100 Years of Insulin: Advancements in Diabetes Treatment Through the Ages
To mark the centennial anniversary of the landmark discovery of insulin, we reflected on improvements in diabetes therapies, highlighted modern technologies, and peered into the not-too-distant future of advancements in diabetes care.
From Antiquity to Insulin
Diabetes mellitus was recognized as a disease as early as 1500 BC, and was the only known form of diabetes until 1935 when Roger Hinsworth discovered and differentiated the two primary types: insulin-dependent Type 1 and insulin-resistant Type 2. Both present dangers to one’s health; for those with Type 1 diabetes, it is important to manage glucose within healthy ranges to avoid potential emergency situations at low levels (hypoglycemia), and also avoid extended time periods in high ranges (hyperglycemia) that risk long term complications such as cardiovascular disease — a risk that is equally present for people with Type 2 diabetes. Today, it is estimated that there are over 463 million people living with diabetes worldwide, with another 374 million people at risk of developing it.
For centuries, a variety of treatments were attempted but the disease was ultimately considered terminal, with a life expectancy of about 3 years. It wasn’t until 1921, that Sir Frederick Grant Banting and Charles Herbert Best discovered insulin as the necessary treatment to manage diabetes (in fact, they became so confident in insulin as a treatment that they tested it on themselves, resulting in experiences of weakness and dizziness- common symptoms of hypoglycemia). After its discovery, insulin production went through a number of developments to improve its efficacy, and today, both fast-acting and long-acting insulins are available to support the management of those with insulin-dependent diabetes. Advancements in oral insulins have been shown to improve glycemic control and promote weight loss for those with insulin-resistant Type 2 diabetes, as well. But proper insulin dosing is just one component of a suitable management plan for diabetes treatment, and proper insulin dosing is only enabled through accurate blood glucose monitoring.
Measuring Blood Glucose
From the early 1900s, blood glucose was semi-quantifiable using urine and a copper reagent. Relatively few advancements took place in the area of glucose measurement until the mid-1960s when the Ames Division of Miles Laboratories developed the first blood glucose test strip, Dextrostix. Performed at doctor’s offices, this 60-second test required a large drop of blood and its glucose measurement was determined via color chart. Home and personal use blood glucose meters were developed throughout the 1970s, but their accuracy was too poor for mass adoption. Then, in 1981, the Dextrometer was launched and marked the beginning of a new era: personal blood glucose monitoring. Other meters would soon enter the market and this new sector of self-monitoring blood glucose devices would soon become the standard of care for diabetes glucose measurement.
Continuous Glucose Monitoring & Hybrid Closed-Loop: The Next Frontier
While the advent of blood glucose meter technology was revolutionary, those meters contain inherent flaws in that they can’t identify trends or, more importantly, provide alerts as soon as blood glucose levels move outside target zones. The next milestone in blood glucose monitoring solved these issues with the development of the continuous glucose monitor (CGM), which provides a constant stream of blood glucose information to the user. Since their market launch in 1999, the accuracy of CGMs have improved to the point that they are on par with the traditional blood glucose meters. Current CGM systems provide an automated blood glucose measurement every five minutes, meaning users receive approximately 300 measurements per day. And it’s not just convenience that is improved with CGMs- studies have shown that HbA1c levels, hypoglycemic events, and a user’s healthcare costs all improve from CGM use.
What’s Next For Diabetes Care?
The next technological evolution for people with insulin dependent diabetes will be a truly closed-loop delivery system, where a CGM and insulin pump share information and adjust insulin delivery for the user in real time. The diabetes community is halfway there with existing ‘hybrid’ closed-loop systems that automate long-acting insulin delivery based on information communicated directly from the user’s CGM device. Although this is highly convenient and has been shown to improve HbA1c levels and time-in-target ratios, it still requires the user to manually determine and deliver fast-acting insulin. A true closed-loop system that removes the need for human input is the next step in insulin delivery advancements, which will fully automate insulin delivery using a highly intelligent algorithm based on information received from the users’ CGM. This will further improve the overall health of the user by eliminating emergency risks and improving time-in-target performance, while also freeing them from many of the daily burdens associated with managing diabetes.
Finally, people with non-insulin dependent Type 2 diabetes, and even those with pre-diabetes, will be excited to hear that there are advancements coming that will improve their disease management, as well. Invasive test meters, still the standard for this group, will be challenged by non-invasive devices that will allow the user to obtain a glucose measurement through fingertip analysis- as easily as someone would unlock a smartphone. By removing the painful process of obtaining a single glucose measurement, these devices will allow users to easily collect many daily measurements. It’s been shown that the more frequently a person with diabetes tests themselves, the more information they will have to either confirm or adjust their treatments of diet, exercise, and prescriptions, leading to a healthier lifestyle and healthier outcomes.
