The Three Types Side by Side
Reviewed by CDE Mehandi Sharma · Updated
Seeing the three together makes the position of LADA clearer than any description does.
| Type 1 | LADA | Type 2 | |
|---|---|---|---|
| Cause | Autoimmune | Autoimmune | Insulin resistance |
| Usual age at onset | Childhood, teens | Over 30 | Over 40 |
| How fast it starts | Weeks | Months to years | Years, often silent |
| Build | Usually lean | Often lean | Often overweight |
| Islet antibodies | Positive | Positive | Negative |
| C-peptide | Very low | Low, falling | Normal or high |
| Insulin at diagnosis | Always | Not in first 6 months | Usually not |
| Ketoacidosis at onset | Common | Uncommon | Uncommon |
Read the middle column carefully. Every entry in it either matches Type 1 or matches Type 2 — which is exactly why LADA gets sorted into the wrong box so easily.
The one row that never bends is the antibody row. Cause is what separates the three, and antibodies are how cause is measured. Build, age and speed of onset are tendencies, and tendencies have exceptions.
The bottom two rows explain the diagnostic confusion in practice. Someone with LADA arrives without a crisis and without an immediate need for insulin — so they look like Type 2 on the day, and only reveal themselves over time.