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,身体脂肪贮存部位的不同对健康的影响更大。德国的研究人员报告说,即使在体重正常的人群中,腹部脂肪过多(形状象苹果)，早死的风险都会增加。

    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.

    位于波茨坦的德国人类营养研究所的流行病学者及内科医生托拜厄斯·比兹肯(Tobias Pischon)博士分析了收集在一个巨大的欧洲受试人数据库中的数据。在359000名被跟踪了近十年的受试者中,腰围尺寸最大者(男性为40.0英寸以上,女性为35.0英寸以上)早死的可能性为腰围最小者(男性为33.8英寸以下,女性为27.6英寸以下)的二倍。至研究未期,腰围最大者中的4232名已死于心脏病、癌症、及其它种种疾病;而同期死亡的腰围最小者中的人数为2115名。最令人惊奇的是,这种联系甚至适用于体重正常男性和女性。

    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.

    当前肥胖指导方针的依据为身体质量指数(BMI),即身高体重比。如许多专家所说,问题在于体重构成既没有分辨出脂肪和肌肉的质量,也没有考虑到脂肪的分布情况。最近的研究揭示,累积在上腹周围和体内深层器官周围的脂肪更有可能导致诸如心脏病和糖尿病之类的疾病,这是因为其代谢更为活跃。此类脂肪细胞又叫作内脏脂肪,具有分泌可破坏体能和生化平衡的激素和细胞因子的倾向;而停留在身体其它部分皮肤下面的脂肪,即皮下脂肪惰性较强,主要作用为能量通道。

    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."

    比兹肯的研究强调了测量较为活跃的内脏脂肪的数量的重要性,正如结果所示,可将腰围作为一个有效的标识及脂肪危险程度的预报器。比兹肯说:“这项研究要表明的是:仅仅将BMI作为依据是远远不够的。腰围甚至与正常体重的个体中较高的死亡率存在一定的关系。

    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,到目前为止,使用腰围这一指标的难点在于这些数据没有指出健康风险升高的临界值。这意味着没有理想的腰围值,不象BMI那样给人们指出了要保持的“正常”或健康的范围。研究发现腰围与死亡风险呈线性增涨,意思是体重一定,腰围大者比腰围小者死亡风险高。比兹肯的小组计算出,腰围每增加5厘米(约2英寸)死亡风险增加男性为17%,女性为13%。比兹肯承认说“没有目标腰围值,而这是棘手之事。我们所能说的是,拥有细腰总是好的。”

    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."

    除过仅增加内脏脂肪之外,腰围是怎样引起较高死亡率的,这方面仍有许多问题需要解决。梅奥门诊部内科及预防心脏病科主任,弗兰西斯科博士(Dr. Franciso Lopez-Jiminez)说,腰围较粗通常表示全身脂肪负担较重,这是心脏病及其他可导致早死的代谢状态的一大促进因素。“这项研究得出的结论是,内科医生必须开始一遍又一遍地测量腰围。腰围在内科极少测量。”