Endocrine Abstracts

Introduction: Prolonged use of Metformin is associated with the development of vitamin B12 deficiency. The aim of our study was to investigate the relationship of clinical manifestations similar to diabetic polyneuropathy with vitamin B12 levels in patients with type 2 diabetes mellitus.

Materials and methods: We examined 35 patients with type 2 diabetes taking Metformin. Mean age 55.9±11.5 years, mean diabetes duration 9.2±7.7 years. All patients were tested for diabetic polyneuropathy (DPN). The level of vitamin B12 was determined by the chemiluminescence immunoassay method.

Results: There was a trend towards a decrease in the level of vitamin B12 in persons with reduced sensitivity compared to persons with preserved sensitivity: 243.85±117.8 versus 336.66±98.3 pg/ml for pain sensitivity; 299.1±84.3 versus 326.9±121.2 pg/ml for tactile sensitivity; 297.0±175.2 versus 357.0±134.9 pg/ml for temperature sensitivity; 117.8±73.3 pg/ml for persons with vibration sensitivity from 0 to 3 points versus 522.5±188.2 pg/ml for persons with vibration sensitivity from 4 to 6 points (P<0.05). Also, among persons with a decrease in tendon reflexes, the level of vitamin B12 was lower (197.0±78.5 pg/ml) compared to persons with preserved reflexes (316.2±117.1 pg/ml).

Conclusion: The presence of clinical manifestations of polyneuropathy was associated with a decrease in the level of vitamin B12 in the blood in patients with type 2 diabetes mellitus taking Metformin, a significant decrease in the level of vitamin B12 was shown in patients with reduced vibration sensitivity. Patients with clinical manifestations of diabetic polyneuropathy should measure vitamin B12 levels.