Di (2-Ethylhexyl) Phthalate (DEHP) Hormone Levels in Males

Di (2-Ethylhexyl) Phthalate (DEHP) Hormone Levels in MalesIntroductionDi (2-ethylhexyl) phthalate (DEHP) is one of phthalate ester and endocrine- disrupting chemical. It is utilise as m whollyeableizer in Polyvinyl chloride (PVC) plastics tubing to make PVC plastic tubing much soft and flexible. Animal data show that target organs of delineation to DEHP argon the liver, kidneys, lungs, and procreative system. DEHP may cause adverse effects of faunas generative system such as reduced fertility, diminish sperm cellatogenesis in males (Rais-Bahrami, 2004). Phthalate monoesters including mono-2-ethylhexyl phthalate (MEHP) is the DEHP metabolites. The primary targets of Phthalate monoesters toxicity ar Leydig cells (LCs) and sertoli cells (SCs). The function of LCs and SCs is spermatogenesis and testosterone production. The toxi dismisst ordain damage the LCs to decrease the secretion of testosterone, which will affect spermatogenesis and decrease the sperm count. nutrient is o ne of the sources of delineation to DEHP for public (U.S. EPA, 2013). DEHP has been detected in numerous foods such as meat, cheese, milk, eggs, cereal products and fish. There is more and more record showing that DEHP induce many adverse effects on the fruitful system such as reproductive endocrine glands included luteinizing endocrine gland (LH), follicle-stimulating endocrine (FSH) and free testosterone (Giuliana G. 2009). As DEHP outhouse cause birth defects or reproductive harm, the government of California listed DEHP as reproductive toxin in 2003 (Chemical foodstuff Reporter, 2003).In addendum to the food intake photo to DEHP, occupational and environmental are the a nonher sources of flick to DEHP (Guowei tear apart et.al., 2006). It is essential to concern whether high levels of DEHP motion-picture show would affect reproductive hormone levels in male. According to the studies of the United States Food and Drug Administration (FDA) and the National Institute of Occupational Safety and Health, they throw embed that DEHP goat cause birth defects in laboratory rodents (Chemical Market Reporter, 2003). However, notwithstanding trammel studies focus on the relationship amidst homoe reproductive hormone and DEHP movie (J. Mendiola et.al., 2011). Hence, in that location are limited evidences to come to an end a correlation amid human reproductive hormone and icon to DEHP. It is important to find out what chemicals will influence human reproductive hormone because it decides the total number of our offspring.Therefore, based on the related human studies, the effects of DEHP exposure on reproductive hormone levels in male would be discussed.MethodThe aim of the literature search was to find the friendships amongst Di (2-ethylhexyl) phthalate (DEHP) and reproductive hormone levels in male. A board research was showtime conducted by Medline (EBSCO HOST), Web of Science and ProQuest. The search term Di (2-ethylhexyl) phthalate/ DEHP AN D reproductive hormones was used and excluded the term animal.The criteria used to select the studies were as followsThe Studies were primary sources and published deep down 10 years, 2004-2014.The Studies must be human use up for adult and non animal study.The Studies should address the connecters between DEHP and reproductive hormone levels in male.The studies were in good quality, such as in high impact agentive roles of 2013.3 main studies met the above criteria for the topic examination. The impact factor on the 3 studies are 3.206 (G. goat god et.al, 2011), 3.206 (J. Mendiola et.al, 2010) and 7.029 (Guowei Pan et.al, 2006). Tot all toldy 3 main studies at the end of literature has been searched. The tercet chosen studies were Cross-sectional study since there are limited long-term studies such as cohort studies and disarrange curtailled trial (RCT) fulfilled the above criteria. forgetG. Pan et.al. (2011) carried a cross-section(a) study to find the dose-response rela tionship between dose-response relationships between cumulative phthalate exposure and reproductive hormones in human. 74 male workers occupationally overt to high levels of DEHP and 63 male construction workers as comparing assemblage matched for age and take in status. The urine and blood were equanimous from each patient on the equivalent day. The authors of study observe a earthshakingly negative correlated between probability indices (HI) and blood blood serum tightnesss of free testosterone (fT) in exposed workers (r = -0.195, p = 0.096), scarce not in unexposed workers.J. Mendiola et.al. (2011) carried a cross-sectional study to find the association between exposures to Di (2-ethylhexyl) phthalate and reproductive hormone levels in men. 425 men were partners of pregnant women who were selected to histrion in the study for Future Families (SFF). All men completed a questionnaire and received a physical examination. The questionnaire included the question about dem ographics, new-made fever, history of sexually transmitted disease, diet and as well as lifestyle factors such as relieve oneself, alcohol and caffeine consumption. The urine strain was collected within 15 min after the blood was collected. The go out was found that Free Androgen Index (FAI) was significantly associated with the meanness of DEHP metabolites in urine. However, total testosterone levels were no associated with urinary concentration of DEHP metabolites.Guowei Pan et.al. (2006) carried a cross-sectional study to find the effect of occupational exposure to high levels of phthalate esters on the balance of gonadotropin and gonadal hormones, which including LH, FSH, free testosterone (fT), and estradiol. 74 male workers at a factory producing unfoamed PVC flooring exposed to di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) as exposure concourse and compared them with haves from 63 male workers from a construction company as comparison assort matched for age and smoking status. Urine and blood samples were collected from each workers between 800 and 1100 hours on the same day, but not on the first day of the workers work week or the day after a night work shift. The authors of study observed there is significant reducing of serum fT in workers with high levels of urinary MEHP (DEHP metabolites) compared with unexposed workers. fT was negative association to MEHP (r = -0.19, p = 0.095) in the exposed group.Discussion learning DesignThe three studies are a cross-sectional study. The limitations of cross-sectional studies are it cannot establish a temporal relationship and take a hop the causal relationship between high levels of DEHP and the reproductive hormone levels in male. It simply can provide a possible risk factor for reproductive hormones for further study.The three studies both have different