Effect of insulin-metformin combination on hepatic steatosis in patients with type 2 diabetes

Prevalence and clinical determinants of non-alcoholic fatty liver disease by liver scores in adults with type 1 diabetes

AIMS

To investigate the prevalence and clinical risk factors for non-alcoholic fatty liver disease (NAFLD) in type 1 diabetes (T1DM) by liver scores.

METHODS

A retrospective, unicenter, cross-sectional analysis was performed of adults with T1DM from 2015 to 2018. Steatosis scores (hepatic steatosis index-HSI, Framingham steatosis index-FSI) and fibrosis scores (FIB-4 index, AST-to-platelet ratio index-APRI) were associated with clinical parameters.

RESULTS

We identified 447 patients, 38 ± 14.5 yrs, 54 % female, BMI 28 ± 5.9 kg/m². Liver steatosis was prevalent at 61 % by HSI ≥ 36 and 52 % by FSI ≥ 23. A majority of these individuals had normal liver transaminase levels. The presence of advanced fibrosis was 4 % by APRI > 0.7 and 4 % by FIB-4 > 2.67. BMI ≥ 25 kg/m² correlated with steatosis scores (P < 0.001) but not fibrosis scores. Older age (≥40 yrs), hypertension, dyslipidemia, and history of cardiovascular disease were associated with steatosis markers. Only 21 % had any abdominal imaging, 2 % had hepatology referral and 1 % had a liver biopsy. Glucagon-like peptide-1 agonist was prescribed in 5 % and thiazolidinedione in 4 %.

CONCLUSION

Liver scores indicating steatosis but not fibrosis is common in adults with T1DM with obesity and/or metabolic syndrome, and is associated with older age, hypertension, and dyslipidemia. NAFLD is under-diagnosed and under-investigated; a minority of patients have had any liver evaluation or treatment.

Assessment of fatty liver and its correlation with glycemic control in patients with type 2 diabetes mellitus attending Dessie Comprehensive Specialized Hospital, Northeast Ethiopia

OBJECTIVES

The purpose of conducting this study was to assess fatty liver disease and its correlation with glycemic control in type 2 diabetes mellitus patients. In addition, evaluation of associated factors and correlation analysis between the fatty liver index and hemoglobin A1C level in patients with type 2 diabetes mellitus was another aim of this study.

METHODS

A hospital-based cross-sectional study was conducted among type 2 diabetes mellitus patients attending at diabetes clinic of Dessie Comprehensive Specialized Hospital located in south Wollo, Ethiopia. It was conducted from July to August 2021. The fatty liver index was calculated to assess fatty liver disease. Simple descriptive statistics, multivariate analysis, and an independent sample t-test were utilized for statistical analysis. Multiple logistic regression analysis was used to determine the associated factors of fatty liver. The p value < 0.05 was considered as statistically significant.

RESULTS

In this study, the mean ± standard deviation values of body mass index among type 2 diabetes mellitus patients were 25.82 ± 3.64, 28.04 ± 2.43, and 22.70 ± 2.62 in both fatty and non-fatty liver cases, respectively. In this study, the prevalence of fatty liver among type 2 diabetes mellitus patients was 58.4%. There was a significant positive correlation between the level of Hemoglobin A1C or glycated hemoglobin and fatty liver index (p value = 0.008, r = 0.35). The development of fatty liver was 4.6 times more likely among patients with type 2 diabetes mellitus who had insufficient physical exercise than sufficient exercise. Patients with insulin and oral hypoglycemic drugs were 0.8 folds less likely to have a fatty liver as compared to oral hypoglycemic drug treatment.

CONCLUSION

The results of this study showed that the prevalence of non-alcoholic fatty liver disease was elevated among patients with type 2 diabetes mellitus who had higher levels of body mass index, waist circumference, triglycerides, glycated hemoglobin, and gamma-glutamyltransferase. Therefore, glycemic control, sufficient physical exercise, and insulin treatment may reduce the risk of fatty liver disease in patients with type 2 diabetes mellitus.

American Association of Clinical Endocrinology Clinical Practice Guideline for the Diagnosis and Management of Nonalcoholic Fatty Liver Disease in Primary Care and Endocrinology Clinical Settings: Co-Sponsored by the American Association for the Study of Liver Diseases (AASLD)

OBJECTIVE

To provide evidence-based recommendations regarding the diagnosis and management of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) to endocrinologists, primary care clinicians, health care professionals, and other stakeholders.

METHODS

The American Association of Clinical Endocrinology conducted literature searches for relevant articles published from January 1, 2010, to November 15, 2021. A task force of medical experts developed evidence-based guideline recommendations based on a review of clinical evidence, expertise, and informal consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RECOMMENDATION SUMMARY

This guideline includes 34 evidence-based clinical practice recommendations for the diagnosis and management of persons with NAFLD and/or NASH and contains 385 citations that inform the evidence base.

CONCLUSION

NAFLD is a major public health problem that will only worsen in the future, as it is closely linked to the epidemics of obesity and type 2 diabetes mellitus. Given this link, endocrinologists and primary care physicians are in an ideal position to identify persons at risk on to prevent the development of cirrhosis and comorbidities. While no U.S. Food and Drug Administration-approved medications to treat NAFLD are currently available, management can include lifestyle changes that promote an energy deficit leading to weight loss; consideration of weight loss medications, particularly glucagon-like peptide-1 receptor agonists; and bariatric surgery, for persons who have obesity, as well as some diabetes medications, such as pioglitazone and glucagon-like peptide-1 receptor agonists, for those with type 2 diabetes mellitus and NASH. Management should also promote cardiometabolic health and reduce the increased cardiovascular risk associated with this complex disease.

Effects of anti-diabetic treatments in type 2 diabetes and fatty liver disease

Introduction: Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) are significant non-communicable diseases that often affect individuals concurrently. In individuals with both T2DM and NAFLD, there is evidence that anti-diabetic therapies may demonstrate potential combined beneficial metabolic and reduced hepatic inflammatory effects.Areas covered: A PubMed and Google Scholar search was performed to find relevant literature. Included studies focused on individuals with T2DM and NAFLD receiving anti-diabetic treatments including bariatric surgery, insulin sensitizers, incretin mimetics, and SGLT2 inhibitors. Additional articles highlight investigational treatments.Expert opinion: In individuals with T2DM and NAFLD, 5-10% weight loss or bariatric surgery if unable to lose weight or maintain weight loss are appropriate. GLP-1 receptor agonists and SGLT2 inhibitors result in weight loss, appear safe and may provide beneficial hepatic outcomes. Whether their effects are related to favorable weight changes or intrinsic hepatic effects is unclear. Thiazolidinediones have advantageous anti-hyperglycemic and hepatic effects but individuals must be monitored for weight gain and edema. Metformin and DPP-4 inhibitor beneficial hepatic effects remain debated. There are opportunities to standardize markers and imaging of NAFLD. Studies powered to evaluate the possible cardiovascular benefits of anti-diabetic therapies in individuals with T2DM and NAFLD are needed.

