A VARIANT of the adiponectin gene could be used in the future to predict people’s risk of cardiovascular events, according to Austrian researchers.
Adiponectin is a polypeptide hormone that controls a number of metabolic processes and which is secreted into the bloodstream by adipocytes – the cells storing fat in fatty tissue. Low levels of adiponectin have been associated with obesity, insulin resistance, diabetes, and increased cardiovascular risk.
Professor Heinz Drexel and his team investigated the connection between the different adiponectin genotypes and cardiovascular risk among coronary patients. They focused on the -11377 promoter polymorphism of the gene, where three different genotypes are associated with different levels of adiponectin: CC, GC and GG genotypes.
Prof Drexel, of the Department of Internal Medicine at the Academic Teaching Hospital Feldkirch in Feldkirch, Austria, explained: “Since there was known to be an association between adiponectin and cardiovascular disease, we felt that an association between the polymorphism and vascular events was quite plausible and decided to investigate further.”
The researchers used PCR to analyse adiponectin genes from 402 men undergoing coronary angiography, and they recorded vascular events prospectively over four years.
Results showed that serum adiponectin levels were highest in the CC genotype and lowest in the GG genotype, while the prevalence of significant coronary stenoses increased gradually from 63% in the CC, to 73.2% in the GC to 88.5% in the GG genotypes (p for trend=0.004). The prevalence of the -11377 CC, GC and GG genotypes in the patients was 56.5%, 37.1% and 6.5% respectively.
Patients with CG and GG genotypes were 1.5 and 2.4 times more at risk of a cardiovascular event than patients with the CC genotype. (Adjusted hazard ratios were 1.582 (0.971-2.577) for the CG genotype and 2.403 (1.108-5.214) for the GG genotype, with p for trend = 0.011).
“We have shown for the first time that the G allele of the -11377 polymorphism of the adiponectin gene identifies individuals at high cardiovascular risk who require intensive treatment for cardiovascular risk factors,” said Professor Drexel.
However, he added that before screening for the polymorphism could be recommended, further studies in other patient populations were needed to confirm the association, and to investigate whether treatments for insulin resistance and metabolic syndrome might be effective in helping to reduce the risk in people with the adverse polymorphism.
Prof Drexel and his team are now investigating cardiovascular risks associated with other polymorphisms of the genes encoding for adiponectin and other adipokines.