Association of genetic variants in the adiponectin encoding gene (ADIPOQ) with type 2 diabetes in Japanese Brazilians
Received 28 April 2008; received in revised form 10 January 2009; accepted 21 January 2009. published online 09 March 2009.
Abstract
Aim
The objective of this study is to assess the contribution of ADIPOQ variants to type 2 diabetes in Japanese Brazilians.
Methods
We genotyped 200 patients with diabetes mellitus (100 male and 100 female, aged 55.0 years [47.5–64.0 years]) and 200 control subjects with normal glucose tolerant (NGT) (72 male and 128 female, aged 52.0 years [43.5–64.5 years]).
Results
Whereas each polymorphism studied (T45G, G276T, and A349G) was not significantly associated with type 2 diabetes mellitus, the haplotype GGA was overrepresented in our diabetic population (9.3% against 3.1% in NGT individuals, P=.0003). Also, this haplotype was associated with decreased levels of adiponectin. We also identified three mutations in exon 3: I164T, R221S, and H241P, but, owing to the low frequencies of them, associations with type 2 diabetes could not be evaluated. The subjects carrying the R221S mutation had plasma adiponectin levels lower than those without the mutation (2.10 μg/ml [1.35–2.55 μg/ml] vs. 6.68 μg/ml [3.90–11.23 μg/ml], P=.015). Similarly, the I164T mutation carriers had mean plasma adiponectin levels lower than those noncarriers (3.73 μg/ml [3.10–4.35 μg/ml] vs. 6.68 μg/ml [3.90–11.23 μg/ml]), but this difference was not significant (P=.17).
Conclusions
We identified in the ADIPOQ gene a risk haplotype for type 2 diabetes in the Japanese Brazilian population.
aDivision of Endocrinology, Department of Medicine, Federal University of São Paulo, São Paulo, SP, Brazil
bHeart Institute (InCor), São Paulo University Medical School, University of São Paulo, SP, Brazil
cSchool of Public Health, University of Sao Paulo, São Paulo, SP, Brazil
Corresponding author. Escola Paulista de Medicina, Disciplina de Endocrinologia, Universidade Federal de São Paulo, Rua Botucatu, 740-2, andar, 04034-970 São Paulo, SP, Brazil. Tel.: +55 11 5576 4229; fax: +55 11 5579 6636.
ABSTRACT