Diabetes Archive

Rising blood sugar signals a need for weight loss and more exercise.

Whenever you have routine blood tests at a physical exam, chances are one of the numbers will be a measurement of your glucose, or blood sugar. A normal blood sugar level is less than 100 milligrams per deciliter of blood (mg/dL) after an eight-hour fast. You have diabetes if your blood sugar is 126 mg/dL or higher. But between those two numbers lie many opportunities for action.

Controlling blood pressure and blood sugar will help both your heart and your kidneys.

On the surface, it's difficult to see how coronary artery disease and kidney damage might be related. But on the cellular level, the two conditions often go hand in hand. A closer look reveals the key. Underlying both conditions are two powerful risk factors: high blood pressure and diabetes, each of which damages the heart and kidneys independently.

Diabetes damages every part of the body, from the brain to the feet. High blood sugar, the hallmark of diabetes, wreaks havoc on blood vessels. It makes sense that keeping blood sugar under control should prevent diabetes-related damage — but how low to push blood sugar is an open question. A study published in The New England Journal of Medicine (NEJM) provides reassuring evidence that so-called tight blood sugar control is good for the heart and circulatory system. A 10-year follow-up of the Veterans Affairs Diabetes Trial showed that participants who aimed for tight blood sugar control had lower blood sugar and fewer heart attacks and strokes than participants whose blood sugar was allowed to float a bit higher. Although tight blood sugar control can help prevent diabetes-related damage, it can have drawbacks such as bouts of low blood sugar (hypoglycemia), which can be dangerous. Current guidelines from the American Diabetes Association recommend tight blood sugar control, but also recognize there’s no one-size-fits-all rule.

Q. I just got diagnosed with diabetes and my doctor said I am at risk for heart disease. Why?

A. Diabetes is considered to be an extremely strong risk factor for heart disease. One reason is that people with diabetes are also more likely to have other conditions that raise their odds of heart disease, such as obesity, high blood pressure, or elevated LDL cholesterol. Also, those factors seem to have more of a detrimental effect on people who have diabetes compared with those who don't.

They're linked to calorie absorption, high blood pressure, and heart trouble.

For weight-conscious people who love the bite of carbonation and the taste of various soft drinks, the advent of sugar-free sodas 60 years ago seemed a blessing: if there were no calories, you didn't have to worry about weight gain—and the diseases that go along with obesity, like diabetes and heart disease. "But there are growing doubts about whether diet sodas really help people lose weight and avoid diabetes," says Dr. Anthony Komaroff, editor in chief of the Health Letter.

What's better for you: moderate but prolonged exercise, or a shorter but more intense workout? A recent study in Annals of Internal Medicine found that both levels of exercise will help you lose about the same amount of belly fat if you burn the same number of calories. But only high-intensity exercise helped control blood sugar levels.

In the study, 300 people with abdominal obesity walked and jogged on treadmills at a moderate or high intensity, burning equivalent numbers of calories. The 217 people who stuck through the study for the entire six months lost on average 1.75 inches from their waistlines—about 5% to 6% of body weight. It made no difference whether they huffed through the higher-intensity workout or the more moderate regimen.

High blood sugar may add to mental decline in people with cardiovascular disease.

Poor sleep is linked to high blood pressure, diabetes, obesity, and heart disease. Now a study published in Neurology Dec. 10, 2014, suggests that people with conditions that rob them of oxygen and deep sleep are more likely to have changes in the brain that may lead to dementia. Researchers say conditions such as emphysema and sleep apnea reduce the amount of oxygen in the blood during sleep, which can lead to silent, undetectable "ministrokes." Researchers also found that people who spend less time in deep sleep, called slow-wave sleep, are more likely to have loss of brain cells than people who spend more time in slow-wave sleep. Slow-wave sleep is important in processing new memories and remembering facts. The researchers noted that past evidence has shown that using a continuous positive airway pressure (CPAP) machine for obstructive sleep apnea may improve cognition, even after dementia has developed. "Sleep quantity and quality are important to maintain optimal health and prevent disease," says sleep expert Dr. Lawrence Epstein, an instructor in medicine at Harvard Medical School. "By getting enough sleep, you ensure that you are getting all the types of sleep, which is necessary to maintain proper functioning." 

Ninety years ago, type 1 diabetes was a death sentence: half of people who developed it died within two years; more than 90% were dead within five years. Thanks to the introduction of insulin therapy in 1922, and numerous advances since then, many people with type 1 diabetes now live into their 50s and beyond. But survival in this group still falls short of that among people without diabetes. A Scottish study published this week in JAMA shows that at the age of 20, individuals with type 1 diabetes on average lived 12 fewer years than 20-year-olds without it. A second study in the same issue of JAMA showed that people with type 1 diabetes with better blood sugar control lived longer than those with poorer blood sugar control.

If you have diabetes or prediabetes and you need motivation to get your blood sugar under control, consider this: a study published Dec. 2, 2014, in Annals of Internal Medicine suggests that diabetes in midlife appears to age the mind at a faster rate in later life. Researchers analyzed changes in the thinking skills of more than 15,000 people during a 20-year period. The average age at the start of the study was 57. Twenty years later, among people with a history of diabetes, there was 19% more decline than expected. There were even declines, although smaller, among people with a high blood sugar condition known as prediabetes. "We know that over time, diabetes, like hypertension, will cause mini-strokes in the brain that will impair one's thinking and memory. This study strengthens the claim that addressing cardiovascular risk factors like diabetes early may prevent dementia in the future," says Dr. David Hsu, a psychiatrist in the Center for Alzheimer Research and Treatment at Harvard-affiliated Brigham and Women's Hospital. You can lower your blood sugar—and your risk of diabetes—by exercising, losing weight, and cutting back on refined grains and added sugars.