2024 Standards of Medical Care in Diabetes, American Diabetes Association

Each year, ADA publishes the Standards of Medical Care in Diabetes, which are created to advise healthcare professionals. Additionally, these guidelines can help people with diabetes advocate to receive the best care possible from their medical providers. What is new: 

 • Figure 2.1 was added as a new figure to provide a structured framework for investigation of suspected type 1 diabetes in newly diagnosed adults. The Standards of Care include that flowchart (Figure 2.1) that recommends the use of autoantibody testing (GAD, IA-2, ZnT8, IAA) in people with suspected type 1 diabetes. The flow chart also indicates that 5-10% of people with adult-onset type 1 diabetes are autoantibody negative. Standardized islet autoantibody tests are recommended for classification of diabetes in adults who have phenotypic risk factors that overlap with those for type 1 diabetes (e.g., younger age at diagnosis, unintentional weight loss, ketoacidosis, or short time to insulin treatment). 

• The FDA approved Teplizumab in 2022; this drug allows for the possibility of delaying the onset of symptomatic type 1 diabetes in those at risk who are 8 years and older. The ADA’s Standards of Care now encourages those 8 and older with stage 2 [preclinical] type 1 diabetes to consider using Teplizumab to delay the onset of stage 3 [symptomatic] type 1 diabetes. [A study published in the October 2023 New England Journal of Medicine showed that two 12-day courses of teplizumab in children and adolescents diagnosed with diabetes less than six weeks earlier [i.e., symptomatic T1D] preserved their ability to make their own insulin.] 

• The Standards of Care diabetes technology section now begins with the following statement: “Diabetes devices should be offered to people with diabetes” and the Standards of Care also recommends that continuous glucose monitors be offered to people with type 1 diabetes at the time of diagnosis [emphasis mine]. 

• The Standards of Care now recommend that people with diabetes, their caregivers, and family members be screened for diabetes distress at least yearly, and potentially more frequently if warranted. Recommendation 5.39 was changed to specify the frequency for diabetes distress screening and to highlight the role of health care professionals in addressing diabetes distress. The accompanying text also includes links to validated measures of diabetes distress. 

• People with diabetes should be classified into appropriate diagnostic categories [for example, type 1 diabetes] to aid in personalized management. 

• During the COVID-19 pandemic, cases of hyperglycemia, DKA, and new diabetes increased, suggesting that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a trigger for or can unmask type 1 diabetes. 

What is not new in 2024 but should be reiterated are standards that are applicable to those with adult-onset type 1 diabetes: 

 • Type 1 diabetes is due to autoimmune β-cell destruction, usually leading to absolute insulin deficiency, including latent autoimmune diabetes in adults. 

• Type 1 diabetes and type 2 diabetes are heterogeneous diseases in which clinical presentation and disease progression may vary considerably. Classification is important for determining personalized therapy, but some individuals cannot be clearly classified as having type 1 or type 2 diabetes at the time of diagnosis. The traditional paradigms of type 2 diabetes occurring only in adults and type 1 diabetes only in children are not accurate, as both diseases occur in all age-groups. The onset of type 1 diabetes may be more variable in adults; they may not present with the classic symptoms seen in children and may experience temporary remission from the need for anticipated full-dose insulin replacement. 

• A person with possible type 1 diabetes who is not treated with insulin will require careful monitoring and education so that insulin can be rapidly initiated in the event of glycemic deterioration. 

 • LADA: There is debate as to whether slowly progressive autoimmune diabetes with an adult onset should be termed latent autoimmune diabetes in adults (LADA) or type 1 diabetes. The clinical priority with detection of LADA is awareness that slow autoimmune β-cell destruction can occur in adults, leading to a long duration of marginal insulin secretory capacity. For this classification, all forms of diabetes mediated by autoimmune β-cell destruction independent of age of onset are included under the rubric of type 1 diabetes. Use of the term LADA is common and acceptable in clinical practice and has the practical impact of heightening awareness of a population of adults likely to have progressive autoimmune β-cell destruction, thus accelerating insulin initiation prior to deterioration of glucose management or development of DKA. 

• It is important for health care professionals to realize that classification of diabetes type is not always straightforward at presentation and that misdiagnosis is common [emphasis mine] and can occur in ∼40% of adults with new type 1 diabetes (e.g., adults with type 1 diabetes misdiagnosed as having type 2 diabetes).