Insulin treatment improves liver histopathology and decreases expression of inflammatory and fibrogenic genes in a hyperglycemic, dyslipidemic hamster model of NAFLD

Background

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are highly prevalent comorbidities in patients with Type 2 diabetes. While many of these patients eventually will need treatment with insulin, little is known about the effects of insulin treatment on histopathological parameters and hepatic gene expression in diabetic patients with co-existing NAFLD and NASH. To investigate this further, we evaluated the effects of insulin treatment in NASH diet-fed hamsters with streptozotocin (STZ) -induced hyperglycemia.

Methods

Forty male Syrian hamsters were randomized into four groups (n = 10/group) receiving either a NASH-inducing (high fat, fructose and cholesterol) or control diet (CTRL) for four weeks, after which they were treated with STZ or sham-injected and from week five treated with either vehicle (CTRL, NASH, NASH-STZ) or human insulin (NASH-STZ-HI) for four weeks by continuous s.c. infusion via osmotic minipumps.

Results

NASH-STZ hamsters displayed pronounced hyperglycemia, dyslipidemia and more severe liver pathology compared to both CTRL and NASH groups. Insulin treatment attenuated dyslipidemia in NASH-STZ-HI hamsters and liver pathology was considerably improved compared to the NASH-STZ group, with prevention/reversal of hepatic steatosis, hepatic inflammation and stellate cell activation. In addition, expression of inflammatory and fibrotic genes was decreased compared to the NASH-STZ group.

Conclusions

These results suggest that hyperglycemia is important for development of inflammation and profibrotic processes in the liver, and that insulin administration has beneficial effects on liver pathology and expression of genes related to inflammation and fibrosis in a hyperglycemic, dyslipidemic hamster model of NAFLD.

Liraglutide or insulin glargine treatments improves hepatic fat in obese patients with type 2 diabetes and nonalcoholic fatty liver disease in twenty-six weeks: A randomized placebo-controlled trial

BACKGROUND

Type 2 diabetes mellitus is closely related to nonalcoholic fatty liver disease(NAFLD). More and more attention has been paid to the efficacy of liraglutide in the treatment of NAFLD, but the clinical evidence is still insufficient.

OBJECTIVE

The purpose of this study was to use proton magnetic resonance spectroscopy (H-MRS) assessment of metformin alone poor blood glucose control of obese patients type 2 diabetes with NAFLD, added with insulin glargine, liraglutide or placebo effect in improving the fatty liver.

METHODS

This is a 26-week, single-center, prospective, randomized placebo-controlled study. From September 2016 to July 2018, 128 patients with type 2 diabetes and NAFLD were enrolled in the China joint logistics team 900 hospital. The primary endpoints were the changes in intrahepatic content of lipid (IHCL), abdominal adiposity [subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT)], from baseline to week 26 (end of treatment) and the changes in liraglutide group or insulin glargine group versus change in placebo group. Secondary endpoints included the changes in liver function (AST and ALT), glycemia (HbA1c and FPG), body weight, and BMI.

RESULTS

A total of 96 patients with type 2 diabetes and NAFLD under inadequate glycemic control by metformin were randomized (1:1:1) to receive add-on insulin glargine, liraglutide, or placebo. After 26 weeks of treatment, compared to the placebo group, in the liraglutide and insulin glargine groups, IHCL significantly decreased from baseline to week 26 (liraglutide 26.4% ± 3.2% to 20.6% ± 3.9%, P < 0.05; insulin glargine 25.0% ± 4.3% to 22.6% ± 5.8%, P > 0.05). SAT and VAT decreased significantly in the liraglutide group and in the insulin glargine group (P < 0.05). ΔSAT and ΔVAT were greater with liraglutide than insulin glargine, they were significantly different between the two groups (ΔSAT, -36 vs. - 24.5, P < 0.05; and ΔVAT, -47 vs. - 16.6, P > 0.05). In the liraglutide group, AST, ALT, and HOMA-IR decreased significantly from baseline. There was no significant difference in glucose-lowering among the three groups. During the treatment, the safety of the three groups performed well.

CONCLUSION

Compared with placebo, treatment with liraglutide plus an adequate dose of metformin (2000 g/ day) for 26 weeks is more effective in reducing IHCL, SAT and VAT in patients with type 2 diabetes and NAFLD. And it has additional advantages in weight loss, waist circumference reduction and liver function improvement.

Efficacy of exenatide and insulin glargine on nonalcoholic fatty liver disease in patients with type 2 diabetes

BACKGROUND

The aim of this study was to investigate the efficacy of exenatide and insulin glargine in patients with newly diagnosed type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD).

METHODS

We performed a 24-week randomized controlled multicentre clinical trial. Seventy-six patients were randomly assigned 1:1 to receive exenatide or insulin glargine treatment. The endpoints included changes in liver fat content (LFC), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) measured by magnetic resonance spectroscopy, blood glucose, liver enzymes, lipid profile, body weight, and Fibrosis-4 index (FIB-4).

RESULTS

LFC, VAT, SAT, and FIB-4 were significantly reduced after exenatide treatment (ΔLFC, -17.55 ± 12.93%; ΔVAT, -43.57 ± 68.20 cm2 ; ΔSAT, -28.44 ± 51.48 cm2 ; ΔFIB-4, -0.10 ± 0.26; all P < .05). In comparison, only LFC (ΔLFC, -10.49 ± 11.38%; P < .05), and not VAT, SAT, or FIB-4 index (all P > .05), was reduced after insulin glargine treatment. Moreover, exenatide treatment resulted in greater reductions in alanine transaminase (ALT), aspartate transaminase (AST), and gamma glutamyl transpeptidase (GGT) than insulin glargine (P < 0.05). The body weight, waist circumference, postprandial plasma glucose, and low-density lipoprotein cholesterol (LDL-C) in the exenatide group also presented greater reductions than the insulin glargine group (P < .05). The proportion of adverse events were comparable between the two groups.

