Medical Post Diabetes Interview - 1
By Dr. Shafiq Qaadri, MD
Is diabetes on the rise in Canada?
Yes, there is certainly an epidemic of diabetes in Canada, as there is elsewhere in the world. It is estimated that from the year 2000 to 2016 the number of people with diabetes will increase from about 1.4 million to 2.5 million—almost a doubling…Unfortunately, we are also seeing diabetes in younger and younger individuals. Even our pediatricians are commonly seeing type II diabetes, which was unheard of previously. And, of course, with earlier development of the disease, there will be more time for the complications to arise.
For example, last week I saw a 28-year-old man, who was overweight, had diabetes, dyslipidemia and hypertension, and certainly all of the features of the metabolic syndrome. Such individuals are at high risk for developing complications.
Why is undiagnosed or unrecognized diabetes so prevalent?
We are improving with regards to the diagnosis of diabetes but it still remains a problem. A few years ago, the estimate was that half of the people with diabetes did not know that they had it. Today, it’s down to a third.
This is because, to a large extent, diabetes is an asymptomatic disease until it’s relatively advanced. It’s unfortunate to have to point out that we still see people with diabetes who are diagnosed for the first time when they present with complications.
What are the glucose levels that physicians should be aware of regarding diabetes?
Right now, we consider a patient to have diabetes if they have a fasting sugar above 7.0 mmol/L, or a 2-hour pc above 11.1 mmol/L, confirmed on a secondary test.
We have two categories of intermediate abnormalities. A patient has impaired fasting glucose if they have a fasting sugar between 6.1 to 6.9 mmol/L. A patient has impaired glucose tolerance, which is the measure of sugar 2 hours after ingestion of a 75 gram glucose challenge, if their sugar is between 7.8 to 11.1 mmol/L.
It turns out that the 2-hour test can become abnormal before the fasting sugar will—so to rely just on fasting sugar to diagnose diabetes would lead to many cases being missed.
Why is diabetes increasing?
There are several reasons.
As a society, we are becoming fatter, less physically active, and we are taking in a less than optimal diet. People are even using the phrase that we are living in a ‘toxic environment.’
In addition, in Canada we have a lot of immigration of individuals who are at high risk of developing diabetes.
In the USA, books are being published with the terms ‘diabesity’ and ‘pre-diabetes.’ Can you comment?
Pre-diabetes is a term that would include impaired fasting glucose and impaired glucose tolerance. So people who don’t meet the diagnostic criteria of diabetes, yet are close, are considered to be in this intermediate stage.
And even if these people do not go on to develop diabetes, they are still at an increased risk for vascular disease.
The term ‘diabesity’ just refers to the common overlap type II diabetes and obesity.
Why is the Hemoglobin A1C (Hb A1C), the glycosylated hemoglobin, not used as a screening test?
It is not as sensitive as the diagnostic criteria. For example, with A1Cs at the upper limit of normal, say 5.8%, patients may have normal glucose tolerance, they may have pre-diabetes, or they may have diabetes.
The A1C test is very useful in terms of monitoring glycemic control, and we continue to recommend that it be done periodically, generally a few times a year.
What are the first line treatments for type II diabetes?
The Canadian Diabetes Association Treatment Guidelines state that lifestyle is an integral part of the management. Weight loss is an important factor since most of our type II patients are overweight; and increased physical activity is also important.
At the same time, what the guidelines recognize that for the vast majority of our patients’ lifestyle changes will not be enough, and most will require pharmacologic therapy.
The guidelines recommend, for the overweight person with type II diabetes, that the first drug be metformin. The reason this was chosen as first-line therapy is that in the landmark United Kingdom Prospective Diabetes Study (UKPDS) the meformin-treated, overweight patients had fewer vascular events, as compared to those patients treated with sulfonylureas or insulin.
If the patient remains hyperglycemic on the maximum dose of 2000 mg of metformin per day, then we add a second-line therapy, a glitazone—either pioglitazone (Actos) or rosiglitazone (Avandia).
These are second-line therapies, even before sulfonylureas?
