“Type 2” That Wasn’t: Catching LADA Before It Catches You
Curtis drove a brown delivery truck through the Texas heat. He worked long days, ate clean, and still watched his glucose climb. Metformin didn’t fix it. Ozempic didn’t move the scale. Mornings ran high; days off ran higher. Something wasn’t adding up.
When Type 2 Doesn’t Behave Like Type 2
LADA—latent autoimmune diabetes in adults—is an adult-onset autoimmune diabetes that can masquerade as type 2 early on. It’s defined by islet autoantibodies with a slower progression to insulin dependence than classic type 1 and may account for ~2–12% of adult-onset diabetes. researchportal.helsinki.fi
The Red Flags
If your story sounds like Curtis’s, watch for these patterns that often prompt testing for autoimmune diabetes in adults:
You’re active and eating intentionally, but glucose still trends up.
Morning highs (“dawn phenomenon”) that don’t budge with lifestyle tweaks.
Therapies that usually help in type 2 underperform or stall.
A GLP-1 may help parts of the picture, but you ultimately feel better on insulin.
(Clinically, the ADA’s Standards of Care recommend considering autoimmune testing in adults when the presentation suggests type 1 diabetes rather than straightforward type 2.) Diabetes Journals
The Tests That Tell the Truth
Ask for two things—both are standard in the literature and consensus guidance:
Autoantibodies: GAD65, IA-2, and ZnT8 (± IAA). Positive results indicate autoimmune diabetes (including LADA) rather than type 2. researchportal.helsinki.fi
C-peptide WITH a simultaneous glucose value. C-peptide reflects your own insulin secretion, but the number only makes sense in the context of current glycemia; many guidelines recommend measuring it alongside glucose (often after a carb-containing meal or stimulus). DiabetesontheNet
Treatment Nuance: Why Getting the Label Right Matters
Once antibodies confirmed Curtis had LADA, insulin made sense—and he felt human again. Early, appropriate insulincan improve control and symptoms in LADA; however, preserving β-cell function with early insulin is not proven. In the randomized BALAD study, bedtime insulin did not preserve C-peptide better than sitagliptin over ~21 months. (Practical implication: choose therapy for metabolic control and safety; don’t count on insulin alone to “save” C-peptide.) Frontiers
Expert summaries for primary care echo this nuance: insulin is effective and safe; avoid sulfonylureas (they may accelerate β-cell loss), and tailor therapy to phenotype and C-peptide. AAFP+1
Hear Curtis tell how he pushed for the right labs—and what changed next in episode 1667 →
🧾 LADA Self-Advocacy Checklist (Print/Bring to Your Visit)
✅ Ask: “Could this be LADA (adult-onset autoimmune diabetes)?”
✅ Order antibodies: GAD65, IA-2, ZnT8 (± IAA) to assess autoimmunity. researchportal.helsinki.fi
✅ Order C-peptide with glucose (fasting or stimulated) so results are interpretable. DiabetesontheNet
✅ Bring data: CGM or meter downloads, highlighting morning highs and days-off patterns.
✅ Document history: weight/activity trends; what helped vs. didn’t.
✅ Ask for an endocrinology referral if results are equivocal or treatment is stalling.
✅ Discuss therapy goals: practical glucose control now; understand that β-cell “preservation” evidence in LADA is mixed, and avoid sulfonylureas. AAFP
✅ Follow the science, not the label: If you feel better on insulin (or your data say so), that’s valid even if you were first told “type 2.” (ADA supports antibody testing when adult presentation suggests autoimmune disease.) Diabetes Journals
Bottom line: If your “type 2” doesn’t act like type 2, test for autoimmunity and interpret C-peptide correctly. Getting the diagnosis right is what unlocked Curtis’s progress—and it can unlock yours, too.