CONCLUSION

Both exenatide and insulin glargine reduced LFC in patients with drug-naive T2DM and NAFLD; however, exenatide showed greater reductions in body weight, visceral fat area, liver enzymes, FIB-4, postprandial plasma glucose, and LDL-C.

Beneficial effects of Aronia melanocarpa berry extract on hepatic insulin resistance in type 2 diabetes mellitus rats

We aimed to investigate) the effects of Aronia melanocarpa berry extract (AMBE) on hepatic insulin resistance and its mechanism at the molecular level in high-fat diet (HFD)- and streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) rats. The rats were supplemented with AMBE at doses of 100 and 400 mg/kg body weight (bw) daily for 8 weeks. AMBE significantly reduced blood glucose and serum insulin levels and the homeostatic model assessment for insulin resistance score; improved glucose tolerance; increased hepatic glycogen content; and regulated glucose metabolism enzyme activity, including glucokinase, pyruvate kinase, phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase in the liver. AMBE also reduced lipid accumulation and oxidative stress along with inflammation in the hepatic tissue of T2DM rats and improved hepatic function. The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was activated by AMBE through the elevation of insulin receptor substrate-2, PI3K, Akt, and glycogen synthase kinase-3β phosphorylation and glucose transporter 2, which might contribute to the promotion of glycogen synthesis and improvement of hepatic insulin resistance. AMBE shows promise as an ingredient of functional foods for alleviating hepatic insulin resistance in T2DM. PRACTICAL APPLICATION: The extract from the berries of Aronia melanocarpa (Michx.) Elliott (AMBE), with its relatively high content of polyphenolic compounds, has been shown to exert hypoglycemic effects in animal models of diabetes. Our findings support the use of A. melanocarpa as a functional food additive for the alleviation of hepatic insulin resistance and the management of glucose homeostasis in T2DM.

Metformin alleviates muscle wasting post-thermal injury by increasing Pax7-positive muscle progenitor cells

BACKGROUND

Profound skeletal muscle wasting and weakness is common after severe burn and persists for years after injury contributing to morbidity and mortality of burn patients. Currently, no ideal treatment exists to inhibit muscle catabolism. Metformin is an anti-diabetic agent that manages hyperglycemia but has also been shown to have a beneficial effect on stem cells after injury. We hypothesize that metformin administration will increase protein synthesis in the skeletal muscle by increasing the proliferation of muscle progenitor cells, thus mitigating muscle atrophy post-burn injury.

METHODS

To determine whether metformin can attenuate muscle catabolism following burn injury, we utilized a 30% total burn surface area (TBSA) full-thickness scald burn in mice and compared burn injuries with and without metformin treatment. We examined the gastrocnemius muscle at 7 and 14 days post-burn injury.

RESULTS

At 7 days, burn injury significantly reduced myofiber cross-sectional area (CSA) compared to sham, p < 0.05. Metformin treatment significantly attenuated muscle catabolism and preserved muscle CSA at the sham size. To investigate metformin's effect on satellite cells (muscle progenitors), we examined changes in Pax7, a transcription factor regulating the proliferation of muscle progenitors. Burned animals treated with metformin had a significant increase in Pax7 protein level and the number of Pax7-positive cells at 7 days post-burn, p < 0.05. Moreover, through BrdU proliferation assay, we show that metformin treatment increased the proliferation of satellite cells at 7 days post-burn injury, p < 0.05.

CONCLUSION

In summary, metformin's various metabolic effects and its modulation of stem cells make it an attractive alternative to mitigate burn-induced muscle wasting while also managing hyperglycemia.

Effect of Weight Loss Medications on Hepatic Steatosis and Steatohepatitis: A Systematic Review

Non-alcoholic fatty liver disease (NAFLD) is a common comorbidity in individuals with obesity. Although multiple pharmacotherapeutics are in development, currently there are limited strategies specifically targeting NAFLD. This systematic review summarizes the existing literature on hepatic effects of medications used for weight loss. Glucagon-like peptide 1 (GLP-1) agonists are the best-studied in this regard, and evidence consistently demonstrates reduction in liver fat content, sometimes accompanied by improvements in histological features of steatohepatitis and reductions in serum markers of hepatic injury such as alanine aminotransferase (ALT). It remains unclear whether these benefits are independent of the weight loss caused by these agents. Literature is limited regarding effects of orlistat, but a small number of reports suggest that orlistat reduces liver fat content and improves histologic features of NASH, benefits which may also be driven primarily by weight loss. A sizeable body of literature on hepatic effects of metformin yields mixed results, with a probability of modest benefit, but no consistent signal for strong benefit. There are insufficient data on hepatic effects of topiramate, phentermine, naltrexone, bupropion, and lorcaserin. Finally, a few studies to date suggest that sodium-glucose co-transporter-2 (SGLT2) inhibitors may reduce liver fat content and cause modest reductions in ALT, but further study is needed to better characterize these effects. Based on available data, GLP-1 agonists have the strongest evidence base demonstrating beneficial effects on NAFLD, but it is not clear if any weight loss medication has effects on NAFLD superior to those of nutritional modification and exercise alone.

Hepatocellular carcinoma imaging systems: why they exist, how they have evolved, and how they differ

Over the past 16 years, several scientific organizations have proposed systems that incorporate imaging for surveillance, diagnosis, staging, treatment, and monitoring of treatment response of hepatocellular carcinoma (HCC). These systems are needed to standardize the acquisition, interpretation, and reporting of liver imaging examinations; help differentiate benign from malignant observations; improve consistency between radiologists; and provide guidance for management of HCC. This review article discusses the historical evolution of HCC imaging systems. We indicate the features differentiating these systems, including target population, screening and surveillance algorithm, diagnostic imaging modalities, diagnostic scope, expertise and technical requirements, terminology, major and ancillary imaging features, staging and transplant eligibility, and assessment of treatment response. We highlight the potential benefits of unifying the systems, which we anticipate will enable sharing, pooling, and meta-analysis of data; facilitate multi-center trials; and accelerate dissemination of knowledge.

Randomized double-blind clinical trial comparing basal insulin peglispro and insulin glargine, in combination with prandial insulin lispro, in patients with type 2 diabetes: IMAGINE 4

AIMS

To evaluate the efficacy and safety of basal insulin peglispro (BIL) with those of insulin glargine, both in combination with prandial insulin lispro, in patients with type 2 diabetes (T2D).

