One-hundred year evolution of prandial insulin preparations: From animal pancreas extracts to rapid-acting analogs.

The first insulin preparation injected in humans in 1922 was short-acting, extracted from animal pancreas, contaminated by impurities. Ever since the insulin extracted from animal pancreas has been continuously purified, until an unlimited synthesis of regular human insulin (RHI) became possible in the '80s using the recombinant-DNA (rDNA) technique. The rDNA technique then led to the designer insulins (analogs) in the early '90s. Rapid-acting insulin analogs were developed to accelerate the slow subcutaneous (sc) absorption of RHI, thus lowering the 2-h post-prandial plasma glucose (PP-PG) and risk for late hypoglycemia as comparing with RHI. The first rapid-acting analog was lispro (in 1996), soon followed by aspart and glulisine. Rapid-acting analogs are more convenient than RHI: they improve early PP-PG, and 24-h PG and A1C as long as basal insulin is also optimized; they lower the risk of late PP hypoglycemia and they allow a shorter time-interval between injection and meal. Today rapid-acting analogs are the gold standard prandial insulins. Recently, even faster analogs have become available (faster aspart, ultra-rapid lispro) or are being studied (Biochaperone lispro), making additional gains in lowering PP-PG. Rapid-acting analogs are recommended in all those with type 1 and type 2 diabetes who need prandial insulin replacement.

Insulin discovery: A pivotal point in medical history.

The discovery of insulin in 1921 - due to the efforts of the Canadian research team based in Toronto - has been a landmark achievement in the history of medicine. Lives of people with diabetes were changed forever, considering that in the pre-insulin era this was a deadly condition. Insulin, right after its discovery, became the first hormone to be purified for human use, the first to be unraveled in its amino acid sequence and to be synthetized by DNA-recombinant technique, the first to be modified in its amino acid sequence to modify its duration of action. As such the discovery of insulin represents a pivotal point in medical history. Since the early days of its production, insulin has been improved in its pharmacokinetic and pharmacodynamic properties in the attempt to faithfully reproduce diurnal physiologic plasma insulin fluctuations. The evolution of insulin molecule has been paralleled by evolution in the way the hormone is administered. Once-weekly insulins will be available soon, and glucose-responsive "smart" insulins start showing their potential in early clinical studies. The first century of insulin as therapy was marked by relentless search for better formulations, a search that has not stopped yet. New technologies may have, indeed, the potential to provide further improvement of safety and efficacy of insulin therapy and, therefore, contribute to improvement of the quality of life of people with diabetes.

A century past the discovery of insulin: global progress and challenges for type 1 diabetes among children and adolescents in low-income and middle-income countries.

Type 1 diabetes is on the rise globally; however, the burden of mortality remains disproportionate in low-income and middle-income countries (LMICs). As 2021 marks 100 years since the discovery of insulin, we revisit progress, global burden of type 1 diabetes trends, and understanding of the pathogenesis and management practices related to the disease. Despite much progress, inequities in access and availability of insulin formulations persist and are reflected in differences in survival and morbidity patterns related to the disease. Some of these inequities have also been exacerbated by health-system challenges during the COVID-19 pandemic. There is a clear opportunity to improve access to insulin and related essential technologies for improved management of type 1 diabetes in LMICs, especially as a part of universal health coverage. These improvements will require concerted action and investments in human resources, community engagement, and education for the timely diagnosis and management of type 1 diabetes, as well as adequate health-care financing. Further research in LMICs, especially those in Africa, is needed to improve our understanding of the burden, risk factors, and implementation strategies for managing type 1 diabetes.

Winner's curse: The sad aftermath of the discovery of insulin.

Every young researcher dreams of making a great discovery, but few achieve it. If they do, success does not guarantee happiness. There is little satisfaction in discovering something if others get the credit, and those who achieve fame must face the 'winner's curse' of living up to their reputation. Few discoveries have been more dramatic than the isolation of insulin which, as Michael Bliss said, resembled a secular miracle. And yet, as he also pointed out, this great discovery brought little happiness to those who made it. Some were sidelined, and Banting and Best were saddled with the winner's curse. Here, we look at the ways in which a great discovery can haunt its discoverers.

