For most people with diabetes, insulin is the most reliable way to lower blood sugar. But is insulin the best way to prevent death and heart disease in Type 2 diabetes?
Recent studies seem to show that people with Type 2 treated with certain oral medications had less risk of dying than did people taking insulin. The insulin-users also had higher rates of cardiovascular disease (CVD). CVD is disease of the heart and blood vessels.
A study from Sweden followed over 20,000 adults diagnosed with Type 2. Half were starting insulin therapy; the other half started one of the newer oral drugs, either a DPP-4 inhibitor or an SGLT2 inhibitor.
DPP-4 inhibitors help raise the body’s level of incretin hormones, such as GLP-1. GLP-1 decreases insulin resistance and promotes insulin production in response to glucose.
SGLT2 inhibitors cause glucose to be eliminated in the urine, lowering blood levels.
Subjects were followed for a year and a half. People using the oral drugs had a 44% decreased risk for all-cause mortality, and 15% less risk of CVD. The oral drugs also were linked with a 74% lower risk of severe low sugars (hypoglycemia).
The SGLT2 inhibitor used in the study (dapagliflozin, brand name Farxiga) lowered the risk for death more than the DPP-4 inhibitors did, but the DPP-4 drugs were associated with a lower risk of severe hypoglycemia. Risk of hypoglycemia might be important, because hypos might themselves cause physical stress that could lead to earlier death.
(By the way, you might be wondering what is meant by death rate or mortality rate. Isn’t everybody’s death rate the same: one to a person? It is, but the statistic “death rate” refers to the number of deaths in a given period, like five years, or whatever the study’s timeframe is.)
A study from Wales last year followed about 12,000 people with Type 2 who used insulin. About half were also taking metformin.
According to Diabetes Self-Management editor Diane Fennell, “the researchers found that people using metformin along with insulin had a 40% reduced risk of death and a 25% reduced risk of major heart problems compared to those using insulin alone. There was not a difference in the risk of cancer between those using metformin and insulin and those using insulin alone.”
Previous studies had analyzed rates of death from cancer in people using insulin or sulfonylureas. Sulfonylureas increase the body’s output of insulin. Those patients had a higher risk of cancer-related death than did those using metformin.
It could be that insulin, a growth hormone, promotes cancer growth, as I wrote about here recently.
People injecting insulin sometimes experience unwanted weight gain, because insulin helps extra glucose be stored as fat instead of having it passed out in the urine.
So, should people with Type 2 avoid taking insulin? Most experts think not. A widely-cited article in the journal Diabetes Care recommends insulin therapy for Type 2 patients whose A1C is 7.0% or above despite oral medications.
The authors state that insulin therapy reduces “microvascular complications” in people with Type 2. Microvascular means damage to the kidneys, eyes, and nerves, where blood vessels are small. “Insulin is not only the most potent, but also the most cost-effective intervention,” they wrote. “We advocate [starting] insulin when glycemic goals are not [reached] after 2–3 months [on two oral drugs.]”
They recommend starting with basal insulin injections once or twice a day. They say that basals will get A1C below 7.0% for most patients, which they call a reasonable goal.
It seems that if you need insulin to get your glucose levels down, it’s better to take it than to run high levels. But because of the risk of hypos, the higher risk of CVD and mortality, the possible risk of cancer, and the difficulty, discomfort, and expense of therapy, it’s better to get your glucose level down without insulin if you can.
You might also have to consider the expense of the new oral therapies. DPP-4 inhibitors and SGLT2 inhibitors are still under patent. For people with no insurance, they can cost roughly $350 to $400 a month. They are convenient (one pill a day), but may not be affordable, depending on your insurance.
It’s good that we have all these medical options for lowering glucose levels. But given the risks and costs, it might be far better if you can lower your glucose through diet, movement, and plant medicines. Read about effective diets here, and potential herbal remedies here.
When it comes to insulin, timing can be just as important as ratios and amounts, says Scott Coulter. Bookmark DiabetesSelfManagement.com and tune in tomorrow to read more.