METHODS

In this phase III, multicentre, double-blind, 26-week study, we randomized patients with T2D [glycated haemoglobin (HbA1c) ≥7 and <12%, on ≥1 insulin injections daily) to BIL (n = 691) or glargine (n = 678), in combination with lispro.

RESULTS

At week 26, the primary objective of non-inferiority of BIL versus glargine for HbA1c reduction was achieved (least squares mean difference -0.21%; 95% confidence interval -0.31 to -0.11%), with statistical superiority of BIL with multiplicity adjustment (p < 0.001). HbA1c at baseline was 8.4% versus 8.5% for BIL versus glargine and at 26 weeks it was 6.8% versus 7.0%. At 26 weeks, more patients reached HbA1c <7% with BIL than with glargine (63.3% vs 53.3%; p < 0.001), the nocturnal hypoglycaemia rate (≤3.9 mmol/l) was lower with BIL (0.51 vs 0.92 events/30 days; p < 0.001), but the daytime hypoglycaemia rate was higher with BIL (5.47 vs 4.53 events/30 days; p < 0.001). The total hypoglycaemia relative rate was 1.10 (p = 0.053). At 26 weeks, patients in the BIL group had lower fasting serum glucose levels, higher basal insulin dosing, with no statistically significant difference in prandial or total insulin dosing, reduced glucose variability and less weight gain (1.3 kg vs 2.2 kg) compared with the glargine group. The BIL group had higher mean triglyceride and aminotransferase levels.

CONCLUSIONS

In patients with T2D, BIL with insulin lispro provided greater improvement in glycaemic control with less nocturnal hypoglycaemia, lower glucose variability and less weight gain compared with glargine. The daytime hypoglycaemia rate and mean triglyceride and aminotransferase levels were higher with BIL.

Randomized, double-blind clinical trial comparing basal insulin peglispro and insulin glargine, in combination with prandial insulin lispro, in patients with type 1 diabetes: IMAGINE 3

AIMS

To compare the efficacy and safety of basal insulin peglispro (BIL), which has a flat pharmacokinetic and pharmacodynamic profile and a long duration of action, with insulin glargine (GL) in patients with type 1 diabetes.

MATERIALS AND METHODS

In this phase III, 52-week, blinded study, we randomized 1114 adults with type 1 diabetes in a 3 : 2 distribution to receive either BIL (n = 664) or GL (n = 450) at bedtime, with preprandial insulin lispro, using intensive insulin management. The primary objective was to compare glycated haemoglobin (HbA1c) in the groups at 52 weeks, with a non-inferiority margin of 0.4%.

RESULTS

At 52 weeks, mean (standard error) HbA1c was 7.38 (0.03)% with BIL and 7.61 (0.04)% with GL {difference -0.22% [95% confidence interval (CI) -0.32, -0.12]; p < 0.001}. At 52 weeks more BIL-treated patients reached HbA1c <7% (35% vs 26%; p < 0.001), the nocturnal hypoglycaemia rate was 47% lower (p < 0.001) and the total hypoglycaemia rate was 11% higher (p = 0.002) than in GL-treated patients, and there was no difference in severe hypoglycaemia rate. Patients receiving BIL lost weight, while those receiving GL gained weight [difference -1.8 kg (95% CI -2.3, -1.3); p < 0.001]. Treatment with BIL compared with GL at 52 weeks was associated with greater increases from baseline in levels of serum triglyceride [difference 0.19 mmol/l (95% CI 0.11, 0.26); p < 0.001] and alanine aminotransferase (ALT) levels [difference 6.5 IU/l (95% CI 4.1, 8.9), p < 0.001], and more frequent injection site reactions.

CONCLUSIONS

In patients with type 1 diabetes, treatment with BIL compared with GL for 52 weeks resulted in a lower HbA1c, more patients with HbA1c levels <7%, and reduced nocturnal hypoglycaemia, but more total hypoglycaemia and injection site reactions and higher triglyceride and ALT levels.

Basal insulin peglispro: Overview of a novel long-acting insulin with reduced peripheral effect resulting in a hepato-preferential action

Basal insulin peglispro (BIL) is a novel basal insulin with a flat, prolonged activity profile. BIL has been demonstrated in a dog model, in healthy men and in patients with type 1 diabetes (T1D) to have significant hepato-preferential action resulting from reduced peripheral activity. In the IMAGINE-Phase 3 clinical trial program, more than 6000 patients were included, of whom ~3900 received BIL. Of the 7 pivotal IMAGINE trials, 3 studies were double-blinded and 3 were in T1D patients. BIL consistently demonstrated a greater HbA1c reduction, less glycaemic variability and a clinically relevant reduction in the rates of nocturnal hypoglycaemia across comparator [glargine and isophane insulin (NPH)] studies. Trials using basal/bolus regimens had higher rates of total hypoglycaemia with BIL due to higher rates of daytime hypoglycaemia. Severe hypoglycaemia rates were similar to comparator among both patients with T1D or type 2 diabetes (T2D). T1D patients lost weight compared with glargine (GL). Patients with T2D tended to gain less weight with BIL than with glargine. Compared to glargine, BIL was associated with higher liver fat, triglycerides and alanine aminotransferase (ALT) levels, including a higher frequency of elevation of ALT ≥3 times the upper limit of normal, but without severe, acute drug-induced liver injury. Injection site reactions, primarily lipohypertrophy, were more frequent with BIL. In conclusion, BIL demonstrated better glycaemic control with reduced glucose variability and nocturnal hypoglycaemia but higher triglycerides, ALT and liver fat relative to conventional comparator insulin. The hepato-preferential action of BIL with reduced peripheral activity may account for these findings.

Different effects of basal insulin peglispro and insulin glargine on liver enzymes and liver fat content in patients with type 1 and type 2 diabetes

AIMS

To compare effects of basal insulin peglispro (BIL), a hepatopreferential insulin, to insulin glargine (glargine) on aminotransferases and liver fat content (LFC) in patients with type 1 and type 2 diabetes (T1D, T2D).

MATERIALS AND METHODS

Data from two Phase 2 and five Phase 3 randomized trials comparing BIL and glargine in 1709 T1D and 3662 T2D patients were integrated for analysis of liver laboratory tests. LFC, measured by magnetic resonance imaging (MRI) at baseline, 26 and 52 weeks, was analyzed in 182 T1D patients, 176 insulin-naïve T2D patients and 163 T2D patients previously treated with basal insulin.

