During the past decade, the United States has been part of the worldwide epidemic of obesity and diabetes. From 1990 to 2000, the percentage of U.S. adults with diabetes rose from 4.9 to 7.3 percent, an astounding increase of 49 percent.1 Now more than 17 million Americans have diabetes mellitus, and the Centers for Disease Control and Prevention estimates that this number will approach 40 million by 2025.2 The health and economic consequences of this illness are staggering. Despite new therapies, diabetes remains among the leading causes of death, adult blindness, and end-stage renal disease in the United States, and it is associated with a shorter life span of five to 10 years.3 The economic consequences are equally overwhelming. The direct and indirect cost of health care associated with diabetes in 1997 was an estimated $98 billion.4
Type 2 diabetes develops from the interaction between a person's genes and the environment. Although the exact genetic basis remains uncertain, there is strong evidence that lifestyle and modifiable risk factors such as obesity and physical inactivity are the primary determinants of the disease. A good analogy is that although genetics loads the gun, environment pulls the trigger.
The environmental climate is discouraging. Modern adults are about 50 percent as active as those living just 50 years ago.5 Almost one third of Americans lead sedentary lives without engaging in any physical activity, and almost another one third are not regularly active. More than one half of the adult population is overweight, and one in five is obese.6 Even children are becoming increasingly affected with one in four children being overweight. The average consumption of sucrose and total calories continues to rise.
Amidst all of these depressing trends and statistics is the good news that the onset of diabetes can be delayed or even prevented by lifestyle changes. In addition to epidemiologic data, recent research from the Diabetes Prevention Program Research Group7 demonstrates that lifestyle changes result in a 58 percent reduction in the risk of developing diabetes. Studies from Scandinavia and China8,9 also provide evidence that lifestyle modification is effective in reducing the risk of diabetes with a similar magnitude of risk reduction. Even more encouraging was that the dropout rate from these trials was only about 10 percent. If a drug company released a medication that was as effective as these lifestyle changes, it would be hailed as a major breakthrough in the care of patients with diabetes. Despite the hope offered by these studies, the investigators used more intensive interventions than are available in the typical primary care practice. There is little study about interventions that will work in the real world of the busy physician.
Recognizing the difficulty in motivating patients, Koenigsberg, et al.,10 present techniques that can be adapted to a family medicine setting and are likely to improve adherence with lifestyle recommendations. While it may be difficult to get patients to exercise regularly, even modest changes can bring about significant benefits. An easy first step is to make sure that physicians address the problem. The national rate for physicians counseling about exercise is low. Physicians who do provide counseling tend to use it for secondary prevention and fail to counsel those at risk of diabetes, missing many opportunities for primary prevention.11 Regular exercise has the potential to reduce morbidity and mortality from diabetes and many other conditions such as vascular disease, hypertension, and osteoporosis. Although the data are mixed about the positive impact of counseling, the potential benefits of exercise combined with the perceived low risk of counseling led the U.S. Preventive Services Task Force to recommend that primary care physicians advise their patients to increase physical activity.
When counseling about exercise, several recommendations seem reasonable. Walking is of proven benefit and remains the exercise of choice. It is affordable, requires no special equipment, can be done throughout the year, and may be the easiest activity to integrate into daily life. A common barrier to exercise is a perceived lack of time. One strategy we use with patients is to discuss ways to integrate exercise into their daily lives, such as always parking at the far end of the parking lot when shopping, or parking a few blocks from a destination and walking the remaining distance. Stair climbing is another way of integrating exercise. We tell our patients, “one flight up, two flights down, keeps the stomach from getting round.”
Another strategy we use is to have patients purchase pedometers for monitoring their physical activity and individualizing a step target. For the average patient, we set an initial target of 5,000 steps per day. If patients do not hit this goal during the day, they go walking that evening until they reach it. Evidence suggests that the amount of exercise accumulated during the day with short periods of exercise matches the benefits of a single longer period of exercise.12 For patients who are sedentary, just getting them to move is a good start. For example, if people were to do nothing other than toss their television remote control away, they would burn about 10 extra calories per day which, over the course of a year, would equal one lb of weight loss.
Although not mentioned by Koenigsberg, et al.,10 there are some caveats to recommending exercise to patients with diabetes. Individuals should be prescreened for macrovascular and microvascular complications. In particular, an evaluation for cardiovascular disease should always be considered, because many patients with type 2 diabetes have significant coronary artery disease at the time of diagnosis. The American Diabetes Association (ADA) recommends stress testing for patients who are older than 35 years and who meet one or more of the following criteria13:
Type 2 diabetes for more than 10 years
Type 1 diabetes for more than 15 years
Any additional risk factors for coronary artery disease such as dyslipidemia, smoking, or hypertension
Microvascular disease such as proliferative retinopathy or nephropathy, including microalbuminuria
Peripheral vascular disease
Assessing the lower limbs for peripheral neuropathy and vascular disease also is important. The ADA Web site (http://www.diabetes.org) offers advice on how to manage these problems and is a good resource for patients and physicians.
Finally, it is important that physicians try to maintain a healthy lifestyle themselves, not only for their own health, but so they can be role models for their patients. Think about this the next time you wait for an elevator at your institution.