Plasma homocysteine levels in indigenous Australians

Objectives: To determine plasma homocysteine levels in indigenous Australia ns living in urban areas, and the relationship of these levels with other r isk factors in this population. Design: Cross-sectional study. Subjects and setting: 365 urban indigenous Australian subjects, 153 men and 212 women, mean (SE) age 42 (1) years, ascertained without regard to histo ry of atherosclerotic disease, in collaboration with community-based health centres in five indigenous communities in south-east Queensland, 1997-1998 . Main outcome measures: Plasma homocysteine levels, age, sex, smoking histor y, metformin therapy, history of atherosclerotic vascular disease, serum cr eatinine level, red cell folate and serum vitamin B-12 levels. Results: 89 subjects (24%) had plasma homocysteine levels 15 mu mol/L or ab ove. Homocysteine levels were higher in men than in women (men: 14.4 mu mol /L; 95% confidence interval [CI], 13.6-15.2; women: 11.9 mu mol/L; 95% CI, 11.4-12.5) (P<0.001); correlated with age (P<0.001); higher in current smok ers (P=0.02); higher in subjects taking metformin therapy (P=0.007); and hi gher in subjects with a history of atherosclerotic vascular disease (P<0.00 1). Homocysteine levels were also correlated with serum levels of creatinin e (P<0.001), red cell folate (P<0.001), and vitamin B-12 (P<0.001). Conclusions: These data indicate that the high plasma levels of homocystein e of Australian indigenous subjects are associated with a history of vascul ar disease, and correlated with, among other things, smoking, and folate an d vitamin B-12 nutritional deficiency. These are potentially reversible ris k factors, and our data suggest that focusing public health initiatives on these issues may reduce the high prevalence of cardiovascular disease in th e Australian indigenous population.