RESULTS

Alanine aminotransferase (ALT) increased in patients treated with BIL, was higher than in glargine-treated patients at 4-78 weeks (difference at 52 weeks in both T1D and T2D: 7 international units/litre (IU/L), P < .001), and decreased after discontinuation of BIL. More BIL patients had ALT ≥3× upper limit of normal (ULN) than glargine. No patient had ALT ≥3× ULN with bilirubin ≥2× ULN that was considered causally related to BIL. In insulin-naїve T2D patients, LFC decreased with glargine but was unchanged with BIL. In T1D and T2D patients previously treated with basal insulin, LFC was unchanged with glargine but increased with BIL. In all three populations, LFC was higher after treatment with BIL vs glargine (difference at 52 weeks: 2.2% to 5.3%, all P < .01).

CONCLUSIONS

Compared to glargine, patients treated with BIL had higher ALT and LFC at 52-78 weeks. No severe drug-induced liver injury was apparent with BIL treatment for up to 78 weeks.

Non-alcoholic fatty liver disease and diabetes

Non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2DM) are common conditions that regularly co-exist and can act synergistically to drive adverse outcomes. The presence of both NAFLD and T2DM increases the likelihood of the development of complications of diabetes (including both macro- and micro- vascular complications) as well as augmenting the risk of more severe NAFLD, including cirrhosis, hepatocellular carcinoma and death. The mainstay of NAFLD management is currently to reduce modifiable metabolic risk. Achieving good glycaemic control and optimising weight loss are pivotal to restricting disease progression. Once cirrhosis has developed, it is necessary to screen for complications and minimise the risk of hepatic decompensation. Therapeutic disease modifying options for patients with NAFLD are currently limited. When diabetes and NAFLD co-exist, there are published data that can help inform the clinician as to the most appropriate oral hypoglycaemic agent or injectable therapy that may improve NAFLD, however most of these data are drawn from observations in retrospective series and there is a paucity of well-designed randomised double blind placebo controlled studies with gold-standard end-points. Furthermore, given the heterogeneity of inclusion criteria and primary outcomes, as well as duration of follow-up, it is difficult to draw robust conclusions that are applicable across the entire spectrum of NAFLD and diabetes. In this review, we have summarised and critically evaluated the available data, with the aim of helping to inform the reader as to the most pertinent issues when managing patients with co-existent NAFLD and T2DM.

Comparative efficacy of anti-diabetic agents on nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus: a systematic review and meta-analysis of randomized and non-randomized studies

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has a high prevalence in patients with type 2 diabetes mellitus (T2DM). In this study, we sought to provide a comprehensive assessment regarding the effects of anti-diabetic agents on NAFLD in patients with T2DM.

METHODS

MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials (RCTs) with different anti-diabetic agents in T2DM. Observational trials were also recruited to expand our population. Hepatic fat content and liver histology were evaluated as primary outcomes. Pooled estimates were calculated using a fixed effect model.

RESULTS

One thousand one hundred ninety-six participants in 19 RCTs and 14 non-randomized studies were included. Evidence from RCTs and observational studies suggested that greater hepatic fat content reduction and improved liver histology were seen in thiazolidinediones for 12-72 weeks; glucagon-like peptide-1 receptor agonists had beneficial effects on hepatic fat content after 26-50 weeks intervention, and insulin/metformin combination with 3-7 months improved hepatic fat content. Initiating metformin or dapagliflozin showed no benefit on hepatic fat content or liver histology in 16-48 weeks. Besides, nateglinide for 18 months was reported in a small sample-size RCT to improve hepatic fat content and liver histology. Sitagliptin therapy of 1 year also provided benefit on nonalcoholic steatohepatitis score in an observational study.

CONCLUSIONS

For T2DM with NAFLD, administrating thiazolidinediones and glucagon-like peptide-1 receptor agonists seems to provide more identified advances in attenuating hepatic fat content. Further RCTs are warranted to assess the efficacy of various hypoglycemic agents on clinical outcomes associated with NAFLD in T2DM. Copyright © 2015 John Wiley & Sons, Ltd.

Randomized Clinical Trial Comparing Basal Insulin Peglispro and Insulin Glargine in Patients With Type 2 Diabetes Previously Treated With Basal Insulin: IMAGINE 5

OBJECTIVE

To evaluate the efficacy and safety of basal insulin peglispro (BIL) versus insulin glargine in patients with type 2 diabetes (hemoglobin A1c [HbA1c] ≤9% [75 mmol/mol]) treated with basal insulin alone or with three or fewer oral antihyperglycemic medications.

RESEARCH DESIGN AND METHODS

This 52-week, open-label, treat-to-target study randomized patients (mean HbA1c 7.42% [57.6 mmol/mol]) to BIL (n = 307) or glargine (n = 159). The primary end point was change from baseline HbA1c to 26 weeks (0.4% [4.4 mmol/mol] noninferiority margin).

RESULTS

At 26 weeks, reduction in HbA1c was superior with BIL versus glargine (-0.82% [-8.9 mmol/mol] vs. -0.29% [-3.2 mmol/mol]; least squares mean difference -0.52%, 95% CI -0.67 to -0.38 [-5.7 mmol/mol, 95% CI -7.3 to -4.2; P < 0.001); greater reduction in HbA1c with BIL was maintained at 52 weeks. More BIL patients achieved HbA1c <7% (53 mmol/mol) at weeks 26 and 52 (P < 0.001). With BIL versus glargine, nocturnal hypoglycemia rate was 60% lower, more patients achieved HbA1c <7% (53 mmol/mol) without nocturnal hypoglycemia at 26 and 52 weeks (P < 0.001), and total hypoglycemia rates were lower at 52 weeks (P = 0.03). At weeks 26 and 52, glucose variability was lower (P < 0.01), basal insulin dose was higher (P < 0.001), and triglycerides and aminotransferases were higher with BIL versus glargine (P < 0.05). Liver fat content (LFC), assessed in a subset of patients (n = 162), increased from baseline with BIL versus glargine (P < 0.001), with stable levels between 26 and 52 weeks.

CONCLUSIONS

BIL provided superior glycemic control versus glargine, with reduced nocturnal and total hypoglycemia, lower glucose variability, and increased triglycerides, aminotransferases, and LFC.