 

How to Dispute 3 Common Myths Promoted by Doctors

I often hear people say that their doctors insist they don’t have Type 1 diabetes/LADA, saying instead that they have Type 2 diabetes; insist that only children and young adults get Type 1 diabetes; or insist that that the person with adult-onset Type 1 diabetes does not need to be treated with insulin. Here are the actual facts from experts in the field and diabetes governing bodies:

If a person has been diagnosed with diabetes and is positive for any one autoantibody, the person has Type 1 diabetes. From the ADA Standards of Care in Diabetes (2023): Type 1 diabetes is due to autoimmune β-cell destruction, usually leading to absolute insulin deficiency, and includes latent autoimmune diabetes of adulthood; all forms of diabetes mediated by autoimmune β-cell destruction are included under the rubric of Type 1 diabetes. The American Association of Clinical Endocrinologists (AACE) now suggests that autoantibody testing be performed to differentiate between Type 1 diabetes and non-autoimmune diabetes (Type 2, MODY, etc.).

Adults represent the majority of new-onset Type 1 diabetes; recent epidemiological data have shown that more than half of all new cases of type 1 diabetes occur in adults (R David Leslie et al. Adult-Onset Type 1 Diabetes: Current Understanding and Challenges. Diabetes Care 2021;44:2449-2456). Also, "Adult-onset type 1 diabetes is frequently misdiagnosed as type 2 diabetes, leading to inappropriate care. Emerging data suggest that up to 62% of type 1 diabetes cases develop after age 20 years" (Annals of Internal Medicine "Age at Diagnosis in U.S. Adults With Type 1 Diabetes," 26 September 2023).

Insulin is the correct treatment for people with Type 1 diabetes, according to a 2021 consensus report by the ADA/EASD: “Most people with Type 1 diabetes should use [insulin] regimens that mimic physiology as closely as possible, irrespective of the presentation.” Regarding adjunct therapies (metformin, pramlintide, GLP-1s, SGLT inhibitors), the authors state, “before these drugs are prescribed, insulin therapy should be optimized.” In other words, the initial treatment of a person with adult-onset Type 1 diabetes should not be to treat them as if they have Type 2 diabetes; the standard initial therapy is insulin (and then adjunct therapies can be considered). (The Management of Type 1 Diabetes in Adults. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) (Diabetes Care, September 30, 2021)).

If your doctor promotes one of these myths, you can ask them why they are contradicting the standards of the medical governing bodies (and cite the references).

The Management of Type 1 Diabetes in Adults. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) (Diabetes Care, September 30, 2021)

ADA/EASD have just come out with a consensus report on the management of Type 1 diabetes in adults, and address adult onset T1D/LADA. Here is my commentary:

The Good:

There is so much good about this ADA/EASD consensus report on the management of Type 1 diabetes in adults, and the authors address adult-onset Type 1 diabetes with a large amount of valuable information.  Here are some takeaways for adult-onset T1D/LADA:

• “Most people with Type 1 diabetes should use regimens that mimic physiology as closely as possible, irrespective of the presentation.” Regarding adjunct therapies (metformin, pramlintide, GLP-1s, SGLT inhibitors), the authors state, “before these drugs are prescribed, insulin therapy should be optimized.” In other words, don’t treat patients with T1D/LADA as if they have Type 2 diabetes. The authors do recognize that some of the adjunct therapies can preserve beta cell mass in the newly diagnosed, and the authors also recognize that for some newly diagnosed, insulin therapy is not appropriate; however, the authors caution that, “Those whose diabetes is treated without insulin will require careful monitoring and education so that insulin can be rapidly initiated in the event of glycemic deterioration.”
• The ADA/EASD Consensus Report authors recognize that misdiagnosis of Type 1 diabetes in adults is common, and that they are typically misdiagnosed as having Type 2 diabetes.  The authors state, “from a patient perspective, a misdiagnosis can cause confusion and misunderstanding.  This can impair the acceptance of the diagnosis and future management plans.”
• The authors encourage autoantibody testing at diagnosis as the primary investigation of an adult with suspected Type 1 diabetes. I don’t think this recommendation is strong enough, because due to blind spots and myths, many doctors are unaware of how common adult-onset Type 1 diabetes actually is.  Autoantibody testing in all newly diagnosed adults would identify the 1 in 10 who have Type 1 diabetes (as I detail in other blogs, ~10% of people diagnosed with “Type 2” diabetes are autoantibody positive, have been misdiagnosed, and in fact have Type 1 autoimmune diabetes).
• The authors state, “The absence of autoantibodies does not exclude Type 1 diabetes, since approximately 5-10% of White European people with new-onset Type 1 diabetes have negative islet antibodies” and “if there is a clinical suspicion of Type 1 diabetes, the individual should be treated with insulin.”
• I also really appreciate the authors’ emphasis on nutrition, exercise, and psychosocial issues.

