Analysis Shows Value of Structured Exercise Programs in Diabetes Care

Insurance Benefits for Exercise Programs Can Cut Health Costs

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FOR the person with type 2 diabetes, or the high-risk individual who is trying to prevent the development of diabetes, there is an enormous body of research literature documenting the benefits of exercise. Indeed, research shows that just six weeks of exercise is enough to change both brain chemistry and body chemistry for the better; diets alone don’t have the same effect. But some questions still remain ‒ how much exercise is needed, and what kind?

A host of studies have linked exercise programs with improved health measures related to blood pressure, lipid levels — including cholesterol and triglycerides — cardiovascular events, cognition, physical performance, premature death and quality of life. Analyses of interventions to promote physical exercise in adults have found that compared with no intervention, exercise programs are cost-effective and have the potential to improve survival rates and health-related quality of life.

A recent systematic review and meta-analysis ‒ undertaken by scientists led by Daniel Umpierre of the Hospital de Clinica de Porto Alegre in Brazil ‒ compares the association between physical activity advice and structured exercise programs, respectively, and markers of diabetes. It reveals that implementing structured exercise training — including aerobic, resistance or both — is associated with a greater reduction in HbA1c levels for patients with diabetes compared to patients in control groups. Results of the study are published in the May 4 issue of the Journal of the American Medical Association (JAMA).

A structured exercise is a task, activity, or question posed by a leader that pushes everyone to reflect, focus, offer ideas and insights, and become engaged in learning. Structured exercises offer group leaders a variety of options for encouraging group participation and discussion, practicing skills, and involving adults who have a range of learning styles and capabilities.

After analyzing the results of 47 randomized clinical trials, the researchers also found that exercising for longer periods of time was better at bringing blood sugar levels down than exercising more intensively. Longer weekly exercise duration was also associated with a greater decrease in these levels, according to results of the analysis of previous studies.

The meta-analysis shows that greatest reductions in HbA1c occurred in patients exercising for more than 150 minutes in total per week. Exercise intensity did not appear to matter. Exercising a minimum of 150 minutes a week (usually broken down to 30 minutes of exercise five days a week) is recommended by such institutions as the American College of Sports Medicine.

"People with type 2 diabetes should engage in regular exercise training, preferentially supervised exercise training," says Beatriz Schaan, the study's senior author. "If these patients can perform training for more than 150 minutes per week, this would be more beneficial concerning their glucose control. However, if they cannot reach this amount of weekly exercise, lower exercise amounts are also beneficial."

The Importance of Exercise in Diabetes Management

A recent joint statement from the American Diabetes Association (ADA) and the American College of Sports Medicine (ACSM) has already underscored the importance of physical exercise to prevent and manage insulin resistance, type 2 diabetes mellitus, gestational diabetes mellitus, and the complications of diabetes.

“Current guidelines recommend that patients with type 2 diabetes should perform at least 150 minutes per week of moderate-intensity aerobic exercise and should perform resistance exercise three times per week,” the authors of the Brazil study wrote. “Regular exercise improves glucose control in diabetes, but the association of different exercise training interventions on glucose control is unclear.”

Indeed, although some clinical trial evidence suggests that aerobic exercise and resistance training can each improve glucose control in patients with type 2 diabetes mellitus, not all clinical trials are consistent with regard to this finding.

However, differences in results of clinical trials about the ability of aerobic exercise and resistance training to improve glucose control are primarily due to differences in trial design, including modality, intensity, exercise program duration, adherence to the programs, sample size, and patient populations.

In the Brazilian study, the authors analyzed 47 randomized controlled trials (RCTs) into the effect of exercise on HbA1c, with a total of 8538 patients. In 23 of these RCTs, patients took part in structured exercise training, and in the other 24 they were simply given advice on physical activity.

Across all studies analyzed, engaging in structured exercise was associated with decreased HbA1c levels compared with controls, whether this was structured resistance training (fall in HbA1c of 0.57%), structured aerobic exercise (fall of 0.75%), or a combination of both (0.51% fall).

A longer total time spent in structured exercise was associated with better glycemic control. If total weekly time in structured exercise exceeded 150 minutes, the average drop in HbA1c was 0.89%, against 0.36% for a time of 150 minutes or less.

Physical activity advice was only associated with a decline in HbA1c if it was combined with dietary advice.

The authors said: “This systematic review and meta-analysis of RCTs demonstrates important findings regarding the prescription of structured exercise training. First, aerobic, resistance, and combined training are each associated with HbA1c decreases, and the magnitude of this reduction is similar across the three exercise modalities.

“Second … structured exercise of more than 150 minutes per week is associated with greater declines in HbA1c than structured exercise of 150 minutes or less per week in patients with type 2 diabetes. This finding is important because the current guideline-recommended exercise duration is at least 150 minutes per week.

They added: “Although high-intensity exercise has been previously shown to have an association with HbA1c reduction, our findings did not demonstrate that more intensive exercise was associated with greater declines in HbA1c.”

In an accompanying editorial, Marco Pahor, director of the University of Florida Institute on Aging, argues that “the meta-analysis … and cumulative evidence from a large number of randomized controlled trials conducted over the past few decades in the area of physical activity and exercise provide solid evidence for public policy makers to consider structured exercise and physical activity programs as worthy of insurance reimbursement to promote health, especially in high-risk populations.”

Insurance Benefits for Exercise Programs Can Cut Health Costs
With respect to type 2 diabetes, Medicare reimburses for approved self-management education and medical nutrition therapy programs. But no specific reimbursement is given for any physical activity or exercise program, despite evidence that such programs can help improve health and cut costs.

