Giving a higher dose of insulin to healthy young men made their stress response even stronger than a lower dose — their blood pressure and heart activity rose more, showing that more insulin leads to more nerve activity, even if blood sugar stays the same.
Scientific Claim
In nonobese young men, insulin infusion at 5 mU/kg/min for 2 hours during euglycemic glucose clamp is associated with a 117% increase in plasma norepinephrine levels from a basal mean of 254 ± 20 pg/ml to 551 ± 88 pg/ml at 150 minutes, along with increases in pulse pressure, mean arterial blood pressure, and pulse rate-systolic blood pressure product, indicating dose-dependent sympathetic nervous system activation.
Original Statement
“and 117% with the 5-mU infusion (from 254 ± 20 pg/ml to 551 ± 88 at 150 min, P < 0.001)... during the 5-mU insulin infusions there were increases in pulse pressure (P < 0.001), mean arterial blood pressure (P < 0.001), and pulse rate - systolic blood pressure product (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 uses 'increases' implying causation, but without confirmed randomization or blinding, causation cannot be established. Only association is supported.
Evidence from Studies
Supporting (1)
Effect of Insulin and Glucose Infusions on Sympathetic Nervous System Activity in Normal Man
This study found that giving insulin to healthy young men without changing their blood sugar made their body’s stress system more active, increasing heart rate, blood pressure, and a stress hormone called norepinephrine — exactly as the claim says.