An analysis of peroxisome proliferator-activated receptor gamma (PPAR-gamma 2) Pro12Ala polymorphism distribution and prevalence of type 2 diabetes mellitus (T2DM) in world populations in relation to dietary habits.
OBJECTIVE
The human peroxisome proliferator-activated receptor gamma (PPAR-gamma) is involved in lipid storage, glucose homeostasis and adipocyte differentiation. The Ala allele of the Pro12Ala polymorphism has been associated with a protective effect against T2DM. Ala allele frequencies are known for many populations, but data are absent for other interesting human groups.


RESULTS
We examined samples from Ethiopia, Benin, Ecuador and Italy. In addition, we performed an analysis of the Pro12Ala polymorphism distribution in world populations, also in relation to T2DM prevalence and the diet lipid content. In the European populations, the Ala allele frequencies are distributed according to a latitudinal trend, with the highest in the northern and central European populations and the lowest in the Mediterranean populations. Considering the world populations, a significant inverse relationship between Ala frequency and T2DM prevalence was observed mainly in populations where energy from lipids exceeded 30% of the total energy intake.


CONCLUSIONS
Northern Europe's cold climate has been hypothesised to have played a role in contributing to the present pattern. Moreover our analysis appears to confirm, at a population level, the protective effect of Ala allele against T2DM, already observed in case-control studies, but only in populations with a diet rich in lipids.
Scacchi
R
R
CNR Institute of Molecular Biology and Pathology, Rome, Italy. renato.scacchi@uniroma1.it
Pinto
A
A
Rickards
O
O
Pacella
A
A
De Stefano
G F
GF
Cannella
C
C
Corbo
R M
RM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000409:Alanine; D001541:Benin / Q000453:epidemiology; D002980:Climate; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000235:genetics*; D004041:Dietary Fats / Q000008:administration & dosage* / Q000009:adverse effects; D004484:Ecuador / Q000453:epidemiology; D004777:Environment; D005002:Ethiopia / Q000453:epidemiology; D005247:Feeding Behavior; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D047495:PPAR gamma / Q000235:genetics*; D011110:Polymorphism, Genetic; D015995:Prevalence; D011392:Proline
D004041:Dietary Fats; D047495:PPAR gamma; D011392:Proline; D000409:Alanine