Metformin scientific update |
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Arch Intern Med. 2006 Oct 9;166(18):1975-9.
Ting RZ, Szeto CC, Chan MH, Ma KK, Chow KM.
Departments of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin.
Risk factors of vitamin B12 deficiency in patients receiving metformin.
BACKGROUND: Identification of risk factors for metformin-related vitamin B(12) deficiency has major potential implications regarding the management of diabetes mellitus. METHODS: We conducted a nested case-control study from a database in which the source population consisted of subjects who had levels of both serum vitamin B(12) and hemoglobin A(1c) checked in a central laboratory. We identified 155 cases of diabetes mellitus and vitamin B(12) deficiency secondary to metformin treatment. Another 310 controls were selected from the cohort who did not have vitamin B(12) deficiency while taking metformin. RESULTS: A total of 155 patients with metformin-related vitamin B(12) deficiency (mean +/- SD serum vitamin B(12) concentration, 148.6 +/- 40.4 pg/mL [110 +/- 30 pmol/L]) were compared with 310 matched controls (466.1 +/- 330.4 pg/mL [344 +/- 244 pmol/L]). After adjusting for confounders, we found clinically important and statistically significant association of vitamin B(12) deficiency with dose and duration of metformin use. Each 1-g/d metformin dose increment conferred an odds ratio of 2.88 (95% confidence interval, 2.15-3.87) for developing vitamin B(12) deficiency (P<.001). Among those using metformin for 3 years or more, the adjusted odds ratio was 2.39 (95% confidence interval, 1.46-3.91) (P = .001) compared with those receiving metformin for less than 3 years. After exclusion of 113 subjects with borderline vitamin B(12) concentration, dose of metformin remained the strongest independent predictor of vitamin B(12) deficiency. CONCLUSIONS: Our results indicate an increased risk of vitamin B(12) deficiency associated with current dose and duration of metformin use despite adjustment for many potential confounders. The risk factors identified have implications for planning screening or prevention strategies in metformin-treated patients.
An Med Interna. 2004 Jun;21(6):288-90.
Solano Remirez M, Gonzalez Arencibia C, Alvarez Frias M, Llorente Diaz B, Echegaray Agara M.
Servicio de Medicina Interna. Hospital de Navarra. Pamplona, Spain.
Lactic acidosis in diabetic patient treated with metformin.
We present a case of metabolic acidosis ina man, recently diagnosed with type 2 Diabetes Mellitus under treatment with metformin. Metformin (along with Fenformin and Butformin) is an oral antihyperglycemic agent belonging to the biguanide group employed in the treatment of non insulin dependent diabetes (NIDDM). Its main use is in associattion with other oral agents in obese diabetic patients with difficult metabolic control. In some of these patients, clearly beneficial developed lactic acidosis, specially in those who have predisposing factors (respiratry failure, liver disease or cardiovascular disease) and/or those who require high dosis. For this reason we describe itacute;s pharmacokinetics, therapeutic indications and its correct use in this type of diabetic patient.
Ann Intern Med. 2005 Mar 1;142(5):323-32.
Herman WH, Hoerger TJ, Brandle M, Hicks K, Sorensen S, Zhang P, Hamman RF, Ackermann RT, Engelgau MM, Ratner RE; Diabetes Prevention Program Research Group.
University of Michigan Health System, Ann Arbor, Michigan, USA.
The cost-effectiveness of lifestyle modification or metformin in preventing type 2 diabetes in adults with impaired glucose tolerance.
BACKGROUND: The Diabetes Prevention Program (DPP) demonstrated that interventions can delay or prevent the development of type 2 diabetes. OBJECTIVE: To estimate the lifetime cost-utility of the DPP interventions. DESIGN: Markov simulation model to estimate progression of disease, costs, and quality of life. DATA SOURCES: The DPP and published reports. TARGET POPULATION: Members of the DPP cohort 25 years of age or older with impaired glucose tolerance. TIME HORIZON: Lifetime. PERSPECTIVES: Health system and societal. INTERVENTIONS: Intensive lifestyle, metformin, and placebo interventions as implemented in the DPP. OUTCOME MEASURES: Cumulative incidence of diabetes, microvascular and neuropathic complications, cardiovascular complications, survival, direct medical and direct nonmedical costs, quality-adjusted life-years (QALYs), and cost per QALY. RESULTS OF BASE-CASE ANALYSIS: Compared with the placebo intervention, the lifestyle and metformin interventions were estimated to delay the development of type 2 diabetes by 11 and 3 years, respectively, and to reduce the absolute incidence of diabetes by 20% and 8%, respectively. The cumulative incidence of microvascular, neuropathic, and cardiovascular complications were reduced and survival was improved by 0.5 and 0.2 years. Compared with the placebo intervention, the cost per QALY was approximately 1100 dollars for the lifestyle intervention and $31 300 for the metformin intervention. From a societal perspective, the interventions cost approximately 8800 dollars and 29,900 dollars per QALY, respectively. From both perspectives, the lifestyle intervention dominated the metformin intervention. RESULTS OF SENSITIVITY ANALYSIS: Cost-effectiveness improved when the interventions were implemented as they might be in routine clinical practice. The lifestyle intervention was cost-effective in all age groups. The metformin intervention did not represent good use of resources for persons older than 65 years of age. LIMITATIONS: Simulation results depend on the accuracy of the underlying assumptions, including participant adherence. CONCLUSIONS: Health policy should promote diabetes prevention in high-risk individuals.
