September 13, 2013
News Review From Harvard Medical School -- Predicting Diabetes Reversal after Surgery
A new scoring system may help predict who will have a reversal of diabetes after weight-loss surgery. The system was based on results for nearly 700 obese diabetics who had weight-loss surgery. Within 5 years, 63% had full or partial remission of diabetes. People in both groups were able to stop taking diabetes medicines. Full remission meant that blood sugar returned to normal. Those with partial remission had lower blood sugar, but it was still above normal. Researchers found that 4 factors helped to predict who would have at least partial remission. It was much less likely to occur in people who took insulin before surgery. Other factors included age, hemoglobin A1c level (a long-term measurement of blood sugar) and what other diabetes drugs a person took before surgery. Researchers assigned points to each factor. Then they tested their new scoring system on a similar group of patients. Among people with the lowest scores, 88% achieved full or partial remission. That fell to 2% for people with the highest scores. Remission rates ranged from 64% to 11% for people in other scoring categories. The journal Lancet Diabetes and Endocrinology published the study. HealthDay News wrote about it September 13.
By Mary Pickett, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Weight-loss surgery can be a great success for some people. But the surgery also can result in problems. The challenge is to weigh the risks and benefits. For young people who do not have diabetes, the risks usually outweigh the benefits.
Often, weight-loss surgery can cause diabetes to go into remission. This means you have normal blood sugar without the use of diabetes medicines. For other patients, obesity surgery may reduce the need for these medicines. Remission occurs most often after a procedure called gastric bypass.
Now researchers have developed a scoring system to predict whether diabetes is likely to go away within the first five years after this surgery. The scoring system uses four facts:
- Hemoglobin A1C level (a measure of long-term blood sugar)
- Whether you take insulin
- What other diabetes medicines you take
The prediction scores are published in the latest issue of the journal Lancet Diabetes & Endocrinology. This has potential to be a very useful tool.
The benefits of weight-loss surgery are remarkable. For a majority of patients, it can put diabetes into remission. It also causes better blood pressure and improved cholesterol levels. A typical patient loses 20% to 28% of the pre-surgery weight within 5 to 6 years. Survival is better, too, unless a serious complication occurs at the time of surgery or soon after.
Weight-loss surgery is generally reserved for those with a very high body mass index (BMI). This is a measure of weight in relationship to height.
A study done in 2010 estimated that someone in his or her early 40s who has a BMI of 45 could add 2½ to 3 years to life expectancy by having surgery. Obesity is defined as a BMI of 30 or more. A BMI above 40 is considered very obese.
What are the complications? Gastric bypass patients can have:
- Slow wound healing
- Injuries during the surgery (such as spleen injury)
- Leaks from the intestine after surgery
- Deep vein thrombosis (a blood clot in a vein)
There is a small chance of death in the time surrounding the operation.
Delayed problems can also occur. It is common for people to develop gallstones after this surgery. Kidney damage also is possible. Many patients have vitamin deficiencies and poor absorption of iron.
What Changes Can I Make Now?
The most important treatments for obesity are:
- A reduced-calorie diet
- Regular exercise
So far, obesity surgery is an option if you have diabetes. However, you also must be seriously obese.
The National Institutes of Health gathered interested doctors at a "Consensus Conference on Obesity" in 2004. This group felt that weight-loss surgery was worth considering for people with diabetes and a BMI above 35. The same BMI level applies to someone with obstructive sleep apnea. In the absence of those conditions, bypass surgery may be recommended for people with a BMI of 40 or more.
Because of the high potential for complications, make your decision about obesity surgery slowly. Carefully consider the risks and benefits.
What Can I Expect Looking to the Future?
The scoring system developed for obesity surgery candidates probably will be used widely. Now we can predict whether diabetes is likely to go into remission. But we don't know how long this will last. More time and research will be needed to find out.
Surgery is not an easy way out of obesity or an easy way out of diabetes. Complications and side effects are possible. Surgery for obesity also does not enable obese people to eat without strict attention to calories. (You might say it is no "cake-walk.") Losing weight and maintaining the loss after obesity surgery require a long-term effort to eat less and stay physically active.