The effect of metformin on leptin in obese patients with type 2 diabetes mellitus and nonalcoholic fatty liver disease

Department of Endocrinology and Metabolism, Faculty of Medicine, Baskent University, 5. sokak No: 48, Bahcelievler, 06490, Ankara, Turkey.
Acta Diabetologica (Impact Factor: 3.68). 11/2008; 46(2):113-8. DOI: 10.1007/s00592-008-0067-2
Source: PubMed

ABSTRACT Insulin resistance is a major feature of type 2 diabetes mellitus, obesity and nonalcoholic fatty liver disease (NAFLD). Several studies pointed out the possible role of increased leptin in NAFLD in humans. The aim of this study is to determine the effect of metformin on plasma leptin levels in obese patients with type 2 diabetes mellitus and NAFLD compared with lifestyle interventions. Thirty-four obese patients with newly diagnosed type 2 diabetes mellitus were prospectively followed for 6 months. All patients had ultrasonographic evidence of NAFLD at baseline. The patients were randomized into two groups: group 1 (n = 15) followed lifestyle changes only and group 2 (n = 19) received metformin (1,700 mg/day). At the end of treatment, BMI, WHR, HbA1c, fasting glucose, leptin, HOMA-IR, alanine aminotransferase values decreased in both groups. No significant difference in the end-points was observed between two groups. Only in group 2, LDL decreased and HDL increased significantly. Liver echogenity decreased significantly at the end of study in both groups. The percentage of patients who no longer had evidence of NAFLD was not significantly different between the groups (20% of patients on lifestyle intervention vs. 16% of patients on metformin). The data demonstrate that, metformin and lifestyle interventions equally affected the plasma leptin levels, BMI and degree of NAFLD in obese patients with type 2 diabetes mellitus. In addition, the effects of metformin on the variables were not found to be mediated by leptin.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Whether metformin may affect thyroid cancer risk has not been studied. This study investigated the association between metformin use and thyroid cancer risk in Taiwanese patients with type 2 diabetes mellitus. Methods The reimbursement databases of all diabetic patients from 1996 to 2009 were retrieved from the National Health Insurance. An entry date was set at 1 January 2006 and 1,414,723 patients with type 2 diabetes were followed for thyroid cancer incidence until the end of 2009. Incidences for ever-users, never-users and subgroups of metformin exposure using tertile cutoffs for cumulative duration of therapy and cumulative dose were calculated and adjusted hazard ratios were estimated by Cox regression. Additional sensitivity analyses were conducted. Results There were 795,321 ever-users and 619,402 never-users, with respective numbers of incident thyroid cancer of 683 (0.09%) and 1,614 (0.26%), and respective incidence of 24.09 and 87.33 per 100,000 person-years. The overall fully adjusted hazard ratio (95% confidence interval) was 0.683 (0.598–0.780), and all categories of the dose-response parameters showed significantly lower risk with P-trends <0.0001. The protective effect of metformin on thyroid cancer incidence was also supported by sensitivity analyses, disregarding age (<50 or ≥50 years) and sex; and was not affected by excluding users of insulin, sulfonylurea, and insulin and/or sulfonylurea respectively, by previous diagnosis of other cancers or by potential detection examinations that might lead to differential diagnosis of thyroid cancer. Conclusions This study provides evidence for the first time that metformin use in patients with type 2 diabetes may reduce the risk of thyroid cancer.
    PLoS ONE 10/2014; 9(10). DOI:10.1371/journal.pone.0109852 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective. Polycystic ovary syndrome (PCOS) is associated with obesity and insulin resistance (IR), key features of nonalcoholic steatohepatitis (NASH). Cytokeratin 18 fragments (M30) have been established as a serum marker for NASH. The insulin sensitizer metformin improves hepatic IR. This study evaluates the influence of MF on serologic NASH (sNASH) in patients with PCOS. Patients and Methods. In 89 patients, metabolic parameters, liver injury indicating fatty liver (LIFL), and M30 were assessed at baseline and after metformin treatment. Patients with initial IR were subdivided into dissolved (PCOS-exIR) and persistent IR (PCOS-PIR) after treatment and compared to an initially insulin sensitive PCOS group (PCOS-C). Results. Improvement of LIFL prevalence could be seen in PCOS-C and PCOS-exIR compared to PCOS-PIR (-19.4, resp., -12.0% versus 7.2%, Chi(2) = 29.5, P < 0.001) without change in sNASH prevalence. In PCOS-PIR, ALT levels increased significantly accompanied by a nominal, nonsignificant M30 increase. Conclusions. Metformin improves LIFL in subgroups of patients with PCOS without influencing sNASH. This could either indicate a missing effect of metformin on NAFLD or slowed disease progression. Further studies are needed to elucidate NAFLD in the context of PCOS and potential therapeutic options.
    International Journal of Endocrinology 01/2015; 2015:254169. DOI:10.1155/2015/254169 · 1.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nonalcoholic fatty liver disease (NAFLD) is currently the most common cause of chronic liver disease in industrialized countries worldwide, and has become a serious public health issue not only in Western countries but also in many Asian countries including Japan. Within the wide spectrum of NAFLD, non-alcoholic steatohepatitis (NASH) is a progressive form of disease, which often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma. In turn, a large proportion of NAFLD/NASH is the liver manifestation of metabolic syndrome, suggesting that NAFLD/NASH plays a key role in the pathogenesis of systemic atherosclerotic diseases. Currently, a definite diagnosis of NASH requires liver biopsy, though various non-invasive measures are under development. The mainstays of prevention and treatment of NAFLD/NASH include dietary restriction and exercise; however, pharmacological approaches are often necessary. Currently, vitamin E and thiazolidinedione derivatives are the most evidence-based therapeutic options, although the clinical evidence for long-term efficacy and safety is limited. This practice guideline for NAFLD/NASH, established by the Japanese Society of Gastroenterology in cooperation with The Japan Society of Hepatology, covers lines of clinical evidence reported internationally in the period starting from 1983 through January 2012, and each clinical question was evaluated using the GRADE system. Based on the primary release of the full version in Japanese, this English summary provides the core essentials of this clinical practice guideline comprising the definition, diagnosis, and current therapeutic recommendations for NAFLD/NASH in Japan. © 2015 The Japan Society of Hepatology.
    Journal of Gastroenterology 02/2015; 45(4). DOI:10.1007/s00535-015-1050-7 · 4.02 Impact Factor