体重指数降低的男性易发生不育

旧金山国立环境医疗卫生生物科学分析方法院完成的一项分析方法发掘出，与正常人体形的女性相较，体形百分比缩减的女性子代可能更多。

Markku Sallmen退职于罗马尼亚业余球队医疗卫生分析方法院。他知道：“数据显示，女性体形每缩减20磅（大约9公斤），子代的可能将缩减10%。”体形百分比是由人的体形和身高计数得来的数据，对大多数人，体形百分比可成为全身成年人的精确指标，也常被用来筛选体形以致于。

分析方法者对农业医疗卫生分析方法计划中申请人的女儿完成了分析方法。这项始于1993年的计划借此是为了测定直接影响农业活动中心农民及其母亲全身健康的环境因素。

国立环境医疗卫生生物科学分析方法院的医学研究家Donna Baird哈佛大学知道：“与体形正常人的妇女相较，以致于或成年人的妇女较易怀孕，但是同样情况的女性确实发挥作用哺育问题尚并未有人分析方法。”这项结果发表在2006年9月《医学研究杂志》上。

子代和体形百分比的有系统源自1468位农民和他们的儿子在登记纳入这项分析方法时收尾的问卷调查。后者收尾母亲全身健康调查表，还包括女儿的哺育日本史，前者报告母亲体形和身高的调查表。分析方法分析方法限于开展业务4年前打算哺育及女方岁数低于40的女儿。

分析方法者将这些女儿分别为子代组和可育组，最多1年并未排卵者归为子代组，在1年中排卵者归为可孕组。大多数女性和女性岁数最多30岁，28%的女儿有子代疼痛。

分析方法者发掘出女性的体形百分比是子代症的实质上可怕环境因素。分析方法员调整了其它直接影响哺育力的环境因素，如女性的高体形百分比、岁数、吸烟、饮酒、暴露于杀虫剂，调整过后，随着体形百分比的缩减，子代长方形频域缩减，在成年人女性，子代率缩减1倍。分析方法者还发掘出无论岁数大小，女性的体形百分比都是子代症的可怕环境因素。

虽然没有频率的数据，但据推测以致于的女性较体形正常人的女性数目极少，从而直接影响了哺育。然而，关于乳腺特点的分析方法发掘出以致于和成年人的女性，乳腺质量更高，甲状腺素不平衡点。

国立环境医疗卫生生物科学分析方法院的主任Did A. Schwartz哈佛大学知道：“这项分析方法明确指出了某些与成年人有关的另外的全身健康问题，抑制成年人可促使女性全身全身健康，其中就还包括他们的排卵全身健康。”该分析方法院还明确指出了一项新的的战略性的计划——“环境生物科学和人类所全身健康的新的中间地带”，这项计划将于明年5月实施，借此在于利用环境医疗卫生生物科学促使市民理解疾病的发病原因并促使人类所全身健康。

Men with increased body mass index (BMI) were significantly more likely to be infertile than normal-weight men, according to research conducted at the National Institute of Environmental Health Sciences (NIEHS), one of the National Institutes of Health."The data suggest that a 20-pound increase in men's weight may increase the chance of infertility by about 10 percent," says Markku Sallmen, lead author on the paper who is now at the Finnish Institute of Occupational Health. BMI is a number calculated from a person's weight and height. BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.The researchers studied couples enrolled in the Agricultural Health Study (AHS), a large project that began in 1993 examining factors that impact the health of farmers and their families in agricultural communities. "Women who are overweight or obese tend to he a more difficult time becoming pregnant than normal-weight women, but whether men who are overweight or obese also he fertility problems had not been studied," says Donna Baird, Ph.D., an NIEHS epidemiologist with the study. The study is published in the September 2006 issue of Epidemiology.The data on infertility and body mass came from questionnaires that 1,468 farmers and their wives completed when they enrolled in the study. The wives completed a family health questionnaire, which included information about the couple's reproductive history. The men reported their weight and height on a questionnaire about their health. The ysis was limited to couples with a pregnancy attempt during the four years before enrollment, and to women under the age of 40. The researchers divided the couples into infertile and fertile groups. The infertile couples were those that tried for longer than a year to conceive, and the fertile couples were those that conceived within a year. The majority of men and women were more than 30 years old. Twenty-eight percent of the couples had experienced infertility.Researchers found that men's BMI was an independent risk factor for infertility. The researchers adjusted for other factors that could affect fertility, including high BMI of the woman, age, cigarette smoking, alcohol intake, and solvent and pesticide exposure. After adjustment, there was a general increase in infertility with increased BMI, reaching a nearly 2-fold increase among obese men. When researchers divided the sample into two equal groups by men's age, they found that men's BMI was a risk factor for infertility in both the older and younger men.The researchers did not he data on frequency of sexual intercourse, so it is possible that overweight men he less sexual intercourse than their normal weight counterparts and this could influence fertility. However, there he been recent studies looking at semen characteristics that show lower semen quality for overweight and obese men, as well as hormonal differences."This study provides data on some additional health problems associated with obesity," said Did A. Schwartz, M.D., director of the National Institute of Environmental Health Sciences. "Preventing obesity can help improve men's overall health, perhaps even their reproductive health."The NIEHS unveiled a new strategic plan, "New Frontiers in Environmental Sciences and Human Health," in May aimed at challenging and energizing the scientific community to use environmental health sciences to understand the causes of disease and to improve human health.源自

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编辑： 张靖