Correlates of serum homocysteine in a Sri Lankan population

Abstract

Correlates of total serum homocysteine concentration in a Sri Lankan population BACKGROUND: Hyperhomocysteinemia, a possible risk factor for vascular disease occurs at a higher prevalence in South Asian countries. Serum homocysteine concentrations are influenced by genetic, nutritional and lifestyle factors. Correlates of total serum homocysteine concentration (tHcy) are not well characterized in the Sri Lankan population. Such information is important in developing therapeutic and preventative strategies. OBJECTIVE: To investigate the factors potentially associated with fasting levels of serum tHcy in a Sri Lankan population. METHODS: In a cross sectional study, 177 apparently healthy volunteers (91 men and 86 women) aged 38-65 years were selected from residents in an urban health administrative area. Individuals with a history of chronic disease and with any pharmacological treatment were excluded from the study. Information on diet, lifestyle factors and medical history were recorded. Anthropometric indices and blood pressure were measured according standard protocols. Fasting serum levels of tHcy, insulin, creatinine, folate and lipids were estimated using standard protocols. RESULTS: Fasting serum tHcy levels were higher in males than in females (geometric mean +/- SD, 13.75 mumol/l +/- 1.41 Vs. 9.58 mumol/l +/- 1.43, p<0.001) and were positively associated with age (r=0.204, p< 0.01) in both sexes. 32.3% of males and 10.3% of females had mild hyperhomocysteinemia (tHcy>15mumol/l). tHcy levels were significantly higher in smokers than in non-smokers (geometric mean +/- SD, 14.58 mumol/l +/- 1.44 Vs.12.71 mumol/l +/- 1.37, p<0.05) and in alcohol consumers than in non-consumers (geometric mean +/- SD, 14.53 mumol/l +/- 1.43 Vs.12.14 mumol/l +/- 1.32, p< 0.02). In males, tHcy levels were negatively related to serum insulin (r= -0.397, p<0.001) and BMI (r= -0.244, p <0.02) and positively related to serum creatinine (r=0.235, p<0.02). In females, there was a positive relationship between tHcy and systolic blood pressure (r= 0.239, p<0.02) but there was no significant correlation with serum insulin. In both sexes, serum tHcy levels strongly correlated with serum folate (r= -0.412, p<0.001). There were no significant associations between tHcy and serum lipids. Stepwise regression analysis confirmed the associations between tHcy and folate (p<0.001 in both sexes), insulin (p=0.026 in males) and creatinine (p=0.036 in males). CONCLUSION: Low intake of folate, alcohol consumption and smoking were associated with increased tHcy concentrations. Serum insulin and creatinine were independent correlates of tHcy in males, but not in females. Difference in tHcy levels between sexes may partly be attributed to differences in lean muscle mass and to a metabolic link between creatinine synthesis and homocysteine production. Insulin may regulate serum tHcy concentrations by homocysteine remethylation or by increasing homocysteine clearance.