Obstet Gynecol Surv. 2005 Mar;60(3):178-9
Baillargeon JP, Jakubowicz DJ, Iuomo MJ, Jakubowicz S, Nestler JE.
Hospital de Clinicas Caracas, Caracas, Venezuela; and the Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia.
Effects of metformin and rosiglitazone, alone and in combination, in nonobese women with polycystic ovary syndrome and normal indices of insulin sensitivity.
The goal of this randomized, controlled, double-blind trial was to learn whether insulin-sensitizing drugs can improve ovulation frequency and serum-free testosterone (T) in nonobese women with polycystic ovary syndrome (PCOS) whose insulin sensitivity was normal. The 100 women enrolled in the study, 17 to 40 years of age, had normal glucose tolerance, fasting insulin, and peak insulin levels during oral glucose tolerance testing (OGTT). The fasting glucose-to-insulin ratio also was normal. Criteria for PCOS were 8 or fewer menstrual periods in the past year and a serum total T exceeding 70 ng/dL. Participants received 850 mg metformin, 4 mg rosiglitazone, a combination of both treatments, or at least 1 placebo twice a day for 6 months. Treatment began when the women were in the equivalent of the follicular phase of the cycle.Only women given rosiglitazone gained significant body weight (1.1 kg), and the posttreatment body mass index was significantly greater in this group. All actively treated women had a significant decline in their waist-to-hip ratio. Systolic blood pressure fell significantly in all actively treated groups but not in placebo recipients. Diastolic pressure decreased and was similar in all groups at the end of the study. Ovulatory cycles were 6- to 8-fold more frequent with treatment and were highest in women given metformin or combination therapy. Ovulation rates at 6 months were markedly increased except in the placebo group. Menstrual bleeding also was greater in treated women. Combination treatment did not yield additive results for either ovulation or menstrual bleeding. Serum total and free T levels decreased significantly with active treatment. Compared with placebo, fasting insulin levels, the area under the insulin curve during an OGTT, and the OGTT-based insulin sensitivity index improved significantly after metformin or combination therapy, but not after rosiglitazone.The investigators concluded that insulin-sensitizing drugs are effective in nonobese women with PCOS even if baseline insulin sensitivity is normal.
Metabolism. 2005 Mar;54(3):314-20.
Jung HS, Youn BS, Cho YM, Yu KY, Park HJ, Shin CS, Kim SY, Lee HK, Park KS.
The effects of rosiglitazone and metformin on the plasma concentrations of resistin in patients with type 2 diabetes mellitus.
Abstract Resistin is a protein secreted from adipose tissue that is thought to play a role in insulin sensitivity. We examined the effects of rosiglitazone and metformin on the plasma resistin levels in individuals with type 2 diabetes mellitus. Patients with type 2 diabetes mellitus who showed poor glycemic control with glimepiride (4 mg/d) were randomized to rosiglitazone (4 mg/d) and metformin (500 mg bid) treatment groups. All subjects continued glimepiride treatment as well. The plasma concentrations of resistin were measured at baseline and at 6 months of treatment for both groups. The anthropometric parameters, fasting plasma glucose, HbA1c, total cholesterol, triglyceride, high-density lipoprotein cholesterol, free fatty acids, and adiponectin concentrations were also measured. After 6 months of treatment, the reduction in plasma glucose levels was similar between the 2 groups. There were no significant changes in the lipid profiles of either group during the study period. The plasma resistin levels decreased in the rosiglitazone group (2.49 +/- 1.93 vs 1.95 +/- 1.59 ng/ml; P < .05) but increased in the metformin group (2.61 +/- 1.69 vs 5.13 +/- 2.81 ng/ml; P < .05). The plasma adiponectin concentrations were increased in the rosiglitazone group (2.91 +/- 1.46 vs 4.23 +/- 1.77 mu g/ml; P < .05) but were unchanged in the metformin group. In summary, rosiglitazone treatment decreased the plasma resistin levels whereas metformin treatment increased them in patients with type 2 diabetes mellitus showing poor glycemic control with sulfonylurea therapy. These results suggest that the observed changes in plasma resistin levels are not the consequences of improved insulin resistance, nor are they consequences of glycemic control. Considering the potential role of resistin in insulin resistance, decrease in resistin levels may contribute to improving insulin action with rosiglitazone treatment.
Metformin description...
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Drug category:Antidiabetic agents
 Metformin scientific update
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