12 Oct Be careful with how you store insulin
New research that set out to analyze the temperatures at which people living with diabetes store
their insulin is now warning against the perils of improper storage for the quality and
effectiveness of the hormone.
More than 30 million people in the United States are currently living with diabetes. Around 95
percent of these people have type 2 diabetes.
People with type 1 diabetes need to have insulin injections or have insulin delivered with a pump
in order to survive. Though some people with type 2 diabetes can control their blood sugar levels
using lifestyle changes and medication, many of them also resort to insulin to regulate blood
Insulin is absolutely vital for helping cells get access to glucose and use it for energy. Without it,
the person's blood sugar levels skyrocket, leading to hyperglycemia.
According to estimates from the Centers for Disease Control and Prevention (CDC), as many as
2.9 million U.S. individuals take only insulin, and another 3.1 million take insulin in addition to
A new study, however, suggests that many of these people might not get the full benefits from
their insulin therapy; the hormone may be stored at incorrect temperatures in people's domestic
fridges, which could make it less effective.
It was led by Dr. Katarina Braune from Charité – Universitaetsmedizin Berlin in Germany
alongside Prof. Lutz Heinemann, from Sciences & Co in Paris, France, and the digital health
company MedAngel BV.
Dr. Braune and colleagues presented their findings at the European Association for the Study of
Diabetes Annual Meeting, held in Berlin, Germany.
Insulin needs to be stored in a refrigerator at a temperature around 2–8°C (36–46°F) in order for
it to be effective. If carried in a pen or vial, it must be stored around 2–30°C (36–86°F).
Dr. Braune and her colleagues examined the temperature at which insulin was stored in domestic
fridges and carried around by 388 people with diabetes living in the U.S. and European Union.
They installed temperature sensors next to the volunteers' home fridges or in their diabetes bags.
These sensors took measurements automatically every 3 minutes, or 480 times per day, for a
period of 49 days.
The measurements were sent to a database though an app. Overall, the analysis comprised 400
temperature logs, 79 percent of which fell outside of the temperature guidelines.
The analysis found that 11 percent of the time — or 2 hours and 34 minutes each day — the
insulin was stored in the fridge at improper temperatures. Carried insulin fell outside of
recommendations only 8 minutes per day.
Freezing was also a significant problem, with sensors detecting temperatures below 0°C around
17 percent of the time, or 3 hours per month.
Dr. Braune comments on the findings, saying, "Many people with diabetes are unwittingly
storing their insulin wrong because of fluctuating temperatures in domestic refrigerators."
"When storing your insulin in the fridge at home, always use a thermometer to check the
temperature. Long-term storage conditions of insulin are known to have an impact on its blood-
glucose-lowering effect." She continues, "For people living with insulin-dependent diabetes who
take insulin several times a day via injections or continuously administer insulin with a pump,
precise dosing is essential to achieve optimal therapeutic outcomes."
"Even gradual loss of potency introduces unnecessary variability in dosing," adds Dr. Braune,
who warns, "More research is needed to examine the extent to which temperature deviations
during domestic storage affect insulin efficacy and patient outcomes."