Tonghua Zang

Serum DDT, age at menarche, and abnormal menstrual cycle length

Background: Although dichlorodiphenyl trichloroethane (DDT) exposure is known to affect human endocrine function, few previous studies have investigated the effects of DDT exposure on age at menarche or menstrual cycle length. Methods: A cross sectional study was conducted to study the effects of DDT exposure on age at menarche and menstrual cycle length among 466 newly married, nulliparous female Chinese textile workers aged 20–34 years enrolled between 1996 and 1998. Serum was analysed for DDT and its major metabolites. Multivariate linear regression was used to estimate DDT exposure effects on age at menarche and multivariate logistic regression was used to estimate DDT exposure effects on odds of experiencing short or long cycles. Results: Relative to those in the lowest DDT quartile, the adjusted mean age at menarche was younger in those in the fourth quartile (−1.11 years). Modeled as a continuous variable, a 10 ng/g increase in serum DDT concentration was associated with an adjusted reduction in age at menarche of 0.20 years. Relative to those in the lowest DDT quartile, odds of any short cycle (<21 days) in the previous year were higher for those in the fourth quartile (odds ratio = 2.78; 95% CI 1.07 to 7.14). There were no associations between serum DDT concentrations and odds of experiencing a long cycle (>40 days). Conclusion: Results suggest that DDT exposure was associated with earlier age at menarche and increased risk of experiencing a shortened menstrual cycle.

Stress and dysmenorrhoea: a population based prospective study.

Background: Dysmenorrhoea is the most common gynaecological disorder in women of reproductive age. Despite the association between stress and pregnancy outcomes, few studies have examined the possible link between stress and dysmenorrhoea. Aims and Methods: Using a population based cohort of Chinese women, the independent effect of women’s perceived stress in the preceding menstrual cycle on the incidence of dysmenorrhoea in the subsequent cycle was investigated prospectively. The analysis included 1160 prospectively observed menstrual cycles from 388 healthy, nulliparous, newly married women who intended to conceive. The perception of stress and the occurrence of dysmenorrhoea in each menstrual cycle were determined from daily diaries recorded by the women. Results: After adjustment for important covariates, the risk of dysmenorrhoea was more than twice as great among women with high stress compared to those with low stress in the preceding cycle (OR = 2.4; 95% CI 1.4 to 4.3). The risk of dysmenorrhoea was greatest among women with both high stress and a history of dysmenorrhoea compared to women with low stress and no history of dysmenorrhoea (OR = 10.4, 95% CI 4.9 to 22.3). Stress in the follicular phase of the preceding cycles had a stronger association with dysmenorrhoea than stress in the luteal phase of the preceding cycles. Conclusion: This study shows a significant association between stress and the incidence of dysmenorrhoea, which is even stronger among women with a history of dysmenorrhoea.

Prevalence of metabolic syndrome and its relation to body composition in a Chinese rural population

Objective: To investigate the prevalence of metabolic syndrome (MetS) with three different working definitions in a rural Chinese population and to examine its relation to body composition.

Association of Brain-Derived Neurotrophic Factor Genetic Val66Met Polymorphism with Severity of Depression, Efficacy of Fluoxetine and Its Side Effects in Chinese Major Depressive Patients

Background: Preclinical studies have shown that brain-derived neurotrophic factor (BDNF) may be involved in antidepressant action, and the BDNF gene has been suggested to be involved in the pharmacological treatment of major depressive disorder (MDD). In this study, the relationship between BDNF Val66Met polymorphism (Single Nucleotide Polymorphism Database ID: rs6265) and severity of depression, efficacy of fluoxetine and its side effects was tested in Chinese patients with MDD. Methods: Patients with MDD took the oral selective serotonin reuptake inhibitor (SSRI) fluoxetine (20 mg/day) for 6 weeks. Its clinical efficacy and side effects were measured by the 17-item Hamilton Rating Scale for Depression and the Treatment-Emergent Symptoms Scale (TESS), respectively. The patients were genotyped for Val66Met polymorphism of the BDNF gene. Results: In the multivariate regression analysis, there was no significant association between severity of depression and BDNF Val66Met polymorphism. There was no association between efficacy of fluoxetine and BDNF Val66Met polymorphism, but there was a marginal positive suggestion that heterozygous patients tended to have a better remission with fluoxetine in comparison with homozygous analogs. Insomnia and decreased sexual desire, side effects of fluoxetine, may have an association with the BDNF Val66Met polymorphism, and Met allele carriers showed a lower incidence of these side effects. Conclusions: These results indicate that there was a lack of association between severity of depression and BDNF Val66Met polymorphism in Chinese patients with MDD. The BDNF Val66Met polymorphism may play a major role in the efficacy and side effects of SSRI (fluoxetine) in Chinese patients with MDD.

Familial Aggregation of Metabolic Syndrome and Its Components in a Large Chinese Population

Objective: To investigate the familial aggregation of metabolic syndrome (MetS) and its components in the Chinese.