The Not-So-Good:

At the beginning of the consensus report, the authors state, “Type 1 diabetes accounts for approximately 5-10% of all cases of diabetes. Although the incidence peaks in puberty and early adulthood, new-onset Type 1 diabetes occurs in all age-groups.” But later in the report, the authors state, “Misclassification of Type 1 diabetes in adults is common, and over 40% of those developing Type 1 diabetes after age 30 years are initially treated as having Type 2 diabetes.” Obviously, if those who are misdiagnosed are not counted amongst those with Type 1 diabetes, T1D is undercounted, and the peak age is not in puberty and early adulthood.

 

Misdiagnosis of Adult-Onset Type 1 Diabetes: Root Cause Analysis

First, a brief summary of the reasons that adults with new-onset Type 1 diabetes are misdiagnosed, followed by a more detailed analysis:

• Persistent myth that Type 1 diabetes is a childhood disease and that adults can’t get it
• Lack of knowledge of the heterogenous phenotype of adult-onset Type 1 diabetes
• Doctors’ lack of time

Why are so many adults with new-onset Type 1 diabetes misdiagnosed? Adult-onset Type 1 diabetes is typically misdiagnosed as Type 2 diabetes, an altogether different disease, based on age not etiology. Misdiagnosis is an epidemic, according to endocrinologist-researcher-professor Dr. Irl B. Hirsch, University of Washington. Interestingly, misdiagnosis is a worldwide problem, occurring in wealthy countries, poorer countries, countries with universal health coverage (Canada, United Kingdom, Australia, etc.), and countries without universal health coverage such as the United States of America. I find it particularly interesting that misdiagnosis is so common in countries with universal health care—logic would say that there would be recognition that appropriate diagnosis and treatment would be about supporting health, well-being, and preventing costly diabetic complications. Even in the USA in a system such as Kaiser Permanente, a fully integrated health system that focuses on keeping its members healthy, misdiagnosis remains a common problem.

There are simple and inexpensive autoantibody tests (GAD, IA-2, IAA, ZnT8, and the older ICA) that can be used to differentiate between Type 1 diabetes (an autoimmune disease) and non-autoimmune diabetes such as Type 2 diabetes. The testing is relatively inexpensive ($55 via JDRF’s T1Detect that was newly launched in December 2020 (https://www.jdrf.org/t1d-resources/t1detect/)), but doctors frequently insist it costs too much in spite of the fact that hospitalization for diabetic ketoacidosis (DKA), which frequently occurs if a person has been misdiagnosed and not treated with insulin, costs an average of $27,000 in the United States. Often the doctor will not perform autoantibody testing because the doctor does not believe it is necessary or appropriate, for the simple reason that they don’t believe that the person has Type 1 diabetes. In the 1970s, the discovery of autoantibodies identified Type 1 diabetes as an autoimmune disease, and in 1977 the first article was published that identified that ~10% of the people diagnosed with Type 2 diabetes were autoantibody positive, had been misdiagnosed, and in fact had Type 1 diabetes. If this knowledge has been available for 44 years, why do we have an epidemic of misdiagnosis?

Medical doctors have been very slow to recognize the prevalence of adult-onset Type 1 diabetes, and the reasons for misdiagnoses I believe are:

