Hyperhomocysteinemia and folate levels in normal healthy Nigerians living in Zaria: Subanalysis of ABU homocysteine cross-sectional survey

Homocysteine, hyperhomocysteinemia, and H-type hypertension

Homocysteine (Hcy) is a sulphur-containing nonessential amino acid derived from the intermediate metabolites of methionine. Methionine is obtained from dietary proteins, such as poultry, meat, eggs, seafood, and dairy products. Abnormalities in Hcy metabolic pathways, deficiencies in dietary methionine, folate, and vitamins B12, B6, and B2 and genetic defects, polymorphisms, or mutations in Hcy metabolism-related enzymes may lead to an increase in plasma Hcy levels. Generally, a plasma Hcy level higher than 10 or 15 μmol/L has been defined as hyperhomocysteinemia (HHcy). An individual with essential hypertension complicated with HHcy is considered to have H-type hypertension (HTH). Currently, HHcy is considered a novel independent risk factor for various cardiovascular diseases. To provide a useful reference for clinicians, the research progress on Hcy, HHcy, and HTH in recent years was systematically reviewed here, with a focus on the source and metabolic pathways of Hcy, plasma Hcy levels and influencing factors, detection methods for plasma Hcy levels, relationship between Hcy concentration and hypertension, pathogenesis of HTH, cardiovascular complications of HTH, and treatment of HTH.

The Roles of Aerobic Exercise and Folate Supplementation in Hyperhomocysteinemia-Accelerated Atherosclerosis

Background

Hyperhomocysteinemia (HHcy) is an independent risk factor for atherosclerosis. Effective interventions to reduce HHcy-accelerated atherosclerosis are required.

Objectives

This study aimed to investigate the effects of aerobic exercise (AE) and folate (FA) supplementation on plasma homocysteine (Hcy) level and atherosclerosis development in a mouse model.

Methods

Six-week-old female apoE-/- mice were grouped into five groups (N = 6-8): HHcy (1.8 g/L DL-homocysteine (DL-Hcy) in drinking water), HHcy + AE (1.8 g/L DL-Hcy and aerobic exercise training on a treadmill), HHcy + FA (1.8 g/L DL-Hcy and 0.006% folate in diet), HHcy + AE + FA (1.8 g/L DL-Hcy, 0.006% folate, and aerobic exercise training on a treadmill), and a control group (regular water and diet). All treatment was sustained for 8 weeks. Triglyceride, cholesterol, lipoprotein, and Hcy levels were determined enzymatically. Plaque and monocyte chemoattractant protein-1 (MCP-1) expression levels in mouse aortic roots were evaluated by immunohistochemistry.

Results

Compared to the HHcy group (18.88 ± 6.13 μmol/L), plasma Hcy concentration was significantly reduced in the HHcy + AE (14.79 ± 3.05 μmol/L, p = 0.04), HHcy + FA (9.4 ± 3.85 μmol/L, p < 0.001), and HHcy + AE + FA (9.33 ± 2.21 μmol/L, p < 0.001) groups. Significantly decreased aortic root plaque area and plaque burden were found in the HHcy + AE and HHcy + AE + FA groups compared to those in the HHcy group (both p < 0.05). Plasma MCP-1 level and MCP-1 expression in atherosclerotic lesions were significantly decreased in the HHcy + AE and HHcy + AE + FA groups compared to the HHcy group (all p < 0.05).

Conclusions

AE reduced atherosclerosis development in HHcy apoE-/- mice independently of reducing Hcy levels. FA supplementation decreased plasma Hcy levels without attenuating HHcy-accelerated atherosclerosis. AE and FA supplementation have distinct mechanisms in benefiting atherosclerosis.

Hyperhomocysteinemia in Patients with Newly Diagnosed Primary Hypertension in Can Tho City, Vietnam

Background: Elevated levels of blood total homocysteine is one of the cardiovascular risk factors in hypertensive patients. Objectives: Determine the prevalence of hyperhomocysteinemia and its associated factors in newly diagnosed primary hypertension patients. Materials and methods: A cross-sectional descriptive study on 105 patients with newly diagnosed primary hypertension at Can Tho University of Medicine and Pharmacy Hospital from May 2017 to May 2018. Total homocysteine levels and related factors were collected at the study time. Results: The mean plasma total homocysteine level was 16.24 ± 4.49 µmol/L. There were 78 patients with elevated plasma total homocysteine levels ≥15 µmol/L, accounting for 74.3% of all patients. Being elderly, gender, hypertension stage, and diabetes were factors associated with hyperhomocysteinemia (p < 0.05). Total homocysteine levels were positively correlated with SBP, DBP, and age with r(SBP) = 0.696, r(DBP) = 0.585, and r(age) = 0.286. Conclusion: Research on the subpopulation of Vietnamese people shows that hyperhomocysteinemia is common in patients with newly diagnosed primary hypertension, and high blood total homocysteine levels are often related to age, sex, hypertension stage, and diabetes.

