| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Departments of Medicine, Vanderbilt University School of Medicine and Nashville Veterans Affairs Medical Center, Nashville, Tennessee 37232
The aims
of this study were 1) to determine whether differential
glycemic thresholds are the mechanism responsible for the sexual
dimorphism present in neuroendocrine responses during hypoglycemia and
2) to define the differences in counterregulatory
physiological responses that occur over a range of mild to moderate
hypoglycemia in healthy men and women. Fifteen (8 male, 7 female) lean
healthy adults underwent four separate randomized 2-h hyperinsulinemic (1.5 mU · kg
1 · min1)
glucose clamp studies at euglycemia (90 mg/dl) or hypoglycemia of 70, 60, or 50 mg/dl. Plasma insulin levels were similar during euglycemic
and hypoglycemic studies (91-96 ± 8 µU/ml) in men and women. Hypoglycemia of 70, 60, and 50 mg/dl all resulted in significant increases (P < 0.05, P < 0.01) in
epinephrine, glucagon, growth hormone, cortisol, and pancreatic
polypeptide levels compared with euglycemic studies in men and women.
Plasma norepinephrine levels were increased (P < 0.05)
only relative to euglycemic studies at a hypoglycemia of 50 mg/dl.
Muscle sympathetic nerve activity (MSNA) increased significantly during
hyperinsulinemic-euglycemic control studies. Further elevations of MSNA
did not occur until hypoglycemia of 60 mg/dl in both men and women.
Plasma epinephrine, glucagon, growth hormone, and pancreatic
polypeptide were significantly increased in men compared with women
during hypoglycemia of 70, 60, and 50 mg/dl. MSNA, heart rate, and
systolic blood pressure responses were also significantly increased in
men at hypoglycemia of 60 and 50 mg/dl. In summary, these studies have
demonstrated that, in healthy men and women, the glycemic thresholds
for activation of epinephrine, glucagon, growth hormone, cortisol, and
pancreatic polypeptide occur between 70 and 79 mg/dl. Thresholds for
activation of MSNA occur between 60 and 69 mg/dl, whereas
norepinephrine is not activated until glycemia is between 50 and 59 mg/dl. We conclude that 1) differential glycemic thresholds
are not the cause of the sexual dimorphism present in counterregulatory
responses to hypoglycemia; 2) reduced central nervous system
efferent input appears to be the mechanism responsible for lowered
neuroendocrine responses to hypoglycemia in women; and 3)
physiological counterregulatory responses (neuroendocrine,
cardiovascular, and autonomic nervous system) are reduced across a
broad range of hypoglycemia in healthy women compared with healthy men.
glucose clamp; microneurography; epinephrine; glucagon
This article has been cited by other articles:
|
|
 |
|
  K. M. Canniff, M. S. Smith, D. B. Lacy, P. E. Williams, and M. C. Moore Glucagon secretion and autonomic signaling during hypoglycemia in late pregnancy Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2006; 291(3): R788 - R795. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. A. Sandoval, D. L. Aftab Guy, M. A. Richardson, A. C. Ertl, and S. N. Davis Acute, same-day effects of antecedent exercise on counterregulatory responses to subsequent hypoglycemia in type 1 diabetes mellitus Am J Physiol Endocrinol Metab, June 1, 2006; 290(6): E1331 - E1338. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Batista, M. S. Smith, W. L. Snead, C. C. Connolly, D. B. Lacy, and M. C. Moore Chronic estradiol and progesterone treatment in conscious dogs: effects on insulin sensitivity and response to hypoglycemia Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2005; 289(4): R1064 - R1073. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. A. Sandoval, D. L. A. Guy, M. A. Richardson, A. C. Ertl, and S. N. Davis Effects of Low and Moderate Antecedent Exercise on Counterregulatory Responses to Subsequent Hypoglycemia in Type 1 Diabetes Diabetes, July 1, 2004; 53(7): 1798 - 1806. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z RADIKOVA, A PENESOVA, J KOSKA, R KVETNANSKY, D JEZOVA, M HUCKOVA, M VIGAS, and L MACHO Does Orthostatic Stress Influence the Neuroendocrine Response to Subsequent Hypoglycemia in Humans? Ann. N.Y. Acad. Sci., June 1, 2004; 1018(1): 576 - 581. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Sandoval, A. C. Ertl, M. A. Richardson, D. B. Tate, and S. N. Davis Estrogen Blunts Neuroendocrine and Metabolic Responses to Hypoglycemia Diabetes, July 1, 2003; 52(7): 1749 - 1755. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Del Parigi, K. Chen, J.-F. Gautier, A. D Salbe, R. E Pratley, E. Ravussin, E. M Reiman, and P A. Tataranni Sex differences in the human brain's response to hunger and satiation Am. J. Clinical Nutrition, June 1, 2002; 75(6): 1017 - 1022. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Geelen, T. Laitinen, J. Hartikainen, E. Lansimies, K. Bergstrom, and L. Niskanen Gender influence on vasoactive hormones at rest and during a 70{degrees} head-up tilt in healthy humans J Appl Physiol, April 1, 2002; 92(4): 1401 - 1408. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M Dart, X.-J. Du, and B. A Kingwell Gender, sex hormones and autonomic nervous control of the cardiovascular system Cardiovasc Res, February 15, 2002; 53(3): 678 - 687. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
