Diabetes mellitus is a group of metabolic disorders characterised by high blood sugar over a prolonged period. Serious long-term complications include cardiovascular disease, chronic kidney disease, stroke, damage to the eyes and foot ulcers. The three main types of diabetes are type 1, wherein the pancreas fails to produce enough insulin; type 2, in which cells fail to respond to insulin properly; and gestational diabetes, which occurs in pregnant women with no previous history of diabetes.
The disease is diagnosed by three markers—a fasting plasma glucose of more than 126, postprandial sugar level of more than 200 and HbA1c of more than 6.5. So, how do we tackle it? The simplest regimen is to start a metformin drug therapy. It reduces the production of glucose in the liver. It is also recommended as first-line drug in prediabetes phase. According to latest guidelines by the American Diabetes Association, the second drug should be either a SGLT2 inhibitor or a GLP-1 agonist. The former is a drug that inhibits glucose reabsorption from the kidney; the latter mimics GLP-1, a hormone that stimulates insulin secretion. The former reduces blood sugar, causes weight loss and decreases symptoms related to heart failure. The only major side effect—it may cause genital infections in patients who do not drink enough water. GLP-1 agonists control sugar level not tamed with tablets and weight loss in obese patients. But, it may cause pancreatitis or pancreatic cancer in certain patients if not take under physician supervision. Also, it is costly.
The third class of recommended drugs is DPP-4 inhibitors. These drugs block DPP-4, a protein that prevents insulin production, thereby increasing the action of insulin.
According to latest guidelines, sulfonylurea—a class of drugs widely prescribed in India because of low cost—can cause hypoglycaemia in elderly patients. If DPP-4 inhibitors are taken together with sulfonylurea, there may be an increased risk of low blood sugar.
Coming to a scenario where a patient has uncontrolled sugar even with oral drugs after five years. This is where insulins come into play. Traditionally, we used a basal or long-acting insulin at night, which acts for 24 hours and controls hyperglycemia. But, in Indian patients, postprandial sugar levels are also high, because of high carbohydrate intake. So, we need to use either prandial insulins thrice a day with meals, or twice daily premixed insulins (two insulins mixed together).
I would like to share a real case of mine. Our orthopaedics team referred to me a diabetic patient scheduled for knee replacement surgery. She had HbA1c of more than 11, a BMI of 34, fasting sugar level of about 200 with postprandial sugar level at 340. I was given a week to control the sugar level. She was already on 80 units of insulin. I gave her the latest degludec insulin (an ultra long acting basal insulin analogue), with aspart (a fast-acting insulin analogue), 20 units in the morning and 20 units in the evening, with a DPP-4/metformin tablet, and a once-a-week GLP-1 injection. In one week, fasting blood sugar was down to 130 and postprandial blood sugar was 170. The surgery took place on time and she was discharged with the same medication. It was just a case of the right insulin used at the right time on the right patient. While these drugs are commonly used in urban India, the purpose of this article is to educate doctors in semi-urban and rural areas that newer modalities are available. Newer drugs are on the way—degludec plus liraglutide injection as well as oral GLP-1 agonist semaglutide. So, there is hope.
The writer is consultant, internal medicine and preventive health, VPS Lakeshore Hospital, Kochi