100 years of physiology, discrimination and wonder.

There has been 100 years of research detailing the role of insulin in glucose, protein and free fatty acid metabolism. We explore the learnings though evolution and changes in management with an understanding of how it has impacted the care of people with diabetes. The discrimination endured is described and recent advances to empower and counter this are highlighted.

100 YEARS OF INSULIN: Arresting or curing type 1 diabetes: an elusive goal, but closing the gap.

Type 1 diabetes is one of the most common chronic diseases in children and adolescents, but remains unpreventable and incurable. The discovery of insulin, already 100 years ago, embodied a lifesaver for people with type 1 diabetes as it allowed the replacement of all functions of the beta cell. Nevertheless, despite all technological advances, the majority of type 1 diabetic patients fail to reach the recommended target HbA1c levels. The disease-associated complications remain the true burden of affected individuals and necessitate the search for disease prevention and reversal. The recognition that type 1 diabetes is a heterogeneous disease with an etiology in which both the innate and adaptive immune system as well as the insulin-producing beta cells intimately interact, has fostered the idea that treatment to specific molecular or cellular characteristics of the patient groups will be needed. Moreover, robust and reliable biomarkers to detect type 1 diabetes in the early (pre-symptomatic) phases are wanted to preserve functional beta cell mass. The pitfalls of past therapeutics along with the perspectives of current therapies can open up the path for future research.

Insulin's centenary: the birth of an idea.

At 2:00 h on Oct 31, 1920, Frederick G Banting, a surgeon practising in London, ON, Canada, conceived an idea to isolate the internal secretion of the pancreas. The following week, he met with noted scientist John J R Macleod in Toronto, ON, Canada, and they developed a research plan. By August, 1921, Banting and his student assistant Charles H Best had prepared an effective extract from a canine pancreas. In January, 1922, biochemist James B Collip isolated insulin that was sufficiently pure for human use. On Oct 25, 1923, Banting and Macleod received the Nobel Prize in Physiology or Medicine for the discovery of insulin. Here, we recount the most relevant events before and after the fateful early morning of Oct 31, 1920, which culminated in the discovery and clinical use of insulin.

Biometrics and citizenship: Measuring diabetes in the United States in the interwar years.

In 1936, the journalist Hannah Lees published "Two Million Tightrope Walkers," drawing attention to the significant number of people in the United States estimated to have diabetes. Focusing on how people with diabetes should live, she emphasized the importance of recording the exact values of everything they ate and avoiding all "riotous living" lest they be unable to keep careful measurements of calories, insulin, and sleep. Employing two meanings of measured - as counted and as moderate - Lees was doing more than communicating how someone might control their disease; she was also calling for a "controlled and self-reliant citizenry." Indeed, Lees insisted that diabetics who followed a regime of measurement "make a good deal better citizens than the average." Drawing on the writings of Lees and other social commentators, I explore the link between biometrics, citizenship, and diabetes in the United States in the interwar years. In particular, I look at how this disease came to symbolize both the regimes of discipline thought to be necessary in a society moving to consumption as its economic motor, and the fears of what could happen if consumption ran amok. Biometrics, I argue, offered clinicians and patients a potent tool for measuring deviance and, potentially, for restoring a person to the "norm."

Pancreatic Extracts for the Treatment of Diabetes (1889-1914): Acomatol.