Yes. Third-line therapies are insulin-secretagogues, such as sufonylureas like glyburide (Diabeta), gliclazide (Diamicron), or glimeperide (Amaryl). There are also non-sulfonylurea secretagogues, and those a repaglinide (Gluconorm) or nateglinide (Starlix).
Other therapies that can be used include acarbose (Prandase).
If the A1C remains elevated despite two or three oral agents, then we typically add insulin at bedtime while maintaining the oral agents. If A1C continues to remain elevated, then we would increase the number of injections.
Another significant change from our previous guidelines is this: if a patient presents with an A1C above 9%, we know that it is extremely unlikely that a single drug will control that patient; therefore, we recommend combination therapy from the start, or insulin therapy from the start.
When did this treatment change occur—mixing both oral and injectable agents?
I think it’s best to say we just evolved there over the years. There are an increasing number of studies that show that the combination of bedtime insulin with pills during the day leads to good control with less weight gain, than giving insulin alone.
A number of studies are indicating that ACE Inhibitor usage leads to a lower incidence of diabetes. Do we have any sense of the mechanism involved?
There are many theories. There is no single mechanism; in fact, this is a story unto itself. There is growing evidence that the regulation of the renin-angiotensin system can improve insulin sensitivity. There are a number of trials with both ACE Inhibitors and ARBs that are showing this.
Physicians are now using metformin in infertility patients to address the hyperinsulinemia found in conditions such as polycystic ovarian syndrome. How and why is this possible?
There is increasing recognition that polycystic ovarian syndrome is an insulin-resistant condition. There are studies using both metformin and glitazones that show that they may improve menstrual period irregularity, may increase ovulatory function, and may increase fertility.
Having said this, none of these agents are formally indicated for those conditions in Canada.
What are the adherence challenges in the management of diabetes?
One of the major issues that we face is polypharmacy.
We practice evidence-based medicine, and we now have a lot of data that shows if we want to reduce complications, we must optimize not only blood glucose, but also blood pressure, lipid levels, use an ACE Inhibitor, use aspirin, and so on. It has been demonstrated that, on average, diabetic patients are on seven different medications. So adherence is a particular challenge, as patients may not understand the importance of their medications, they may get confused, and some of the pills may be associated with side effects or adverse events.
Studies show that patients who are less adherent to their medication regimen will have higher A1Cs, and have higher risk of complications.
What can we do as physicians to ensure that our patients adhere to their treatments?
There are a number of things. Firstly, use treatment regimens that are as simple as possible. Try to reduce the pill burden. Decrease the number of times a day when people have to take medication…Use combination tablets when possible. Make sure your patients understand why they are taking the medications.
In fact, one thing physicians frequently don’t do is actually verify that the patients understand their treatment regimen. We should also discuss potential adverse events, so people know what to expect. Also, if patients do have a problem, they should come in to discuss their difficulty, at the time of the problem, not three months later at the time of the next visit.
For example, there have been a number of studies that have looked at adherence with medication in diabetes. Results vary from study to study, but typical findings regarding adherence with oral agents is between 65 to 85 percent; and with regard to insulin in type II patients, it’s estimated that only 60 percent of prescribed doses are actually taken.
Have we as doctors communicated to our patients that diabetes is actually, at heart, a cardiovascular disease?
I think in the past we have been guilty of being too glucocentric, talking just about glucose levels. There is increasing recognition that there is a huge overlap between diabetes and cardiovascular disease. For example, up to 80 percent of people with diabetes will die because of vascular disease.
Given this overlap, we have to do whatever we can, in a comprehensive way, to reduce the risk and burden of vascular disease in diabetes.
What is your final message regarding the management of diabetes?
Over the last few years, we have had increasing evidence that we can have an impact on the outcome of diabetes in our patients. Given the fact that we are seeing more and more diabetes, at younger and younger ages, we are going to have a huge public health burden unless we address these issues. These efforts should include prevention of diabetes, treatment, management of complications, as well as aggressive management of the associated metabolic abnormalities.
Dr. Shafiq Qaadri is a Toronto family physician and Continuing Medical Education (CME) lecturer. www.doctorQ.ca
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