Too Old for Type 1? The Dangerous Myth Behind LADA Misdiagnosis

I am a Registered Nurse and Certified Diabetes Care and Education Specialist who uses therapeutic carbohydrate reduction (TCR) based on Dr. Richard K. Bernstein’s protocols to help people using insulin normalize their blood glucose levels. I’m also a lifelong type 1 diabetic (T1D) who uses TCR to help manage my diabetes. An issue I have come across numerous times is a patient who has been misdiagnosed as having type 2 diabetes, when in fact, they have latent autoimmune diabetes in adults (LADA). It is an extremely common myth, even in today’s medical community, that children are diagnosed with type 1 diabetes, and adults with type 2. What has been discovered in recent years, is that over 50% of people diagnosed with type 1 diabetes are adults, and that T1D can be diagnosed at any age.(1)

LADA is frequently misdiagnosed as type 2 diabetes because many adults do not need insulin when they’re first diagnosed, and may initially look clinically similar to people with type 2 diabetes.(2) LADA is slow progressing, and it may take years before the person becomes fully insulin dependent. Being overweight or obese does not rule out LADA. Most patients with LADA tend to be leaner than T2D’s, but some are overweight or obese and demonstrate metabolic syndrome features. People with LADA may show signs of insulin resistance, and have higher bolus (mealtime insulin) needs than basal (long-acting, “background” insulin) as they still have some phase 2 insulin response, but phase 1 is impaired.

Mistaking LADA for T2DM can be a deadly mistake. Those with insulin deficiency can eventually go into Diabetic Ketoacidosis (DKA) which can cause coma or death. Lowering carbohydrate intake can reduce insulin needs and prolong the period before supplemental insulin is needed, but it won’t reverse LADA like it can T2D. Exercise, oral medications like Metformin and injectable GLP-1 medications can also lower insulin needs, but ultimately, LADA is a state of insulin deficiency.(2) While all these things can help, insulin is what is missing and insulin is what is required for life. Prolonging the time before starting insulin, while tempting, can lead to suboptimal health and well-being.

If you suspect that you may have type 1 diabetes/LADA, or if you’re a healthcare provider with a patient who doesn’t present with the T2DM phenotype, or if there is a family history of T1DM, test the five antibodies for T1D; GAD-65, IA-2, IAA, ICA and ZNT8, as well as a c-peptide level, which is analyzed in context with the current blood glucose level. If c-peptide is normal or low, the diagnosis is likely T1D/LADA. T2D typically presents with high c-peptide. Don’t assume it’s T2D. You just may save a life (and it might be your own)!

REFERENCES

1. Adult-Onset Type 1 Diabetes: Current Understanding and Challenges, Diabetes Care, 2021
2. Latent Autoimmune Diabetes in Adults: A Review on Clinical Implications and Management, Diabetes and Metabolism Journal, 2018