by Gary Scheiner MS, CDE and Alicia Downs MSN, RN, CDE
Several pharmaceutical companies recently have submitted data to the FDA to gain approval for SGLT2 inhibitor medications to treat type 1 diabetes, alongside insulin. These medications, taken in pill form and sometimes combined with other drugs like metformin, are already on the market for people with type 2 diabetes, and are being prescribed off label for people with type 1 diabetes by some health care providers.
So what do these medications do? How can they benefit people with type 1 diabetes? And what are the risks?
In the kidney, SGLT2 “channels” are responsible for preventing the body from losing excess glucose in the urine by pulling glucose back into the bloodstream. In people without diabetes, this keeps blood sugars from dropping too low when excess fluid leaves the body via urination. SGLT2 medications inhibit that action, reducing the reabsorption of glucose and letting that glucose pass into the urine.
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The first obvious benefit of this is less glucose in the bloodstream: lower blood sugars and lower HbA1c. And because extra glucose excretion takes place all the time, blood sugars tend to peak less after meals.
An added “side” benefit for some is weight loss. Loss of urine in the glucose equates with a loss of calories, as every gram of glucose contains four calories. Also, reduced insulin requirements make weight loss a bit easier.
SGLT2 inhibitors have been linked to reduced incidence of cardiovascular disease and stroke – a definite plus for those with multiple risk factors for heart disease. When we urinate away sugar, we also urinate away water, resulting in a reduction in blood pressure.
Any medication that works on the kidneys has potentially harmful side effects. Most common among these: genital yeast infections and urinary tract infections. The extra glucose in the urine feeds bacteria throughout the urinary tract, allowing infection which can spread to the bladder and kidneys.
The second most-common side effect is low blood pressure. This increases the risk of falling or fainting. The risk is highest for those who take other fluid-reducing medications, blood pressure-lowering medications, or certain pain relievers and anti-anxiety medications. This loss of fluid can also cause electrolyte imbalances that can be life threatening.
Also, SGLT2 medications cause the kidneys to continue lowering blood glucose levels even when those levels are in a normal range, increasing the risk of hypoglycemia. People using these medications may need to adjust basal (long-acting) and bolus (mealtime & correction) insulin doses.
One serious side effect that is specific to people with type 1 diabetes is the risk of diabetic ketoacidosis (DKA). This is due to the fact that SGLT2 inhibitors contribute to dehydration, reduced insulin dosing, and a reduced ability to clear ketones through the urine. And DKA can occur even when blood sugar levels are reasonably close to being in range with this medication. Normally, unexplained high blood sugar levels prompt people with type 1 diabetes to troubleshoot and remedy whatever is causing the problem, but without the high readings to alert us to a problem, treatment may be delayed until significant damage is done.
To mitigate the risks associated with SGLT2 medication, insulin users should:
-Practice excellent bathroom hygiene to reduce the risk of urinary tract infections
-Drink plenty of water every day to prevent low blood pressure
-Make sure labwork includes tests for electrolyte balance and renal function
-Check for ketones even with slight blood sugar elevations and when ill.
-Establish a sick-day plan that specifically includes when to stop SGLT2 medications and increase insulin doses
-Never skip insulin doses, and discuss all planned or unplanned dosage reductions with your HCP
-Consume sufficient carbohydrates to avoid ketosis
Use of non-traditional medications is becoming increasingly popular for treating type 1 diabetes. As with all diabetes therapies, the risks and benefits need to be weighed carefully and discussed with a healthcare provider who knows your personal health history.
Gary Scheiner is Owner and Clinical Director of Integrated Diabetes Services, a private practice specializing in intensive insulin therapy for children and adults.
Alicia Downs RN, MSN, CDE is the Director of Patient Care and Education at Integrated Diabetes Services, specializing in managing diabetes with co-occurring diagnoses. Both have T1 and use insulin pump & CGM technology as well as non-insulin options for management.
Visit www.integrateddiabetes.com for more information.