• The persistent myth that Type 1 diabetes is a childhood disease, when in fact the majority of new onset Type 1 diabetes is seen in adults [Footnote 1]. Thus, when an adult shows up at a doctor’s office with an elevated blood glucose, the doctor often makes the assumption that the adult has Type 2 diabetes. Since the 1970s and the founding of the Juvenile Diabetes Foundation (now JDRF), the image of sick children has been leveraged to fund research into a disease which is not at all a childhood disease. How do we shift to educating people on the true scope of the problem while not alienating the donors and money that is still needed to research a cure or at least better treatments? Prior to the 1970s, Type 1 diabetes was not viewed as a childhood disease [Footnote 2], and in fact the long-time head of JDRF International, actress Mary Tyler Moore, was diagnosed with Type 1 diabetes at age 33. Other myths are that overweight people, black people, Asian people, and Latino people (BIPOC) don’t get Type 1 diabetes—all of these are false.
• Lack of awareness of the variability in presentation of adult-onset Type 1 diabetes: from Dr. Hirsch’s viewpoint, there is such a heterogeneous phenotype in adult-onset Type 1 diabetes, from a classic phenotype of rapid onset (rapid weight loss, Caucasian, normal BMI, polyuria, polydipsia, polyphagia) to a very slowly progressive Type 1 phenotype (sometimes called LADA (Latent Autoimmune Diabetes in Adults) or SPIIDM (slowly progressive insulin-dependent (Type 1) diabetes mellitus)), that makes it more challenging to correctly diagnose—the presentation of Type 1 diabetes in adults is highly variable. Doctors are not trained or educated on the heterogenous phenotype of adult-onset Type 1 diabetes.
• Doctors’ lack of time (“assembly-line medicine” means that good doctors cannot care for complex patients in 10 or 15 minutes): Both my cousin Diane, a family practice doctor, and Dr. Hirsch say that doctors’ lack of time with patients can lead to misdiagnosis. Dr. Hirsch emphasizes that in the primary care setting, adult-onset Type 1 diabetes is not on the physician’s radar or in their bandwidth. They see so many Type 2s, due to the overwhelming incidence of Type 2 diabetes, and the doctors have so little time. But it is interesting that countries that have universal health coverage still have the epidemic of misdiagnosis—theoretically those doctors should have more time. However, a friend in the UK says that doctors there have even LESS time due to chronic underfunding of medical staff—that lack of time diminishes the quality of care.
• Sound bite nation: we live in a world of instant access to information, non-stop content, and an endless list of things to do. It is no wonder that doctors suffer from the same problem that so many of us struggle with in our everyday lives: not enough time. Just like us, doctors will revert to their “time savers” and “shortcuts” when faced with too many tasks and not enough hours. If a doctor only has 10 minutes with a patient, it is not surprising they once they have “AN” answer, they stop looking and rarely question if they truly found “THE RIGHT” answer. The “art of the interview,” where the doctor asks questions and has the opportunity to listen to the patient is lost due to lack of time—many medical detective doctors will tell you if you can just listen, the patient will provide the answer (disease, diagnosis).
• Many doctors aren’t practicing science they are practicing medicine and doing much by rote. Science requires scientific inquiry, whereas medicine often does not—doctors put a label on a person (adult with elevated blood glucose = Type 2) rather than using scientific methodology to obtain a correct diagnosis. Again, the “lack of time” discussed above can contribute to this. Most doctors will tell you they practice evidence-based medicine—that means someone else designed the study, completed the research, analyzed the findings, and developed the conclusions. The doctor then uses this research to inform their practice, but clearly this is not happening in the case of adult-onset Type 1 diabetes. The best doctors I have had are inquisitive and question everything—they are researchers at heart, medical detectives, and not just medical practitioners.
• Incorrect information is provided by leading health organizations in the United States such as National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Centers for Disease Control and Prevention (CDC), and the American Academy of Family Physicians (AAFP). The NIDDK website says, “Type 1 diabetes is usually diagnosed in children and young adults,” the CDC website says, “Type 1 diabetes is usually diagnosed in children, teens, and young adults,” and the AAFP website says, “Type 1 diabetes is caused by autoimmune destruction of the islet cells of the pancreas, and onset is typically in childhood,” [Footnote 3] when the majority of new-onset Type 1 diabetes is actually seen in adults. These organizations should be the source of factual and accurate information, not clinging to the myth that Type 1 diabetes is a childhood disease. Organizations such as the CDC should be at the forefront of response to the epidemic of misdiagnosis, not promoting misinformation. Some countries acknowledge that Type 1 diabetes is not a childhood disease; Diabetes Australia, on their website, states that it is a myth that you only get Type 1 diabetes when you are young, and that “new research suggests almost half of all people who develop the condition are diagnosed over the age of 30.” It would be interesting to know if Australia has less misdiagnosis as a result of the greater awareness that people of all ages are diagnosed with Type 1 diabetes.
• Lack of appropriate diagnostic criteria and lack of standard of care: diagnostic criteria for diabetes mellitus is based on fasting plasma glucose or hemoglobin A1c without any differentiation between Type 1 diabetes, Type 2 diabetes, MODY (maturity onset diabetes of the young), and other forms of diabetes. Autoantibody testing is the gold standard for identifying if a person with diabetes has Type 1 autoimmune diabetes, yet this is not part of the diagnostic criteria. In addition, even if a c-peptide test [Footnote 4] is performed, adults with slowly progressive Type 1 diabetes can have a normal range result, and if their doctor believes the myth that “Type 1 means you make no insulin” the person may be diagnosed as having Type 2 diabetes. Additionally, in the United States a medical doctor faces no repercussions if he/she misdiagnoses a person with adult-onset Type 1 diabetes and provides inappropriate or substandard treatment. The American Association of Clinical Endocrinologists (AACE) now suggests that autoantibody testing be performed to differentiate between Type 1 diabetes and non-autoimmune diabetes (Type 2, MODY, etc.), but it is not a requirement. Thus, there is no obligation to diagnose, classify, and appropriately treat the different diseases that fall under the term “diabetes.” If there were a standard or guideline, doctors would be held accountable to the minimum standard of care: anything less would be malpractice.

