Even when blood sugar was kept normal, giving insulin made the body’s stress system more active than when nothing was given — suggesting insulin itself, not just the experiment, triggered the response.
Scientific Claim
In nonobese young men, insulin infusion at 2 mU/kg/min for 2 hours during euglycemic glucose clamp produces a greater plasma norepinephrine response than a control condition with no insulin or glucose infusion, indicating that insulin, not just experimental conditions, drives sympathetic activation.
Original Statement
“The plasma NE response was greater with the 5-mU than with the 2-mU insulin infusion (P < 0.001), and similarly, was greater during the 2-mU insulin infusion than during a control test in which neither insulin nor glucose was infused (P < 0.001).”
Evidence Quality Assessment
Claim Status
overstated
Study Design Support
Design cannot support claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The abstract implies insulin 'causes' the difference, but without confirmed control for all confounders, only association can be claimed. The verb 'drives' is too strong.
More Accurate Statement
“In nonobese young men, insulin infusion at 2 mU/kg/min for 2 hours during euglycemic glucose clamp is associated with a greater plasma norepinephrine response than a control condition with no insulin or glucose infusion, indicating that insulin exposure is linked to increased sympathetic activation.”
Evidence from Studies
Supporting (1)
Effect of Insulin and Glucose Infusions on Sympathetic Nervous System Activity in Normal Man
The study showed that giving insulin to healthy young men, without changing their blood sugar, made their body’s stress system more active—shown by higher levels of a stress hormone called norepinephrine. This proves insulin itself, not just the experiment, caused the reaction.