Effect of lifestyle modification on adipokine levels in obese subjects with insulin resistance.
OBJECTIVE
To study the effect of weight loss in response to a lifestyle modification program on the circulating levels of adipose tissue derived cytokines (adipokines) in obese individuals with insulin resistance.


METHODS
Twenty-four insulin-resistant obese subjects with varying degrees of glucose tolerance completed a 6-month program consisting of combined hypocaloric diet and moderate physical activity. Adipokines [leptin, adiponectin, resistin, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6)] and highly sensitive C-reactive protein were measured before and after the intervention. Insulin sensitivity index was evaluated by the frequently sampled intravenous glucose tolerance test.


RESULTS
Participants had a 6.9 +/- 0.1 kg average weight loss, with a significant improvement in sensitivity index and reduction in plasma leptin (27.8 +/- 3 vs. 23.6 +/- 3 ng/mL, p = 0.01) and IL-6 (2.75 +/- 1.51 vs. 2.3 +/- 0.91 pg/mL, p = 0.012). TNF-alpha levels tended to decrease (2.3 +/- 0.2 vs. 1.9 +/- 0.1 pg/mL, p = 0.059). Adiponectin increased significantly only among diabetic subjects. The reductions in leptin were correlated with the decreases in BMI (r = 0.464, p < 0.05) and with changes in highly sensitive C-reactive protein (r = 0.466, p < 0.05).


CONCLUSIONS
Weight reduction in obese individuals with insulin resistance was associated with a significant decrease in leptin and IL-6 and a tendency toward a decrease in circulating TNF-alpha, whereas adiponectin was increased only in diabetic subjects. Further studies are needed to elucidate the relationship between changes of adipokines and the health benefits of weight loss.
Monzillo
Lais U
LU
Clinical Research Center, Joslin Diabetes Center, and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.
Hamdy
Osama
O
Horton
Edward S
ES
Ledbury
Sarah
S
Mullooly
Cathy
C
Jarema
Catherine
C
Porter
Satoko
S
Ovalle
Kerry
K
Moussa
Amr
A
Mantzoros
Christos S
CS
D052242:Adiponectin; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D016207:Cytokines / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D004038:Diet, Reducing; D015444:Exercise / Q000502:physiology*; D005951:Glucose Tolerance Test; D006729:Hormones, Ectopic / Q000097:blood; D006801:Humans; D007333:Insulin Resistance; D036341:Intercellular Signaling Peptides and Proteins; D015850:Interleukin-6 / Q000097:blood; D020738:Leptin / Q000097:blood*; D008019:Life Style; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D011506:Proteins / Q000032:analysis; D052243:Resistin; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D052242:Adiponectin; D001786:Blood Glucose; D016207:Cytokines; D006729:Hormones, Ectopic; D036341:Intercellular Signaling Peptides and Proteins; D015850:Interleukin-6; D020738:Leptin; D011506:Proteins; C499624:RETN protein, human; D052243:Resistin; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein