Plasma total homocysteine: usual values and main determinants in adults living in the Great Tunis region.

BACKGROUND: Elevated total plasma homocysteine (tHcy) is an established risk factor for occlusive vascular disease and is thought to increase the risk of pregnancy loss, birth defects, and cognitive impairment in the elderly. OBJECTIVES: To determine tHcy standard values and the prevalence of hyperhomocysteinemia (HHC) and to examine their association with demographic and life style factors in the Greater Tunis population. METHODS: This cross-sectional study included 2712 subjects (1228 males and 1484 females) aged 35 - 70 years, living in the Greater Tunis region. tHcy was analyzed by a fluorescent polarizing immunoassay method. HHC was considered as tHcy > or = 15 micromol/L. RESULTS: HHC was observed in 23.7% of subjects. Plasma tHcy was higher in males than females (median (5th - 95th percentile): 13.5 [8.75 - 26.3] micromol/L vs. 10.7 [6.94 - 19.6] micromol/L). The tHcy concentration was significantly increased in smokers, alcoholics, in subjects with vitamin B12 and folate deficiencies, and hyperuricemia. In multivariate analysis, HHC was associated with male gender, vitamin B12 deficiency, clearance of creatinine, alcohol consumption, and hyperuricemia. CONCLUSIONS: HHC is common in Tunisian adults. Male gender, advanced age, renal insufficiency, low vitamin B12 status, hyperuricemia, and alcohol consumption are the main determinants of HHC in this population.