Features of lipid metabolism in Arctic residents depending on ethnicity and lifestyle.

Introduction: Metabolic adaptations can differ significantly among Arctic residents with different ethnicities, lifestyles and adherences to traditional diets. The objective of this study was to examine the status of saturated fatty acids (SFAs) and triglycerides and the variability of BMI among Russian Arctic residents according to ethnicity and lifestyle.

Methods: The study involved adult females and males living in the territories of the Russian Arctic. The participants were divided into three groups: Indigenous reindeer herders leading a nomadic lifestyle (NIP), Indigenous people leading a sedentary lifestyle (SIP) and the Caucasian population (CP). The content of SFAs (C6-C24) and metabolic characteristics was determined using gas chromatographic and spectrophotometric methods. The study also included a quantitative comparison of the consumption of certain categories of food products. To analyze data, we used the descriptive analyses by non-parametric methods, as well as multiple linear regression analysis.

Results: The study found that the Caucasian females had higher triglyceride levels (p<0.001), higher total content of long-chain SFAs (LCSFAs) (C13-C18) (p=0.002) and that the SIP females had reduced content of very-long-chain fatty acids (C20-C24) (p=0.039). These changes were not statistically significant for the males, partly due to the almost identical levels of triglycerides C16:0 and C18:0 in the NIP and the CP. The content of medium-chain SFAs (MCSFAs) (C6-C12) was higher in the SIP (p<0.001 for females; p=0.002 for males). The Indigenous males tended to have a lower BMI compared to the Caucasian males, resulting in a lower prevalence of overweight or obesity: 49.3% in the NIP (p=0.006) and 57.4% in the SIP versus 69.3% in the CP. In female participants, these frequencies did not differ, being 64%, 65.4% and 66% respectively. The NIP and SIP groups had higher consumption of traditional foods, carbohydrate-rich foods, meat products and vegetable oils, the latter of which was positively associated with SFA content.

Conclusion: The study revealed the dependence of the studied parameters of lipid metabolism on ethnicity (Indigenous v Caucasian) and lifestyle (nomadic v sedentary). The population metabolic variability was expressed as the increase in the levels of LCSFAs and triglycerides in the CP, reflecting, most likely, an imbalance in the processes of their accumulation and consumption with a predominantly western type of nutrition. Indigenous populations, despite changes in diet towards an increased consumption of carbohydrate-rich products, have preserved an adaptive metabolism with the predominant use of lipids as energy resources. Higher levels of MCSFAs in the SIP, who are less adherent to a traditional diet compared to the NIP, may be compensatory, with a growing role of such fatty acids in energy consumption and thermogenesis.