A different kind of medication can lower blood sugar through the kidneys.
Most diabetes drugs target insulin levels — by increasing the body’s sensitivity to insulin or stimulating more insulin secretion. But the U.S. Food and Drug Administration (FDA) has been approving a class of drugs that target the kidneys instead and could make a big difference for obese type 2 diabetics — as long as they have normal kidneys.
The “SGLT2” inhibitors — canagliflozin (Invokana), dapagliflozin (Farxiga), and empagliflozin (Jardiance) — lower blood sugar by causing the kidneys to remove sugar from the body through the urine. The most common approach is to take one of these drugs combined with the best-known diabetes medication, metformin (Glucophage).
One big warning: be alert for signs of ketoacidosis, which can put you in the emergency room, the FDA reports. Ketones are a chemical byproduct when the body is forced to break down fat for energy because it lacks the insulin needed to use glucose, the normal energy source. Ketoacidosis is rare in type 2 diabetics, but has occurred in some taking SGLT2 inhibitors — even when their blood sugar levels weren’t too high. Breathing problems, nausea, vomiting, abdominal pain, confusion, and unusual fatigue and sleepiness are all danger signs, sometimes triggered by an illness, not drinking or eating sufficiently, or taking less insulin than usual. If you suspect ketoacidosis, keep taking your medication but seek immediate medical help, the FDA advises.
Patients with moderate kidney disease may not tolerate the new drugs, and they’re not recommended at all for people with more severe kidney trouble. Pregnant women, children, type 1 diabetics, and people who tend to have excess ketones in their blood or urine should stay away.
The SGLT2 inhibitors are linked to slight weight loss, maybe 4 pounds, and lower blood pressure in people with hypertension. The most common unwanted side effects are genital yeast and urinary tract infections, dehydration, and a modest increase, of about 5 percent, in levels of LDL (“bad”) cholesterol.
Metformin continues to be a first choice medicine for new diabetes patients, since it doesn’t lead to weight gain, has a long safety record, and may be good for the heart. In fact, although it has been ruled out in patients with kidney trouble, there is evidence that the protocol is too strict and Metformin could work for patients with “mild–moderate, but stable, chronic kidney disease,” according to a 2014 overview by the American Diabetes Association.
Obese patients who are already taking large doses of insulin may be able to cut back if they add a SGLT2 to their regime, the Association notes.
Losing extra weight, following medical advice on your diet, and getting enough exercise are no less important now that there are new drug options. Should you run or lift weights? Probably both. A 2014 review of 12 trials found no major difference in the safety or heart benefits of aerobics or power-lifting for type 2 diabetes patients. However, the combination of strength training and aerobics may be the best strategy, along with dietary changes, for lowering blood sugar levels. The key is to find exercise routines you enjoy and will maintain.
July 17, 2015
Christopher Nystuen, MD, MBA