Vitamin D and cardio-metabolic biomarkers: small-scale comparative study between Libyan migrants and resident women in Serbia

Abstract

Libyan women are at high risk of vitamin D deficiency, mostly due to their lifestyle and low exposure to sun. In the last decades, Libyan residents have been forced to seek refuge in countries such as Serbia, a country with high incidence of cardio-metabolic diseases. Serbian residents tend to be deficient in vitamin D, mostly due to the lack of vitamin D fortification policy. The aim of this study was to evaluate vitamin D status in Libyan adult women migrating to Serbia, with the assessment of cardio-metabolic and nutritional biomarkers, including erythrocytes fatty acid composition, magnesium concentration, and dietary intake. The same markers were measured in Serbian women, and comparisons between the groups were made. Despite low vitamin D dietary intake in both study groups, we observed lower plasma vitamin D status in Libyan women. This was accompanied by a significantly lower concentration of magnesium in Libyan women. Libyan women had significantly higher omega-3 index and lower n-6/n-3 ratio in erythrocytes’ phospholipids. We observed significant negative correlation between vitamin D and n-6 polyunsaturated fatty acids (PUFA) concentrations in both study groups. Despite lower vitamin D status in the Libyan group, erythrocyte fatty acid composition, along with blood lipids’ concentrations, indicated a lower cardiovascular risk. Based on our results, the discrepancy in the vitamin D status could not be ascribed to the participants’ dietary intake of the micronutrient, rather is potentially associated with ethnic-specific cardio-metabolic profile, which should be confirmed in larger cohorts.

Comparative assessment of erythrocyte sphingolipid levels as potential cardiovascular health markers in women from Libya and Serbia: a small-scale study

“…The lower cholesterol and sphingolipid levels in the red blood cell membrane observed in Libyan women suggest a lower cardiovascular risk in this group, which agrees with the data of our previous study in which lower serum cholesterol levels were found in the group of Libyan women compared with Serbian women [ 24 ]. The association between blood cholesterol and CVDs is well established, and lowering of serum low-density lipoprotein (LDL)-cholesterol is identified as a primary target of dietary and pharmaceutical therapies [ 29 ].…”

“…Furthermore, there is an association between vitamin D deficiency and an increased risk of CVD, including hypertension, heart failure, and atherosclerosis [ 16 ]. In our previous study, dietary intake and status of vitamin D in Libyan migrant and Serbian resident women was below recommended levels for this population group [ 24 ]. Interestingly, we found a direct correlation between serum vitamin D status and erythrocytes’ sphingolipid levels in this study.…”

“…A total of 13 Libyan emigrant and 15 Serbian healthy women participated in the study. Participants’ general characteristics and study design were described in detail previously [ 24 ]. Written informed consent was obtained from all participants prior to the enrolment, and the study was undertaken according to the Helsinki Declaration 1983 principles (approved by the Clinical Hospital Centre Zemun, Belgrade, Serbia, E0120/2017 and E0123/2017).…”

“…Total lipid extracts were prepared from erythrocytes using the organic solvents, chloroform, and isopropanol (7:11, by volume) [ 25 ]. The analysis of fatty acids is described in detail in the previous study [ 24 ]. Omega-3 Index was calculated as the sum of eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) percentages of totally detected fatty acids.…”

“…In our previous work, we investigated vitamin D status and some related parameters (like blood lipids and magnesium levels) in small groups of Libyan migrants and women residing in Serbia [ 24 ]. We found that the average vitamin D intake was below the proposed dietary reference values in both groups accompanied by its low serum level.…”