Plasma total homocysteine in a representative sample of 972 British men and women aged 65 and over

Abstract

Objectives: To provide a reference range for plasma total homocysteine (tHcy), an independent risk factor for vascular disease, and to explore relationships with nutritional indices for people aged 65 y and over, in the UK National Diet and Nutrition Survey (NDNS). Design: The survey procedures described in the National Diet and Nutrition Survey Report (1997) included a health-and-lifestyle interview, a four-day weighed diet record, anthropometric and blood pressure measurements and a fasting blood sample for biochemical indices, including tHcy. Setting: Eighty randomly selected postcode sectors from mainland Britain during 1995–1996. Subjects: Of 2060 people interviewed, 1527 were visited by the nurse, 1276 gave a blood sample and 972 had tHcy measured. About 80% were in their own homes and the remainder were in nursing homes or similar institutions. Results: Significant cross-sectional relationships, both univariate and multivariate were found between tHcy and index concentrations of folate and vitamin B₁₂ (P<0.0001), and between tHcy and plasma creatinine, urea, calcium, zinc, α₁-antichymotrypsin, lutein and cysteine (P=0.013 to <0.0001). Dietary nutrient analyses showed an association with folate intake. tHcy was also correlated with age and with domicile (free-living or institution), with history of vascular disease and with use of four classes of drugs, two of which are prescribed for vascular diseases. There was a north-south gradient in tHcy (P=0.005), and also in food choices, blood micronutrient indices and vascular disease prevalence. Conclusions: The concentrations of tHcy found in this study provide a reference range for people aged 65 y and over, in mainland Britain. tHcy is a valuable functional index of micronutrient status and intakes for British people aged 65 y and over, which can assist the development of health-promotion strategies. Sponsorship: This study was part of the National Diet and Nutrition Survey of people aged 65 y and over, which was funded jointly by the Ministry of Agriculture, Fisheries and Food and the Department of Health, and conducted by Social Community Planning and Research in conjunction with the MRC Dunn Nutrition Unit. The authors acknowledge financial support for the study from the Department of Health, the European Commission and British Heart Foundation.