Resting leptin responses to acute and chronic resistance training in type 2 diabetic men and women.
OBJECTIVE
To evaluate the plasma leptin levels approximately 24 h post-exercise in control and type 2 diabetic subjects and to establish if observed changes in leptin concentrations were acute or chronic effects of a resistance training program.


METHODS
Thirty men and women (17 controls and 13 type 2, obese diabetics, age 40-55 y) had resting blood samples drawn at 08:00 h (12 h postprandial) at the beginning of the study (pre-training), 24 h after a three repetition maximal weight lifting bout (acute) and 72 h after their last training bout of 6 weeks of resistance training (chronic). The two groups were not matched with respect to body mass index and the control subjects were not normal weight. Subjects weight-trained three times a week, for 6 weeks, for 1 h, training both the upper and lower body.


RESULTS
Serum leptin concentrations were significantly higher in the type 2 diabetics than in the control group at pre-training (41.4+/-8.9 vs 11.4+/-3.0 ng/ml, P<0.05, respectively). Compared to pre-training, the leptin levels decreased significantly (P<0.01) after acute exercise in the diabetics but not in the control subjects (diabetics 30.9+/-7.1 vs controls 10.6+/-2.6 ng/ml). Approximately 72 h after 6 weeks of exercise training, the leptin concentrations were no longer lower than the pre-training values in either group (36.9+/-8.8 vs 11.9+/-8.8 ng/ml, respectively, P=NS). When leptin concentrations were log transformed and adjusted for fat mass there were still significant changes in leptin levels over time and between the control and diabetic group (P<0.05).


CONCLUSIONS
The type 2 diabetics showed a significant 30% reduction in resting leptin levels 24 h after a single bout of resistance exercise. This was an acute response to resistance exercise and not a chronic training effect (no difference between pre-training and chronic). The decreased resting leptin concentrations approximately 24 h post-acute exercise may be due to reduced glucose availability to the adipose tissue, particularly in the diabetic subjects. There is no chronic effect of resistance exercise on leptin concentrations.
Kanaley
J A
JA
Department of Exercise Science, Syracuse University, New York, USA. jakanale@sued.syr.edu
Fenicchia
L M
LM
Miller
C S
CS
Ploutz-Synder
L L
LL
Weinstock
R S
RS
Carhart
R
R
Azevedo
J L
JL
D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D001823:Body Composition; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology*; D012737:Sex Factors; D013997:Time Factors; D014891:Weight Lifting / Q000502:physiology*
D001786:Blood Glucose; D020738:Leptin