Folate and cobalamin deficiencies and hyperhomocysteinemia in Bangladesh

Abstract

Background: Indian Asian men residing in the United Kingdom have a higher prevalence of hyperhomocysteinemia than do their European counterparts. This has been largely attributed to dietary deficiencies in cobalamin associated with vegetarianism among these Indian Asians.

Objective: We aimed to ascertain the prevalence of folate and cobalamin deficiencies and hyperhomocysteinemia in Bangladesh.

Design: Plasma concentrations of homocysteine, folate, and cobalamin and urinary concentrations of creatinine were assessed in 1650 adults in Bangladesh.

Results: The prevalence of hyperhomocysteinemia (men: >11.4 micromol/L; women: >10.4 micromol/L) was markedly (P < 0.0001) greater among men (63%; x +/- SD: 15.3 +/- 9.5 micromol/L) than among women (26%; 9.5 +/- 4.7 micromol/L). Folate was lower (9.8 +/- 6.5 and 12.3 +/- 7.6 nmol/L, respectively), whereas cobalamin was higher (281 +/- 115 and 256 +/- 118 pmol/L, respectively) (P < 0.0001 for both) among men than among women. Folate explained 15% and cobalamin explained 5% of the variation in homocysteine concentrations. For men, folate (P = 0.005) and cobalamin (P = 0.03) were positively correlated with urinary creatinine. Smoking (P < 0.0003) and betelnut use (P < 0.0002) were independent negative predictors of folate.

Conclusions: Bangladeshi men have a high prevalence of hyperhomocysteinemia, which is more closely associated with folate than with cobalamin, although other factors, eg, smoking and betelnut use, may also contribute to its cause. The positive correlations between urinary creatinine and plasma folate and cobalamin were unanticipated and could suggest that, in marginal nutrition, these vitamins may be limiting for creatine biosynthesis.

FIGURE 1

Frequency distributions for women ( ) and men ( ) for homocysteine (A; n = 676 M; n = 968 F), folate (B; n = 676 M; n = 972 F), and cobalamin (C; n = 676 M; n = 972 F). Homocysteine, folate, and cobalamin were skewed and were, therefore, log transformed.

FIGURE 2

Plasma folate quartiles by smoking and betelnut use among smokers, betelnut users, smokers and betelnut users, and control subjects. The subgroups in each folate quartile were as follows: quartile 1: 39% (n = 111), 30% (n = 85), 28% (n = 78), and 17% (n = 136); quartile 2: 27% (n = 75), 31% (n = 86), 25% (n = 70), and 22% (n = 179); quartile 3: 20% (n = 56), 23% (n = 65), 24% (n = 67), and 28% (n = 222); and quartile 4: 14% (n = 40), 16% (n = 45), 23% (n = 64), and 33% (n = 261), respectively. In the regression model that controlled for age and sex, the cigarette smoking × betelnut use interaction was significant (P = 0.04).