High molecular weight adiponectin levels are neither influenced by adiponectin polymorphisms nor associated with insulin resistance in mixed-ancestry hyperglycemic subjects from South Africa

Abstract
Background: High molecular weight (HMW) adiponectin has antiatherogenic, antiinflammatory and antidiabetic properties and these effects have been linked to its effect on high density lipoprotein cholesterol (HDL-c). Single nucleotide polymorphisms (SNPs) in the adiponectin gene influence adiponectin levels. We examined the relationship between HMW-adiponectin levels and cardiometabolic traits in normo- and hyperglycemic mixed ancestry South Africans and correlated these levels to two common polymorphisms. Methods: HMW-adiponectin was determined in 101 subjects from the Cape Town Bellville South community-based study on a mixed ancestry population. Comparisons were made between individuals with normo- and hyperglycemia. Two common SNPs, ADIPOQ SNPs rs17300539 and rs266729, known to affect adiponectin levels were also tested for. Levels of HMW-adiponectin were then correlated with cardiometabolic traits in all groups. Results: Levels of HMW-adiponectin were not significantly different in the normo- and hyperglycemic groups (median 11.6 vs. 10.5 μg/mL, p=0.3060) and in men and women (8.44 vs. 11.34 μg/mL, p=0.67). ADIPOQ SNPs rs17300539 and rs266729 did not influence levels of HMW-adiponectin. Robust correlation analyses revealed a significant positive correlation between HMW-adiponectin and HDL-c (r=0.45; 95%CI: 0.27–0.59), similarly in normo- and hyperglycemic participants (p>0.99). This association was substantially attenuated in robust linear regressions adjusted for age, gender and adiposity. Conclusions: Adiponectin levels in this population were not determined by the commonest SNPs of the adiponectin gene, were unaffected by glycemic status; but were significantly correlated with HDL-c levels. Previous studies have attributed some of the beneficial effects of adiponectin to its effect on HDL-c.
Uvod: Adiponektin velike molekulske te`ine (VMT) ima antiaterogena, antiinflamatorna i antidijabetska svojstva i ovi efekti su dovedeni u vezu s njegovim dejstvom na HDL holesterol (HDL-h). Polimorfizmi pojedina~nih nukleotida (SNP) u genu za adiponektin uti~u na nivoe adiponektina. Ispitivali smo odnos izme|u nivoa adiponektina VMT i kardiometa - boli~kih odlika kod Ju`noafrikanaca me{ovite rase sa normo - glikemijom i hiperglikemijom i napravili korelaciju izme|u ovih nivoa i dva ~esta polimorfizma. Metode: Adiponektin VMT odre|en je kod 101 ispitanika me{ovite rase iz zajednice Ju`ni Belvil u Kejptaunu koja je kao populacija obuhva}ena studijom. Pore|enja su izvr{ena izme|u pojedinaca sa normoglikemijom i hiperglikemijom. Dva uobi~ajena SNP-a, polimorfizmi pojedina~nih nukleotida ADIPOQ rs17300539 i rs266729, za koje se zna da uti~u na nivoe adiponektina, tako|e su testirani. Nivoi adiponektina VMT su zatim dovedeni u korelaciju sa kardiometa - boli~kim odlikama u svim grupama. Rezultati: Nivoi adiponektina VMT nisu se zna~ajno razlikovali izme|u grupa sa normoglikemijom i hiperglikemijom (medijana 11,6 vs. 10,5 mg/mL, p=0,3060) niti izme|u mu{ka raca i `ena (8,44 vs. 11,34 mg/mL, p=0,67). Poli - morfizmi pojedina~nih nukleotida ADIPOQ rs17300539 i rs266729 nisu uticali na nivoe adiponektina VMT. Robusne korelacione analize pokazale su da postoji zna~ajna pozitivna korelacija izme|u adiponektina VMT i HDL-h (r=0,45; 95%CI: 0,27–0,59) sli~na kod ispitanika sa normoglikemijom i hiperglikemijom (p>0,99). Ova povezanost je znatno oslabila nakon robusnih linearnih regresija prilago|enih prema starosti, polu i adipozitetu. Zaklju~ak: Nivoi adiponektina u ovoj populaciji nisu bili odre |eni naj~e{}im polimorfizmima pojedina~nih nukleotida gena za adiponektin, niti je na njih uticao glikemijski status, ali su bili u zna~ajnoj korelaciji sa nivoima HDL-h. Prethodne studije su neke od povoljnih efekata adiponektina pripisale njegovom dejstvu na HDL-h.
Description
CITATION: Zemlin, A. E., et al. 2016. High molecular weight adiponectin levels are neither influenced by adiponectin polymorphisms nor associated with insulin resistance in mixed-ancestry hyperglycemic subjects from South Africa. Journal of Medical Biochemistry, 35(4):417-427, doi:10.1515/jomb-2016-0024.
The original publication is available at https://www.degruyter.com
Publication of this article was funded by the Stellenbosch University Open Access Fund.
Keywords
HMW-adiponectin, Polymorphisms, Genetic, Hyperglycemia -- Heredity, Metabolic heart disease, Endocrine glands -- Diseases
Citation
Zemlin, A. E., et al. 2016. High molecular weight adiponectin levels are neither influenced by adiponectin polymorphisms nor associated with insulin resistance in mixed-ancestry hyperglycemic subjects from South Africa. Journal of Medical Biochemistry, 35(4):417-427, doi:10.1515/jomb-2016-0024