中年發(fā)福？這可能是激素惹的禍

For middle-aged women struggling with their weight, a recent spate of scientific findings sounds too good to be true. And they may be, researchers caution.

對(duì)于苦苦減肥的中年女性來(lái)說(shuō)，最近涌現(xiàn)的一批科學(xué)發(fā)現(xiàn)聽(tīng)上去太美好了，簡(jiǎn)直不像真的。而研究人員也告誡，可能的確是這樣。

Studies in mice indicate that a single hormone whose levels rise at menopause could be responsible for a characteristic redistribution of weight in middle age to the abdomen, turning many women from “pears” to “apples.” At the same time, the hormone may spur the loss of bone.

對(duì)小鼠進(jìn)行的研究表明，于更年期開(kāi)始升高的一種激素可能是導(dǎo)致體重向腹部重新分配這一中年人典型特征的重要原因，將許多女性從“梨形身材”轉(zhuǎn)為“蘋(píng)果形身材”。與此同時(shí)，這種激素可能導(dǎo)致骨質(zhì)疏松。

In mouse studies, blocking the hormone solves those problems, increasing the calories burned, reducing abdominal fat, slowing bone loss and even encouraging physical activity.

在小鼠研究中，阻斷這種激素可以解決這些問(wèn)題，增加熱量燃燒，減少腹部脂肪，減緩骨質(zhì)疏松，甚至可以激發(fā)身體活力。

The notion that such a simple intervention could solve two big problems of menopause has received the attention of researchers and has prompted commentaries in prestigious journals like The New England Journal of Medicine and Cell Metabolism.

這種據(jù)稱可以解決更年期兩大問(wèn)題的簡(jiǎn)單干預(yù)措施，得到了研究人員的關(guān)注，并得到《新英格蘭醫(yī)學(xué)雜志》(New England Journal of Medicine)和《細(xì)胞-代謝》(Cell Metabolism)等著名期刊的報(bào)道。

“It’s a super interesting idea,” said Dr. Daniel Bessesen, an obesity expert and professor of medicine at the University of Colorado School of Medicine. With obesity rising, “we definitely need some new ideas.”

“這是一個(gè)超級(jí)有趣的想法，”科羅拉多大學(xué)醫(yī)學(xué)院肥胖問(wèn)題專家和醫(yī)學(xué)教授丹尼爾·貝塞森(Daniel Bessesen)說(shuō)。隨著肥胖問(wèn)題的增加，“我們肯定需要一些新的想法。”

The work began when Dr. Mone Zaidi, a professor of medicine at the Icahn School of Medicine at Mount Sinai in New York City, became curious about whether a reproductive hormone — F.S.H., or follicle-stimulating hormone — affects bone density.

這項(xiàng)工作始于紐約市西奈山伊坎醫(yī)學(xué)院(Icahn School of Medicine at Mount Sinai)的醫(yī)學(xué)教授莫尼·扎伊迪(Mone Zaidi)，他對(duì)FSH生殖激素(或稱促卵泡激素)給骨密度帶來(lái)的影響感到好奇。

It had long been assumed that the hormone’s role was limited to reproduction. F.S.H. stimulates the production of eggs in women and sperm in men.

長(zhǎng)期以來(lái)，人們認(rèn)為這種激素的作用僅限于繁殖。FSH激素可以促進(jìn)女性卵子和男性精子的產(chǎn)生。

Researchers knew that blood levels of F.S.H. soar as women’s ovaries start to fail before menopause. At the same time, women rapidly lose bone — even when blood levels of estrogen, which can preserve bone, remain steady.

研究人員已經(jīng)知道，當(dāng)女性的卵巢在更年期前開(kāi)始逐漸喪失功能之際，血液中FSH的含量會(huì)上升。與此同時(shí)，女性開(kāi)始出現(xiàn)骨質(zhì)疏松——即便血液中能維持骨質(zhì)的雌激素水平保持穩(wěn)定也是如此。

Dr. Zaidi reasoned that F.S.H. could be a culprit in bone loss. So he and his colleagues created an antibody that blocked F.S.H. in female mice whose ovaries had been removed.

扎伊迪認(rèn)為FSH激素可能是骨質(zhì)疏松的罪魁禍?zhǔn)?。所以他和同事們?chuàng)造了一種阻斷FSH激素的抗體，對(duì)已被切除卵巢的雌性小鼠使用。

Since the mice were making no estrogen at all, they ought to have been losing bone. Indeed, the bone marrow in such mice usually fills with fat instead of developing bone cells. Much the same happens in women: That’s why their bones become less dense.