I welcome your thoughts on the root causes of misdiagnosis—did I miss one? My next blog will be on possible solutions.

Footnote 1: Miriam E Tucker, “Half of All Type 1 Diabetes Develops after 30 Years of Age.” Medscape, September 20, 2016. [Note that this study found that 50% of people diagnosed with Type 1 diabetes were diagnosed older than 30 years (and the study subjects only went up to 60 years, so greater than 50% are diagnosed over the age of 30)]. The Medscape article is based on data presented September 16, 2016, at the European Association for the Study of Diabetes (EASD) 2016 Annual Meeting by Dr Nicholas JM Thomas, of the Institute of Biomedical and Clinical Science, University of Exeter Medical School, United Kingdom (later published as Frequency and phenotype of type 1 diabetes in the first six decades of life: a cross-sectional, genetically stratified survival analysis from UK Biobank. Lancet Diabetes Endocrinol. 2018 February; 6(2): 122-129). See also "Most New Onset Type 1 Diabetes Occurs in Adulthood: It is Time to Dispel the Myth that Type 1 Diabetes is a Childhood Disease" link here

Footnote 2: See my blog "Historical References to Adult-Onset Type 1 diabetes: How Did Type 1 Diabetes Ever Become Defined as a Childhood Disease?" link here

Footnote 3: All websites viewed on December 30, 2020.

Footnote 4: The beta cells in the pancreas produce insulin and C-peptide, and testing for c-peptide measures how much endogenous insulin a person is making. Typically, people with rapid onset Type 1 diabetes will have low levels of c-peptide, indicating insufficient insulin production, but often people with slowly progressive Type 1 diabetes have normal to slightly low c-peptide levels. People with true Type 2 diabetes tend to have high c-peptide levels. 

CREDIT AND THANKS: to Brea Di Dato, Chris Petersen, Brande Gentry, and Jenny Coe, who reviewed this blog and made excellent suggestions

How Does Type 1 Diabetes Develop? T1D Etiopathogenesis

Often, I hear people say that a certain event caused them to develop Type 1 diabetes, such as an accident, a stressful time in their lives, or pregnancy, but in fact the actual disease process begins far before such an event, perhaps years before. Another misconception that I hear often is that the autoantibodies destroy the pancreatic beta cells, but it is actually killer T cells. Type 1 diabetes is characterized by immune-mediated destruction of pancreatic beta cells in genetically predisposed individuals, which results in severe insulin deficiency and the need for exogenous insulin to sustain life.  In Type 1 autoimmune diabetes, the healthy insulin-producing beta cells of the pancreas are destroyed by T-cells of the immune system, which mistake the beta cells as “foreign” and attack them. Here are the sequential steps in the development of Type 1 diabetes:

Step 1: Genetic Predisposition

People genetically predisposed to Type 1 diabetes have either HLA-DR3-DQ2 or HLA-DR4-DQ8 haplotypes, or both [Footnote 1].  Some HLA epitopes protect against the development of Type 1 diabetes; the presence of resistance HLA epitopes has been correlated with a later age of onset (adult-onset Type 1 diabetes) [Footnote 2].

Step 2: Immune Activation/Environmental Trigger

It is still not known what triggers the immune-mediated destruction of the beta cells, but it is related to environmental factors that are still poorly defined [Footnote 3]. Type 1 diabetes was first described in detail in about 100 C.E. by Aretaeus of Cappadocia [Footnote 4], so whatever the environmental factors are, they have been present for thousands of years.

Step 3: Immune Response/Development of Autoantibodies

During the immune activation and immune response involved in Type 1 diabetes, the immune system mistakenly attacks beta cells in the pancreas and destroys them over time, ultimately resulting in insulin deficiency. This process leads to the production of islet-specific autoantibodies (GAD, ICA, IA-2, IAA, and ZnT8); the autoantibodies are not pathogenic, but they represent biomarkers of the pathogenesis [Footnote 5].  Or put another way, diabetes autoantibodies are proteins that mark insulin-producing beta cells for destruction, but the autoantibodies are not believed to be directly pathological.