Association of BDNF Val66Met Polymorphism with both baseline HRQOL scores and improvement in HRQOL scores in Chinese major depressive patients treated with fluoxetine

To explore the association of brain‐derived neurotrophic‐factor (BDNF) Val66Met polymorphism with both baseline health related quality of life (HRQOL) scores and improvement in HRQOL scores in Chinese major depressive patients treated with fluoxetine.

Familial aggregation and heritability of electrocardiographic intervals and heart rate in a rural Chinese population.

Background: Estimates of the genetic influences on electrocardiographic (ECG) parameters are inconsistent in previous reports, and no such studies have been performed in China. So we estimated genetic contributions to PR and QRS intervals and the rate‐adjusted QT interval (Bazetts QTc) in a Chinese rural population.

Genetic and Environmental Influences on Serum Lipid Tracking: A Population-Based, Longitudinal Chinese Twin Study

We conducted cross-sectional and longitudinal twin analysis to explore genetic and environmental contribution to serum lipid tracking during childhood and adolescence. The study sample was part of a population-based twin cohort that was recruited in the rural areas of the Anhui Province of China. The baseline recruitment of twins was carried out from 1998 through 2000 and the follow-up from 2005 through 2007. Serum lipids showed significant tracking during childhood and adolescence. Participants with lipids at the highest tertile at the baseline tended to remain high at follow-up across ages and Tanner stages, whereas subjects with lipids at the lowest tertile at the baseline tended to remain low at follow-up. Using twin modeling, we showed that genetic and environmental factors contributed to individual variations in lipid levels and tracking from the baseline to the follow-up visit. The estimated tracking correlations for total cholesterol, triglyceride, and LDL cholesterol were in the range of 0.25–0.53 and were predominantly influenced by genetic factors. In contrast, the phenotypic tracking of HDL cholesterol was influenced by both genetic and environmental factors. Our study underscores the importance of considering both environmental and genetic factors in studying the etiology of dyslipidemia.

Familial aggregation of bone mineral density and bone mineral content in a Chinese population.

Familial aggregation of bone mineral density (BMD) and bone mineral content (BMC) has been shown in twin and familial studies, but most sample sizes were small. We here report a large familial aggregation study in a Chinese population. A total of 13,973 siblings aged 25–64 years from 3,882 families were enrolled from Anhui, China. We assessed the whole-body, hip and lumbar spine BMD and BMC by dual-energy X-ray absorptiometry (DXA). Intra-class correlation coefficients of BMD and BMC between siblings varied among different skeletal sites and between different age groups of male sib-pairs and premenopausal and postmenopausal female sib-pairs, with a range of 0.228 to 0.397. The sibling recurrence risk ratio (λs) of osteoporosis was 2.6 in our population. We also evaluated the joint association of the BMD values of the first siblings and the second siblings with the risk of low BMD (defined as less than the 10th percentile of the same group population) of their younger siblings. If both the first and second siblings’ BMDs were in the lowest tertile, the odd ratios (ORs) of low BMD in their subsequent siblings were 8.32 [95% confidence interval (CI) 5.59–12.39)], 8.71 (95% CI 5.74–13.22) and 5.90 (95% CI 3.57–9.76) for total body, total hip and lumbar spine, respectively. This study demonstrates a significant familial aggregation of BMD and BMC in a large sample of rural Chinese adults.

Association between serum total homocysteine and arterial stiffness in adults: a community-based study

Both increased arterial stiffness and higher total homocysteine (tHcy) are associated with an elevated risk for cardiovascular disease. However, the relationship between tHcy and arterial stiffness is still inconclusive. The authors aimed to test the relationship of tHcy with carotid‐femoral pulse wave velocity (cfPWV) and examine the possible effect modifiers in adults. A study was conducted from July to September 2016 in Jiangsu Province, China. A total of 16 644 participants were enrolled in the final analysis. Increased arterial stiffness is defined as a cfPWV ≥10 m/s. Overall, there was a positive association between tHcy and cfPWV levels (per 5‐μmol/L tHcy increase: β = 0.10; 95% confidence interval [CI], 0.08–0.13) and increased arterial stiffness (per 5‐μmol/L tHcy increase: odds ratio, 1.11; 95% CI, 1.07–1.14). Compared with participants with tHcy <10 μmol/L, the significantly higher cfPWV levels were observed in those with tHcy ≥15 μmol/L (β = 0.37; 95% CI, 0.28–0.47). Accordingly, a higher prevalence of increased arterial stiffness was found in patients with tHcy10 to <15 μmol/L (odds ratio, 1.18; 95% CI, 1.05–1.33) and tHcy ≥15 μmol/L (odds ratio, 1.50; 95% CI, 1.32–1.71) as compared with participants with tHcy <10 μmol/L. Furthermore, the stronger positive association was found in participants who were older (≥60 years, P for interaction = .008), had low body mass index (<25 kg/m2, P for interaction = .026), high systolic blood pressure levels (≥145 mm Hg [median], P for interaction = .048), or diabetes mellitus (P for interaction = .045). The present study demonstrated that serum tHcy concentrations were positively associated with cfPWV and the prevalence of increased arterial stiffness. These results suggest that the cardiovascular effects of tHcy may partly be mediated through arterial stiffness.