Lifestyle and socioeconomic factors are often associated with the higher incidence of obesity, type 2 diabetes and cardiovascular disease in native Hawaiians, but new research has found that genetic lineage from Polynesia also increases the risk for certain chronic ailments.
Using genetic data from nearly 4,000 individuals involved in a long-term multiethnic health study, a team of researchers led by Charleston Chiang of the University of Southern California Center for Genetic Epidemiology found that for every 10% increase in ‘ a person’s Polynesian genetic ancestry, the chance of being diabetic and suffering from heart failure increased by 8.6% and 11% respectively.
A greater amount of Polynesian genetic ancestry was also linked to a higher body mass index, a measure of body fat, according to the study published today in PLOS Genetics.
But genetics is not the only, or even the biggest, determining factor for obesity and chronic diseases in any ethnic group, the study stressed, saying: ‘lifestyle, socio-economic and other environmental factors can play a big or bigger role . However, we hope that the genetic studies will be a window to understand the biology behind these diseases, in a way that is targeted and ultimately beneficial to the health of the underserved population. ”
Epidemiological studies have shown that 49% of adult indigenous Hawaiians are obese, compared to 21% of European Americans and 13% of Japanese Americans living in Hawaii, according to the new report, co-authors Lynne Wilkens and Loic Le Marchand of the University of Hawaii Cancer Center. Native Hawaiians are also two to three times more likely to develop type 2 diabetes and 1.7 times more likely to have cardiovascular disease than European Americans.
Chiang said the team’s findings did not surprise him as much as the lack of genomic resources for studying native Hawaiians, which he described as ‘almost’. ‘
‘I know from previous epidemiology studies that native Hawaiians are known to be at increased risk for various cardio-metabolic diseases or traits when they compare them to European or Asian Americans, but from a genetic point of view I think they are greatly underestimated. , so we were there to fill the void kind of. ”
Chiang and his team at the USC Center for Genetic Epidemiology are particularly important in filling the gaps to understand the genetic underpinnings of disease risk in ethnic populations.
‘The genetic field has always been very focused on European populations because there is a long history for it, and of course many of the genetic studies were driven by European or Western researchers who had a long history of these well-maintained groups. European populations. It therefore made sense in some ways that many of these genetic studies were done in Europeans, ‘he said.
To broaden the research, USC and the UH Cancer Center launched the Multiethnic Cohort Study in the mid-1990s, with 104,000 Hawaii residents and 112,000 Los Angeles residents including five ethnic groups, including Native Hawaiians. Participants completed a comprehensive questionnaire on their diet, medication, physical activity, family medical history, and other personal information, with updates every five years to detect the development of cancer and chronic diseases.
Of the larger group, Chiang’s team achieved its findings by examining the genome-wide genetic data of approximately 3,940 self-identified native Hawaiians, tracing the components inherited from Polynesian ancestors, and linking them to the health conditions experienced by participants the study was reported.
“For me, it is the first step towards more personalized medicine, knowing that it is the particular characteristics of a person for disease or risk assessment,” Chiang said.
Although the descent of an individual does not determine his or her destiny in terms of health outcomes, the study said that further research ‘may be able to identify genetic variants and underlying biological factors specific to the Polynesian population, which the choice of lifestyle or pharmaceutical interventions enables to reduce their higher risk for these diseases. ”