Step 4: Triggering Event

The triggering event is any event that stresses the body, such as illness, accident, or even pregnancy.  The stressful event means that the body requires additional insulin for proper functioning, but the ongoing destruction of the beta cells means that insufficient insulin is secreted in response to the stressor. This event is a tipping point or “the straw that broke the camel’s back,” but it is not causal.

Step 5: Development of Overt Type 1 Diabetes

Type 1 Diabetes TrialNet has identified three stages of progression in Type 1 diabetes. In stage 1, a person tests positive for autoantibodies, blood sugar levels remain normal, and the individual is asymptomatic. In Stage 2, individuals are autoantibody positive, there is a loss of beta cells, blood sugar levels are abnormal, and typically there are no symptoms. In stage 3, Type 1 diabetes symptoms are present due to significant beta cell loss. Common symptoms include increased thirst and urination, extreme hunger, unexplained rapid weight loss, blurred vision, and extreme fatigue. Exogenous insulin is necessary to sustain life. Note that in adults with slowly progressive Type 1 diabetes, symptoms may be far milder, which often leads to adults with new-onset T1D being misdiagnosed as having Type 2 diabetes (an altogether different disease).

Footnote 1: The majority of studies of HLA association with Type 1 diabetes have used Caucasian subjects.

Footnote 2:  Multiple HLA Epitopes Contribute to Type 1 Diabetes Susceptibility.  CL Roark et al. Diabetes 2014 Jan; 63(1): 323-331.

Footnote 3:  American Diabetes Association (ADA) Classification and Diagnosis of Diabetes: Standards of Medical Care in Diabetes—2020. Diabetes Care 2020; 43 (Suppl 1): S14-S31.

Footnote 4: Aretaeus of Cappadocia, “Diabetes is a remarkable affliction, not very frequent among men… The course is the common one, namely, the kidneys and the bladder; for the patients never stop making water, but the flow is incessant, as if from the opening of aqueducts… The nature of the disease, then, is chronic, and it takes a long period to form; but the patient is short-lived, if the constitution of the disease be completely established; for the melting is rapid, the death speedy. Moreover, life is disgusting and painful; thirst, unquenchable; excessive drinking, which, however, is disproportionate to the large quantity of urine, for more urine is passed; and one cannot stop them either from drinking or making water. Or if for a time they abstain from drinking, their mouth becomes parched and their body dry; the viscera seems as if scorched up; they are affected with nausea, restlessness, and a burning thirst; and at no distant term they expire. They thirst, as if scorched up with fire … But if it increases still more, the heat is small indeed, but pungent, and seated in the intestines; the abdomen is shriveled, the veins protuberant, and there is general emaciation, when the quantity of urine and the thirst have already increased; and when, at the same time, the sensation appears at the extremity of the member, the patients immediately make water. Hence, the disease appears to me to have got the name diabetes as if from the Greek word διαβήτης (which signifies a siphon), because the fluid does not remain in the body, but uses the man’s body as a ladder, whereby to leave it. They survive not for long, for they pass urine with pain, and the emaciation is dreadful; nor does any great portion of the drink get into the system, and many parts of the flesh pass out along with the urine”. From Adams F (ed), 1856.The extant works of Aretaeus the Cappadocian. The Sydenham Society, London.

Footnote 5: If a single islet autoantibody or multiple islet autoantibodies are detected in a person diagnosed with diabetes (fasting blood sugar greater than 125 mg/dl), the diagnosis of Type 1 autoimmune diabetes is confirmed.

ADA Acknowledges “Misdiagnosis is Common,” CDC Indirectly Acknowledges Undercounting of Cases of Type 1 Diabetes

Twenty-five years ago, I began my advocacy on behalf of people with adult-onset Type 1 diabetes, shortly after I was misdiagnosed at age 35.  At that time, it was the position of the American Diabetes Association (ADA) and Centers for Disease Control and Prevention (CDC) that Type 1 diabetes was a childhood disease, and the organizations did not acknowledge misdiagnosis as a problem.  Back then, doctors would become enraged when I used the term “misdiagnosis.”  Finally, more than a quarter century later, the ADA has stated that misdiagnosis is common (since Type 1 and Type 2 are altogether different diseases, yes, it is misdiagnosis).  Additionally, CDC’s National Diabetes Statistics Report 2020 indirectly references the problem of undercounting of Type 1’s and misdiagnosis, by categorizing people who self-report in surveys that they went on insulin within one year of diagnosis as having Type 1 diabetes.

