Pro12Ala polymorphism of the PPARgamma2 locus modulates the relationship between energy intake and body weight in type 2 diabetic patients.
OBJECTIVE
We explore the relationship among BMI, habitual diet, and the Pro12Ala polymorphism in the peroxisome proliferator-activated receptor (PPAR)gamma2.


METHODS
The Pro12Ala variant was characterized in 343 unrelated type 2 diabetic patients who were consecutively seen at the outpatient clinic of a health district of the province of Naples. Anthropometric and laboratory parameters were measured; habitual diet was assessed by a validated semiquantitative food frequency questionnaire.


RESULTS
The overall frequency of Ala12 was 12% (n = 42). BMI was significantly higher in Ala carriers than non-Ala carriers, whereas total daily energy intake or macronutrient composition of the diet were similar in the two groups. For further analysis, participants were stratified according to genotype and sex-specific quartiles of energy intake. BMI increased in both genotype groups with increasing energy intake (P < 0.03). BMI was similar in Ala carriers and non-Ala carriers (30.0 vs. 30.1 kg/m2, P > 0.10) in the lower quartile of energy intake but significantly higher in Ala carriers in the upper quartile (36.0 vs. 32.1 kg/m2, P < 0.001). Average daily energy intake and diet composition were comparable within each quartile for carriers or noncarriers of the Ala allele. Relative to the noncarriers, Ala carriers had a significantly lower energy intake per kilogram body weight, thus suggesting that the Ala allele is associated with a higher food efficiency. The confounding role of medications, glucose control, and physical exercise was ruled out.


CONCLUSIONS
This study provides evidence of a differential susceptibility to fat accumulation, and, hence, weight gain, in response to habitual high energy intake for Ala carriers compared with Pro/Pro homozygotes.
Vaccaro
Olga
O
Department of Clinical and Experimental Medicine, University of Naples, Federico II, via S. Pansini 5, 80131 Naples, Italy. ovaccaro@unina.it
Lapice
Emanuela
E
Monticelli
Antonella
A
Giacchetti
Manuela
M
Castaldo
Imma
I
Galasso
Rocco
R
Pinelli
Michele
M
Donnarumma
Giovanna
G
Rivellese
Angela A
AA
Cocozza
Sergio
S
Riccardi
Gabriele
G
D000328:Adult; D000368:Aged; D000409:Alanine; D019943:Amino Acid Substitution; D015992:Body Mass Index; D003404:Creatinine / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D003927:Diet, Diabetic; D004734:Energy Metabolism / Q000235:genetics*; D005247:Feeding Behavior; D005260:Female; D006580:Genetic Carrier Screening; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008875:Middle Aged; D047495:PPAR gamma / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011392:Proline; D015430:Weight Gain / Q000235:genetics*
D047495:PPAR gamma; D011392:Proline; D003404:Creatinine; D000409:Alanine