Brett Molina, USA TODAY – Insulin use is expected to rise 20 percent by 2030, and many people who need it for Type 2 diabetes won’t have access, a study from Stanford University suggests.
Globally, 511 million adults are expected to have Type 2 diabetes in 12 years, up from 406 million this year, the study found. More than half of those people come from China, India and the U.S.
The study found 79 million people worldwide will require insulin to treat the disease, but only 38 million will have access.
“These estimates suggest that current levels of insulin access are highly inadequate compared to the projected need, particularly in Africa and Asia, and more efforts should be devoted to overcoming this looming health challenge,” Sanjay Basu, an assistant professor of medicine at Stanford, said.
Researchers are urging governments to make insulin more available and affordable to boost access.
A big concern with accessibility to insulin is high costs.
In May, William T. Cefalu, the chief scientific, medical and mission officer with the American Diabetes Association, testified before the Senate to discussing insulin prices, which have tripled between 2002 and 2013. Read more.
How Insulin Is Made
Purified animal-sourced insulin was initially the only type of insulin available to diabetics.
The amino acid structure of insulin was characterized in the early 1950s by Frederick Sanger, and the first synthetic insulin was produced simultaneously in the labs of Panayotis Katsoyannis at the University of Pittsburgh and Helmut Zahn at RWTH Aachen University in the early 1960s. Synthetic crystalline bovine insulin was achieved by Chinese researchers in 1965.
The first genetically engineered, synthetic “human” insulin was produced using E. coli in 1978 by Arthur Riggs and Keiichi Itakura at the Beckman Research Institute of the City of Hope in collaboration with Herbert Boyer at Genentech.
Genentech, founded by Swanson, Boyer and Eli Lilly and Company, went on in 1982 to sell the first commercially available biosynthetic human insulin under the brand name Humulin. The vast majority of insulin currently used worldwide is now biosynthetic recombinant “human” insulin or its analogues.
Recombinant insulin is produced either in yeast (usually Saccharomyces cerevisiae) or E. coli.
In yeast, insulin may be engineered as a single-chain protein with a KexII endoprotease (a yeast homolog of PCI/PCII) site that separates the insulin A chain from a c-terminally truncated insulin B chain.
A chemically synthesized c-terminal tail is then grafted onto insulin by reverse proteolysis using the inexpensive protease trypsin; typically the lysine on the c-terminal tail is protected with a chemical protecting group to prevent proteolysis.
The ease of modular synthesis and the relative safety of modifications in that region accounts for common insulin analogs with c-terminal modifications (e.g. lispro, aspart, glulisine).
The Genentech synthesis and completely chemical synthesis such as that by Bruce Merrifield are not preferred because the efficiency of recombining the two insulin chains is low, primarily due to competition with the precipitation of insulin B chain.