These changes from leading organizations are very positive—we have come a long way, but we are not there yet.  Misdiagnosis and undercounting continue to hamper people’s access to the appropriate care and treatment of Type 1 diabetes.  But this change of position by the ADA and CDC is a fantastic step which will hopefully pave the way for people with adult-onset Type 1 diabetes to receive a correct diagnosis, appropriate care, and overall better outcomes.

In this blog I provide excerpts from ADA’s Standards of Medical Care in Diabetes 2020 and CDC’s National Diabetes Statistics Report 2020.

Here are some pearls from ADA Standards of Medical Care in Diabetes 2020 [all emphasis is mine]:

“Type 1 diabetes and type 2 diabetes are heterogeneous diseases in which clinical presentation and disease progression may vary considerably. Classification is important for determining therapy, but some individuals cannot be clearly classified as having type 1 or type 2 diabetes at the time of diagnosis. The traditional paradigms of type 2 diabetes occurring only in adults and type 1 diabetes only in children are no longer accurate, as both diseases occur in both age-groups. Children with type 1 diabetes typically present with the hallmark symptoms of polyuria/polydipsia, and approximately one-third present with diabetic ketoacidosis (DKA). The onset of type 1 diabetes may be more variable in adults; they may not present with the classic symptoms seen in children and may experience temporary remission from the need for insulin.

It is important for the provider to realize that classification of diabetes type is not always straightforward at presentation and that misdiagnosis is common (e.g., adults with type 1 diabetes misdiagnosed as having type 2 diabetes; individuals with maturity-onset diabetes of the young [MODY] misdiagnosed as having type 1 diabetes, etc.). Although difficulties in distinguishing diabetes type may occur in all age-groups at onset, the diagnosis becomes more obvious over time.

Characterization of the underlying pathophysiology is more developed in type 1 diabetes than in type 2 diabetes. It is now clear from studies of first-degree relatives of patients with type 1 diabetes that the persistent presence of two or more islet autoantibodies is an almost certain predictor of clinical hyperglycemia and diabetes. The rate of progression is dependent on the age at first detection of autoantibody, number of autoantibodies, autoantibody specificity, and autoantibody titer.

There is debate as to whether slowly progressive autoimmune diabetes with an adult onset should be termed latent autoimmune diabetes in adults (LADA) or whether the clinical priority is awareness that slow autoimmune β-cell destruction means there may be long duration of marginal insulin secretory capacity. For the purpose of this classification, all forms of diabetes mediated by autoimmune β-cell destruction are included under the rubric of type 1 diabetes.

Immune-mediated diabetes, previously called “insulin-dependent diabetes” or “juvenile-onset diabetes,” accounts for 5–10% [Note 1] of diabetes and is due to cellular-mediated autoimmune destruction of the pancreatic β-cells. Autoimmune markers include islet cell autoantibodies and autoantibodies to GAD (GAD65), insulin, the tyrosine phosphatases IA-2 and IA-2β, and zinc transporter 8 (ZnT8). The disease has strong HLA associations, with linkage to the DQA and DQB genes. These HLA-DR/DQ alleles can be either predisposing or protective.

The rate of β-cell destruction [in Type 1 diabetes] is quite variable, being rapid in some individuals (mainly infants and children) and slow in others (mainly adults). Children and adolescents may present with DKA as the first manifestation of the disease. Others have modest fasting hyperglycemia that can rapidly change to severe hyperglycemia and/or DKA with infection or other stress. Adults may retain sufficient β-cell function to prevent DKA for many years; such individuals may have remission or decreased insulin needs for months or years and eventually become dependent on insulin for survival and are at risk for DKA

Although patients are not typically obese when they present with type 1 diabetes, obesity is increasingly common in the general population and there is evidence that it may also be a risk factor for type 1 diabetes. As such, obesity should not preclude the diagnosis.”

Melitta’s Note 1:  Type 1 diabetes that is correctly diagnosed accounts for 5-10% of all cases of diabetes.  However, as the Standards of Care point out, misdiagnosis is common, and in fact ~10% of people diagnosed with “Type 2” diabetes are autoantibody positive, have been misdiagnosed, and in fact have Type 1 diabetes.  Therefore, Type 1 diabetes represents more than 5-10% of all cases of diabetes.  See the CDC National Diabetes Statistics Report for additional information.

