood pressure, weight, height, waist circumference, and hip circumference were measured and bone measurements were done using Quantitative Ultrasound System. RESULTS: Four dietary patterns were identified by factor analysis: Western food, animal protein, calcium food, and Chinese traditional patterns. The prevalence of overweight/obesity and osteopenia/osteoporosis were 8.2% (108/1319) and 28.1% (371/1319). The highest tertile of Western food pattern scores had greater odds of overweight/obesity (highest vs. lowest tertile, odds ratio [OR] = 2.00, 95% confidence interval [CI], 1.24-3.22), and the highest tertile of Chinese traditional pattern scores had lower risk of overweight/obesity (highest vs. lowest tertile, OR = 0.65, 95% CI, 0.53-0.80) in an adjusted model. The calcium food pattern and Chinese traditional pattern were negatively associated with the risk of osteopenia/osteoporosis (highest vs. lowest tertile, OR = 0.59, 95% CI, 0.41-0.87; OR = 0.78, 95% CI, 0.55-0.89) after adjusting for confounders. CONCLUSION: These findings suggested that there was a positive correlation between Chinese traditional dietary pattern and healthy BMI and BMD and that this same association existed between calcium food pattern and BMD in Chinese freshmen. In contrast, the Western-style diet was negatively correlated with healthy BMI in Chinese freshmen.