Clinical Scorecard: Outcomes of rhIGF-1 Therapy in Patients with Severe Insulin Resistance Syndromes: Insights from a Single-Center Study
At a Glance
Category
Detail
Condition
Donohue syndrome (DS) and Rabson-Mendenhall syndrome (RMS), extreme forms of insulin resistance due to biallelic insulin receptor gene mutations
Key Mechanisms
rhIGF-1 binds IGF-1 receptor, insulin receptor, and hybrid receptors activating shared post-receptor signaling pathways to partially bypass insulin receptor defects
Target Population
Patients with genetically confirmed or clinically diagnosed DS and RMS exhibiting severe insulin resistance
Care Setting
Specialist tertiary care centers with capacity for long-term metabolic and multisystem monitoring
Key Highlights
rhIGF-1 treatment shows short-term metabolic benefits including improved glycemic control, fasting tolerance, and some growth enhancement in early life
Long-term benefits of rhIGF-1 are limited; treatment does not prevent progression to diabetes mellitus and may have variable tolerance
New clinical features associated with severe insulin receptoropathies include cataract, liver hemangioma, and impaired hepatic protein synthesis
Guideline-Based Recommendations
Diagnosis
Genetic testing for biallelic INSR mutations to confirm diagnosis of DS or RMS
Clinical assessment of growth restriction, dysmorphism, metabolic profile including fasting hypoglycemia and postprandial hyperglycemia
Management
Consider off-label rhIGF-1 therapy to improve metabolic control and growth in early years
Monitor for intolerance or poor response to rhIGF-1; discontinue if adverse effects or lack of benefit
Recognize that rhIGF-1 does not prevent progression to diabetes mellitus; prepare for evolving metabolic management
Monitoring & Follow-up
Longitudinal monitoring of glycemic control (fasting glucose, HbA1c), insulin levels, and growth parameters
Surveillance for multisystem complications including renal tubular dysfunction, cataracts, liver abnormalities
Regular assessment for hypoglycemic episodes and soft tissue overgrowth during rhIGF-1 therapy
Risks
Potential hypoglycemic episodes associated with rhIGF-1 treatment
Soft tissue overgrowth reported in some cases
Variable tolerance with some patients experiencing poor response or intolerance leading to early mortality
Patient & Prescribing Data
Patients with severe insulin resistance syndromes (DS and RMS) treated with rhIGF-1 over periods up to 16 years
Early metabolic improvements observed; however, long-term uninterrupted rhIGF-1 therapy may not prevent diabetes progression; treatment responses are heterogeneous
Clinical Best Practices
Obtain informed consent and perform thorough genetic and clinical evaluation before initiating rhIGF-1
Start rhIGF-1 at appropriate dosing with careful titration and monitoring for efficacy and adverse effects
Maintain multidisciplinary care involving endocrinology, genetics, nephrology, and other specialties for comprehensive management
Document and report long-term outcomes to contribute to evidence base for this rare condition
Consider alternative or adjunctive therapies as research evolves given limited efficacy of rhIGF-1 alone
