Changes in liver tests during 1-year treatment of patients with Type 2 diabetes with pioglitazone, metformin or gliclazide

Alleviation of cisplatin-induced hepatotoxicity by gliclazide: Involvement of oxidative stress and caspase-3 activity

AIMS

Cisplatin (CP), as an effective alkylating agent, is widely used in cancer treatment, while hepatotoxicity is one of its side effects. Gliclazide (GLZ), as an oral hypoglycemic drug, has antioxidant and anti-inflammatory properties. This study was designed to investigate the protective effect of GLZ against CP-induced hepatotoxicity in mice.

METHODS

In this experimental study, 64 adult male mice randomly were allocated into eight groups (8 mice/group). Control, GLZ (5, 10, and 25 mg/kg, orally), CP (10 mg/kg, single dose, intraperitoneally), and CP+GLZ (in three doses). GLZ was administrated for 10 consecutive days. CP was injected on the 7th day of the study. At the end of the experiment, hepatotoxicity was evaluated by serum and tissue biochemical, histopathological, and immunohistochemical assessments.

RESULTS

The data were revealed that CP increased oxidative stress (increased MDA and reduced GSH), liver damage enzymes (ALT, AST, and ALP), and immunoreactivity of caspase-3 in liver tissue of CP-injected mice. Also, CP induced histopathological changes such as eosinophilic of hepatocytes, dilatation of sinusoids, congestion, and proliferation of Kupffer cells. GLZ administration significantly ameliorated serum functional enzyme and hepatic oxidative stress markers in CP-injected mice. In addition, the histological and immunohistochemical alterations were ameliorated in GLZ-treated mice. Of the three doses, 10 and 25 mg/kg were more effective.

CONCLUSIONS

In conclusion, GLZ with its antioxidant, anti-inflammatory, and anti-apoptotic activities, can be suggested as a promising drug in the treatment of CP-induced hepatotoxicity.

Metformin monotherapy for adults with type 2 diabetes mellitus

BACKGROUND

Worldwide, there is an increasing incidence of type 2 diabetes mellitus (T2DM). Metformin is still the recommended first-line glucose-lowering drug for people with T2DM. Despite this, the effects of metformin on patient-important outcomes are still not clarified.

OBJECTIVES

To assess the effects of metformin monotherapy in adults with T2DM.

SEARCH METHODS

We based our search on a systematic report from the Agency for Healthcare Research and Quality, and topped-up the search in CENTRAL, MEDLINE, Embase, WHO ICTRP, and ClinicalTrials.gov. Additionally, we searched the reference lists of included trials and systematic reviews, as well as health technology assessment reports and medical agencies. The date of the last search for all databases was 2 December 2019, except Embase (searched up 28 April 2017).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with at least one year's duration comparing metformin monotherapy with no intervention, behaviour changing interventions or other glucose-lowering drugs in adults with T2DM.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles/records, assessed risk of bias, and extracted outcome data independently. We resolved discrepancies by involvement of a third review author. For meta-analyses we used a random-effects model with investigation of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall certainty of the evidence by using the GRADE instrument.

MAIN RESULTS

We included 18 RCTs with multiple study arms (N = 10,680). The percentage of participants finishing the trials was approximately 58% in all groups. Treatment duration ranged from one to 10.7 years. We judged no trials to be at low risk of bias on all 'Risk of bias' domains. The main outcomes of interest were all-cause mortality, serious adverse events (SAEs), health-related quality of life (HRQoL), cardiovascular mortality (CVM), non-fatal myocardial infarction (NFMI), non-fatal stroke (NFS), and end-stage renal disease (ESRD). Two trials compared metformin (N = 370) with insulin (N = 454). Neither trial reported on all-cause mortality, SAE, CVM, NFMI, NFS or ESRD. One trial provided information on HRQoL but did not show a substantial difference between the interventions. Seven trials compared metformin with sulphonylureas. Four trials reported on all-cause mortality: in three trials no participant died, and in the remaining trial 31/1454 participants (2.1%) in the metformin group died compared with 31/1441 participants (2.2%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on SAE: in two trials no SAE occurred (186 participants); in the other trial 331/1454 participants (22.8%) in the metformin group experienced a SAE compared with 308/1441 participants (21.4%) in the sulphonylurea group (very low-certainty evidence). Two trials reported on CVM: in one trial no CVM was observed and in the other trial 4/1441 participants (0.3%) in the metformin group died of cardiovascular reasons compared with 8/1447 participants (0.6%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on NFMI: in two trials no NFMI occurred, and in the other trial 21/1454 participants (1.4%) in the metformin group experienced a NFMI compared with 15/1441 participants (1.0%) in the sulphonylurea group (very low-certainty evidence). One trial reported no NFS occurred (very low-certainty evidence). No trial reported on HRQoL or ESRD. Seven trials compared metformin with thiazolidinediones (very low-certainty evidence for all outcomes). Five trials reported on all-cause mortality: in two trials no participant died; the overall RR was 0.88, 95% CI 0.55 to 1.39; P = 0.57; 5 trials; 4402 participants). Four trials reported on SAE, the RR was 0,95, 95% CI 0.84 to 1.09; P = 0.49; 3208 participants. Four trials reported on CVM, the RR was 0.71, 95% CI 0.21 to 2.39; P = 0.58; 3211 participants. Three trial reported on NFMI: in two trials no NFMI occurred and in one trial 21/1454 participants (1.4%) in the metformin group experienced a NFMI compared with 25/1456 participants (1.7%) in the thiazolidinedione group. One trial reported no NFS occurred. No trial reported on HRQoL or ESRD. Three trials compared metformin with dipeptidyl peptidase-4 inhibitors (one trial each with saxagliptin, sitagliptin, vildagliptin with altogether 1977 participants). There was no substantial difference between the interventions for all-cause mortality, SAE, CVM, NFMI and NFS (very low-certainty evidence for all outcomes). One trial compared metformin with a glucagon-like peptide-1 analogue (very low-certainty evidence for all reported outcomes). There was no substantial difference between the interventions for all-cause mortality, CVM, NFMI and NFS. One or more SAEs were reported in 16/268 (6.0%) of the participants allocated to metformin compared with 35/539 (6.5%) of the participants allocated to a glucagon-like peptide-1 analogue. HRQoL or ESRD were not reported. One trial compared metformin with meglitinide and two trials compared metformin with no intervention. No deaths or SAEs occurred (very low-certainty evidence) no other patient-important outcomes were reported. No trial compared metformin with placebo or a behaviour changing interventions. Four ongoing trials with 5824 participants are likely to report one or more of our outcomes of interest and are estimated to be completed between 2018 and 2024. Furthermore, 24 trials with 2369 participants are awaiting assessment.

