A common polymorphism in the promoter of the IGF-I gene associates with increased fasting serum triglyceride levels in glucose-tolerant subjects.
OBJECTIVE
The aim of the present study was to examine if absence of a common allele in a microsatellite polymorphism in the insulin-like growth factor I (IGF-I) promoter was associated with type 2 diabetes and alterations in quantitative traits in glucose-tolerant subjects.


METHODS
The IGF-I promoter polymorphism was investigated in a case-control study comprising 694 type 2 diabetic patients and 218 glucose-tolerant control subjects, and in two genotype-quantitative trait studies involving 208 glucose-tolerant first-degree offspring of type 2 diabetic patients and 218 unrelated middle-aged subjects with normal glucose tolerance.


RESULTS
No associations were found between the lack of the common promoter allele and type 2 diabetes (P = 0.25) or estimates of glucose metabolism in glucose-tolerant subjects. Presence of the wild-type allele was associated with an increase in fasting serum triglyceride levels in the group of 208 glucose-tolerant first-degree offspring of type 2 diabetic patients (P = 0.002). This finding was replicated in an independent sample of 218 unrelated middle-aged subjects with normal glucose tolerance (P = 0.007).


CONCLUSIONS
The present study provides evidence that the common wild-type allele of the IGF-I promoter polymorphism is associated with increased levels of fasting serum triglyceride in glucose-tolerant whites.
Steno Diabetes Center and Hagedorn Research Institute, Gentofte, Copenhagen, Denmark. emdn@steno.dk
Eva-Maria D
EM
Nielsen
Lars
L
Hansen
Maria
M
Lajer
Kirstine L
KL
Andersen
Søren M
SM
Echwald
Søren A
SA
Urhammer
Torben
T
Hansen
Oluf
O
Pedersen
D000368:Aged; D000483:Alleles; D016022:Case-Control Studies; D005260:Female; D005838:Genotype; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics* / Q000378:metabolism; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D014280:Triglycerides / Q000097:blood*
D014280:Triglycerides; D007334:Insulin-Like Growth Factor I; D005947:Glucose