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.

對于苦苦減肥的中年女性來說，最近涌現(xiàn)的一批科學發(fā)現(xiàn)聽上去太美好了，簡直不像真的。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.

對小鼠進行的研究表明，于更年期開始升高的一種激素可能是導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“蘋果形身材”。與此同時，這種激素可能導致骨質(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題的簡單干預措施，得到了研究人員的關注，并得到《新英格蘭醫(yī)學雜志》(New England Journal of Medicine)和《細胞-代謝》(Cell Metabolism)等著名期刊的報道。

“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.”

“這是一個超級有趣的想法，”科羅拉多大學醫(yī)學院肥胖問題專家和醫(yī)學教授丹尼爾·貝塞森(Daniel Bessesen)說。隨著肥胖問題的增加，“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.

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

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.

長期以來，人們認為這種激素的作用僅限于繁殖。FSH激素可以促進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，當女性的卵巢在更年期前開始逐漸喪失功能之際，血液中FSH的含量會上升。與此同時，女性開始出現(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.

扎伊迪認為FSH激素可能是骨質(zhì)疏松的罪魁禍首。所以他和同事們創(chuàng)造了一種阻斷FSH激素的抗體，對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.

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

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.

但是在扎伊迪的實驗室中，接受抗體的小鼠沒有產(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.

“這是一個非常奇怪的發(fā)現(xiàn)，”他回憶自己當時把這個發(fā)現(xiàn)告訴了朋友、緬因州醫(yī)學中心研究所(Maine Medical Center Research Institute)的骨科專家克利福德·J·羅森(Clifford J. Rosen)。扎伊迪勸說羅森，在后者的實驗室中獨立地重復這一實驗。

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，‘我不相信，我覺得行不通，而且會花掉很多錢。’”但是他獲得了研究資助，兩個實驗室得以開始研究。

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.

動物和人體內(nèi)有兩種脂肪：白脂肪主要儲存能量，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，但研究人員發(fā)現(xiàn)，成年人也攜帶少量棕色脂肪。在接受實驗的小鼠當中，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，羅森尚未對結(jié)果是否適用于人類做出判斷。“我認為這個想法有一定的可信度，”他說。“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.

科羅拉多大學醫(yī)學教授溫迪·柯爾特(Wendy Kohrt)一直在研究更年期對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.

柯爾特給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)在五個月內(nèi)，這些女性的脂肪向腹部的移動平均增長了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.

當參與者停止服用藥物，或者柯爾特給她們雌激素時，這種效應會被逆轉(zhuǎn)。