Correlates of plasma homocysteine, cysteine and cysteinyl-glycine in respondents in the British National Diet and Nutrition Survey of Young People Aged 4–18 Years, and a comparison with the Survey of People Aged 65 Years and Over

Abstract

Plasma total homocysteine (tHcy), cysteine and cysteinyl-glycine were measured in a representative sample of 922 young people aged 4–18 years, participating in the National Diet and Nutrition Survey in mainland Britain in 1997. Both tHcy and cysteine increased markedly with age; cysteinyl-glycine less so. Neither tHcy nor cysteine differed between genders; cysteinyl-glycine was higher in males. tHcy concentrations were lowest in the winter; cysteine and cysteinyl-glycine varied only slightly with season. In respondents aged >15 years, tHcy was higher in smokers, but in respondents aged 7–11 years, tHcy was higher in those whose mothers smoked. tHcy was inversely correlated with serum folate, serum vitamin B12and vitamin B6status, but neither cysteine nor cysteinyl-glycine shared these relationships. The relationships between tHcy and B-vitamin status indices ran parallel with those of the 65 years and over survey, but at much lower tHcy concentrations for any given B-vitamin concentration. Age-adjusted tHcy was not correlated with anthropometric indices, blood pressure, haematology, plasma creatinine, urea or cholesterol, but was directly correlated with fasting triacylglycerol. We conclude that disease-risk indices, like tHcy and perhaps cysteine, if established during early life, may be modulated by diet and lifestyle, thereby providing an opportunity for public health intervention.