Questions remain as to what format reimbursable exercise and physical activity programs should take, what population group should be targeted, and at what stage of life or health status would a lifestyle intervention be most cost-effective to implement.

Some insurance providers already include a fitness benefit for members, such as monthly membership at certain fitness centers or access to personal trainers or exercise classes at reduced cost. Indeed, use of such health plan-sponsored club benefits by older adults has been linked to slower increases in total health care costs.

In one study, older adults who visited a health club two or more times a week over two years incurred $1,252 less in health-care costs in the second year than those who visited a health club less than once a week. Programs among people with lower incomes can also pay off, because people in that group are otherwise more likely to forego health-promoting physical activity because of economic constraints or safety concerns.

“People are willing to invest in improved health, but if you have a fixed amount of resources then you want to choose where you get the most health for the dollar,” said Erik Groessl, an assistant professor of family and preventive medicine at the University of California, San Diego, and director of the UCSD Health Services Research Center. Groessl was not involved in the current analysis.

Group training or walking programs, for example, can be cost-effective, sustainable forms of physical activity that don’t require expensive health care professionals or equipment. But more costly interventions that yield dramatic results might also be worth the expense.

“There is a lot of evidence that physical activity works, and I think it’s time to start putting it into practice more widely,” Groessl said.

Sources: JAMA, University of Florida News, Medpage Today

Middle-Age Diabetics Carry Double the Risk for Developing Geriatric Ailments

Diabetes affects multiple organ systems and has the potential to contribute significantly to the development of a number of issues that we associate with aging. A new study has found that adults between 51 and 70 with diabetes develop age-related ailments like cognitive impairment, incontinence, falls, dizziness, vision impairment and pain at a faster rate than those without diabetes.

For adults aged 51-60 with diabetes, the odds of developing new geriatric conditions were nearly double those of their counterparts who didn't have diabetes. By the time people with and without diabetes reach 80, the overall effects of aging and impact of other diseases start to reduce the disparities between the two groups, the researchers found.

The research was based on nationally representative data from the University of Michigan Health and Retirement Study and the results published in the March issue of the Journal of General Internal Medicine.

"The findings suggest that adults with diabetes should be monitored for the development of these conditions beginning at a younger age than we previously thought… "If we know to start looking for these conditions earlier, we can manage and treat them more effectively," said lead author Christine Cigolle, M.D., M.P.H., an assistant professor of family medicine and internal medicine at the University of Michigan Medical System and research scientist at the VA Ann Arbor Healthcare System

These findings echo the findings of another study published in the journal Diabetes last year. Margaret Gatz and researchers from Sweden showed that getting diabetes before the age of 65 corresponds to a 125 percent increased risk for Alzheimer's disease.

This risk of Alzheimer's disease or other dementia was significant for mid-life diabetics — as opposed to those who develop diabetes after 65 — even when controlling for family factors. In other studies, genetic factors and childhood poverty have been shown to independently contribute to the risk of both diabetes and dementia.

Indeed, the chances of a diabetic developing Alzheimer's disease may be even greater in real life than in the study, the researchers said. They identified several factors that might have led them to underestimate the risk of dementia and Alzheimer's among those who develop diabetes before the age of 65.

Diabetes usually appears at a younger age than dementia does, the researchers noted. Diabetes is also associated with a higher mortality rate, which may reduce the size of the sample of older adults. In addition, approximately 30 percent of older adults with diabetes had not been diagnosed.

The results of the study implicate adult choices such as exercise, diet and smoking, as well as glycemic control in patients with diabetes, in affecting risk for Alzheimer's disease and diabetes, according to the researchers.

In fact, researchers from Mayo Clinic's Florida campus say that dementia in some diabetics appears to be caused often by vascular disease in the brain, and the dementia that develops in people without diabetes is more likely associated with deposition of the plaque seen in people with Alzheimer's disease.

"This helps in understanding diabetes and dementia. It suggests that the vascular dementia seen in diabetics, which appears to be related to small blood vessel disease and strokes, can potentially be averted if development of diabetes is prevented," says Mayo neurologist Neill Graff-Radford, M.D.

The results agree with a number of autopsy studies conducted on patients with dementia and diabetes, in which vascular abnormalities were found to be related to the dementia but the Alzheimer's pathology of plaque and tangles was not, he says.

The findings also suggest that an experimental blood test to predict development of Alzheimer's disease may be more accurate than some studies of people with dementia have suggested, because those studies included participants with diabetes, says Dr. Graff-Radford. "We now propose that future studies of this test should take into account diabetic status," he says.

The test is based on discoveries made by Mayo neuroscientists, which measure the ratio of two different kinds of amyloid beta proteins in blood. Plaque found in the brains of Alzheimer's disease patients at autopsy started when the toxic form of amyloid beta, known as Aβ42, began to be deposited.

The findings also make sense biologically, Dr. Graff-Radford says. Both the insulin hormone and amyloid beta proteins are degraded by the insulin-degrading enzyme (IDE). He adds that if the blood contains excess insulin, as is the case in diabetics, then IDE preferentially degrades insulin instead of amyloid. "That means there would be higher levels of both Aβ42 and Aβ40 in the blood of diabetics," he says.

Indeed, patients with dementia and diabetes appear to display a different pattern of injuries in their brains than patients with dementia but without diabetes, Joshua A. Sonnen, M.D. of the University of Washington, Seattle, discovered. The association between diabetes mellitus and increased risk for dementia in the elderly is well documented. Several possible mechanisms have been proposed for this association, including the direct effects of high blood glucose and insulin, the build-up of beta-amyloid plaques in the brain and the effects of diabetes-related vascular disease on blood vessels in the brain.