Objective: To evaluate whether low levels of holotranscobalamin (holoTC) or elevated levels of methylmalonic acid (MMA), both indicators of vitamin B 12 deficiency, might predispose to new cardiovascular events following an acute myocardial infarction (MI). Design: A prospective prognostic study. Setting: One hospital center in Stavanger, Norway. Subjects: A total of 300 patients admitted with an acute MI. Methods: Registration of new TnT positive coronary events (defined as TnT40.05 mg/l and a typical MI pattern) and/or cardiac death during a median follow-up time of 45 months. Results: We compared the recurrence of events in the lowest quartile of holoTC (Q1o73.9 pmol/l) to the event rate above the 25% percentile (Q2-4). For methylmalonic acid (MMA) the same comparison was carried out for the upper quartile (Q4X0.24 mmol/l) as compared with the event rate below the 75% percentile (Q1-3). After 18 and 45 months of follow-up, the odds ratio (OR) for Q1 vs Q2-4 for holoTC was 1.15 (95% confidence interval (CI) 0.91-1.46, P ¼ 0.25) and 1.05 (95% CI 0.86-1.29, P ¼ 0.64), respectively. For MMA the OR for Q4 vs Q1-3 was 0.95 (95% CI 0.76-1.19, P ¼ 0.67) after 18 months and 1.01 (95% CI 0.83-1.23, P ¼ 0.90) after 45 months. Conclusion: This study showed no increased risk of future cardiovascular events associated with low levels of holoTC or high levels of MMA following an acute MI.

Background: Data on early biochemical and hematological responses to cobalamin therapy in vitamin B₁₂-deficient patients are scarce. Therefore, we investigated whether cobalamin injections would include prompt biochemical and hematological responses in vitamin B₁₂-deficient patients. Subjects and Methods: Seven female patients (mean age: 69.4 years, range: 61-78) with a mean serum cobalamin level of 104 ± 38 pmol/l mean ± SD and 7 male patients (mean age: 67.0 years, range: 53-78) with a mean serum cobalamin level of 84 ± 40 (±SD) participated in the study. They were administered 1 mg i.m. cyanocobalamin per week for 3 weeks. Blood samples were collected before and 1, 3, 7, 14 and 21 days after cobalamin injection. The concentrations of plasma aminothiols and serum methylmalonic acid (MMA) were measured with high-performance liquid chromatography and gas chromatography/mass spectrometry, respectively, and hematological parameters were determined with a hematological analyzer. Results: Already 1 day after intramuscular Cobalamin injections, the concentrations of serum vitamin B₁₂ and plasma total cysteine were significantly increased while the concentrations of serum folate, plasma total homocysteine and serum MMA were decreased. Mean cell volume was also significantly decreased first after 14 days of therapy. Conclusion: Intramuscular cobalamin administration causes swift and significant changes in plasma aminothiols, whereas the first change in hematological parameters was detected only after 14 days.

Urinary bone resorption markers, CrossLaps and hydroxyproline are compared in a non-selected group of 93 women. The correlation between CrossLaps and hydroxyproline is satisfactory. The r value is 0.79. Furthermore, it is investigated whether CrossLaps can substitute for hydroxyproline in the estimation of bone loss, using a model based on the combination of several biochemical markers. The results indicate that the two systems reflect related or parallel events, and show that CrossLaps is suitable for use in a normal clinical chemistry laboratory.