Association between Plasma Metal Levels and Diabetes Risk: a Case-control Study in China.

OBJECTIVE: Many metals, some of which have been classified as environmental endocrine disruptors, are used extensively in everyday consumer products and are ubiquitous in our living environment. In the present study, we aimed to explore the associations between the prevalence risk of type 2 diabetes and plasma levels of 20 trace elements as well as those of heavy metals in a Han Chinese population. METHODS: We conducted a case-control study to investigate the associations between plasma concentrations of 20 metals and diabetes in Jiangsu province. A total of 122 newly diagnosed cases of type 2 diabetes and 429 matched controls were recruited from community physical examinations in Suzhou City of Jiangsu Province. Plasma metal levels were measured by inductively-coupled plasma mass spectrometry. RESULTS: After adjusting for confounders, plasma vanadium, chromium, manganese, copper, zinc, arsenic, selenium, strontium, palladium, cadmium, cesium, and barium were associated with diabetes risk (P < 0.05). The adjusted OR increased with increasing concentration of vanadium, manganese, copper, zinc, and cesium. CONCLUSION: Many metals, including manganese, copper, zinc, arsenic, selenium, and cadmium in plasma, are associated with the morbidity of diabetes. Monitoring of environmental metal levels and further studies are urgently needed.

Occurrence, distribution and risk assessment of suspected endocrine-disrupting chemicals in surface water and suspended particulate matter of Yangtze River (Nanjing section).

The occurrence and distribution of eight selected endocrine-disrupting chemicals were investigated in samples of surface water and suspended particulate matter (SPM) in Nanjing section of Yangtze River over a year (the flow period, the wet period and the dry period). All target compounds were detected at least once in surface water with 4-tert-butylphenol (4-TBP), nonyphenol (NP) and bisphenol A (BPA) as the dominant compounds, with concentrations in the range of 225-1121ng/L, 1.4-858ng/L and 1.7-563ng/L, respectively. Except for December, all selected compounds for the other sampling times were not found in all sampling points. NP (mean concentration 69.8µg/g) and BPA (mean concentration 51.8µg/g) were also the dominant estrogens in SPM. In addition, the highest total compounds concentrations were found in December in both phases, which could be due to the low flow conditions and temperature during this season. Meanwhile, a significant positive correlation was found between the total compounds concentrations in the water phase and those in SPM phase. Risk assessment based on the calculated risk quotients (RQ) showed that low and moderate risk for the aquatic environment from presence of the target compounds at all sampling points with exception of 4-TBP and NP which might pose a high risk to aquatic organisms.

[Association of 8-hydroxyguanine glycosidase OGG1 Ser326Cys polymorphism with male infertility].

OBJECTIVE: To explore the association of 8-hydroxyguanine glycosidase OGG1 Ser326Cys polymorphism with semen quality and the risk of male infertility. METHODS: This case-control study included 620 idiopathic infertile patients and 385 normal fertile controls. We determined their genotypes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and analyzed their semen quality by computer-aided semen analysis (CASA). RESULTS: The individuals with OGG1 326 Cys/Cys showed significantly lower sperm motility and concentration ([52.1 +/- 26.7]% and (3.75 +/- 0.91) x 10(6)/ml, ln transformed value) than the Ser/Ser carriers ([59.0 +/- 21.8] % and (4.12 +/- 0.88) x 10(6)/ml, ln transformed value) (P < 0.05). The risk of male infertility increased 69% in the OGG1 326Cys allele carriers as compared with the Ser carriers (OR = 1.69, 95% CI: 1.24 -2.31). CONCLUSION: OGG1 326 Ser/Cys polymorphism might contribute to the risk of male infertility in the southern Chinese population.

[Bulky DNA adducts in human sperm correlate with semen parameters and sperm apoptosis].

OBJECTIVE: To explore the correlation of sperm polycyclic aromatic hydrocarbons (PAH)-DNA adducts with semen quality and sperm apoptosis. METHODS: We collected semen samples from 433 infertile Chinese men, detected sperm PAH-DNA adducts using immunofluorescence staining and flow cytometry, and determined the rate of sperm apoptosis by TUNEL. RESULTS: Multiple linear regression analysis showed that the level of sperm PAH-DNA adducts was correlated negatively with sperm concentration (beta = -0.632), total sperm count (beta = -0.830) and sperm motility (beta = -9.647), but positively with the rate of sperm apoptosis (beta = 0.130). CONCLUSION: Sperm PAH-DNA adducts are evidently correlated with semen quality and sperm apoptosis, and play an important role in the evaluation of male productivity.

Genetic variants in TP53 and MDM2 associated with male infertility in Chinese population.

The TP53, a transcriptional regulator and tumor suppressor, is functionally important in spermatogenesis. MDM2 is a key regulator of the p53 pathway and modulates p53 activity. Both proteins have been functionally linked to germ cell apoptosis, which may affect human infertility, but very little is known on how common polymorphisms in these genes may influence germ cell apoptosis and the risk of male infertility. Thus, this study was designed to test whether three previously described polymorphisms 72Arg>Pro (rs1042522) and the Ex2+19C>T (rs2287498) in TP53, and the 5' untranslated region (5' UTR) 309T>G (rs937283) in MDM2, are associated with idiopathic male infertility in a Chinese population. The three polymorphisms were genotyped using OpenArray assay in a hospital-based case-control study, including 580 infertile patients and 580 fertile controls. Our analyses revealed that TP53 Ex2+19C>T and MDM2 309T>G polymorphisms are associated with male infertility. Furthermore, we detected a nearly statistically significant additive interaction between TP53 rs2287498 and MDM2 rs937283 for the development of male infertility (P(interaction)=0.055). In summary, this study found preliminary evidence, demonstrating that genetic variants in genes of the TP53 pathway are risk factors for male infertility.