BACKGROUND: Historical review on the early development of organotherapy for diabetes [pancreatic extracts (PE)] and its relationship with the social and political circumstances. AREAS OF UNCERTAINTY: The diagnosis of diabetes relied only in the presence of glycosuria and cardinal symptoms. Blood glucose determinations were not regularly available, requiring large volumes for sampling. Micromethods for glycemia were developed just in the last years of the investigated period. Hypoglycemia remains undiscovered. Isolation and purification of PE were difficult tasks due to the unknown chemical structure of the antidiabetic hormone. DATA SOURCES: (1) Berliner Medizinhistoriches Museum der Charité (Humboldt University). (2) GeDenKort Charité-Wissenschaft in Verantwortung. (3) Geheim Staatsarchiv Preußischer Kulturbesitz. (4) Archival Collections, University of Toronto: Thomas Fisher Rare Book Library. Academy of Medicine Collection, F. G. Banting Papers, C. H. Best Papers, J. J. R. Macleod Papers. (5) National Library of Medicine: Pubmed search for the topic of history of insulin. History of Medicine-on syllabus archive. (6) Selected books: The Discovery of Insulin (M. Bliss); Diabetes, Its Medical and Cultural History (D. von Engelhardt); Brown-Séquard (M. J. Aminoff); Diabetes: The Biography (R. Tattersall); The Endocrine Organs (E. Schäfer); The Internal Secretions (E. Gley); Health, race and German politics between national unification and Nazism, 1870-1945 (P. Weindling). THERAPEUTIC ADVANCES: Demonstration that diabetes is a pancreatic disease. The outstanding progress of medical physiology led to the birth of endocrinology and the key concepts of homeostasis. Experimental scientists designed new procedures for complete pancreatectomy and elaboration of PE containing the antidiabetic principle. Organotherapy achieved complete success in the treatment of myxedema and partial success in the treatment of experimental and clinical diabetes. CONCLUSIONS: The organotherapy of diabetes was an obliged step to facilitate the identification of the antidiabetic hormone. Organotherapy of diabetes was a paradigm for the integration of basic and applied knowledge about hormone action and development of endocrine pharmacology.

Essential Contributions of Pathologists and Laboratory Physicians Leading to the Discovery of Insulin.

CONTEXT.­: Frederick Banting, Charles Best, J. Bertrand Collip, and J. J. R. Macleod contributed to the discovery of insulin in 1921-1922. Recent advances in anatomic pathology, experimental pathology, and clinical pathology were necessary for the research in Toronto, Ontario, Canada, to begin and to succeed. OBJECTIVE.­: To explore the role of pathology and laboratory medicine in laying the foundation for the discovery of insulin. DESIGN.­: Available primary and secondary historical sources were reviewed. RESULTS.­: During a 3-decade period, pathologists, through autopsy pathology and experimental animal studies, were able to provide solid evidence that the pancreatic islets were the source of the internal secretion responsible for proper carbohydrate metabolism. Banting, a surgeon with no previous research experience, read about these studies in a case report with an extensive literature review by pathologist Moses Barron; this piqued Banting's interest and caused him to approach Macleod, a Toronto physiology professor, with an idea that initiated the research. Advances in clinical laboratory medicine, which allowed them to measure blood glucose levels using small blood volumes, were critical to their success. CONCLUSIONS.­: By 1921-1922, the pieces necessary to solve the puzzle were available. The primary reason that the time was ripe for the discovery was the contributions of pathologists and laboratory physicians in the preceding 3 decades. As the 100th anniversary approaches, our profession can take pride in its important contributions to the discovery of insulin, which is broadly recognized as one of the most important medical research advances of the 20th century.

Experiences of First Insulin-Treated Patients (1922-1923).