Effects of Insulin Glargine and Liraglutide Therapy on Liver Fat as Measured by Magnetic Resonance in Patients With Type 2 Diabetes: A Randomized Trial

OBJECTIVE

This study determined the effects of insulin versus liraglutide therapy on liver fat in patients with type 2 diabetes inadequately controlled with oral agents therapy, including metformin.

RESEARCH DESIGN AND METHODS

Thirty-five patients with type 2 diabetes inadequately controlled on metformin monotherapy or in combination with other oral antidiabetic medications were randomized to receive insulin glargine or liraglutide therapy for 12 weeks. The liver proton density fat fraction (PDFF) was measured by MRS. The mean liver PDFF, the total liver volume, and the total liver fat index were measured by MRI. The Student t test, the Fisher exact test, and repeated-measures ANOVA were used for statistical analysis.

RESULTS

Insulin treatment was associated with a significant improvement in glycated hemoglobin (7.9% to 7.2% [62.5 to 55.2 mmol/mol], P = 0.005), a trend toward a decrease in MRS-PDFF (12.6% to 9.9%, P = 0.06), and a significant decrease in liver mean MRI-PDFF (13.8% to 10.6%, P = 0.005), liver volume (2,010.6 to 1,858.7 mL, P = 0.01), and the total liver fat index (304.4 vs. 209.3 % ⋅ mL, P = 0.01). Liraglutide treatment was also associated with a significant improvement in glycated hemoglobin (7.6% to 6.7% [59.8 to 50.2 mmol/mol], P < 0.001) but did not change MRS-PDFF (P = 0.80), liver mean MRI-PDFF (P = 0.15), liver volume (P = 0.30), or the total liver fat index (P = 0.39).

CONCLUSIONS

The administration of insulin glargine therapy reduced the liver fat burden in patients with type 2 diabetes. However, the improvements in the liver fat fraction and glycemia control were not significantly different from those in the liraglutide group.

Molecular and immunohistochemical effects of metformin in a rat model of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a serious health issue worldwide. The disease is characterized by insulin resistance (IR), which leads to dyslipidemia and alterations in the expression levels of a number of genes. Metformin is the standard treatment for T2DM; however, the exact mechanism underlying metformin regulation is not fully understood. The aim of the present study was to investigate the effects of metformin on serum lipid profiles and the expression levels of various genes that are associated with IR, as well as the histopathological changes in the liver and pancreas. A T2DM rat model was established by feeding the rats a high-fat diet for 4 weeks, combined with a dose of streptozotocin (35 mg/kg body weight). Following the successful induction of T2DM, metformin was administered orally (400 mg/kg/day) for 4 weeks. The results indicated that metformin improved the symptoms of IR by normalizing the serum lipid profiles in the diabetic rats. Furthermore, metformin upregulated the expression of insulin receptors and genes associated with lipid metabolism, including acyl-CoA oxidase, carnitine palmitoyl transferase-1 and peroxisome proliferator activated receptor-α. In addition, treatment with metformin downregulated the expression levels of fetuin-A and retinol binding protein-4 (RBP-4), while normalizing the expression of perilipin that had been reduced in the T2DM rats. Metformin administration induced regenerative changes in the hepatocyte cytoplasm and parenchyma. In the pancreas, treatment with metformin was shown to induce positive signaling for insulin and the regeneration of pancreatic β cells. In summary, metformin treatment ameliorated a number of the harmful effects associated with T2DM via the modulation of the expression levels of fetuin-A, RBP-4, perilipin and various genes associated with lipid metabolism, resulting in regenerative changes in the liver and pancreatic cells.

Bariatric surgery and non-alcoholic Fatty liver disease: current and potential future treatments

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are increasingly common cause of chronic liver disease worldwide. The diagnosis of NASH is challenging as most affected patients are symptom-free and the role of routine screening is not clearly established. Most patients with severe obesity who undergo bariatric surgery have NAFLD, which is associated insulin resistance, type 2 diabetes mellitus (T2DM), hypertension, and obesity-related dyslipidemia. The effective treatment for NAFLD is weight reduction through lifestyle modifications, antiobesity medication, or bariatric surgery. Among these treatments, bariatric surgery is the most reliable method for achieving substantial, sustained weight loss. This procedure is safe when performed by a skilled surgeon, and the benefits include reduced weight, improved quality of life, decreased obesity-related comorbidities, and increased life expectancy. Further research is urgently needed to determine the best use of bariatric surgery with NAFLD patients at high risk of developing liver cirrhosis and its role in modulating complications of NAFLD, such as T2DM and cardiovascular disease. The current evidence suggests that bariatric surgery for patients with severe obesity decreases the grade of steatosis, hepatic inflammation, and fibrosis. However, further long-term studies are required to confirm the true effects before recommending bariatric surgery as a potential treatment for NASH.

Effect of insulin versus triple oral therapy on the progression of hepatic steatosis in type 2 diabetes

BACKGROUND

Hyperinsulinemia has been associated with hepatic fat deposition and ensuing insulin resistance. It is unknown if treatment with exogenous insulin in patients with type 2 diabetes, who are most prone to hepatic fat accumulation, would promote the occurrence or worsening of nonalcoholic fatty liver disease.

METHODS

Patients with treatment-naive type 2 diabetes (N = 16) were treated with insulin and metformin for a 3-month lead-in period, then assigned triple oral therapy (metformin, glyburide, and pioglitazone) or continued treatment with insulin and metformin. Hepatic triglyceride content (HTC)-measured by magnetic resonance spectroscopy, serum lipids, glucose, liver function tests, and inflammatory and thrombotic biomarkers were followed for a median of 31 months.

RESULTS

The 45% decline in HTC during the lead-in period persisted through the follow-up period with no difference between treatment groups at the end of the study (5.26 ± 4.21% in the triple oral therapy vs 7.47 ± 7.40% for insulin/metformin), whereas glycemic control was comparable.

CONCLUSIONS

Improvements in HTC with initial insulin/metformin therapy persisted through the median 31-month follow-up period regardless of the treatment. More importantly, insulin-based treatment did not appear to promote or worsen nonalcoholic fatty liver disease.

Bariatric surgery as potential treatment for nonalcoholic fatty liver disease: a future treatment by choice or by chance?

