Pitfalls in the management of diabetes
In the first of a series of interactive clinical conversations on the pitfalls in the management of type 2 diabetes mellitus (T2DM) held last week, noted endocrinologist Augusto Litonjua, cardiologist Nelson Abelardo, and kidney specialist Agnes Estrella tackled common dilemmas and challenges clinicians encounter when they treat their diabetic patients. I was privileged to facilitate the discussion.
The expert panel stressed that physicians need to reexamine their current goals and treatments to prevent serious long-term complications, some of which may be related to the treatment and inappropriate aggressiveness in lowering the blood sugar to near-normal levels.
Blood sugar determination whether fasting (before breakfast after an overnight fast) or postprandial (after meals) is usually done to diagnose T2DM, but the glycated hemoglobin (HbA1c) test is likewise useful in diagnosing diabetes and monitoring the response to treatment. The HbA1c reflects the average blood sugar levels during the past three months. It’s like getting the weighted average of the blood sugar levels during the previous three months.
What exactly is the HbA1c? When the blood sugar is high, the glucose not used by the body and no longer stored in the various tissues of the body stays in the blood and attaches to the red blood cells, which normally has a life span of three to four months. The HbA1c test therefore measures the amount of sugar (glucose) attached to the red blood cells.
The HbA1c result, expressed in percent, corresponds to an estimated average glucose, or eAG, indicating the average blood sugar levels in the previous three months. The eAG is indicated in the same units (mg/dl) as the blood sugar.
For example, an HbA1c level of 6 percent corresponds to an eAG of 126 mg/dl, which theoretically is the upper limit of normal. But in general, for most diabetics under treatment, the HbA1c goal is between 6.5 and 7 percent, corresponding to an eAG of 140 to 154 mg/dl.
Dr. Litonjua explained that this HbA1c goal (6.5 to 7 percent) should not be a rigid goal, and should be individualized depending on the age, presence of other illnesses, and overall condition of the patient.
In the elderly, for example, the physician should not be very strict in trying to achieve a near normal blood sugar and HbA1c levels. They may have a higher risk of falling, fainting, getting hurt and suffering from fractures with low levels of blood sugar (hypoglycemia). For elderly and frail diabetics, an HbA1c target of less than 8.5 percent, corresponding to an eAG of less than 197 mg/dl should be good enough.
For young, otherwise healthy diabetics, an HbA1c of around 6.5 percent or even lower would be ideal, provided there are no episodes of hypoglycemia.
Doctors Abelardo and Estrella warned the audience on the hazards of overzealous or aggressive treatment of diabetics on the heart and kidneys. Hypoglycemic episodes can cause potentially life-threatening irregular heartbeats (arrhythmia) and lack of oxygen (myocardial ischemia) which may lead to heart attack and even sudden death. So the risk of aggressive blood sugar control far outweigh the potential benefit of controlling the blood sugar to near normal levels, explained Dr. Abelardo.
To illustrate his point, Dr. Abelardo cited several landmark clinical trials which showed paradoxical findings. High-risk diabetics given intensive treatment to control the blood sugar levels to near normal levels had more heart attacks, strokes and all causes of deaths than those who were treated less aggressively.
Prone to hypoglycemia
For her part, Dr. Estrella explained that diabetics with kidney involvement already (chronic kidney disease or CKD secondary to diabetic nephropathy) are more prone to hypoglycemia and its attendant complications. A big number of diabetics eventually develop CKD, which may progress to end-stage renal disease (ESRD) requiring lifelong dialysis or kidney transplantation.
This is the reason why checking for protein spillage in the urine (microalbuminuria) at least once a year is important in detecting the onset of CKD early enough which can be improved with available treatments for the diabetes and the blood pressure.
It may seem ironical but hypoglycemia is actually linked with increased weight gain in diabetics. Dr. Litonjua explained that relatively low blood sugar levels cause “defensive eating” in diabetics and they may not realize they’re putting on weight. Weight gain is a common side-effect of several commonly used antidiabetic agents. So if the patient is overweight already, the physician should avoid prescribing these drugs.
To prevent hypoglycemia and weight gain in diabetics, the newer classes of drugs like the DPP4 (dipeptidyl peptidase-4) inhibitors, GLP-1 (glucagon-like peptide-1), and the SGLT2 (sodium glucose cotransporter-2) are preferred. To improve further the long-term outlook (prognosis) of the heart and kidneys of diabetics, the expert panel also recommended the use of a renin-angiotensin (RAS) blocker, specifically an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB).
Statins, which are generally prescribed for patients with elevated cholesterol levels, should also be given all diabetics even if their cholesterol levels are normal because of their benefits in diabetics not related to the drug’s cholesterol-lowering effects. For those with chest pains or other symptoms of coronary artery disease (CAD) due to narrowing of the heart arteries, blood thinners (antiplatelet agents) like the good old aspirin will also be beneficial.
The Diabetic Forum, an interactive clinical conversation between the expert panel and doctor-participants, is being conducted in various cities nationwide throughout the year. It is organized by LRI-Therapharma, as part of its continuing medical education program for doctors. The doctor-participants take part in the interactive discussion of cases presented, and if the time permits, they may ask additional questions to the experts in the panel. To know the schedule of the forum in one’s area and to reserve a seat, interested physicians may contact the LRI-Therapharma representative in the area, or may call/text the organizers (0917-8207678).