Hyperhomocysteinaemia is associated with low plasma apolipoprotein AI levels in patients with impaired glucose tolerance.

Homocysteine suppresses hepatic apolipoprotein AI synthesis in mice. We assessed the relationship between homocysteine and apolipoprotein AI levels in patients with impaired glucose tolerance. A total of 217 participants, including 95 impaired glucose tolerance patients and 122 healthy subjects, were classified as normal control subjects without hyperhomocysteinaemia, control subjects with hyperhomocysteinaemia, impaired glucose tolerance patients without hyperhomocysteinaemia (n-IGT) and impaired glucose tolerance patients with hyperhomocysteinaemia (H-IGT). The impaired glucose tolerance patients had higher plasma levels of homocysteine and homeostasis model assessment index of insulin resistance values, and lower plasma apolipoprotein AI levels than the normal control and control subjects with hyperhomocysteinaemia (all p < 0.01). Decreased plasma apolipoprotein AI levels and increased homeostasis model assessment index of insulin resistance values were observed in the H-IGT group compared with the n-IGT group (p < 0.05). Plasma homocysteine levels were negatively correlated with apolipoprotein AI levels after adjusting for age, gender, body mass index and homeostasis model assessment index of insulin resistance. Plasma homocysteine level independently influenced the apolipoprotein AI levels (β = -0.02, p < 0.05). In conclusion, increased plasma homocysteine levels were associated with decreased apolipoprotein AI levels in impaired glucose tolerance subjects.