CDC National Diabetes Statistics Report 2020

“Most estimates of diabetes in this report do not differentiate between type 1 and type 2 diabetes. However, as type 2 diabetes accounts for 90% to 95% of all diabetes cases, the data presented here are more likely to be characteristic of type 2 diabetes, except as noted.

Prevalence of diagnosed diabetes:

• 210,000 children and adolescents younger than age 20 years—or 25 per 10,000 US youths— had diagnosed diabetes. This includes 187,000 with type 1 diabetes.
• 1.4 million adults aged 20 years or older—or 5.2% of all US adults with diagnosed diabetes—reported both having type 1 diabetes and using insulin.
• 2.9 million adults aged 20 years or older—or 10.9% of all US adults with diagnosed diabetes—started using insulin within a year of their diagnosis

APPENDIX B of the National Diabetes Statistics Report: Detailed Methods and Data Sources: Validated methods to distinguish between types of diabetes in surveys are not available. The percentage of adults aged 20 years or older with diagnosed diabetes who self-reported type 1 diabetes plus current insulin use and the percentage of adults aged 20 years or older with diagnosed diabetes who started using insulin within a year of their diagnosis were estimated from 2017 NHIS data. To estimate the number of adults aged 20 years or older with type 1 diabetes, these percentages were then applied to the derived number of adults aged 20 years or older with diagnosed diabetes.”

Reflections on Living with Type 1 Diabetes for 25 Years

April 13, 1995:  When I was 35 years old, my health declined rapidly, and I was hospitalized in diabetic ketoacidosis (DKA). Before 1922 and the discovery of insulin, I would have died then and there.  I was devastated, and I cried through the entire night at the hospital.  I knew several people who had Type 1 diabetes, and their lives were really difficult, and I feared that for myself. In that moment, I never imagined I would live another 25 years with this disease, free of complications, much less learn to thrive with it.  I was also incredibly active and loved traveling the world, and I thought that I would be constrained.  When I was diagnosed, my mother was about to leave for a trip to Bhutan, in the Himalayas, where she would be completely unreachable.  Mom told me she wouldn’t go, which was quite unlike her, but I insisted she go on her trip to Bhutan and she did (years later, I would travel to Bhutan as well). My father called me every day while Mom was gone, to check up on me.  Even though family and friends did their best to comfort me and be there for me, it was the scariest moment of my life.  

Fast forward 25 years, and I am happy to say I have a great life.  There have been bumps and challenges along the way but through each of those obstacles, I have become stronger and more resolved to live my best life and help others along the way.  I am using technology to manage my diabetes that I never thought I would see in my lifetime.  I wear an insulin pump (Tandem tSlim with ControlIQ) that is linked with a continuous glucose monitor (CGM) in what is called automated insulin delivery. It is nothing short of a miracle. I continue to travel the world, not without some challenges along the way, but I do it (except not now, since we are sheltering in place due to the coronavirus). My last big trip was 2+ weeks trekking in the Peruvian Andes, where our highest elevation was a 14,550 ft pass.

I have learned a lot along the way and my journey is far from over. I am very grateful that I am a scientist, because managing Type 1 diabetes is a big science experiment. I have successfully advocated for the recognition that Type 1 diabetes is not a childhood disease—I still have a long way to go and much to accomplish, but I have seen progress.  I started a blog to help people who are diagnosed with Type 1 diabetes as adults, most of whom are tragically misdiagnosed as having Type 2 diabetes, an altogether different disease, due to the persistence of the myth that Type 1 diabetes is a childhood disease. I met many others with Type 1 diabetes, and discovered I am not alone.  I belong to a club of very determined people who are living every day with purpose and zest. The Type 1 friends I have met along the way are such a gift—thank you all. I have learned to slow down—when I was first diagnosed, my older sister told me that I was too driven and needed to slow down, and she was right.  Six months before I was diagnosed I began practicing yoga, and yoga and meditation have helped me to unwind.

After 25 years of living with Type 1 diabetes, my approach is now grounded in experience.  I take the best care of myself as possible, embrace and lean on my support network along the way, do a lot of exercise/yoga/meditation (my magic pills), help others especially the newly diagnosed (kindness and compassion are necessities), and live my life to the fullest (which includes a lot of traveling).  It hasn’t always been easy, and it was a really rocky start at diagnosis, but I have done my best for these 25 years and I have an amazing life for which I am grateful every day.