Diabetes

New trial muddies the water about diet, exercise, and diabetes

Howard LeWine, M.D.
Howard LeWine, M.D., Chief Medical Editor, Internet Publishing, Harvard Health Publications

Long-awaited results from a nearly 10-year trial exploring the effect of changes in diet and exercise among people with diabetes weren’t what most people expected. The Look AHEAD trial found that intensive efforts to lose weight by eating less and exercising more didn’t provide any more protection against heart disease—a common co-traveler with diabetes—than standard diabetes support and education. The spin from some media reports is that weight loss doesn’t reduce heart disease risk among people with type 2 diabetes, but I think that’s the wrong interpretation. The results of the Look AHEAD trial don’t contradict the value of lifestyle changes. People in the intensive change group improved their blood sugar with fewer drugs, saving an estimated $600 per year, they were also less likely to have developed chronic kidney disease and less self-reported vision problems. The Look AHEAD results reinforce for me that diabetes care needs to be tailored to the individual.

Cities can learn lessons about diabetes from rural areas

Daniel DeNoon
Daniel DeNoon, Executive Editor, Harvard Heart Letter

City dwellers often think of rural America as a throwback to past “good old days.” But when it comes to obesity and diabetes, people living outside urban areas offer a frightening glimpse of the future. While more than 8% of Americans now have diabetes, in some rural counties 20% of the residents have diabetes. Those counties also tend to have high rates of obesity. Barriers to healthy living contribute to both obesity and diabetes. So does lack of primary care physicians. One answer may be greater reliance on community health workers—lay people trained to provide diabetes education and outreach. In Birmingham, Alabama, the Cities for Life program has doctors refer people with diabetes to “patient navigators” who help them find local resources such as nearby exercise classes or mobile farmers’ markets.

Discovery could someday help people with diabetes make more insulin

Anthony Komaroff, M.D.
Anthony Komaroff, M.D., Executive Editor, Harvard Health Letter

A lot is known about diabetes. But a discovery that could change how this disease is treated shows just how much more there is to learn. A team of Harvard Medical School researchers has discovered a hormone called betatrophin made by liver and fat cells that signals the body to make more insulin-producing beta cells. A report of their work appears in this month’s issue of the prestigious scientific journal Cell. In mice with diabetes, experimentally turning on the production of betatrophin inside liver and fat cells caused an increase in beta cells and a dramatic improvement in blood sugar. It will, of course, take much more research in mice—and then in humans—to determine if this newly discovered hormone can serve as a treatment for diabetes. So it’s too soon to get excited that the discovery of betatrophin will translate directly into a new treatment for diabetes. But it is another example of the human body’s power to naturally repair itself.

Many miss prediabetes wake-up call

Anthony Komaroff, M.D.
Anthony Komaroff, M.D., Executive Editor, Harvard Health Letter

Type 2 diabetes doesn’t usually appear all of a sudden. Many people have a long, slow, invisible lead-in to it called prediabetes. During this period, blood sugar levels are higher than normal. However, they’re not high enough to cause symptoms or to be classified as diabetes. It’s still possible at this stage to prevent the slide into full-blown diabetes. Think of prediabetes as a wake-up call. Unfortunately, few people ever hear the alarm. A new report from the Centers for Disease Control and Prevention shows that among Americans age 20 and older, only 10% of those with prediabetes know they have it. Given that as many as 73 million Americans have prediabetes, that’s a lot of missed opportunities to prevent the ravages of diabetes. One reason many people don’t know that they may be headed toward diabetes is they’ve never had their blood sugar tested. This simple test isn’t part of routine preventive care, but perhaps it should be.

Studies explore global burden of disease and heart disease in the United States

Patrick J. Skerrett, Former Executive Editor, Harvard Health

If you like numbers and statistics, especially those about health, two reports released this week should keep you occupied for days: the massive Global Burden of Disease study was published in The Lancet, and the American Heart Association released its annual “Heart and stroke statistics” report. The Global Burden of Disease project found that average life expectancy continues to rise in most countries. It also found that infection and other communicable causes of disease no longer dominate deaths and disability. Today, so-called non-communicable causes like traffic accidents, violence and war, heart disease, cancer, and other chronic conditions account for two-thirds of world deaths and the majority of years lost to disability and death. According to the American Heart Association’s annual report, the percentage of deaths due to heart attack, stroke, and other cardiovascular diseases has fallen by nearly one-third since 1999, but don’t expect that to continue. Increases in high blood pressure, high cholesterol, diabetes, overweight, and inactivity threaten to reverse these gains.

