The Annual Congress of the American Association for Clinical Endocrinologists (AACE) and the European Congress on Obesity 2013
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by Margaret Nguyen
We attended many conferences in the past two months and have been blown away by the work researchers are doing to better understand and treat diabetes and obesity. Often, the talks centered on novel molecules or techniques to care for both conditions better, but there were also sessions on the practical day-to-day management of diabetes. The following are the lessons we’ve learned from the best thinkers in the field.
Downloading Data is a Key Part of Diabetes Care
During his talk at the Annual Congress of the American Association of Clinical Endocrinologists in sunny Phoenix, Arizona, Dr. Bruce Bode (Atlanta Diabetes Associates, Atlanta, GA) emphasized the critical importance of downloading insulin pump data. Unfortunately, he stated that about 30-40% of endocrinologists and 80% of internists do not download pump data (for patients, we have heard estimates that around 90% do not regularly download data). Dr. Irl Hirsch (University of Washington, Seattle, WA) also urged providers in the audience to download diabetes data. He credited the lack of insurance reimbursement and limited time as the reason why more providers do not work with the data from blood glucose monitors, pumps, and continuous glucose monitors (CGM). However, Dr. Hirsch also noted that he did not understand how it is possible to make treatment recommendations without data.
Once data is downloaded, Dr. Bode said there are two red flags that usually get his attention and cause him to change insulin doses. First, when a patient’s blood glucose average minus the standard deviation (a calculation that measures the fluctuation between blood glucose measurements) is less than 75 mg/dl, it suggests that there is a lot of glycemic variability. Some researchers believe that large fluctuations in blood sugar can cause oxidative stress and contribute to long-term complications like blood vessel damage; however, this is still an ongoing debate in the academic community, and the effects of glycemic variability need to be further studied. Second, Dr. Bode often makes changes if bolus insulin accounts for less than 50% of the total daily insulin dose – in his view, these patients often have a higher likelihood of hypoglycemia.
To guide therapy adjustments, Dr. Hirsch recommends that the blood glucose standard deviation should ideally be no more than a third of the mean blood glucose, though less than half of the mean is still acceptable (e.g., for an average blood glucose of 100 mg/dl, a standard deviation less than 33 mg/dl is ideal, though less than 50 mg/dl is acceptable). Dr. Hirsch acknowledged a standard deviation less than one third of the mean is often very difficult for people with type 1 diabetes; those who are able to achieve this goal might be making some of their own insulin.
Dr. Hirsch also advised that patients do best when they override their bolus calculator 20-25% of the time. Overriding the bolus calculator means that users are adjusting for things in real-time, such as blood glucose trends or anticipated exercise. In his view, adjusting over 30% of the calculations often means one of the bolus calculator’s settings is incorrect.
Should a Meal’s Fat Content Affect How Much Insulin to Dose?
During the European Congress on Obesity in Liverpool, UK, researchers discussed Dr. Howard Wolpert’s paper on the impact of dietary fat on blood sugar (Wolpert et al., Diabetes Care, April 2013). The participants were put on a closed-loop system and monitored for 18 hours after eating. While on the closed-loop system, they ate two meals – both had the same carbohydrate and protein content, but had different amounts of fat. When the participants had more fat in their meals, they needed more insulin (as measured by the closed-loop system’s inulin dosing) and had higher blood sugars.
The question is how much insulin should be taken? Dr. Hirsch said that there is often no way to know how to do this accurately every time, as the blood glucose change due to a meal’s fat and carbohydrate content is different for every meal. Dr. Bode discussed one way he knew to take account of fat content for insulin dosing: with a high-fat meal, add 20-30% more insulin and give the insulin dose as a dual wave bolus (a combination of a normal bolus and an extended bolus over several hours). Dr. Hirsch’s rule of thumb was to add 10-20% more insulin for meals with a lot of protein or fat.
On the other hand, Dr. Hirsch commented that it’s already difficult to calculate how much insulin is needed from carb counting alone – adding other layers of calculations might not be that helpful. In any case, both physicians asserted that a CGM is the best tool available to figure out if the right amount of insulin is taken. Additionally, Dr. Hirsch expressed optimism for upcoming technologies like Medtronic’s MiniMed 530G (a low-glucose-suspend insulin pump currently under FDA review) and eventually, the artificial pancreas.
Continuous Glucose Monitoring and Healthcare Coverage
In a panel discussion, Drs. Bode and Hirsch also highlighted the benefits of using a CGM. Indeed, Dr. Bode stated that many patients who use both a pump and a CGM often give up the pump before they give up the sensor.
Despite its value, it was somewhat discouraging to hear that reimbursement for CGM is still insufficient, or even unavailable, for many patients. For example, Medicare does not cover personal use of CGM, which makes this potentially life-saving technology (i.e., detecting and preventing hypoglycemia) quite expensive for older individuals with diabetes. To emphasize the important role CGM can play in this population, Dr. Hirsch cited T1D Exchange data: 12% of those who have had diabetes for over 40 years and are older than 50 years have experienced having a seizure or being in a coma from hypoglycemia. There are some cases of Medicare covering a CGM, but both Drs. Bode and Hirsch said that it took dedicated patients who wrote letters, called, and demanded that they get coverage for a CGM. Certainly, there are no guarantees, but persistence might currently be the only option. Dr. Hirsch advocated for a CGM trial with Medicare patients to demonstrate the technology’s benefits on hypoglycemia. Encouragingly, the American Diabetes Association and Lilly announced a partnership on June 4 to better understand diabetes care in older adults. We hope some of the research efforts include studies on CGM in this population.
European Congress on Obesity 2013 – The Mediterranean Diet
At the European Congress on Obesity in Liverpool, UK, we appreciated hearing Dr. Miguel Ángel Martínez-González (University of Navarra, Pamplona, Spain) speak on his landmark study about the Mediterranean diet, PREDIMED (PREvención con DIeta MEDiterránea). The investigation in which he was the senior author was recently published in the prestigious New England Journal of Medicine (Estruch et al., NEJM, April 2013).
The study found that a Mediterranean diet reduced the risk of heart disease by 30% in people with a high risk for the disease. This type of diet consists of mainly plant-based foods (e.g., fruits, vegetables, whole grains, legumes, and nuts), healthy fats (e.g., virgin olive oil, nuts, and seeds), fish and poultry. The PREDIMED study had nearly 7,500 participants ranging from 55 to 80 years old. They had either type 2 diabetes or three or more metabolic syndrome risk factors (e.g. hypertension, elevated LDL cholesterol, low HDL cholesterol, etc.), but did not have heart disease. Dietitians taught everyone in the study what to eat. The control group was advised to simply reduce their dietary fat, while two other groups ate a Mediterranean diet supplemented with either nuts or virgin olive oil. Different participants stayed in the trial for different years, but after an average of 4.8 years, those who were in either of the two Mediterranean diet groups fared better than those in the control group.
PREDIMED is the first randomized controlled trial in nutrition aimed to prevent cardiovascular disease. Oftentimes, lifestyle modifications, such as changing what people eat or how much exercise they do, are very difficult to sustain over long periods of time. However, participants in the study were able to maintain the Mediterranean diet for nearly five years! We hope that there will be more nutritional studies that investigate interventions with the potential to work well after the trials end.
