青年期における妊娠中の出生前喫煙暴露と難聴について

IMPORTANCE: Although smoking and secondhand smoke exposure are associated with sensorineural hearing loss (SNHL) in children and adults, the possible association between prenatal smoke exposure and hearing loss has not been investigated despite the fact that more than 12% of US children experience such prenatal exposure each year.
OBJECTIVE: To investigate whether exposure to prenatal tobacco smoke is independently associated with SNHL in adolescents.
DESIGN: Cross-sectional data were examined for 964 adolescents aged 12 to 15 years from the National Health and Nutrition Examination Survey 2005-2006.
PARTICIPANTS: Participants underwent standardized audiometric testing, and serum cotinine levels and self-reports were used to identify adolescents exposed to secondhand smoke or active smokers.
MAIN OUTCOMES AND MEASURES: Prenatal exposure was defined as an affirmative parental response to, Did [Sample Person’s Name] biological mother smoke at any time while she was pregnant with [him/her] Sensorineural hearing loss was defined as an average pure-tone hearing level more than 15 dB for 0.5, 1, and 2 kHz (low frequency) and 3, 4, 6, and 8 kHz (high frequency).
RESULTS: Parental responses affirmed prenatal smoke exposure in 16.2% of 964 adolescents. Prenatal smoke exposure was associated with elevated pure-tone hearing thresholds at 2 and 6 kHz (P < .05), a higher rate of unilateral low-frequency SNHL (17.6% vs 7.1%; P < .05) in bivariate analyses, and a 2.6-fold increased odds of having unilateral low-frequency SNHL in multivariate analyses (95% CI, 1.1-6.4) after controlling for multiple hearing-related covariates.
CONCLUSIONS AND RELEVANCE: Prenatal smoke exposure is independently associated with higher pure-tone hearing thresholds and an almost 3-fold increase in the odds of unilateral low-frequency hearing loss among adolescents. These novel findings suggest that in utero exposure to tobacco smoke may be injurious to the auditory system.

背景：喫煙が感音難聴に関連することはわかっているが、妊娠中の暴露についてはまだわかっていない。アメリカでは12%もの子供がそのような妊娠中の喫煙の暴露を受けている。
目的：妊娠中の喫煙暴露が青年期の感音難聴に独立に関連するか調べる。
デザイン：National Health and Nutrition Examination survey 2005-2006から12歳から15歳まで964人を対象とした横断的なデータ調査。
対象：標準的な聴力検査を実施。血清コチニンレベルの測定・アンケートにより喫煙者か間接喫煙かを調査。
アウトカム：出生前の喫煙暴露は、親に対して「[あなた]の生物学的親は妊娠中に喫煙をしたことがありますか？」という問いにより定義した。 感音難聴は、0.5kHz, 1kHz, 2kHz, 3kHz, 4kHz, 6kHz, 8kHzにおいて正常より15dB異常閾値上昇を認める場合とした。
結果：964人中、出生前に暴露したのは16.2%であった。2kHzと6kHzにおいて純音聴力の閾値上昇を認め(p < .05)、2変量解析では片側低音障害難聴が有意に多かった (17.6%/7.1%, p < .05)。その他の難聴に関連する因子を加えた多変量解析では、片側低音障害型感音難聴のオッズ比は2.6倍であった(95%信頼区間, 1.1-6.4)。
まとめ：妊娠中の間接喫煙は独立に高音域の純音聴力に関係があり、青年期において片側低音難聴のオッズ比は3倍程度であった。子宮内での間接喫煙は聴覚系に障害をもたらすといえる。

If you go to see Silicon Valley, what you'll see are buildings. But it's the
people that make it Silicon Valley, not the buildings. I read occasionally
about attempts to set up "technology parks" in other places, as if the active
ingredient of Silicon Valley were the office space. An article about Sophia
Antipolis bragged that companies there included Cisco, Compaq, IBM, NCR, and
Nortel. Don't the French realize these aren't startups?

Building office buildings for technology companies won't get you a silicon
valley, because the key stage in the life of a startup happens before they
want that kind of space. The key stage is when they're three guys operating
out of an apartment. Wherever the startup is when it gets funded, it will
stay. The defining quality of Silicon Valley is not that Intel or Apple or
Google have offices there, but that they were started there.

So if you want to reproduce Silicon Valley, what you need to reproduce is
those two or three founders sitting around a kitchen table deciding to start a
company. And to reproduce that you need those people.

    -- Paul Graham
    -- How to Be Silicon Valley ( http://www.paulgraham.com/siliconvalley.html )

Chandeler: All right, let's get some perspective here, ok? These things, they
happen for a reason.

Monica: Yeah. You!

Chandler: All right, Pheebs, back me up here, ok? You believe in that karma
crap, don't you?

Phoebe: Yeah, by the way, good luck in your next life as a dung beetle.

    -- David Crane & Marta Kauffman
    -- "Friends" (T.V. Show) ( http://en.wikipedia.org/wiki/Friends )