Morbid obesity is strongly associated with nonalcoholic fatty liver disease (NAFLD) which is one of the most common causes of chronic liver disease worldwide. The current best treatment of NAFLD and NASH is weight reduction through life style modifications, antiobesity medication, and bariatric surgery. Importantly, bariatric surgery is the best alternative option for weight reduction if lifestyle modifications and pharmacological therapy have not yielded long-term success. Bariatric surgery is an effective treatment option for individuals who are grossly obese and associated with marked decrease in obesity-related morbidity and mortality. The most common performed bariatric surgery is Roux-en-Y gastric bypass (RYGB). The current evidence suggests that bariatric surgery in these patients will decrease the grade of steatosis, hepatic inflammation, and fibrosis. NAFLD per se is not an indication for bariatric surgery. Further research is urgently needed to determine (i) the benefit of bariatric surgery in NAFLD patients at high risk of developing liver cirrhosis (ii) the role of bariatric surgery in modulation of complications of NAFLD like diabetes and cardiovascular disease. The outcomes of the future research will determine whether bariatric surgery will be one of the recommended choice for treatment of the most progressive type of NAFLD.

Effect of insulin versus triple oral therapy on the progression of hepatic steatosis in type 2 diabetes

BACKGROUND

Hyperinsulinemia has been associated with hepatic fat deposition and ensuing insulin resistance. It is unknown if treatment with exogenous insulin in patients with type 2 diabetes, who are most prone to hepatic fat accumulation, would promote the occurrence or worsening of nonalcoholic fatty liver disease.

METHODS

Patients with treatment-naive type 2 diabetes (N = 16) were treated with insulin and metformin for a 3-month lead-in period, then assigned triple oral therapy (metformin, glyburide, and pioglitazone) or continued treatment with insulin and metformin. Hepatic triglyceride content (HTC)-measured by magnetic resonance spectroscopy, serum lipids, glucose, liver function tests, and inflammatory and thrombotic biomarkers were followed for a median of 31 months.

RESULTS

The 45% decline in HTC during the lead-in period persisted through the follow-up period with no difference between treatment groups at the end of the study (5.26 ± 4.21% in the triple oral therapy vs 7.47 ± 7.40% for insulin/metformin), whereas glycemic control was comparable.

CONCLUSIONS

Improvements in HTC with initial insulin/metformin therapy persisted through the median 31-month follow-up period regardless of the treatment. More importantly, insulin-based treatment did not appear to promote or worsen nonalcoholic fatty liver disease.

Role of obesity and lipotoxicity in the development of nonalcoholic steatohepatitis: pathophysiology and clinical implications

As obesity reaches epidemic proportions, nonalcoholic fatty liver disease (NAFLD) is becoming a frequent cause of patient referral to gastroenterologists. There is a close link between dysfunctional adipose tissue in NAFLD and common conditions such as metabolic syndrome, type 2 diabetes mellitus, and cardiovascular disease. This review focuses on the pathophysiology of interactions between adipose tissue and target organs in obesity and the resulting clinical implications for the management of nonalcoholic steatohepatitis. The release of fatty acids from dysfunctional and insulin-resistant adipocytes results in lipotoxicity, caused by the accumulation of triglyceride-derived toxic metabolites in ectopic tissues (liver, muscle, pancreatic beta cells) and subsequent activation of inflammatory pathways, cellular dysfunction, and lipoapoptosis. The cross talk between dysfunctional adipocytes and the liver involves multiple cell populations, including macrophages and other immune cells, that in concert promote the development of lipotoxic liver disease, a term that more accurately describes the pathophysiology of nonalcoholic steatohepatitis. At the clinical level, adipose tissue insulin resistance contributes to type 2 diabetes mellitus and cardiovascular disease. Treatments that rescue the liver from lipotoxicity by restoring adipose tissue insulin sensitivity (eg, significant weight loss, exercise, thiazolidinediones) or preventing activation of inflammatory pathways and oxidative stress (ie, vitamin E, thiazolidinediones) hold promise in the treatment of NAFLD, although their long-term safety and efficacy remain to be established. Better understanding of pathways that link dysregulated adipose tissue, metabolic dysfunction, and liver lipotoxicity will result in improvements in the clinical management of these challenging patients.

Nonalcoholic fatty liver disease: a review of the spectrum of disease, diagnosis, and therapy

Worldwide, there is an epidemic of obesity and overweight, with two-thirds of Americans affected. A strong association exists between excessive body weight and nonalcoholic fatty liver disease (NAFLD), the most common etiology of abnormal liver function tests. Nonalcoholic fatty liver disease is a spectrum of liver disease, from a "bland" fatty infiltration to chronic hepatitis (nonalcoholic steatohepatitis or NASH), that can result in cirrhosis and organ failure. With the increasing prevalence of obesity in the world, the proportion of people affected by NAFLD is only expected to be parallel. Although primarily noted in obese individuals, NAFLD has also been associated with a number of surgical procedures, metabolic conditions, and medications. NASH is commonly underdiagnosed as most affected patients are symptom free, and routine screening is not performed. Noninvasive diagnostic testing is not sensitive in diagnosis or staging the severity of disease. Fatty infiltration and oxidative injury to the hepatocytes are believed to be the major factors behind the progression of disease from simple fatty infiltration of the liver to chronic hepatitis. Understanding the inflammatory pathways involved in NASH is a subject of extensive research. Currently, few proven treatment options exist, and controlled weight reduction is the only safe modality recommended for treatment of NASH.

Metformin regulates hepatic lipid metabolism through activating AMP-activated protein kinase and inducing ATGL in laying hens

Although many clinical trials have showed that metformin improves non-alcoholic fatty liver disease, which is a common liver disease associated with hepatic enzyme abnormalities, an animal model is required to investigate the effects of altered gene expression and post-translational processing (proteins) in mediating the observed responses. Laying hens appear to develop fatty livers, as in the case in human beings, when ingesting energy in excess of maintenance, and they can be used as an animal model for observing hepatic steatosis. The aim of this study was to investigate whether metformin could improve the non-alcoholic fatty liver of laying hens and to examine the possible mechanisms of lipid-lowering effects. Forty-eight Leghorn laying hens of Hy-Line variety W-36 - 44 weeks with 64.8% hen-day egg production - were randomly assigned into 4 treatments, each receiving 0, 10, 30, or 100mg of metformin with saline per kg body weight by daily wing vein injection. Results showed that, compared with the control, significant decreases existed in the laying rates; plasma triglyceride, cholesterol, and insulin levels; body weights; abdominal fat weights; hepatic lipid contents; and hepatic fatty acid synthase expression of layers receiving 30 or 100mg per kg body weight, whereas significant increases in their hepatic 5'adenosine monophosphate-activated protein kinase, acyl-CoA carboxylase phosphorylation, adipose triglyceride lipase, and carnitine palmitoyl transferase-1 expression were observed. These data suggest that metformin could reduce lipid deposits in the liver and that the laying hen is a valuable animal model for studying hepatic steatosis.

