Marked gender difference in plasma total homocysteine concentrations in indian adults with low vitamin B₁₂

Plasma total homocysteine (tHcy) is higher in men than women.

To explore the gender differences in tHcy in relation to determinants of one-carbon metabolism in Indian people with low B₁₂ and adequate folate.

The study took place in rural and urban areas of Pune, India.

Participants were 441 men from the cross-sectional Coronary Risk of Insulin Sensitivity in Indian Subjects study (CRISIS) and premenopausal wives of 146 men (median ages 38 and 34 years, respectively).

Gender difference in fasting tHcy in relation to plasma albumin and creatinine concentrations, lifestyle factors, diet and lean mass, plasma B₁₂ and red cell folate (RCF) was assessed.

Prevalence of high tHcy (> 15 µmol/L, median 14.4 µM) was 40 %, low B12 (< 150 pmol/L, 114 pmol/L) 66 %, and low RCF (< 283 nmol/L, 525 nmol/L) 8 %. Men had higher (1.8x) plasma tHcy concentrations (16.2 µmol/L) than women (9.5 µmol/L). Only 50 % of the gender difference was explained by age, lean mass, B₁₂, and RCF. The difference remained after controlling for other explanatory variables. Women with a tHcy of 9.3 µM had the same B₁₂ concentration (129 pmol/L) as men with a tHcy of 15 µM; and for a tHcy of 10.0 µmol/L women had the same RCF concentration (533 nmol/L) as men with a tHcy of 15 µmol/L.

Adult Indian women have markedly lower tHcy concentrations compared to men. This suggests a lower threshold for supplementation to improve reproductive and cardiovascular outcomes.