The effects of a low-carbohydrate versus low-fat diet on adipocytokines in severely obese adults: three-year follow-up of a randomized trial.
BACKGROUND
Adipocytokines are associated with insulin resistance and cardiovascular disease and can be modified with weight loss. While we previously demonstrated weight loss and a reduction in leptin in obese adults who followed a low-carbohydrate diet for 6 months, the long-term effects of this diet on adipocytokines are unknown.


METHODS
132 obese adults with a body mass index of > or = 35 kg/m2 were randomized to receive one year of dietary counseling to follow either a low-carbohydrate diet < 30 g/day (LC) or a caloric-restricted diet (reduced by 500 calories/day with < 30% of calories from fat) (LF). Weight, leptin, adiponectin, TNF-alpha, CRP, and insulin were measured at 0, 6, and 36 months (24 months post-counseling). Follow-up data at was collected for 53 participants who returned at 36 months.


RESULTS
Mean weight change from baseline was not different between the groups at 36 months. Between 6 and 36 months weight was unchanged for LF, while LC appeared to regain weight [+ 4.84 +/- 35.6 kg (+ 3.0%)]. This difference, however, was not significant (p = 0.08). Leptin was unchanged in LF at both 6 and 36 months. In LC leptin decreased by 8.49 +/- 6.4 ng/mL or 22.7% at 6 months (p < 0.001) and increased by 10.68 +/- 25.2 ng/mL or 41.9% between 6 and 36 months (p = 0.02). There were no differences in insulin, adiponectin, TNF-alpha, or CRP between the groups.


CONCLUSIONS
Favorable changes in leptin that accompany weight loss are not sustained in individuals who followed a low-carbohydrate diet for one year. A low-carbohydrate diet had no significant effect on insulin, adiponectin, TNF-alpha, or CRP compared to a low-fat diet at 36 months.
Cardillo
S
S
Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
Seshadri
P
P
Iqbal
N
N
D052242:Adiponectin / Q000097:blood; D001835:Body Weight; D002097:C-Reactive Protein / Q000032:analysis; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D002149:Energy Intake; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000178:diet therapy*; D016032:Randomized Controlled Trials as Topic; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
C499918:ADIPOQ protein, human; D052242:Adiponectin; D007328:Insulin; D020738:Leptin; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein