Latent autoimmune diabetes in adults
Latent autoimmune diabetes in adults (LADA) is a slowly progressive autoimmune beta-cell destruction that presents in adulthood without an initial insulin requirement, so it is frequently misclassified as type 2 diabetes until positive islet autoantibodies are identified. First-line management follows a standard stepwise diabetes approach, but basal insulin should be started proactively as beta-cell failure progresses, since earlier insulin reduces stress on the remaining beta cells.
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What this article covers
- Overview
An autoimmune diabetes with a slow clinical tempo: latent autoimmune diabetes in adults is classified with immune-mediated (type 1A) diabetes, sharing its autoantibody-driven beta-cell destruction…
- Epidemiology
An under-recognized subset of adult-onset diabetes, likely underdiagnosed because most adults presenting without an initial insulin requirement are diagnosed with type 2 diabetes without antibody testing.
- Risk factors
Positive islet autoantibodies at any adult age, most often GAD65.
- Pathophysiology
Autoantibody-mediated beta-cell destruction is the core mechanism, directed at the same targets implicated in type 1A diabetes: glutamic acid decarboxylase (GAD65), tyrosine phosphatase islet…
- Clinical features
Adult-onset hyperglycemia without an initial insulin requirement, closely resembling the presentation of type 2 diabetes.
- Differential diagnosis
Type 1 diabetes mellitus: rapid beta-cell destruction with insulin dependence and a tendency toward diabetic ketoacidosis at or soon after diagnosis, unlike the slow, initially non-insulin-dependent…
- Diagnosis
The clinching basis is a positive islet autoantibody in an adult who meets standard diabetes glucose criteria but is not initially insulin-dependent: A1c 6.5% or higher, fasting glucose 126 mg/dL or…
- Management
First, initiate lifestyle modification (weight management, dietary change, physical activity), as in any newly diagnosed diabetes.
- Complications
Microvascular complications (retinopathy, nephropathy, neuropathy) develop with sustained hyperglycemia, as in type 1 and type 2 diabetes.
- Prognosis
Progression to insulin dependence is expected, not exceptional, occurring over months to years after diagnosis in essentially all patients with positive autoantibodies.
- Prevention
No means exist to prevent the underlying autoimmune process, since latent autoimmune diabetes in adults is driven by an intrinsic autoimmune susceptibility.
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Related articles
- Type 1 diabetes mellitus
Type 1 diabetes mellitus is an insulin-deficient state from autoimmune (type 1A) or idiopathic (type 1B) destruction of pancreatic beta cells, presenting with hyperglycemia that can range from mild to life-threatening diabetic ketoacidosis. Diagnosis combines standard glycemic criteria with autoantibody testing (GAD65, IA-2), and lifelong insulin therapy, generally as a basal-bolus regimen, is required from diagnosis, with self-monitoring or continuous glucose monitoring to guide dosing.
- Type 2 diabetes mellitus
Type 2 diabetes is hyperglycemia from insulin resistance with progressive relative insulin deficiency, diagnosed by a hemoglobin A1c of 6.5% or higher, a fasting glucose of 126 mg/dL or higher, or a 2-hour oral glucose tolerance test value of 200 mg/dL or higher. First-line treatment is lifestyle modification plus metformin, with an SGLT2 inhibitor or GLP-1 receptor agonist added early for patients with atherosclerotic disease, kidney disease, or heart failure.
- Monogenic diabetes mellitus
Monogenic diabetes (maturity-onset diabetes of the young, MODY) is an autosomal dominant single-gene defect in beta-cell insulin secretion, presenting before age 25 years with a strong family history of atypical diabetes and no autoantibodies. Diagnosis rests on genetic testing, and treatment is guided by the specific gene mutation, with metformin, sulfonylurea, or insulin used empirically while confirmatory genetic results are pending.
- Insulin therapy in diabetes mellitus
Insulin therapy replaces or supplements endogenous insulin to control hyperglycemia, and is lifelong and mandatory in type 1 diabetes because of absolute beta-cell failure, while in type 2 diabetes it is added when oral and noninjectable agents fail to reach glycemic goals. First-line therapy is a basal-bolus regimen started at 0.4-1.0 units/kg/day in type 1 diabetes, or basal insulin glargine 10 units/day (or 0.1-0.2 units/kg/day) in type 2 diabetes, titrated to a fasting glucose target.