Gender-specific effect of Pro12Ala polymorphism in peroxisome proliferator-activated receptor gamma-2 gene on obesity risk and leptin levels in a Tunisian population.
OBJECTIVE
This study was undertaken to investigate the impact of the Pro12Ala (rs1801282) polymorphism of the peroxisome proliferator-activated receptor gamma-2 (PPARgamma-2) gene on obesity or body mass index (BMI) and plasma leptin, insulin, adiponectin and lipid levels in a sample of the Tunisian population.


METHODS
The study included 387 obese patients and 288 control subjects. The Pro12Ala genotype was determined by polymerase chain reaction followed by a digestion with the restriction of endonuclease BstUI.


RESULTS
In the whole population, there is no significant difference in genotype frequencies of the Pro12Ala polymorphism between obese patients and controls. However, separate analysis by gender revealed that obese men (but not women) had significantly higher frequency of Pro/Ala genotypes compared to controls (12.2% vs. 4.1%; chi(2)=6.76, p=0.009). In comparison to Pro/Pro homozygotes, Ala-allele bearers had a significantly higher risk of obesity [OR (95% CI)=3.26 (1.28-8.33)]. When obese subjects were stratified according to type 2 diabetes status, the association with obesity was only significant in obese non-diabetic patients [OR (95% CI)=3.74 (1.43-9.74), p=0.007]. Additionally, obese male patients carrying the Ala-allele had significantly higher body mass index (p=0.007) and plasma leptin levels (p=0.023) compared to those homozygous for Pro-allele. The significant effect of Pro12Ala polymorphism on plasma leptin levels disappeared after adjustment for age and BMI.


CONCLUSIONS
The present study provides evidence that the Pro12Ala polymorphism of the PPARgamma-2 gene is associated with obesity in non-diabetic men from Tunisian origin.
Ben Ali
Samir
S
Research Laboratory LR99ES11, Biochemistry Department, Rabta University Hospital, Tunis, Tunisia.
Ben Yahia
Fatma
F
Sediri
Yousra
Y
Kallel
Amani
A
Ftouhi
Bochra
B
Feki
Moncef
M
Elasmi
Monia
M
Haj-Taieb
Sameh
S
Souheil
Omar
O
Sanhagi
Haifa
H
Slimane
Hedia
H
Jemaa
Riadh
R
Kaabachi
Naziha
N
D000409:Alanine / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D009765:Obesity / Q000235:genetics*; D047495:PPAR gamma / Q000235:genetics*; D011392:Proline / Q000235:genetics*; D012307:Risk Factors; D012737:Sex Factors; D014416:Tunisia
D020738:Leptin; D047495:PPAR gamma; D011392:Proline; D000409:Alanine