(Reuters Health) - The cost of insulin prevents many people with diabetes from taking it as directed, a small survey suggests.

At the Yale Diabetes Center in New Haven, Connecticut, where the survey was conducted, one in four people using insulin reported taking less of it than doctors recommend because they can’t afford it. These patients may have a higher risk of complications than individuals who always take their medicine, researchers say.

The 199 patients who participated in the survey had been prescribed insulin within the past six months. Overall, 51 patients, or 26 percent, said that they skipped doses, took smaller doses than prescribed, or stopped insulin altogether because of costs, researchers report in JAMA Internal Medicine.

“Skimping on insulin is frighteningly common,” said senior study author Dr. Kasia Lipska of the Yale School of Medicine.

Researchers looked at patients with two types of diabetes, both of which are chronic diseases that affect the way the body regulates blood sugar.

The most common form, type 2 diabetes, is linked to obesity and aging and happens when the body can’t properly use or make enough of the hormone insulin to convert blood sugar into energy. The less common form, type 1 diabetes, develops in childhood or young adulthood and occurs when the pancreas produces no insulin at all.

When people with type 1 diabetes don’t take insulin as prescribed, the result can quickly be fatal. With type 2 diabetes, failure to take needed insulin can increase the risk of long-term complications like blindness, kidney failure, nerve problems and amputations.

“Not taking enough insulin has devastating consequences for people with diabetes,” Lipska said by email.

More than one-third of patients who didn’t take insulin as prescribed also didn’t tell their doctors about the cost concerns that contributed to this decision, the study found.

And, people who reported cost-related under use of insulin were almost three times more likely to have poorly controlled blood sugar than patients who took insulin as prescribed by their doctor.

The study wasn’t a controlled experiment designed to prove whether or how cost-related decisions to cut back on needed insulin might directly impact patients’ health. It also involved patients at a single medical center, and results might be different elsewhere.

Even so, the findings highlight the need for doctors to speak frankly with patients about costs, and make sure patients understand any more affordable alternatives as well as any health consequences of skipping medication, Lipska said.

“Patients should know that older versions of insulin, called human insulin, such as NPH and Regular insulin, are available for $25 per vial and actually can be purchased without a prescription,” Lipska said. “I advise that patients work with their clinicians to figure out the best option that fits their circumstances.”

In some cases, people at lower incomes may actually have an easier time affording insulin than more affluent patients because they get insurance through Medicaid, which may have lower out-of-pocket costs for insulin than private health insurance offered to workers by many employers, said Dr. Elisabeth Rosenthal, author of an accompanying editorial and editor-in-chief of Kaiser Health News.

“Even people earning $100,000 a year are not using as much insulin as prescribed,” Rosenthal said by email.

Almost 40 percent of patients making between $50,000 and $99,000 a year also reported taking less insulin than prescribed, the study found.

“Patients are stuck in a terrible place - choosing between their health and their finances,” Rosenthal said. “That’s particularly true of people with type 1 diabetes, which often starts in childhood, because they need insulin to live.”

SOURCE: bit.ly/2G1RPBI and bit.ly/2KXDuoy JAMA Internal Medicine, online December 3, 2018.