Biomaterial Database

Vitamin B12 status in metformin treated patients: systematic review. 2014

Qilin Liu, and Sheyu Li, and Heng Quan, and Jianwei Li

Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu, China.

OBJECTIVE Randomized controlled trials and observational studies have yielded inconsistent results on the effects of metformin on vitamin B12 reduction. We therefore performed a systematic review to analyze the effects of metformin on vitamin B12 concentration. METHODS PubMed, Medline, Embase, and the Cochrane central registry of controlled trials were searched to identify randomized controlled trials and observational studies exploring the association between metformin and vitamin B12 concentration in patients with type 2 diabetes mellitus or polycystic ovary syndrome. The main outcome measure was changes in serum vitamin B12 concentration after 6-208 weeks of treatment with metformin, as compared with placebo or other anti-hyperglycemic therapy. RESULTS Six randomized controlled trials met the inclusion criteria. Serum vitamin B12 concentrations were significantly lower in patients treated with metformin than in those who received placebo or rosiglitazone (mean difference [MD], -53.93 pmol/L; 95% confidence interval [CI], -81.44 to -26.42 pmol/L, P = 0.0001). Subgroup analysis identified four trials in which patients received a lower dose of metformin (<2000 mg/d) and two in which they received a higher dose (≥2000 mg/d), with MDs in vitamin B12 concentration after metformin treatment of -37.99 pmol/L (95% CI, -57.44 to -18.54 pmol/L, P = 0.0001) and -78.62 pmol/L (95% CI, -106.37 to -50.86 pmol/L, P<0.00001), respectively. CONCLUSIONS The reduction of vitamin B12 may be induced by metformin in a dose dependent manner.

UI	MeSH Term	Description	Entries
D007004	Hypoglycemic Agents	Substances which lower blood glucose levels.	Antidiabetic,Antidiabetic Agent,Antidiabetic Drug,Antidiabetics,Antihyperglycemic,Antihyperglycemic Agent,Hypoglycemic,Hypoglycemic Agent,Hypoglycemic Drug,Antidiabetic Agents,Antidiabetic Drugs,Antihyperglycemic Agents,Antihyperglycemics,Hypoglycemic Drugs,Hypoglycemic Effect,Hypoglycemic Effects,Hypoglycemics,Agent, Antidiabetic,Agent, Antihyperglycemic,Agent, Hypoglycemic,Agents, Antidiabetic,Agents, Antihyperglycemic,Agents, Hypoglycemic,Drug, Antidiabetic,Drug, Hypoglycemic,Drugs, Antidiabetic,Drugs, Hypoglycemic,Effect, Hypoglycemic,Effects, Hypoglycemic
D008687	Metformin	A biguanide hypoglycemic agent used in the treatment of non-insulin-dependent diabetes mellitus not responding to dietary modification. Metformin improves glycemic control by improving insulin sensitivity and decreasing intestinal absorption of glucose. (From Martindale, The Extra Pharmacopoeia, 30th ed, p289)	Dimethylguanylguanidine,Dimethylbiguanidine,Glucophage,Metformin HCl,Metformin Hydrochloride,HCl, Metformin,Hydrochloride, Metformin
D011085	Polycystic Ovary Syndrome	A complex disorder characterized by infertility, HIRSUTISM; OBESITY; and various menstrual disturbances such as OLIGOMENORRHEA; AMENORRHEA; ANOVULATION. Polycystic ovary syndrome is usually associated with bilateral enlarged ovaries studded with atretic follicles, not with cysts. The term, polycystic ovary, is misleading.	Stein-Leventhal Syndrome,Polycystic Ovarian Syndrome,Polycystic Ovary Syndrome 1,Sclerocystic Ovarian Degeneration,Sclerocystic Ovaries,Sclerocystic Ovary Syndrome,Ovarian Degeneration, Sclerocystic,Ovarian Syndrome, Polycystic,Ovary Syndrome, Polycystic,Ovary, Sclerocystic,Sclerocystic Ovary,Stein Leventhal Syndrome,Syndrome, Polycystic Ovary,Syndrome, Stein-Leventhal
D003924	Diabetes Mellitus, Type 2	A subclass of DIABETES MELLITUS that is not INSULIN-responsive or dependent (NIDDM). It is characterized initially by INSULIN RESISTANCE and HYPERINSULINEMIA; and eventually by GLUCOSE INTOLERANCE; HYPERGLYCEMIA; and overt diabetes. Type II diabetes mellitus is no longer considered a disease exclusively found in adults. Patients seldom develop KETOSIS but often exhibit OBESITY.	Diabetes Mellitus, Adult-Onset,Diabetes Mellitus, Ketosis-Resistant,Diabetes Mellitus, Maturity-Onset,Diabetes Mellitus, Non-Insulin-Dependent,Diabetes Mellitus, Slow-Onset,Diabetes Mellitus, Stable,MODY,Maturity-Onset Diabetes Mellitus,NIDDM,Diabetes Mellitus, Non Insulin Dependent,Diabetes Mellitus, Noninsulin Dependent,Diabetes Mellitus, Noninsulin-Dependent,Diabetes Mellitus, Type II,Maturity-Onset Diabetes,Noninsulin-Dependent Diabetes Mellitus,Type 2 Diabetes,Type 2 Diabetes Mellitus,Adult-Onset Diabetes Mellitus,Diabetes Mellitus, Adult Onset,Diabetes Mellitus, Ketosis Resistant,Diabetes Mellitus, Maturity Onset,Diabetes Mellitus, Slow Onset,Diabetes, Maturity-Onset,Diabetes, Type 2,Ketosis-Resistant Diabetes Mellitus,Maturity Onset Diabetes,Maturity Onset Diabetes Mellitus,Non-Insulin-Dependent Diabetes Mellitus,Noninsulin Dependent Diabetes Mellitus,Slow-Onset Diabetes Mellitus,Stable Diabetes Mellitus
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014805	Vitamin B 12	A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. INTRINSIC FACTOR is important for the assimilation of vitamin B 12.	Cobalamin,Cyanocobalamin,Cobalamins,Eritron,Vitamin B12,B 12, Vitamin,B12, Vitamin
D016032	Randomized Controlled Trials as Topic	Works about clinical trials that involve at least one test treatment and one control treatment, concurrent enrollment and follow-up of the test- and control-treated groups, and in which the treatments to be administered are selected by a random process, such as the use of a random-numbers table.	Clinical Trials, Randomized,Controlled Clinical Trials, Randomized,Trials, Randomized Clinical
D016896	Treatment Outcome	Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.	Rehabilitation Outcome,Treatment Effectiveness,Clinical Effectiveness,Clinical Efficacy,Patient-Relevant Outcome,Treatment Efficacy,Effectiveness, Clinical,Effectiveness, Treatment,Efficacy, Clinical,Efficacy, Treatment,Outcome, Patient-Relevant,Outcome, Rehabilitation,Outcome, Treatment,Outcomes, Patient-Relevant,Patient Relevant Outcome,Patient-Relevant Outcomes