身高指数增加的男性易发生不育

美国国立卫生保健生物科学分析机构进行时的一项分析推测，与正常体形的年长相比，体形百分比增高的年长男婴可能性大得多。

Markku Sallmen就职于芬兰正职卫生分析机构。他时说：“数据推测，年长体形每增高20磅（约9公斤），男婴的可能性将增高10%。”体形百分比是由人的体形和身材高大计算来作的数据，对大多数人，体形百分比可踏入身体成年人的有用指标，也常被用来筛查体形较重。

分析者对农业卫生分析原计划中特许的夫妻进行时了分析。这项追溯到1993年的原计划用以是为了检测阻碍农业社区劳动及其家人成年人症的原因。

国立卫生保健生物科学分析机构的药理学家Donna Baird博士时说：“与体形正常的妇女相比，较重或成年人的妇女较难流产，但是除此以外情况的年长是否存有生育缺陷仍未有人分析。”这项结果发表在2006年9月《药理学杂志》上。

男婴和体形百分比的有系统来源于1468位劳动和他们的妻子在申请纳入这项分析时进行时的问卷调查。后者进行时家人成年人症调查表，最主要夫妻的生育史，前者报告家人体形和身材高大的调查表。分析分析局限申请特许4年前打算生育及女方成年少于40的夫妻。

分析者将这些夫妻分为男婴组和可育组，将近1年未受孕者归为男婴组，在1年内受孕者归为可孕组。大多数年长和女性成年将近30岁，28%的夫妻有男婴症状。

分析者推测年长的体形百分比是男婴症的独立危险原因。分析员调整了其它阻碍生育力的原因，如女性的高体形百分比、成年、吸烟、饮酒、暴露于杀虫剂，调整过后，随着体形百分比的增高，男婴红褐色线性增高，在成年人年长，男婴领军增高1倍。分析者还推测无论成年大小，年长的体形百分比都是男婴症的危险原因。

虽然没有kHz的数据，但据推测较重的年长较体形正常的年长次数少，从而阻碍了生育。然而，关于精子物理性质的分析推测较重和成年人的年长，精子密度较低，代谢不平衡。

国立卫生保健生物科学分析机构的主任Did A. Schwartz博士时说：“这项分析提出了某些与成年人有关的另外的成年人症缺陷，抑制作用成年人可促进年长身体成年人症，其中就最主要他们的生殖成年人症。”该分析机构还提出了一项新的战略的原计划——“周边环境生物科学和人类成年人症的新前沿”，这项原计划将于明年5月实施，用以在于能用卫生保健生物科学促进公众了解营养不良的发病原因并促进人类成年人症。

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.来源于

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