Nutritional determinants of plasma total homocysteine distribution in the Canary Islands

Abstract

Objective: We sought to define plasma homocysteine reference values in healthy individuals in the Canary Islands and to determine its relations to folate and vitamin B12 intakes and concentrations. Design: Cross-sectional study. Setting: Population-based representative sample of 557 participants, aged 18-65 years, from the Canary Islands Nutrition Survey (ENCA). Subjects: All participants completed two 24-h dietary recalls and a general questionnaire collecting socio-demographic and health-related lifestyle information. Interventions: Plasma homocysteine and serum vitamin B12 levels were measured by immunoassay, whereas folate levels through an automated ionic capturing method. Results: Median plasma homocysteine was 11.9 mmol/l, higher in men (13.1 mmol/l) than in women (10.9 mmol/l) (Po0.001) and positively associated with age in both sexes (Po0.001). The prevalence of hyperhomocysteinaemia (X15 mmol/l), 21.4%, was also greater in men (32.2%) than in women (13.4%). There were significant negative correlations between plasma homocysteine and serum (r ¼ À0.32, Po0.001) and erythrocyte (r ¼ À0.26, Po0.001) folate, as well as serum vitamin B12 (r ¼ À0.28, Po0.001) concentrations. When divided in quartiles of vitamin intakes or concentrations, men with the lowest vitamin B12 and folate serum values had significantly higher plasma homocysteine concentrations than those in the other three quartiles. In women, hyperhomocysteinaemia was higher in the lowest quartiles of folate intake and serum and erythrocyte folate concentrations. Conclusions: These data provide further evidence that hyperhomocysteinaemia is a sensitive marker of inadequate folate and vitamin B12 status, allowing for the identification of those with greatest need for nutritional interventions.

The <b><i>MTHFR</i></b> C677T Polymorphism Is Related to Plasma Concentration of Oxidized Low-Density Lipoprotein in Adolescents with Cardiovascular Risk Factors

“…The inverse correlation between homocysteine and folic acid revealed in our study has already been verified in children and adolescents [29,30]. Additionally, folic acid and vitamin B 6 and B 12 deficiencies, including subclinical ones, have been frequently reported in children and adolescents [22,26,29,31].…”

MTHFR polymorphisms and serum cobalamin affect plasma homocysteine concentrations differentially in females and males

“…Age group, ln S-folate and ln S-cobalamin all had a significant effect on the tHcy levels and therefore all ANCOVA calculations adjusted for age in four groups (18-25, 25-45, 45-55 and 65-75 years), ln S-folate and ln S-cobalamin. It was previously found in this cohort that alcohol intake, smoking and BMI did not predict homocysteine concentrations (21), therefore these variables were not included in the present study.…”

“…ENCA is a cross-sectional study from the Canary Islands (Spain) which was conducted to survey the nutritional status and selected metabolic and genetic variables of the population of the Canary Islands. The sampling procedures and participation rates have been described previously (21,22). The present study was approved by the Research Ethics Committee of the Hospital Universitario Insular of Gran Canaria (Las Palmas, Canary Islands, Spain).…”

“…Homocysteine and B vitamin analyses. As described previously (21), the blood samples were obtained in the morning after subjects had fasted for 12 h. The S-folate levels were measured at the Haematology Unit of the Hospital Universitario Insular of Gran Canaria (Canary Islands, Spain) through an automated ionic capturing method with Abbott AXSYM equipment (Abbot, Berkshire, England, UK). Cobalamin was analysed via the micro-particle enzyme immune assay method with Abbott AXSYM equipment also at the Haematology Unit.…”

Oral versus intramuscular administration of vitamin B12 for the treatment of patients with vitamin B12 deficiency: a pragmatic, randomised, multicentre, non-inferiority clinical trial undertaken in the primary healthcare setting (Project OB12)

“…In Spain, the prevalence of vitamin B12 deficiency may reach 18% according to a meta-analysis of the studies undertaken up to 1999 [6]. However, population-based studies performed in Catalonia and the Canary Islands [7,8], both of which used a serum vitamin B12 cut-off of 200 pg/ml, returned values of 1.9% and 3.4% respectively. What does appear to be constant in all studies reviewed for the present work is that the prevalence of deficiency is greater among people aged 65–76 years.…”