BACKGROUND: Historical description of first insulin trials just after its discovery. AREAS OF UNCERTAINTY: The review includes first initiatives of insulin treatment. The probability of other trials, not reported to the Insulin Committee of the University of Toronto and conducted in the years 1922 and 1923, is quite low. DATA SOURCES: (1) Archival Collections, University of Toronto: Insulin Discovery and Early Developments of Insulin (University of Toronto Libraries digital special collection, with a particular section entitled "From a Patient's Point of View" containing letters, patient charts, newspaper clippings, and photographs). (2) Thomas Fisher Rare Book Library: Academy of Medicine Collection, F. G. Banting Papers, C. H. Best Papers, J. B.Collip Papers, W. R. Feasby Papers, E. Hugues Papers, J. J. R. Macleod Papers. (3) National Library of Medicine: PubMed search for the topic of history of insulin, History of Medicine-on syllabus archive. (4) Selected Journals for History of Medicine: Bulletin of the History of Medicine, Journal of the History of Medicine and Allied Sciences, Medical History. (5) Selected books: The Discovery of Insulin (M. Bliss); Diabetes, Its Medical and Cultural History (D. von Engelhardt); H. C. Hagedorn and Danish Insulin (T.Deckert), Continuing Quest (W. A. Tomkins). THERAPEUTIC ADVANCES: This historical review shows the quick progress from impure pancreatic extract to the selective isoelectric precipitation of the hormone, which made possible the introduction of insulin in the clinic. CONCLUSIONS: The coordination between the Departments of Physiology (Connaught Laboratories) and Medicine (Toronto General Hospital) was essential for the discovery and implementation of insulin therapy. The Insulin Committee was decisive for the negotiation with the pharmaceutical industry, the purification, grand-scale production, patents' achievement, and provision of licenses to expert clinicians and prestigious health centers. At the end of the year 1923, insulin treatment was already extended to Europe (mainly Scandinavia, Great Britain, and Spain). Insulin discovery and treatment changed the clinical spectrum of diabetes.

Hundred Years of Insulin Therapy: Purified Early Insulins.

BACKGROUND: The discovery of insulin has changed dramatically the outcome of patients with type 1 diabetes, giving them the possibility to survive. This is of particular concern due to the fact that type 1 diabetes most frequently occurs in children who were destined to die in ketoacidosis coma. AREAS OF UNCERTAINTY: From insulin discovery to the availability of human insulin and human insulin analogs to be used in diabetes therapy, a series of problems have arisen as the difficulty of insulin purifications, the animal insulin used by the first researches were in fact contaminated by proteins, fats, and other impurities, and the presence of side effects such as allergy, antibodies generation, and lipoatrophy. DATA SOURCE LITERATURE: Data strictly related to the argument have been searched in Pub Med and used. RESULTS: Starting from insulin discovery in 1921 to nowadays, significant efforts have been made by a series of researches to purify animal insulin, discover the molecular structure of human insulin, and develop methods to synthetize human insulin and then insulin analogs. CONCLUSIONS: The history of insulin discovery here reported is fascinating; insulin is a hormone, a product of biotechnology, a field of research that saved and save the life of many diabetic patients.

Pueraria lobata for Diabetes Mellitus: Past, Present and Future.

Gegen (Radix Puerariae Lobatae), the root of Pueraria lobata, is an edible and medicinal herb which has been used in treating diabetic symptoms in the orient for thousands of years. We present an evidence map of the efficacy and safety of Gegen and Gegen formulas (GGFs) that use Gegen as an essential herb for diabetes, and also its mechanism of actions. We comprehensively searched the ancient medical records to identify empirical evidence; conducted a systematic review (SR) based on moderate- to high-quality randomized controlled trials (RCTs) to synthesize the clinical evidence; and reviewed the possible mechanisms of its antidiabetic effects. Empirical application of Gegen in treating diabetic symptoms dated back to more than 2000 years ago. Common herbs used in RCTs that accompany with Gegen included Radix et Rhizoma Glycyrrhizae, Radix et Rhizoma Ginseng, Rhizoma Dioscoreae, Poria, and Radix Ophiopogonis. The combinations used today are consistent with their usage in ancient times. Results of the SR showed that GGFs could benefit patients with type 2 diabetes for blood glucose control. When in combination with hypoglycemic agents or insulin, GGFs enhanced the glucose-lowering effect as well as the lipid-lowering effects. Also, the incidence and the risk of adverse events (AE), especially the hypoglycemic episodes, were lower in the combination group. No serious or life-threatening AE was reported. The experimental evidence presented that Gegen and GGFs might exert and enhance the anti-diabetic effects through activation of multiple mechanisms, such as reducing insulin resistance, increasing insulin release, inhibiting glucose absorption and reabsorption, and improving insulin sensitivity, glucose uptake, and metabolism.