Anthropometric, biochemical, and haematological indicators associated with hyperhomocysteinemia and their relation to global DNA methylation in a young adult population

Increased homocysteine (Hcy) levels have been associated with a higher risk of cardiovascular and neurodegenerative diseases. Passive DNA demethylation has been suggested as one of the mechanisms implicated in the development of these conditions, and most studies have investigated this relationship in older adult populations. Therefore, this study aimed to evaluate the relationship between corporal composition and biochemical and haematological indicators with plasma homocysteine levels and genome-wide methylation (Alu, LINE-1, and SAT2) in a population of healthy young adults (median age, 18 years). We showed that the prevalence of hyperhomocysteinemia was significantly higher in men (18.5%) than in women (6.6%) (P = 0.034). Increased Hcy level was substantially associated with higher levels of body mass index and visceral fat in females, whereas in males, it was significantly associated with reduced red cell distribution width and high-density lipoprotein (HDL) cholesterol (HDL-C) levels and increased low-density lipoprotein/HDL ratio. Hypomethylation of Alu was significantly associated with reduced levels of HDL-C (<40.0 mg dL^-1), whereas hypomethylation of LINE-1 and SAT2 was significantly associated with higher levels of skeletal muscle (<39.3%) in males. These results highlight the participation of hormonal factors in regulating Hcy metabolism, primarily in the female population, whereas changes in DNA methylation observed in males might be associated with the consumption of a protein diet with high levels of methionine, independent of increased Hcy levels.

Prevalence of hyperhomocysteinaemia, selected determinants and relation to hypertension severity in Northern-Nigerian hypertensives: the ABU homocysteine survey

Background

This study aimed at evaluating the prevalence of hyperhomocysteinaemia in Northern-Nigerian hypertensives and its association with hypertension severity and some major determinants as data regarding these are lacking in sub-Saharan Africa.

Method

A Community-based cross-sectional study done on 120 randomly-selected hypertensive patients who responded to an ABU radio frequency modulated invitation for free health-screening at the Ahmadu Bello University (ABU) Medical Centre from January 2016 to June 2016. The percentage of participants with high homocysteine levels, their anthropometric parameters and blood pressures were determined. Plasma homocysteine (hcy) was classified as normal (5–15), moderate (>15–30), intermediate (31–100) and severe (>100) µmol/L. Kruskal-Wallis test was applied and log-transformed homocysteine (Ln₁₀Homocysteine) was correlated with systolic and diastolic blood pressures as well as age, body mass index, fasting blood glucose, glomerular filtration rate, hypertension duration and Ln₁₀folate in males and females using the Pearson's Correlation analysis.

Results

There were 83(69.2%) females and 37(30.8%) males with Median homocysteine of 20.8 µmol/L and 22.0 µmol/L respectively (p=0.003). Hyperhomocysteinaemia was found in 118(98.3%) hypertensives while 2(1.7%) subjects had normo-homocysteinaemia. Moderate hyperhomocysteinaemia (Median, 20.8 µmol/L) was identified in 105(87.5%) and intermediate (Median, 40 µmol/L) in 13(10.8%) (p<0.001). No subject had severe hyperhomocysteinaemia. Homocysteine was higher (p=0.003) in subjects with Stage 2 systolic hypertension. Ln₁₀Homocysteine was significantly (p<0.001) correlated with blood pressure (SBP: r=0.45; DBP: r=0.40) and age (r=0.33).

Conclusion

The prevalence of hyperhomocysteinaemia in North-Western Nigerian hypertensives is high as against normal healthy controls. Plasma homocysteine is higher with severe systolic hypertension and positively associated with age.

Funding

No specific grants but Micro Nova Pharmaceuticals Limited, Nigeria and Emzor Pharmaceutical Industries, Lagos, Nigeria supported with drugs.