eing overweight is one thing, but where your body fat is stored may make more of a difference to your health. Researchers in Germany report that even among people who are normal weight, having excess fat around the abdomen — being apple-shaped, that is — can increase the risk of premature death.

    肥胖是一件事,可是,身體脂肪貯存部位的不同對健康的影響更大。德國的研究人員報告說,即使在體重正常的人群中,腹部脂肪過多(形狀象蘋果)，早死的風險都會增加。

    Dr. Tobias Pischon, an epidemiologist and physician at the German Institute of Human Nutrition in Potsdam, analyzed data collected in a large European database of subjects. Among 359,000 subjects who were followed for nearly 10 years, those with the largest waist measurements, 40.4 inches or greater for men and 35.0 inches or more for women, were twice as likely to die prematurely than those with smaller waists, less than 33.8 inches for men and 27.6 inches for women. By the end of the study, 4,232 of the largest waisted people had died of various causes, from heart disease to cancer and other ailments, while 2,155 of the smallest waisted people had died in the same period. Most surprising was that the association applied even to men and women who were not overweight: People with bigger waists had a greater risk of early death.

    位于波茨坦的德國人類營養(yǎng)研究所的流行病學者及內(nèi)科醫(yī)生托拜厄斯·比茲肯(Tobias Pischon)博士分析了收集在一個巨大的歐洲受試人數(shù)據(jù)庫中的數(shù)據(jù)。在359000名被跟蹤了近十年的受試者中,腰圍尺寸最大者(男性為40.0英寸以上,女性為35.0英寸以上)早死的可能性為腰圍最小者(男性為33.8英寸以下,女性為27.6英寸以下)的二倍。至研究未期,腰圍最大者中的4232名已死于心臟病、癌癥、及其它種種疾病;而同期死亡的腰圍最小者中的人數(shù)為2115名。最令人驚奇的是,這種聯(lián)系甚至適用于體重正常男性和女性。

    Current obesity guidelines rely on the body mass index (BMI), a ratio of height and weight. The problem, as many experts have noted, is that the weight component does not distinguish between fat and muscle mass nor does it account for how fat distributed. Recent research suggests that the fat that accumulates around the midsection — and deep in the body around the organs — is more likely to contribute to conditions such as heart disease and diabetes, since it is more metabolically active. Known as visceral fat, these adipose cells tend to secrete hormones and cytokines that can throw the body's energy and biochemical balance off kilter; subcutaneous fat, on the other hand, which rests just under the skin in other parts of the body, is more inert, serving mostly as an energy sink.

    當前肥胖指導方針的依據(jù)為身體質(zhì)量指數(shù)(BMI),即身高體重比。如許多專家所說,問題在于體重構(gòu)成既沒有分辨出脂肪和肌肉的質(zhì)量,也沒有考慮到脂肪的分布情況。最近的研究揭示,累積在上腹周圍和體內(nèi)深層器官周圍的脂肪更有可能導致諸如心臟病和糖尿病之類的疾病,這是因為其代謝更為活躍。此類脂肪細胞又叫作內(nèi)臟脂肪,具有分泌可破壞體能和生化平衡的激素和細胞因子的傾向;而停留在身體其它部分皮膚下面的脂肪,即皮下脂肪惰性較強,主要作用為能量通道。

    Pischon's study highlights the growing importance of measuring the amount of the more active visceral fat, and as the results suggest, waist circumference can be an effective marker and a good predictor of how dangerous that fat can be. "What this study shows is that it is not sufficient to simply rely on BMI," says Pischon. "Waist circumference can even be related to higher mortality in normal weight individuals."

    比茲肯的研究強調(diào)了測量較為活躍的內(nèi)臟脂肪的數(shù)量的重要性,正如結(jié)果所示,可將腰圍作為一個有效的標識及脂肪危險程度的預(yù)報器。比茲肯說:“這項研究要表明的是:僅僅將BMI作為依據(jù)是遠遠不夠的。腰圍甚至與正常體重的個體中較高的死亡率存在一定的關(guān)系。

    But the difficulty with waist circumference is that so far, the data do not point to a threshold at which health risks shoot up. That means that unlike BMI, which gives people a "normal" or healthy range to adhere to, there is no ideal waist measurement. The study found that waist circumference and risk of death increased linearly, meaning that at any given weight, those with greater waist measurements were at greater risk of dying than those with smaller waists. Pischon's team calculated that for every 5 cm (about 2 inches) increase in girth, the risk of dying increased by 17% for men and by 13% for women. "There is no goal waist circumference, and that is the difficult thing," acknowledges Pischon. "All we can say is that it's always good to have a low waist circumference."

    但是,到目前為止,使用腰圍這一指標的難點在于這些數(shù)據(jù)沒有指出健康風險升高的臨界值。這意味著沒有理想的腰圍值,不象BMI那樣給人們指出了要保持的“正常”或健康的范圍。研究發(fā)現(xiàn)腰圍與死亡風險呈線性增漲,意思是體重一定,腰圍大者比腰圍小者死亡風險高。比茲肯的小組計算出,腰圍每增加5厘米(約2英寸)死亡風險增加男性為17%,女性為13%。比茲肯承認說“沒有目標腰圍值,而這是棘手之事。我們所能說的是,擁有細腰總是好的。”

    Much still needs to be worked out about how waist circumference is contributing to the greater risk of death — in addition to simply adding visceral fat, says Dr. Franciso Lopez-Jiminez, director of clinical practice and preventive cardiology at the Mayo Clinic, greater waist circumference generally also indicates a greater burden of fat overall, which is a big contributor to heart disease and other metabolic conditions that can lead to early death. "The take-home message from this study is that clinicians need to start measuring waist circumference more and more," he says. "It is rarely measured in clinical practice."

    除過僅增加內(nèi)臟脂肪之外,腰圍是怎樣引起較高死亡率的,這方面仍有許多問題需要解決。梅奧門診部內(nèi)科及預(yù)防心臟病科主任,弗蘭西斯科博士(Dr. Franciso Lopez-Jiminez)說,腰圍較粗通常表示全身脂肪負擔較重,這是心臟病及其他可導致早死的代謝狀態(tài)的一大促進因素。“這項研究得出的結(jié)論是,內(nèi)科醫(yī)生必須開始一遍又一遍地測量腰圍。腰圍在內(nèi)科極少測量。”