title: Polymorphisms associated with a tropical climate and root crop diet induce susceptibility to metabolic and cardiovascular diseases in Solomon Islands.
abstract: The people of the Solomon Islands represent an Austronesian (AN)-speaking population's adaptation to a humid tropical environment and subsistence of tuberous crops. Genome-wide association studies (GWASs) of other populations (e.g. the Human Genome Diversity Project [HGDP]) have suggested the existence of genotypes adaptive to ecoregion, diet, and subsistence, and that those genotypes are also associated with metabolic and cardiovascular diseases. Recently, the incidence of non-communicable diseases has been increasing in the Solomon Islands. In the present study, we explored the association of genotypes adaptive to a tropical environment and tuberous crop diet with metabolic and cardiovascular conditions in rural and urban AN-speaking Melanesian and Micronesian populations of the Solomon Islands. A total of 561 participants were genotyped for single nucleotide polymorphisms (SNPs) potentially associated with a tropical environment (rs174570 and rs2237892) and a tuberous crop diet (rs162036, rs185819, and rs2722425). The results showed that the allele frequencies of the Solomon Islands populations adopted patterns similar to those in populations from other hot, tropical areas with a tuberous crop diet in previous studies. Furthermore, rs162036, rs185819, rs2237892, and rs2722425 were all strongly associated with one or more metabolic and cardiovascular conditions. The derived allele of rs2722425 (i.e. rs2722425-G) was significantly associated with an elevated LDL level (P = 0.000264) even after the significance level was adjusted for multiple testing (i.e., α = 0.0005). Our results suggest that the inhabitants of the Solomon Islands exhibit the effects of the tropical environment and tuberous crop diet on their allele frequencies, and that their susceptibility to metabolic and cardiovascular diseases is therefore considered to be associated with their environment and diet.
authors.affiliation: Graduate School of Asian and African Area Studies, Kyoto University, Kyoto, Japan.
authors.forename: Takuro
authors.identifier: http://orcid.org/0000-0001-7772-3053
authors.initials: T
authors.lastname: Furusawa
authors.affiliation: Graduate School of Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Izumi
authors.initials: I
authors.lastname: Naka
authors.affiliation: Graduate School of Health Sciences, Hokkaido University, Hokkaido, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Yamauchi
authors.affiliation: The Japanese Red Cross Akita College of Nursing, Akita, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Natsuhara
authors.affiliation: National Gizo Hospital, Ministry of Health and Medical Services, Gizo, Solomon Islands.
authors.forename: Ricky
authors.initials: R
authors.lastname: Eddie
authors.affiliation: Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kimura
authors.affiliation: Department of International Health, Kobe University Graduate School of Health Sciences, Kobe, Japan.
authors.forename: Minato
authors.initials: M
authors.lastname: Nakazawa
authors.affiliation: Graduate School of Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ishida
authors.affiliation: Japan Wildlife Research Center, Tokyo, Japan.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Ohtsuka
authors.affiliation: Graduate School of Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Ohashi
mesh_terms: D000328:Adult; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000235:genetics; D018556:Crops, Agricultural; D004032:Diet; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D055106:Genome-Wide Association Study; D006801:Humans; D008297:Male; D008542:Melanesia / Q000453:epidemiology; D008659:Metabolic Diseases / Q000453:epidemiology* / Q000235:genetics; D008875:Middle Aged; D018517:Plant Roots; D020641:Polymorphism, Single Nucleotide; D014329:Tropical Climate