由于小鼠根本不會(huì)產(chǎn)生雌激素，所以應(yīng)該已經(jīng)開(kāi)始出現(xiàn)骨質(zhì)疏松。事實(shí)上，這樣的小鼠中的骨髓中通常充滿脂肪，而不是產(chǎn)生骨骼細(xì)胞。女性也是如此：所以她們的骨密度會(huì)下降。

But in Dr. Zaidi’s lab, the mice that received the antibody did not developed fat-filled bone marrow — and, to his enormous surprise, they lost large amounts of fat.

但是在扎伊迪的實(shí)驗(yàn)室中，接受抗體的小鼠沒(méi)有產(chǎn)生充滿脂肪的骨髓，而且令他驚訝的是，它們還喪失了大量的脂肪。

“This is a weird, weird finding,” he recalled telling his friend Dr. Clifford J. Rosen, a bone specialist at Maine Medical Center Research Institute. Dr. Zaidi persuaded Dr. Rosen to help repeat the experiments independently, each in his own lab.

“這是一個(gè)非常奇怪的發(fā)現(xiàn)，”他回憶自己當(dāng)時(shí)把這個(gè)發(fā)現(xiàn)告訴了朋友、緬因州醫(yī)學(xué)中心研究所(Maine Medical Center Research Institute)的骨科專家克利福德·J·羅森(Clifford J. Rosen)。扎伊迪勸說(shuō)羅森，在后者的實(shí)驗(yàn)室中獨(dú)立地重復(fù)這一實(shí)驗(yàn)。

At first, Dr. Rosen was dubious: “I said, ‘I don’t believe it, I think it’s not going to work, and it will cost a lot of money.’” But he received a grant for the research, and the two labs got started.

起初，羅森表示懷疑：“我說(shuō)，‘我不相信，我覺(jué)得行不通，而且會(huì)花掉很多錢。’”但是他獲得了研究資助，兩個(gè)實(shí)驗(yàn)室得以開(kāi)始研究。

Two and a half years later, they had their results — and they replicated Dr. Zaidi’s original findings. The researchers also came up with a theory that might explain increased metabolic rates in mice in which F.S.H. is blocked.

兩年半后，他們?nèi)〉昧顺晒?mdash;—他們復(fù)制了扎伊迪的最初發(fā)現(xiàn)。研究人員還提出了一種可能解釋FSH被阻斷時(shí)小鼠代謝率升高的理論。

There are two kinds of fat in the body: White fat primarily stores energy, and brown fat burns calories and throws off heat.

動(dòng)物和人體內(nèi)有兩種脂肪：白脂肪主要儲(chǔ)存能量，棕脂肪燃燒卡路里，釋放熱量。

Brown fat is more common in children, but researchers have found that adults also carry small amounts. In the experimental mice, white fat was being converted to brown fat.

棕脂肪在兒童中更為常見(jiàn)，但研究人員發(fā)現(xiàn)，成年人也攜帶少量棕色脂肪。在接受實(shí)驗(yàn)的小鼠當(dāng)中，白脂肪被轉(zhuǎn)化為棕脂肪。

At the moment, Dr. Rosen is withholding judgment about whether the results will apply to humans. “I think the idea has some credibility,” he said. “But does it mean anything? I don’t know.”

目前，羅森尚未對(duì)結(jié)果是否適用于人類做出判斷。“我認(rèn)為這個(gè)想法有一定的可信度，”他說(shuō)。“但它有什么樣的意義?我不知道。”

But these are not the only researchers to find a link between obesity and the strange interplay of hormones.

但他們不是唯一在肥胖和激素的怪異作用之間找到關(guān)聯(lián)的研究人員。

Wendy Kohrt, a professor of medicine at the University of Colorado, has been studying the effects of menopause on women’s body fat and the amount of calories women burn.

科羅拉多大學(xué)醫(yī)學(xué)教授溫迪·柯?tīng)柼?Wendy Kohrt)一直在研究更年期對(duì)女性體脂以及女性卡路里燃燒的影響。

Dr. Kohrt has given healthy premenopausal women a drug that blocks production of estrogen and F.S.H., putting them into a reversible state of menopause.

柯?tīng)柼亟o予健康的更年期前女性一種阻止雌激素和FSH生產(chǎn)的藥物，使她們處于可逆的更年期狀態(tài)。

Within five months, she found, the women’s fat moves to their abdomens, increasing by 11 percent on average. And they burn 50 fewer calories per day.

她發(fā)現(xiàn)在五個(gè)月內(nèi)，這些女性的脂肪向腹部的移動(dòng)平均增長(zhǎng)了11%。她們每天的熱量燃燒減少了50卡路里。

The effect is reversed when the participants stop taking the drug or when Dr. Kohrt gives them estrogen.

當(dāng)參與者停止服用藥物，或者柯?tīng)柼亟o她們雌激素時(shí)，這種效應(yīng)會(huì)被逆轉(zhuǎn)。