Vitamin B12 deficiency is associated with cardiovascular autonomic neuropathy in patients with type 2 diabetes

AIMS: Vitamin B12 deficiency could be associated with cardiovascular autonomic neuropathy (CAN) in diabetes patients. We aim to investigate the association between serum levels of vitamin B12 and CAN in type 2 diabetes patients.METHODS: 469 ambulatory type 2 diabetes patients (mean diabetes duration 10.0years (IQR 5.0;17.0), mean age 59.0years (SD 11.6), 63% men, mean B12 289.0pmol/l (IQR 217;390)) were screened for CAN using three cardiovascular reflex tests, five minute resting heart rate (5min RHR) and heart rate variability indices.RESULTS: Serum levels of vitamin B12 were significantly lower in patients treated with metformin and/or proton pump inhibitors (PPIs) compared with patients not treated (pCONCLUSION: Vitamin B12 may be inversely associated with CAN in patients with type 2 diabetes. Confirmatory studies investigating a causal role of vitamin B12 for the development of diabetic CAN are warranted.