Health for life

Its such a no-brainer, right?  If persons at risk for diabetes would only eat right and exercise more, theyd avoid the disease.  And for those who develop diabetes, diet and exercise will reduce death rates and complications.

Yes and no, say Elizabeth Sumamo Schellenberg and colleagues at the University of Alberta.  Their review of the mixed published scientific evidence on the topic appears in the October 15 issue of the Annals of Internal Medicine.  The purpose of their study was to ascertain the impact of diet and exercise on the prevention of "Type 2 diabetes," as well as lowering complications among persons with who had established Type 2 diabetes. 

To be included, studies had to be prospective and compare the outcomes from an intervention versus a randomly selected control group. The study could only be included if it examined the impact of exercise plus diet and "one other component," such as "counseling, smoking cessation and behavior modification."  The outcomes had to include the development of Type 2 diabetes (in the prevention trials) or complications (in the treatment trials).

1289 candidate studies were found but only 20 made the grade. Nine were prevention trials and 11 were treatment trials.

For the prevention trials:

The interventions lasted from 6 to 72 months, with follow-up going for 3 to 20 years for between 39 to 3234 participants.  The counseling varied and included group and/or individual with or without tobacco cessation, telephony, goal setting, cooking classes or pills involving a range of physician and non-physician professionals.

Results?

Seven of the nine studies showed that diabetes can be delayed. When the results were pooled, compared to the control patients, the risk of developing diabetes over 10 years was only a third and the difference was statistically significant.

But, there was no detectable impact on cardiovascular disease events or on eye, kidney or nerve damage. That may have been due to not all the studies including these outcomes as well as the time it takes for these complications to occur once diabetes develops.  With more patients or more time, a difference could have become apparent.
 
For the treatment trials:

The interventions lasted from 6 to 48 months with follow-up for 6 to 93 months. The counseling was as varied as the prevention trials but included glucose and blood pressure monitoring as well as stress management and, in one instance, a three day residential retreat. There was likewise the range of professionals who provided the interventions.

Results? 

Compared to the control patients, there was no statistically significant difference in all-cause mortality.  Some individual studies had beneficial outcomes involving cardiovascular events or diabetes complications, but they included the aggressive use of medications.  There were no sustained impacts on weight or dietary intake.  And if pills were not included, there was also no real improvement in measures of blood glucose control.

The Disease Management Care Blogs take?

The good news is that there is good evidence that exercise and diet can prevent diabetes.  The bad news is that it takes years for that "return on investment" to declare itself and typically involves interventions that fall outside the traditional health care delivery system.  Its unlikely, thinks the DMCB, that current iterations of payment orm (value based purchasing, bundled payments or upside risk) can be marshaled to make this a reality.  That being said, population health management (PHM) companies like Omada Health are making their evidence-based services available to, for example, employers who have a longer term commitment to the well being of their "human capital" outside of the traditional insurance market.

The bad news is that once diabetes declares itself, diet and exercise dont result in life extension, and control of complications as well as overall blood sugar levels is more a function of pills than lifestyle. Accordingly, expectations need to be realisitically shared with patients and PHM should emphasize taking the pills as prescribed.

Image from Wikipedia

Researchers may soon be able to add yet another item to the list of exercises well-documented health benefits: A preliminary study suggests that when cancer survivors exercise for several weeks after they finish chemotherapy, their immune systems remodel themselves to become more effective, potentially fending off future incidents of cancer. The finding may help explain why exercise can significantly reduce the chances of secondary cancers in survivors or reduce the chances of cancer altogether in people who have never had the disease.

Laura Bilek, Graham Sharp, and Geoffrey Thiele, all of the University of Nebraska Medical Center, and Daniel Shackelford, Colin Quinn, and Carole Schneider, all of Rocky Mountain Cancer Rehabilitation Institute, analyzed T cells in the blood of cancer survivors before and after a 12-week exercise program. They found that a significant portion of these immune cells converted from a senescent form, which isnt as effective at combating disease, to a naïve form, ready to fight cancer and infections.

Their poster presentation entitled, "Effect of Exercise on T Cells in Cancer Survivors," will be discussed at The Integrative Biology of Exercise VI meeting being held October 10-13 at the Westin Westminster Hotel in Westminster, CO. This popular meeting is a collaborative effort between the American Physiological Society, the American College of Sports Medicine and the Canadian Society for Exercise Physiology. The conference is supported in part by the National Institute of Arthritis and Musculoskeletal and Skin Diseases, an institute of the National Institutes of Health, GlaxoSmithKline, Inc., Stealth Peptides, Inc., and Seahorse Biosciences.

Exercise and Immunity

Study leader Laura Bilek explains that previous research had turned up a variety of positive associations between exercise and cancer -- notably, that exercise can reduce the risk of getting initial incidence of several different types of cancers, can often improve prognosis in cancer patients, and can reduce the risk of recurrence and secondary cancers survivors of some types of cancers. However, the mechanism behind these phenomena has been unknown.

Since other research has suggested that exercise can remodel the immune system, making it more effective at fighting disease in general, Bilek and her colleagues decided to investigate how exercise affects the immune system of cancer patients. Working with a group of 16 cancer survivors, all but one of who recently finished chemotherapy cancer treatment, the researchers focused on T cells, a type of immune cell that attacks a variety of infectious agents as well as cancer cells. After chemotherapy, previous research had shown that the majority of T cells become senescent, with a decreased ability to fight infections and cancers. However, Bilek says, rebuilding the population of responsive (naïve) T cells is critical for regaining normal immune function and cancer-fighting ability.

The researchers first took blood samples from each of the volunteers to examine how many senescent and naïve T cells each had. Then, these study subjects were all enrolled into 12-week exercise programs at the Rocky Mountain Cancer Rehabilitation Institute. All programs were individualized for the study participants, incorporating elements of cardiovascular exercise, strength and endurance training, and exercises for flexibility, posture, and balance, with extra emphasis in areas where participants were weak.

After the 12-week program, the researchers drew a second blood sample from each volunteer and ran the same T cell analysis.

Another Reason to Work Out Results showed that the ratio of senescent to naïve T cells changed favorably in the majority of participants, with most of the study subjects regaining greater numbers of the naïve variety.

"What were suggesting is that with exercise, you might be getting rid of T cells that arent helpful and making room for T cells that might be helpful," Bilek says.

She adds that this finding highlights the importance of exercise for all, including those with cancer and cancer survivors. These two populations might benefit especially from the heightened "cancer surveillance" -- the ability of the immune system to seek out and destroy budding cancers -- that this study suggests exercise brings, Bilek explains.

"Theres a litany of positive benefits from exercise," Bilek says. "If exercise indeed strengthens the immune system and potentially improves cancer surveillance, its one more thing we should educate patients about as a reason they should schedule regular activity throughout their day and make it a priority in their lives."