Surprises from science

Howard LeWine, M.D.
Howard LeWine, M.D., Chief Medical Editor, Internet Publishing, Harvard Health Publications

Many medical studies confirm what we know or suspect. Every once in a while, though, one surprises us, turning “conventional wisdom” on its head. That just happened with the sudden shutdown of a long-running diabetes trial called Look AHEAD (Action for Health in Diabetes). Begun in 2001 and scheduled to last another two years, Look AHEAD was designed to see if an intensive diet and weight loss program could reduce the number of heart attacks, strokes, and other cardiovascular problems in people with type 2 diabetes. An early peek at the data showed that the program had little apparent effect, and the investigators concluded it would be futile to continue. This does not mean that we should ignore diet and exercise in treating of type 2 diabetes. Instead, the details of the study results, which haven’t yet been published, are likely to reveal other explanations.

Diabetes: steps forward, falling behind

Patrick J. Skerrett, Former Executive Editor, Harvard Health

As part of its 200th anniversary celebration, today’s New England Journal of Medicine carries an article called “The Past 200 Years in Diabetes.” It describes some of the advances made in understanding and treating this disease, like the discovery of insulin and the development of personal blood-sugar monitors. But it doesn’t tell much about how living with diabetes has changed. Just 50 years ago, checking blood sugar and administering insulin were big ordeals, and people with diabetes weren’t expected to live more than a few years after their diagnoses. today, it’s a cinch to check blood sugar with a quick finger prick, and pen-like devices almost painlessly deliver insulin, and people with diabetes who take care of themselves have almost normal life expectancies. Advances in protecting and treating the heart, eyes, kidneys, and limbs have helped reduce complications from diabetes.

Use glycemic index to help control blood sugar

Patrick J. Skerrett, Former Executive Editor, Harvard Health

Picture an old-fashioned roller coaster with plenty of ups and downs. That’s what your blood sugar and insulin levels look like over the course of a day. The highs that follow meals and snacks drop to lows later on. Learning to eat in a way that makes your blood sugar levels look more like a kiddie coaster with gentle ups and downs than a strap-’em-in, hang-on-tight ride with steep climbs and breathtaking drops can make a difference to your health. How can you do this? A tool called the glycemic index (GI) can help. It rates carbohydrate-containing foods by how much they boost blood sugar (blood glucose). Using the glycemic index to choose a healthier diet is easier than you might think. Focus on foods with a low glycemic index (55 or less), and try to limit those with a high glycemic index (70 or higher).

Diabetes can strike—hard—even when weight is normal

Howard LeWine, M.D.
Howard LeWine, M.D., Chief Medical Editor, Internet Publishing, Harvard Health Publications

We tend to think of type 2 diabetes as a disease that afflicts people who are overweight. But it can also appear in people with perfectly healthy weights—and be more deadly in them. A study published in the Journal of the American Medical Association indicates that normal-weight people diagnosed with type 2 diabetes have double the risk of dying from heart disease and other causes than overweight people with diabetes. Such apparent “protection” by excess weight has been called the obesity paradox. It’s been seen with other conditions, like heart failure and end-stage kidney disease. That doesn’t mean gaining weight is a healthy strategy. Instead, it probably means that something else besides weight—like the amount of fat around the waist—may be contributing to the onset and severity of type 2 diabetes. These new findings underscore the importance of strength training for everyone, no matter what their weight.

Natural “exercise” hormone transforms fat cells

Heidi Godman
Heidi Godman, Executive Editor, Harvard Health Letter

Exercise makes cells burn extra energy—that’s one way it helps control weight. It also generates a newly discovered hormone, called irisin, that transforms energy-storing white fat cells into energy-burning brown fat cells. Irisin also appears to help prevent or overcome cellular changes that lead to type 2 diabetes. The hormone does this by helping transform energy-storing white fat cells into energy-burning brown fat cells. White adipose tissue, more commonly known as body fat, is the tissue that dimples thighs, enlarges waists and derrieres, and pads internal organs. Each white fat cell stores a large droplet of fat. Brown fat, in comparison, is chock full of energy-burning mitochondria. Its main function is to generate body heat by burning fat. A team led by Dr. Bruce Spiegelman, professor of cell biology and medicine at Harvard Medical School, has identified irisin in mice and humans and showed how irisin transforms white fat cells into brown ones, at least in mice.