Vitamin B12 Deficiency Across Three Generations Adversely Influences Long-chain Polyunsaturated Fatty Acid Status and Cardiometabolic Markers in Rats

BACKGROUND AND AIMS

Vitamin B₁₂ and omega-3 fatty acid deficiency is prevalent in the vegetarian population and is associated with adverse pregnancy outcomes and cardiometabolic risk. The present study investigates the long-term effects of vitamin B₁₂ deficiency/supplementation in the presence of omega-3 fatty acids on cardiometabolic profile and long-chain polyunsaturated fatty acid levels (LCPUFA) in the F₃ generation offspring.

METHODS

Three generations of rats were fed the following diets: control; vitamin B₁₂ deficient; vitamin B₁₂ supplemented; vitamin B₁₂ deficient + omega-3 fatty acid supplemented; vitamin B₁₂ + omega-3 fatty acid supplemented. Animals were sacrificed at 3 months of age.

RESULTS

Vitamin B₁₂ deficiency lowered (p <0.01 for both) plasma eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), liver DHA (p <0.05), plasma/liver omega-3 fatty acids (p <0.05 for both), increased triglycerides (p <0.05) and systolic BP (p <0.01) and lowered cholesterol levels (p <0.05) as compared to control. Vitamin B₁₂ deficiency in the presence of omega-3 fatty acids improved plasma/liver EPA, DHA and omega-3 fatty acid profile and maintained cholesterol, triglyceride and BP levels. Vitamin B₁₂ supplementation lowered liver DHA (p <0.05) and cholesterol (p <0.01), whereas BP was similar to control. Combined supplementation of vitamin B₁₂ and omega-3 fatty acids improved omega-3 fatty acid profile, lowered cholesterol/triglyceride levels and maintained the BP similar to that of control.

CONCLUSION

Vitamin B₁₂ deficiency across three generations adversely affects LCPUFA and cardiometabolic profile in the adult offspring. This study provides clues for a combined supplementation of vitamin B₁₂ and omega-3 fatty acids to reduce the risk for noncommunicable diseases.

Association of plasma fatty acid composition with plasma irisin levels in normal weight and overweight/obese children

BACKGROUND

Irisin has been suggested to protect against overweight. There are no previous data on the association of plasma fatty acid (FA) composition with plasma irisin.

OBJECTIVES

We studied the association of FA composition with plasma irisin in normal weight and overweight/obese children.

METHODS

This cross-sectional study included pre-pubertal children (388 normal weight children and 55 overweight/obese children); 6-9 years of age, taking part in the Physical Activity and Nutrition in Children Study. After an overnight fast, we measured plasma FA composition by gas chromatography and plasma irisin levels by enzyme-linked immunosorbent assay.

RESULTS

Higher proportion of total monounsaturated fatty acids in plasma cholesteryl esters (CEs) (β = 0.139, P = 0.003) and phospholipids (PLs) (β = 0.147, P = 0.002) and lower proportion of total polyunsaturated fatty acids in plasma CE (β = -0.130, P = 0.006) and PL (β = -0.165, P < 0.001) were associated with higher plasma irisin level in the whole study group. The association of plasma FA composition with plasma irisin level was stronger among overweight/obese children compared to normal weight children. Higher proportion of γ-linolenic acid (β = 0.324, P = 0.017) and lower proportion of linoleic acid (β = -0.397, P = 0.005) in plasma CE were related to higher plasma irisin level among overweight/obese children, indicating the direct association of estimated D6D activity in plasma CE (β = 0.343, P = 0.011) with plasma irisin. Furthermore, higher proportion of oleic acid in plasma CE (β = 0.345, P = 0.012) and PL (β = 0.292, P = 0.033) and higher proportion of adrenic acid (β = 0.366, P = 0.008) and docosapentaenoic acid (β = 0.351, P = 0.010) in plasma PL were associated with higher plasma irisin level among overweight/obese children.

CONCLUSION

Metabolically unfavourable plasma FA profile was associated with higher plasma irisin level especially in overweight/obese children, suggesting that excess body fat might modulate these relationships.

Human plasma lipidome is pleiotropically associated with cardiovascular risk factors and death

BACKGROUND

Cardiovascular disease (CVD) is the most common cause of death in the United States and is associated with a high economic burden. Prevention of CVD focuses on controlling or improving the lipid profile of patients at risk. The human lipidome is made up of thousands of ubiquitous lipid species. By studying biologically simple canonical lipid species, we investigated whether the lipidome is genetically redundant and whether its genetic influences can provide clinically relevant clues of CVD risk.

METHODS AND RESULTS

We performed a genetic study of the human lipidome in 1212 individuals from 42 extended Mexican American families. High-throughput mass spectrometry enabled rapid capture of precise lipidomic profiles, providing 319 unique species. Using variance component-based heritability analyses and bivariate trait analyses, we detected significant genetic influences on each lipid assayed. Median heritability of the plasma lipid species was 0.37. Hierarchical clustering based on complex genetic correlation patterns identified 12 genetic clusters that characterized the plasma lipidome. These genetic clusters were differentially but consistently associated with risk factors of CVD, including central obesity, obesity, type 2 diabetes mellitus, raised serum triglycerides, and metabolic syndrome. Also, these clusters consistently predicted occurrence of cardiovascular deaths during follow-up.

CONCLUSIONS

The human plasma lipidome is heritable. Shared genetic influences reduce the dimensionality of the human lipidome into clusters that are associated with risk factors of CVD.

Time-dependent changes and association between liver free fatty acids, serum lipid profile and histological features in mice model of nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Methionine-choline deficient (MCD) diet duration necessary for development of non-alcoholic fatty liver disease (NAFLD) and the dynamic of lipid profile and fatty acids are not completely established. The study examined dynamics and association between liver free fatty acids (FFA), serum lipid profile and liver morphological changes on MCD diet-induced NAFLD in mice.

METHODS

Male C57BL/6 mice (n = 28) were divided into four groups (n = 7 per group): control: fed with standard chow, MCD diet-fed groups: 2, 4 or 6 weeks. After treatment, liver and blood samples were taken for histopathology, serum lipid profile, and liver FFA composition.

RESULTS

Hepatic FFA profile showed a decrease in saturated acids, arachidonic and docosahexaenoic acid, whereas proportions of docosapentaenoic, oleic and linoleic acid were increased. Total cholesterol, HDL and triglycerides progressively decreased, whereas LDL level progressively increased. Focal fatty change in the liver appeared after 2 weeks, whereas diffuse fatty change with severe inflammation and ballooned hepatocytes were evident after 6 weeks.

CONCLUSIONS

Six-week diet model may be appropriate for investigation of the role of lipotoxicity in the progression of NAFLD. Therefore, supplementation with n-3 polyunsaturated acid like DHA, rather than DPA, especially in the initial stage of fatty liver disease, may potentially have preventive effects and alleviate development of NAFLD/NASH and may also potentially reduce cardiovascular risk by moderating dyslipidemia.