Objective: Hyperhomocysteinemia is a risk factor for atherothrombosis. Through unknown mechanisms, individuals with type 2 diabetes appear particularly susceptible. We determined whether components of homocysteine metabolism are associated with intima-media thickness in individuals with and without type 2 diabetes. Methods and results: In a cross-sectional design, we studied 231 Caucasian individuals, 60.6% having type 2 diabetes. We measured fasting homocysteine, vitamin B6 and vitamin B12 in plasma, and folate, S-adenosylmethionine and S-adenosylhomocysteine in plasma and erythrocytes. A homocysteine concentration >12 μmol/l was associated with a greater intima-media thickness of +0.07 mm (95% CI, +0.01 to +0.13; P = 0.03) among diabetic individuals and of -0.004 mm (95%CI, -0.08 to +0.07; P = 0.92) among non-diabetic individuals. An erythrocyte S-adenosylmethionine concentration above >4000 nmol/l was associated with a smaller intima-media thickness of -0.04 mm (95%CI, -0.10 to +0.02; P = 0.17) for diabetic individuals versus -0.12 mm (95%CI, -0.20 to -0.36; P = 0.005) for non-diabetic individuals. Conclusions: With regard to carotid intima-media thickness, individuals with diabetes appear more susceptible to the detrimental effects of homocysteine than non-diabetic individuals. In addition, diabetic individuals may lack the protective effect on the vascular wall conferred by high concentrations of S-adenosylmethionine. These findings may help explain why hyperhomocysteinemia is an especially strong risk factor for atherothrombosis among individuals with type 2 diabetes. © 2003 Elsevier Ireland Ltd. All rights reserved.
Becker, A., Henry, R. M. A., Kostense, P. J., Jakobs, C., Teerlink, T., Zweegman, S., ... Stehouwer, C. D. A. (2003). Plasma homocysteine and S-adenosylmethionine in erythrocytes as determinants of carotid intima-media thickness: Different effects in diabetic and non-diabetic individuals: The Hoorn study. Atherosclerosis, 169(2), 323-330. https://doi.org/10.1016/S0021-9150(03)00199-0