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Even though diabetes is on the rise, insulin therapy—the cornerstone of treatment—is still viewed with a mix of fear and wariness by many primary-care doctors and patients. But endocrinologists, who specialize in diabetes, warn that waiting too long to begin insulin therapy, is a bad idea for people with type 2 diabetes, who can go on to develop heart disease, kidney disease, blindness and other serious medical problems.

"People have some very negative ideas about starting insulin therapy," says Matthew Riddle, MD, a professor of medicine in the division of endocrinology, diabetes and clinical nutrition at the Oregon Health and Science University in Portland. "But insulin treatment really allows people to feel well again and, if it's done early enough, it will protect against diabetic complications."

Too Much Sugar
Type 2 diabetes occurs when the body's cells become resistant to insulin, which is the hormone that controls blood sugar levels. The body's ability to secrete insulin is also impaired, so the increased need for blood sugar regulation cannot be met.

A person's diabetes treatment strategy will depend upon how high their blood sugar levels are and whether they are experiencing symptoms such as thirst or frequent urination. While some people may require insulin therapy right away, others may be able to bring down their blood sugar levels with lifestyle changes, such as exercise and a healthy diet.

But Dr. Riddle cautions that the lifestyle modifications people manage to make are often not dramatic enough to control their blood sugar levels. If lifestyle changes aren't working, oral medications—which are more convenient and require less effort than insulin therapy—are the usually first step in drug therapy for diabetes.

There are different types of oral medications and each type improves the body's secretion of its own supply of insulin. The sulfonylureas stimulate the pancreas to make more insulin; the biguanides help the liver respond better to insulin; the thiazolidinediones make other parts of the body more sensitive to insulin; and the alpha-glucosidase inhibitors delay the absorption of food after it's eaten in order to blunt the blood sugar rise that can occur after meals.

Missing Out Due to Misconceptions
While oral medications, taken alone or in combination with each other, can control blood sugar for years, in most cases the disease eventually progresses. The pancreas no longer releases sufficient amounts of insulin, and blood sugar levels rise to unacceptable levels. Insulin therapy, which is usually given by self-injection, is typically recommended by the time someone has taken oral medications between 10 and 15 years.

"For people who no longer have success with the pills," Dr. Riddle says, "starting insulin allows the blood sugar to be controlled once again and stops the clock on diabetes complications."

Yet many doctors and patients are reluctant to make the transition to insulin therapy. Some of these patients hesitate because they interpret their need for insulin as a failure on their part.

"There are a lot of misconceptions about insulin therapy," says Etie Moghissi, MD, a clinical professor of medicine at the University of Southern California and the director of the Diabetes Care Center at Centinela Hospital Medical Center in Inglewood, Calif. "One develops because physicians tell patients that if you don't follow this diet, I'm going to put you on insulin, so insulin therapy is looked at as a penalty rather than as part of the natural progression of the disease."

Another patient misconception, Dr. Moghissi says, is about long-term complications. "They remember that their aunt began insulin therapy and soon after went on dialysis or had a limb amputated," she says. "They associate the complication with the initiation of insulin therapy, rather than years of out-of-control diabetes."

On the doctors' side, Dr. Moghissi says, the issue may be finding the time, in an overwhelmed primary-care office, to train a patient how to manage their insulin therapy. Such training involves learning how and when to inject the insulin and how to avoid hypoglycemia, which is marked by very low levels of blood sugar that can occur when insulin "peaks" between meals or overnight, or at other times. Some primary-care doctors may refer patients to community diabetes education programs for this training.

Certain primary-care doctors may also delay insulin therapy because they believe that injected therapies are unpopular. Dr. Riddle explains that, in fact, people usually find insulin therapy relatively easy to adapt to, and that some doctors "tend to underestimate what patients are willing to do when it is necessary." Additionally, insulin pens are now available, which allows for an easier and more accurate administration of insulin.

Sorting Out Side Effects
Other doctor and patient concerns pertain to the cost of insulin therapy, and side effects such as weight gain and hypoglycemia. While people on insulin therapy still experience weight gain and have to be cautious about hypoglycemia, Drs. Moghissi and Riddle say that today's insulins are very pure, allowing for better blood sugar control, fewer allergic reactions and fewer episodes of hypoglycemia. Originally, doctors used insulin derived from cattle or pigs, but they now use either a human insulin manufactured by "recombinant" methods or insulin with a structure that closely resembles human insulin.

The risk of hypoglycemia is also better managed today because insulin is available in different forms, including short-acting, medium-acting and long-acting forms. While the short-acting treatment lasts a few hours, longer-term therapies may be given just once a day. Sometimes, a longer-acting insulin is given as "background" while the shorter-acting insulin is given with meals and will closely "match" the rise in blood sugar that occurs when you eat.

The bottom line, diabetes specialists say, is that if other methods are not controlling blood sugar levels, don't risk diabetes complications by avoiding insulin therapy.

"The general advice is that type 2 diabetes should be treated carefully and aggressively from the start," Dr. Riddle says. "When the pills don't work, it's really not a good idea to wait to start insulin. Insulin therapy is a safe, effective treatment that has proven itself, and it's become even more important now that people are living longer with diabetes and need to maintain blood sugar control for the whole lifespan."