Hepatic steatosis and Type 2 diabetes: current and future treatment considerations

Hepatic steatosis, considered the first step in the pathophysiologic continuum of non-alcoholic fatty liver disease, is estimated to afflict 30% of the US population and over 75% of patients with Type 2 diabetes. Given the expected rise in the prevalence of obesity and Type 2 diabetes in the following decades, hepatic steatosis will, if not already, become an epidemic. The consequences of hepatic steatosis are numerous, and range from progression to chronic liver disease, with its associated morbidity and mortality, to worsening insulin resistance and Type 2 diabetes, as well as being an independent contributor to cardiovascular disease. All such consequences are more likely to occur in patients with Type 2 diabetes who are already at high risk of cardiovascular events. In this article we review the evidence behind the available therapeutic options for hepatic steatosis, and identify challenges and unmet needs in the field.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

BACKGROUND

Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age.

OBJECTIVES

To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies.

SEARCH STRATEGY

A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators.

SELECTION CRITERIA

Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy.

DATA COLLECTION AND ANALYSIS

The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data.

MAIN RESULTS

Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies.

AUTHORS' CONCLUSIONS

There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

BACKGROUND

Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age.

OBJECTIVES

To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies.

SEARCH STRATEGY

A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators.

SELECTION CRITERIA

Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy.

DATA COLLECTION AND ANALYSIS

The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data.

MAIN RESULTS

Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies.

AUTHORS' CONCLUSIONS

There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.

Nonalcoholic fatty liver disease in type 2 diabetes mellitus

PURPOSE OF REVIEW

To increase awareness about the close interrelationship between nonalcoholic fatty liver disease and type 2 diabetes mellitus, and of recent diagnostic and treatment advances in the field.

RECENT FINDINGS

The perception of nonalcoholic fatty liver disease as an uncommon and benign condition is rapidly changing. Approximately 70% of persons with type 2 diabetes mellitus have a fatty liver and the disease follows a more aggressive course with necroinflammation and fibrosis (i.e. nonalcoholic steatohepatitis) in diabetes. New evidence suggests that it is not steatosis per se but the development of lipotoxicity-induced mitochondrial dysfunction and activation of inflammatory pathways that leads to progressive liver damage. Nonalcoholic steatohepatitis is a leading cause of end-stage liver disease and contributes to cardiovascular disease in patients with type 2 diabetes mellitus. Because nonalcoholic steatohepatitis may develop even in the presence of normal liver transaminases, a liver biopsy is still necessary for a definitive diagnosis. However, new imaging methods and plasma biomarkers are emerging as alternative diagnostic tools. Lifestyle intervention is the gold standard for the management of nonalcoholic steatohepatitis. Recent randomized controlled trials suggest thiazolidiendiones are promising therapeutic agents.

SUMMARY

Nonalcoholic steatohepatitis is a frequently overlooked and potentially severe complication of type 2 diabetes mellitus. Patients may benefit from its early diagnosis and treatment.

Current treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in Western World and frequently associated with insulin resistance and overweight and occurs often with type 2 diabetes. Interestingly, NAFLD is not only regarded as a hepatic component of the metabolic syndrome but also as an independent risk factor and a marker for increase in cardiovascular disease (CVD). Significantly, NAFLD is associated with an increased risk of all-cause mortality and predicts future CVD events independent of age, sex, LDL-cholesterol and features of metabolic syndrome. Although there was initial concern about drug toxicity with NAFLD, increasing evidence suggests that commonly used drugs such as metformin and statins do not cause harm and the thiazolidinediones (TZDs) may even confer a therapeutic benefit in NAFLD. Interestingly, medical and surgical treatments of obesity show potential benefit in treating NAFLD. In this review, we have focused on the safety and therapeutic impact of TZDs, statins, metformins and obesity medications in NAFLD. The potential benefit of bariatric surgery and the role of weight loss per se in treating NAFLD are also discussed.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

BACKGROUND

Metformin is an oral anti-hyperglycemic agent used in the treatment of type 2 diabetes mellitus. The results of the UK Prospective Diabetes Study indicate that metformin treatment is associated with a reduction in total mortality compared to other anti-hyperglycemic treatments. Metformin, however, is thought to increase the risk of lactic acidosis, and is considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age.

OBJECTIVES

To assess the incidence of fatal and nonfatal lactic acidosis with metformin use compared to placebo and other glucose-lowering treatments in patients with type 2 diabetes mellitus. A secondary objective was to evaluate the blood lactate levels for those on metformin treatment compared to placebo or non-metformin therapies.

SEARCH STRATEGY

A search was performed of The Cochrane Library (up to 8/2005), MEDLINE (up to 8/2005), EMBASE (up to 11/2000), OLD MEDLINE, and REACTIONS (up to 8/2005), in order to identify all studies of metformin treatment from 1966 to August 2005. The Cumulated Index Medicus was used to search relevant articles from 1959 to 1965. The search was augmented by scanning references of identified articles, and by contacting principal investigators. Date of latest search: August 2005.

SELECTION CRITERIA

Prospective trials in patients with type 2 diabetes that lasted longer than one month were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy. Observational cohort studies of metformin treatment lasting greater than one month were also included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials to be included, assessed study quality and extracted data. The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for placebo or other treatments. The upper limit for the true incidence of cases in the metformin and non-metformin groups were calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed effect model for continuous data.

MAIN RESULTS

Pooled data from 206 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 47,846 patient-years of metformin use or in 38,221 patients-years in the non-metformin group. Using Poisson statistics with 95% confidence intervals the upper limit for the true incidence of metformin-associated lactic acidosis was 6.3 cases per 100,000 patient-years, and the upper limit for the true incidence of lactic acidosis in the non-metformin group was 7.8 cases per 100,000 patient-years. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to placebo or other non-biguanide therapies. The mean lactate levels were slightly lower for metformin treatment compared to phenformin (WMD -0.75 mmol/L, 95% CI -0.86 to -0.15).

AUTHORS' CONCLUSIONS

There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments if prescribed under the study conditions.