Micro- and macrovascular complications and hyperhomocysteinaemia in type 1 diabetic patients.

OBJECTIVE: To determine the range of plasma homocysteine values in a cohort of type 1 diabetic subjects and to analyse the relationship between homocysteine levels and chronic degenerative complications. MATERIAL AND METHODS: 71 type 1 diabetic inpatients admitted for poor glycaemic control and/or treatment of complications, especially macroangiopathic, were included in this study. Chronic diabetic complications, smoking prevalence, as well as current use of drugs were recorded, alongside fasting plasma homocysteine. RESULTS: Age and diabetes duration were 51 (34-63) and 23 (13-32) years respectively (median [percentile 25-75]). HbA(1)c was 9.3% (8.2-10.5). Homocysteine was 9.2 (7.1-13.6) micromol/l, and 17% of patients had elevated homocysteinaemia on the basis of a laboratory cutoff value of 15 micromol/l. Folic acid and vitamin B(12) levels were within the normal range. Univariate statistical analysis showed a significant positive association between homocysteine and age (P<0.001), diabetes duration (P<0.001), systolic blood pressure (P<0.001), plasma creatinine (P<0.001), cholesterol/HDL-C (P=0.021) as well as with retinopathy (P=0.016) and all complications (P<0.001), and a negative correlation with folic acid (P=0.004) and creatinine clearance (P<0.001). Using a multiple regression analysis taking into account major variables, we confirmed an independent association of homocysteine with age (P=0.003), creatinine (P<0.001) and folic acid (P=0.014), but not with vascular complications. CONCLUSIONS: Increased homocysteine is present in 17% of a limited group of poorly controlled type 1 diabetic patients, and is associated with age, creatinine and folic acid levels. In this type 1 population, there was no independent correlation of homocysteine with vascular complications, in particular macroangiopathy.