Physiological rationale for expanding the spectrum of traditional lipid metabolism parameters in indigenous males of the Arctic region

BACKGROUND: Early physiological and biochemical studies reported relatively favorable lipid profiles in terms of protection against cardiovascular risk factors. However, in recent decades, a shift toward a more atherogenic lipid profile has been observed in some apparently healthy individuals living in the North. An expanded lipid panel includes the assessment of apolipoproteins and free fatty acids. There is a growing need for in-depth investigation of lipid metabolism in individuals without clinical signs of its disturbance residing in the Arctic zone to enable early diagnosis, timely correction, and prevention of cardiovascular diseases. AIM: To substantiate the selection of a set of lipid metabolism alteration markers in apparently healthy indigenous males of the Arctic region. MATERIALS AND METHODS: A total of 112 apparently healthy men permanently residing in the Arkhangelsk Region were examined. Serum levels of total cholesterol, high-, low-, and very-low-density lipoproteins, triglycerides, atherogenic index, concentrations of saturated, monounsaturated, and polyunsaturated fatty acids, as well as the apolipoprotein A to B ratio were determined. RESULTS: It was found that, although the levels of total cholesterol, high-, low-, and very-low-density lipoproteins, triglycerides, and the atherogenic index did not exceed reference values in apparently healthy residents of the Arctic region, elevated levels of very-low-density lipoproteins (19.8% of participants), triglycerides (17.2%), and the atherogenic index (52.1%) were observed. Apolipoprotein A levels were below reference values but exceeded apolipoprotein B levels in 39.1% of cases; the apolipoprotein A to B ratio was elevated in 51.2% of subjects. High levels of the palmitic (12.5%) and stearic (10.7%) saturated fatty acids were observed. In contrast, levels of polyunsaturated fatty acids were below the median in the case of ω-6 linoleic (21.4%) and arachidonic (51.5%) acids, as well as ω-3 alpha-linolenic (51.8%), eicosapentaenoic (40.8%), and docosahexaenoic (48.3%) acids. Moderate correlations were identified between triglyceride levels and saturated fatty acids, as well as weaker correlations with polyunsaturated fatty acids. CONCLUSION: Markers of subclinical lipid metabolism disturbances in indigenous residents of the Arctic region include relatively low levels of apolipoprotein A, a higher apolipoprotein B to A ratio, and reduced concentrations of ω-3 (alpha-linolenic, eicosapentaenoic, docosahexaenoic) and ω-6 (linoleic, arachidonic) polyunsaturated fatty acids.