Leptin responses to antecedent exercise and hypoglycemia in healthy and type 1 diabetes mellitus men and women.
These studies examined the effects of hypoglycemia or exercise on leptin levels in 47 (23 women, 24 men) healthy (age 26+/-2 years, body mass index 23+/-0.5 kg.m(-2)) and type 1 diabetes mellitus (T1DM) subjects (age 29+/-2 years, body mass index 27+/-2 kg.m(-2)). In Study 1, healthy and T1DM subjects were exposed to morning and afternoon 120-min hyperinsulinemic hypoglycemic ( approximately 50 mg/dl) or euglycemic ( approximately 90 mg/dl) clamps. In Study 2, healthy subjects were studied during morning and afternoon 90-min exercise bouts at 50% VO(2max). In Study 1, basal levels of leptin were significantly greater in T1DM vs. the healthy subjects (13.8+/-3 vs. 5.4+/-1 ng/dl; P<.05). However, during the last 30 min of morning hypoglycemia, plasma leptin levels significantly decreased from 5.4+/-1 to 4.0+/-1 ng/dl (P<.05) and remained low during afternoon hypoglycemia (4.3+/-1 ng/dl) in healthy but not T1DM subjects. In Study 2, plasma leptin levels did not significantly change during exercise the bout in healthy men, but significantly decreased 3 h after morning exercise, and continued to decrease during afternoon exercise in healthy women (P<.0001). Thus, plasma leptin levels decrease in response to hypoglycemia in healthy but not T1DM subjects. However, T1DM patients do have increased basal leptin levels compared to healthy man. Lastly, there is a marked sexual dimorphism in plasma leptin responses to repeated episodes of exercise.
Sandoval
Darleen A
DA
Department of Medicine, Vanderbilt University School of Medicine and Nashville Veterans Affairs Medical Center, Nashville, TN 37232, USA. darleen.sandoval@mcmail.vanderbilt.edu
Galassetti
Pietro
P
Tate
Donna
D
Neill
Anthony
A
Davis
Stephen N
SN
D000222:Adaptation, Physiological; D000328:Adult; D016022:Case-Control Studies; D002940:Circadian Rhythm / Q000502:physiology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood*; D008297:Male; D012016:Reference Values; D013312:Stress, Physiological / Q000097:blood* / Q000503:physiopathology
D007328:Insulin; D020738:Leptin