Insulin resistance in amyotrophic lateral sclerosis

Area of Science:

• Neurology
• Metabolic Disorders
• Neurodegenerative Diseases

Background:

• Glucose intolerance is frequently observed in patients with amyotrophic lateral sclerosis (ALS).
• A debate exists on whether this carbohydrate abnormality is intrinsic to ALS or a consequence of reduced glucose use from muscle atrophy.
• Previous hypotheses suggested a reduced glucose receptor space in neuromuscular diseases like ALS.

Purpose of the Study:

• To investigate in vivo insulin sensitivity in patients with ALS.
• To determine if insulin resistance in ALS is related to decreased glucose receptor space or represents a primary metabolic defect.

Main Methods:

• The euglycemic insulin clamp technique was employed to assess insulin sensitivity.
• ALS patients and two control groups, matched for ideal body weight, participated in the study.

Main Results:

• The glucose infusion rate, a measure of in vivo insulin sensitivity, was significantly lower in ALS patients compared to both normal and disease controls.
• This finding indicates that insulin resistance in ALS is not explained by a reduction in glucose receptor space.

Conclusions:

• Insulin resistance is a significant finding in amyotrophic lateral sclerosis (ALS).
• The observed insulin resistance in ALS is not attributable to decreased glucose receptor space.
• Evidence suggests a primary carbohydrate metabolism abnormality is involved in the ALS disease process.