Multiple linear regression model for the post-methionine load increase in homocysteine. Top, in subjects with diabetes, bottom, control subjects. Dependent variable: log(rise in plasma homocysteine). Independent variables: log(serum vitamin B12), log(post-methionine plasma betaine) and log(baseline fasting homocysteine). Bars show the significance of the factors as t-values, negative for a negative relationship and positive for a positive relationship; dashed lines p = 0.05; dotted lines p = 0.001. Pie graphs at the right show the proportion of variance (dark segment) explained by regression: unexplained variance in grey.