Subclinical atherosclerosis and impaired cardiac autonomic control in pediatric patients with Vitamin B12 deficiency.

Objective: Homocysteine (Hcy) is an independent risk factor for predisposing to atherosclerosis and endothelial dysfunction. Hcy levels increase with Vitamin B12 deficiency. The aim of this study was to investigate the association between carotid intima-media thickness (CIMT) and the autonomic modulation of heart rate variability (HRV) in early detection of atherosclerosis and impaired cardiac autonomic control in pediatric patients with Vitamin B12 deficiency.

Materials and Methods: Sixty patients with Vitamin B12 deficiency (14.4 ± 1.72 years, 36 female) and 40, age, sex, and body mass index-matched healthy controls (13.4 ± 1.86 years, 24 female) had performed 24-h Holter monitoring, carotid ultrasonography, and echocardiography. Linear regression models assessed associations between to HRV parameters and CIMT and the blood markers.

Results: We defined Vitamin B12 deficiency as a serum level, 200 pg/mL. Hcy (P < 0.001) and CIMT (P < 0.001) levels were significantly higher in the patient group compared with the control group. Hcy level was found to be the most important independent variable affecting CIMT. Each 1 degree increase in Hcy, it was observed that the CIMT value increased by 0.01 mm (B = 0.01; t = -2.39; P < 0.05). Low-frequency power (LF), high-frequency power (HF) (P < 0.001), and the square root of the mean of the squared differences of two consecutive RR intervals (rMSSd) (P = 0.04) were significantly lower in the B12 deficient patients. Furthermore, Hcy level was found to be the most important independent variable affecting LF, HF, and rMSSd.

Conclusions: Subclinical atherosclerosis was associated with cardiovascular autonomic imbalance in pediatric patients with Vitamin B12 deficiency. Homocysteinemia may be an important marker for the prediction of future cardiovascular disease.