What is metabolic syndrome?

DEAR DOCTOR K: My doctor says I have metabolic syndrome. He said it's "like diabetes but not diabetes," which I don't understand. Can you explain what it is, and how I can fix it?

DEAR READER: Metabolic syndrome is quite common, but not very well known. Many of my patients have it; nearly 50 million Americans have it -- and many of them don't know it. Metabolic syndrome is dangerous. If you have it, you have a much higher risk of several major health conditions. Recent studies find that your risk of developing diabetes is four to five times higher. I guess that's what your doctor meant when he said it was "like diabetes but not diabetes." Your risk of stroke or a heart attack is about double. Your risk of dying prematurely is 30 to 60 percent higher.

Can you explain what a low glycemic index diet is?

DEAR DOCTOR K: Diabetes runs in my family, and my mother says I should eat a "low glycemic index" diet. Can you explain what this is?

DEAR READER: Carbohydrates ("carbs," for short) are one of the main types of nutrients in food. Common sources of carbs include bread, pasta, cereals, fruit, milk, vegetables and beans. The carbs we eat are mostly too big for us to digest. Carbs are long strings of a certain type of molecule. Think of them as a string of pearls. When they hit the gut, digestive enzymes start to chop them up. It is the one-pearl and two-pearl strings that are the sugars that get digested and travel from the gut into the blood.

I have Type 2 diabetes, how can I achieve a healthy pregnancy?

DEAR DOCTOR K: I have Type 2 diabetes, and I would like to get pregnant. What can I do to increase my chances of having a healthy baby?

DEAR READER: Like you, some women already have either Type 1 or Type 2 diabetes before they become pregnant. There also is a kind of temporary diabetes that develops during pregnancy called gestational diabetes. It goes away after the baby is born. You're right to be concerned. Type 1, Type 2 and gestational diabetes all cause high blood sugar and can cause pregnancy complications. But for this column, I'll focus on pregnancy and Type 2 diabetes.

Is tight blood sugar control right for all type 2 diabetics?

DEAR DOCTOR K: I have Type 2 diabetes. For years, my doctor emphasized the importance of tight blood sugar control. But I recently read that tight control might not make sense for everyone. Why not?

DEAR READER: Millions of people with diabetes, and their doctors, are asking themselves the same question. It's a confusing and controversial area. I'll do my best to put it in context and to explain my own views. People with Type 2 diabetes have high levels of blood sugar if they don't take medication that lowers their blood sugar level.

How do I protect myself against diabetic ketoacidosis?

DEAR DOCTOR K: I have had Type 1 diabetes for 20 years. I'm worried I may get ketoacidosis, even though I never have. How do I protect myself?

DEAR READER: You are at risk for ketoacidosis, but the fact that you've never had it is encouraging. It means you're already doing the things you need to do to prevent it. That's important, because diabetic ketoacidosis is a serious complication of Type 1 diabetes. Let's start with a few basics. Type 1 diabetes is often called "insulin-requiring" diabetes.

What are “sugar alcohols”?

DEAR DOCTOR K: I have Type 2 diabetes. Many low-carb and sugar-free products contain "sugar alcohols." What are they? Do they count as carbohydrates?

DEAR READER: Type 2 diabetes is marked by elevated levels of blood glucose, or sugar. Untreated or poorly controlled diabetes can lead to serious complications including heart attacks, kidney failure, amputation and blindness. An important part of controlling blood sugar involves making healthy food choices.

Could stem cells be used to treat Type 1 diabetes?

DEAR DOCTOR K: My teenage daughter has had Type 1 diabetes since she was 8 years old. Fortunately, exercise, a good diet and insulin treatments have kept her healthy. I recently heard of a breakthrough at Harvard that might someday cure Type 1 diabetes. Can you explain?

DEAR READER: The research you're referring to was conducted in the Harvard laboratory of Dr. Douglas Melton. Like you, Dr. Melton has a child with Type 1 diabetes. When his child became sick, he redirected his laboratory to the goal of finding a cure.

What is diabetic nephropathy?

DEAR DOCTOR K: I have diabetes. My doctor says I'm at risk for diabetic nephropathy. What is that? What can I do to prevent it?

DEAR READER: Diabetic nephropathy is kidney disease that is a complication of diabetes. Your kidneys are made up of hundreds of thousands of small tubes that filter your blood and help remove waste from your body. In people with poorly controlled diabetes, these structures thicken and become scarred. Over time, the kidneys lose their ability to remove waste products from the blood.

What are signs of hypoglycemia?

DEAR DOCTOR K: I recently started taking medication for Type 2 diabetes. My doctor warned me about hypoglycemia. What signs should I look out for? What should I do if I experience them?

DEAR READER: People with Type 2 diabetes have high levels of sugar, or glucose, in their blood. Diabetes medications work to lower blood sugar to near-normal levels. But sometimes diabetes medications bring blood sugar down too low, a condition called hypoglycemia (hi-po-gly-SEE-me-uh).

What’s the link between diabetes and heart disease?

DEAR DOCTOR K: When I was diagnosed with diabetes, my doctor said I am now also at increased risk for heart disease. What's the connection?

DEAR READER: The link between diabetes and cardiovascular disease is stronger than many people realize: About two-thirds of people with diabetes die of heart disease or stroke. I spoke to my colleague Dr. Benjamin Scirica, a cardiologist at Harvard-affiliated Brigham and Women's Hospital, about the link between the two conditions. He explained that diabetes harms the heart in several ways.