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

Interplay between Vitamin D and Sphingolipids in Cardiometabolic Diseases

Sphingolipids (SLs) are structural, bioactive molecules with several key cellular roles, whereas 1,25-dihydroxyvitamin D (1,25(OH)D), the active form of vitamin D, is considered the major regulator of calcium homeostasis, although it also exerts other extraskeletal effects. Many studies reported the physiological connection between vitamin D and SLs, highlighting not only the effects of vitamin D on SL metabolism and signaling but also the influence of SLs on vitamin D levels and function, thus strongly suggesting a crosstalk between these molecules. After a brief description of 1,25(OH)D and SL metabolism, this review aims to discuss the preclinical and clinical evidence on the crosstalk between SLs and 1,25(OH)D, with a special focus on cardiometabolic diseases.

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

Aim: Cardiovascular diseases (CVDs) represent the major cause of morbidity and mortality worldwide including Libya, where they account for 43% of all deaths. Sphingolipids are involved in the pathology of numerous diseases including cardiovascular diseases and are proposed as potential biomarkers of cardiovascular health that could be more effective compared to traditional clinical biomarkers. The aim of this study was to determine the sphingolipid content in the erythrocyte membrane of Libyan migrant and Serbian resident women. In addition, to examine if sphingolipid levels could be used as a novel indicator of cardiovascular risk, we evaluated possible correlations with some well-established biomarkers of cardiovascular health.Materials and Methods: A total of 13 Libyan and 15 Serbian healthy women participated in the study. The high-performance version thin-layer chromatography (HPTLC) using the image analysis tool JustTLC was applied for quantification of erythrocytes' sphingolipids.Results: Lower mean values of erythrocytes' sphingolipids and cholesterol concentrations were found in the group of Libyan emigrants compared to Serbian resident women. Besides, in this group of apparently healthy women (n = 28), the sphingolipid content of erythrocytes was inversely related to the Omega-3 index (r =-0.492, p = 0.008) and directly linked to vitamin D status (r = 0.433, p = 0.021) and membrane cholesterol levels (r = 0.474, p = 0.011).Conclusion: The erythrocytes' sphingolipid levels should be measured/assessed as an additional biomarker of CV health, by applying a simple and routine method. Still, further investigation in a larger population-specific context is warranted.

Association between population vitamin D status and SARS-CoV-2 related serious-critical illness and deaths: An ecological integrative approach

BACKGROUND

Vitamin D population status may have possible unappreciated consequences to the coronavirus disease 2019 (COVID-19) pandemic. Α significant association between vitamin D sufficiency and reduction in clinical severity and inpatient mortality from COVID-19 disease has recently been shown, while a recent study has claimed lower COVID-19 cases in European countries with a better vitamin D status. Low serum 25-hydroxyvitamin-D [25(OH)D] was identified as an independent risk factor for COVID-19 infection and hospitalization, and administration of 0.532 mg (21280 IU) of calcifediol or 25(OH)D, followed by 0.266 mg on days 3 and 7 and then weekly until discharge or intensive care unit admission significantly reduced the need for intensive care unit treatment.

AIM

To elucidate the role of vitamin D European population status in the COVID-19 pandemic, data from the Worldometer were analyzed.

METHODS

Linear regression explored the correlation between published representative-standardized population vitamin D concentrations and the number of total cases/million (M), recovered/M, deaths/M and serious-critically ill/M from COVID-19 for 26 European countries populated > 4 M (Worldometer). Life expectancy was analyzed with semi-parametric regression. Weighted analysis of variance/analysis of covariance evaluated serious-critical/M and deaths/M by the vitamin D population status: Deficient < 50, insufficient: 50-62.5, mildly insufficient > 62.5-75 and sufficient > 75 nmol/L, while controlling for life expectancy for deaths/M. Statistical analyses were performed in XLSTAT LIFE SCIENCE and R (SemiPar Library).

RESULTS

Linear regression found no correlation between population vitamin D concentrations and the total cases-recovered/M, but negative correlations predicting a reduction of 47%-64%-80% in serious-critical illnesses/M and of 61%-82%-102.4% in deaths/M further enhanced when adapting for life expectancy by 133-177-221% if 25(OH)D concentrations reach 100-125-150 nmol/L, sustained on August 15, 2020, indicating a truthful association. Weighted analysis of variance was performed to evaluate serious-critical/M (r 2 = 0.22) by the vitamin D population status and analysis of covariance the deaths/M (r 2 = 0.629) controlling for life expectancy (r 2 = 0.47). Serious-critical showed a decreasing trend (P < 0.001) from population status deficient (P < 0.001) to insufficient by 9.2% (P < 0.001), to mildly insufficient by 47.6% (P < 0.044) and to sufficient by 100% (reference, P < 0.001). For deaths/M the respective decreasing trend (P < 0.001) was 62.9% from deficient (P < 0.001) to insufficient (P < 0.001), 65.15% to mildly insufficient (P < 0.001) and 78.8% to sufficient (P = 0.041).

CONCLUSION

Achieving serum 25(OH)D 100-150 nmol/L (40-60 ng/mL) (upper tolerable daily doses followed by maintenance proposed doses not requiring medical supervision, Endocrine Society) may protect from serious-critical illness/death from COVID-19 disease.