新型ウイルス、重症患者に男性と過体重の人が多いのはなぜ？

【パリＡＦＰ＝時事】新型コロナウイルス感染症（COVID-19）の治療現場では、女性よりも男性の方が重症化しやすい傾向が見られる。ただ、その理由はまだよく分かっていない。（写真は資料写真）
　「過体重や既往症のある人ではリスクが高い。これに加えて女性よりも男性の方が重い症状となるケースが多い」と英ロンドン大学ユニバーシティー・カレッジのデレク・ヒル教授は話す。
　英ＩＣＵの独立監査機関であるＩＣＮＡＲＣの初期の統計によると、集中治療を受けた人のうち７３％が男性、７３．４％が過体重だった。
　仏パリにあるピティエサルペトリエール大学病院の救急科専門医マテュー・シュミット医師は、全患者の「４分の３」が男性だとテレビ局の取材で語っている。
　米ニューヨーク・ブルックリンで、ＣＯＶＩＤ-１９を発症した患者を治療しているマウントサイナイ医療システムの形成外科医ハニ・スビタニ氏も米紙ニューヨーク・タイムズに対し、「集中治療室で働いているが、運び込まれる患者の８０％は男性だと思う」と述べた。

■先天免疫と健康意識の差？
　では、なぜ男性の方が症状が重いのか？
　専門家の中には、男性が弱いのではなく、女性の免疫力が強いのだという主張がある。仏トゥールーズ大学病院感染症科のピエール・デロベル医長は、「先天免疫は女性の方が強い。特に閉経期前はそうだ」と述べる。
　また、英ウォーリック大医学部の名誉講師で非常勤医のジェームス・ギル医師も、「女性の免疫系の方がより活発であり、つまり感染症からの回復力が強いのかもしれない」と話した。
　もう一つの仮説は、「単に男性の方が喫煙、飲酒、肥満などについて健康意識が低いから」というものだ。ギル医師は、おそらく前者の生物学的な要因と、後者の環境的な要因が重なっていると推測している。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2020/04/14-15:33）

In the emergency rooms of virus hotspots around the world, medical staff are seeing a greater number of men than women suffering severe symptoms of COVID-19, with obesity emerging as another potentially aggravating factor. But experts are still unsure why.
What first began to appear as a pattern in China, where the virus emerged at the end of last year, has echoed through hospitals in Europe and the United States as the pandemic spreads.
More men than women have serious problems, and patients who are overweight or have previous health problems are at higher risk, said Derek Hill, Professor of Medical Imaging Science at University College London.
Early statistics from Britain's independent Intensive Care National Audit and Research Centre on people treated in intensive care for the virus confirm this phenomenon: 73 percent are men and 73.4 percent are classed as overweight.
According to preliminary data of outcomes for those patients who had either recovered or died of COVID-19 in the period before April 3, obese patients were also less likely to recover after receiving critical care.
Some 42.4 percent of people with a body mass index (BMI) over 30 were able to go home after successful treatment, compared with 56.4 percent of patients with a BMI of less than 25.
French emergency rooms have seen a very large proportion of overweight or obese patients, ICU doctor Matthieu Schmidt at the Pitie-Salpetriere hospital in Paris told broadcaster France 2, adding that three quarters of all patients were men.
In New York there is a similar picture emerging.
I'm in the emergency room, and it's remarkable -- I'd estimate that 80 percent of the patients being brought in are men, Hani Sbitany, a reconstructive surgeon at Mount Sinai Health System who has been treating COVID-19 patients in Brooklyn.
It's four out of five patients, he told the New York Times.
But why are so many men affected? Just months after the new coronavirus appeared, experts say it is too early to tell for certain.
The high incidence of men presenting with more severe symptoms is for now an observation, said Jean-Francois Delfraissy, who leads the coronavirus science council advising the French government.
While he said there was no clear explanation, he raised the theory that men had a higher frequency of multiple pathologies.
I am very humble vis-a-vis this virus. I did not know it three and a half months ago. There are lots of question marks, he told France Info radio.
- Biology and behaviour -
Some experts say that it might not be men's vulnerability that makes the difference, but women's immune strength.
Innate immunity is better in women, especially before menopause, said Pierre Delobel, head of the infectious diseases department at the Toulouse University Hospital
James Gill, a locum doctor and honorary clinical lecturer at Warwick Medical School, said one idea was that women may have a more aggressive immune system, meaning a greater resilience to infections.
Another, he said was that the assumption that simply men don't look after their bodies as well, with higher levels of smoking, alcohol use, obesity, adding that the answer may be a mixture of both biology and environmental factors.
Obesity adds to health risks in general, with an increase in the incidence of diabetes and hypertension -- both identified as aggravating factors of COVID-19 in Italian and Chinese studies, along with age and to a lesser extent heart cardiovascular and cerebrovascular disease.
This raises a particular concern for the United States, where some 42 percent of adults are obese, according to the US Centers for Disease Control and Prevention, which has warned people with a BMI over 40 could be at higher risk of severe illness from COVID-19.
We are worried about our American friends. They will probably have more problems because of obesity, said Delfraissy.