Kriska A
Graduate School of Public Health, Department of Epidemiology, University of Pittsburgh, Pennsylvania 15261, USA.
Sports Med. 2000 Mar;29(3):147-51. doi: 10.2165/00007256-200029030-00001.
From observational studies to clinical trials in a variety of populations and age groups, evidence is mounting in support of the hypothesis that physical activity plays a significant role in the prevention of type 2 diabetes mellitus. Based on the current findings, it is likely that physical activity can reduce the risk of diabetes mellitus development. What is less clear is how much physical activity is necessary, and for how long. Obviously, we are more likely to see the anticipated physiological changes if we maximise the dose. Yet, although maximal is better from a physiological point of view, we 'in the trenches' have also recognised the fact that a sedentary individual will most likely not continue to undergo a high intensity activity exercise regimen. In contrast, evidence is mounting regarding long term compliance to moderate levels of activity, which appear to be easier to adopt in one's lifestyle and are less likely to result in injury. More importantly, there appear to be beneficial changes in insulin sensitivity and glucose tolerance in the sedentary individual who incorporates moderate levels of activity such as walking into the their lifestyle, although the onset of beneficial metabolic changes appear to occur much more slowly and less dramatically than what occurs with a high intensity regimen. Even if activity is shown to be beneficial, we are faced with the challenge of reaching the sedentary individuals who would most likely benefit from an increase in physical activity in the first place. This task is a difficult one because of the difficulty in quantifying the sum total of an entire day's worth of movement, rather than that of a few relatively higher intensity leisure activities. What is needed is a measure or combination of measures of physical activity that are simple to use, relatively inexpensive, and adequately capture the subtle changes in physical activity through the day that we are encouraging. It is unlikely that the protective nature of a physically active lifestyle in preventing diabetes mellitus will have a lasting impact once a switch to a sedentary way of life is made. Therefore, from a public health viewpoint, long term commitments to increased activity are required. This is the ultimate challenge.
从针对各种人群和年龄组的观察性研究到临床试验，越来越多的证据支持这样一种假说：体育活动在预防2型糖尿病中起着重要作用。基于目前的研究结果，体育活动很可能能够降低糖尿病发生的风险。但尚不清楚的是，需要多少体育活动以及持续多长时间。显然，如果我们将剂量最大化，就更有可能看到预期的生理变化。然而，尽管从生理学角度来看，最大化剂量更好，但我们“身处一线”也认识到这样一个事实，即久坐不动的人很可能无法持续进行高强度的运动锻炼方案。相比之下，越来越多的证据表明，长期坚持适度水平的活动更容易融入个人生活方式，且受伤的可能性较小。更重要的是，对于将适度水平的活动（如步行）融入生活方式的久坐不动的人来说，胰岛素敏感性和葡萄糖耐量似乎会出现有益的变化，尽管有益的代谢变化的出现似乎比高强度锻炼方案要慢得多，也不那么显著。即使已证明活动有益，我们仍面临一项挑战，即如何让最有可能从增加体育活动中受益的久坐不动的人参与进来。这项任务很艰巨，因为难以量化一整天的运动量，而不仅仅是一些强度相对较高的休闲活动量。我们需要一种或多种简单易用、相对便宜且能充分捕捉我们所鼓励的全天体育活动细微变化的体育活动测量方法。一旦转而采用久坐不动的生活方式，积极的生活方式在预防糖尿病方面的保护作用不太可能产生持久影响。因此，从公共卫生的角度来看，需要长期致力于增加活动量。这是最终的挑战。
