Hypoglycemia, but not insulin, acutely decreases LH and T secretion in men.
Level 3 - non-randomized controlled study
Controlled physiological clamp experiment in humans (allocation not specified as randomized)
PubMed 11600562 · doi:10.1210/jcem.86.10.7892
What was done
Thirty healthy men underwent 6-hour euglycemic and hypoglycemic clamp experiments. Half were infused with insulin at 1.5 mU/min·kg and the other half at 15.0 mU/min·kg. Plasma glucose was maintained constant during euglycemic sessions and decreased stepwise during hypoglycemic sessions. LH, total and free testosterone, DHEA, and FSH concentrations were measured.
What was found
The abstract reports no numerical values. LH and total and free testosterone concentrations decreased during hypoglycemia regardless of insulin infusion rate, while remaining unchanged under euglycemic conditions. DHEA increased during hypoglycemia but not euglycemia. FSH concentrations were unaffected by insulin rate or glycemic condition.
Why it matters
These findings suggest that acute neuroglycopenia, rather than elevated insulin levels per se, suppresses the hypothalamic-pituitary-gonadal axis, pointing to glucose-sensing neural mechanisms in hypoandrogenemia.
Limits
The abstract provides no numerical data, effect sizes, or p-values. The study was conducted in a small cohort of 30 healthy men during acute 6-hour clamps, which may not reflect chronic metabolic disturbances seen in diabetes or metabolic syndrome.
Cited by
- contradicts When blood sugar rises, insulin rises, which directly leads to an increase in testosterone levels.