advantages and disadvantages. The sample size of the study of Guowei Pan et.al. (2006) and G. Pan et.al. (2011) is relative sm all. They are all less than 100 people in exposed group and comparison group. The study of J. Mendiola et.al. (2011) has relative large sample size (N=425) but it does not acquire a comparison group.The study of Guowei Pan et.al. (2006) and G. Pan et.al. (2011) only investigated the confounding effect of the influence of occupational exposure to DEHP. The study of J. Mendiola et.al. (2011) in like manner only investigated the confounding effect of the influence of environmental exposure to DEHP. They did not considered the confounding effect of the influence of food intake exposure to DEHP.Study populationRandomization is a basic and essential technique to deflect selection bias in Epidemiology Study and It can show let out association between exposure and outcome is true or not.However, the participants of three studies are not strictly random. It may cause false association between high exposure of DEHP and male reproductive hormone. In the study of Guowei Pan et.al. (2006) and G. Pan et.al. (2011), the authors wanted to compare the reproductive hormone levels between exposed group and comparison group. Therefore, they selected exposed group in a factory producing unfoamed PVC flooring and utilize DEHP as plasticizers and comparison group in a construction company. The authors can ensure the exposed group was exposed to DEHP by dermal contact and/ or through make clean inhalation in their work. A comparison group who without occupational exposure to DEHP and matched for age and smoking status to exposed group. The comparison group can help authors to exclude other factors that may influence reproductive hormone levels in male in addition to DEHP exposure.The study of J. Mendiola et.al. (2011) did not contain a comparison group. All the participants were conducted in the study for Future Families and at prenatal clinics affiliated with university hospital in five United States cities. delineation assessmentThe concentration of MEHP and reproductive hormo ne were depositd by use different methods. Both methods have advantages and limitations.Table 1 The methods used to determine the concentration of MEHPThree studies used similar method to determine the urinary concentrations of DEHP metabolites. Thus, the urinary DEHP metabolite concentration of three studies will not have significant difference.Table 2 The methods used to measure the levels of reproductive hormoneThe advantages of using radioimmunoassay are high sensitivity and highly specific. However, using radioimmunoassay method is really dangerous because it uses radiolabelled reagents. Thus, the labs require specially trained person and special endorse to handle radioactive material. The following methods have less dangerous than radioimmunoassay.chemiluminescent immunoassay (CLIA) is it has been applied broadly to the clinical diagnosis and environmental analysis. It can show the result quickly because it does not require long incubation time (Ayio, K. 2010). Also, CLIA has high specificity and relatively simple and inexpensive instrumentation (J.L.S. genus AraJO-FILHO et.al 2011). An electrochemiluminescence immunoassay (ECLIA) procedure was based on solid-phase sandwich immunoassay method. Thus, ECLIA has the brag sensitivity to determine plasma and urine sample (Xiao-yan, C. 2013).The advantages of TR-IFMA are high sensitivity due to lower background values, higher specificity as only intact molecules of FSH and LH can be measured. (Van Casteren JI et.al 2000)Result analysisThe result of J. Mendiola et.al. (2011) in addition to showing the relationship between reproductive hormone in male and the concentration of DEHP metabolite (N=425), it also found some factors such as age, Body Mass Index (BMI) and smoking etc may influence the reproductive hormone in male. Therefore, J. Mendiola et.al. (2011) had done variable analysis for reproductive hormone in male and the concentration of DEHP metabolite (N=363) to control for factors such as age, B MI and smoking states etc. It can increase the truth of the studies. Although the study did not contain a comparison group, J. Mendiola et.al. (2011) tried agreeable the factors found in the questionnaire of participants to minimize the influence of confounding factors to the data analysis.G. Pan et.al. (2011) was using post indices (HI) to show the result. The hazard index is the sum of hazard quotients. The ratio of hazard index is compared to 1.0. If the ratio is less than 1, then the systemic effects are assumed not to be of concern if the hazard quotient is greater than 1, then the systemic effects are assumed to be of concern (U.S. EPA, 2012). It is more easily to show the result and indicate whether DEHP exposure as the concerned factors for reproductive hormone to public and epidemiology.In addition to showing the relationships between serums free Testosterone in workers and the exposure to high levels of DEHP, Guowei Pan et.al. (2006) also compared the demographic charac teristics including age, marriage status, smoking and alcohol consumption and plastic material contact of exposed group (N=74), comparison group (N=63) and all the workers (N=137). Also, all the results of this study were compared to exposed group and comparison group. The result can be shown the different of reproductive hormone levels between exposed group and comparison group easily.Limitation of studiesThe data and result of the three studies were limited by using a single urine and blood/serum samples to determine the levels of DEHP and hormone. It may cause a bias in berth sampling because the result is not reflecting average hormone levels. The endogenous serum LH and FSH concentration had significant change by assessing in different time. The urine samples only reflect the recent exposure to DEHP because phthalates have short half-lives.Also, the concentration of DEHP in three studies was based on the concentration of urinary metabolites of DEHP (MEHP). Therefore, the conce ntration of DEHP may be not the real concentration of participants.ConclusionThe result of three study indicate that there are adverse effects of high levels of DEHP exposure on reproductive hormone levels in male. However, there is no clear evidence to prove a causal relationship between high levels of DEHP and the reproductive hormone levels in male because cross-sectional studies cannot reflect the causal relationship between them. richly level of DEHP can as an investigative target included in long term studies such as cohort study and randomized controlled trial of reproductive hormone levels in male. The further research is call for to prove that high levels of DEHP exposure will decrease the reproductive hormone levels in human.