AUTHORS' CONCLUSIONS

There is no clear evidence whether metformin monotherapy compared with no intervention, behaviour changing interventions or other glucose-lowering drugs influences patient-important outcomes.

Metformin and second- or third-generation sulphonylurea combination therapy for adults with type 2 diabetes mellitus

BACKGROUND

The number of people with type 2 diabetes mellitus (T2DM) is increasing worldwide. The combination of metformin and sulphonylurea (M+S) is a widely used treatment. Whether M+S shows better or worse effects in comparison with other antidiabetic medications for people with T2DM is still controversial.

OBJECTIVES

To assess the effects of metformin and sulphonylurea (second- or third-generation) combination therapy for adults with type 2 diabetes mellitus.

SEARCH METHODS

We updated the search of a recent systematic review from the Agency for Healthcare Research and Quality (AHRQ). The updated search included CENTRAL, MEDLINE, Embase, ClinicalTrials.gov and WHO ICTRP. The date of the last search was March 2018. We searched manufacturers' websites and reference lists of included trials, systematic reviews, meta-analyses and health technology assessment reports. We asked investigators of the included trials for information about additional trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) randomising participants 18 years old or more with T2DM to M+S compared with metformin plus another glucose-lowering intervention or metformin monotherapy with a treatment duration of 52 weeks or more.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles and records, assessed risk of bias and extracted outcome data independently. We used a random-effects model to perform meta-analysis, and calculated risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the certainty of the evidence using the GRADE instrument.

MAIN RESULTS

We included 32 RCTs randomising 28,746 people. Treatment duration ranged between one to four years. We judged none of these trials as low risk of bias for all 'Risk of bias' domains. Most important events per person were all-cause and cardiovascular mortality, serious adverse events (SAE), non-fatal stroke (NFS), non-fatal myocardial infarction (MI) and microvascular complications. Most important comparisons were as follows:Five trials compared M+S (N = 1194) with metformin plus a glucagon-like peptide 1 analogue (N = 1675): all-cause mortality was 11/1057 (1%) versus 11/1537 (0.7%), risk ratio (RR) 1.15 (95% confidence interval (CI) 0.49 to 2.67); 3 trials; 2594 participants; low-certainty evidence; cardiovascular mortality 1/307 (0.3%) versus 1/302 (0.3%), low-certainty evidence; serious adverse events (SAE) 128/1057 (12.1%) versus 194/1537 (12.6%), RR 0.90 (95% CI 0.73 to 1.11); 3 trials; 2594 participants; very low-certainty evidence; non-fatal myocardial infarction (MI) 2/549 (0.4%) versus 6/1026 (0.6%), RR 0.57 (95% CI 0.12 to 2.82); 2 trials; 1575 participants; very low-certainty evidence.Nine trials compared M+S (N = 5414) with metformin plus a dipeptidyl-peptidase 4 inhibitor (N = 6346): all-cause mortality was 33/5387 (0.6%) versus 26/6307 (0.4%), RR 1.32 (95% CI 0.76 to 2.28); 9 trials; 11,694 participants; low-certainty evidence; cardiovascular mortality 11/2989 (0.4%) versus 9/3885 (0.2%), RR 1.54 (95% CI 0.63 to 3.79); 6 trials; 6874 participants; low-certainty evidence; SAE 735/5387 (13.6%) versus 779/6307 (12.4%), RR 1.07 (95% CI 0.97 to 1.18); 9 trials; 11,694 participants; very low-certainty evidence; NFS 14/2098 (0.7%) versus 8/2995 (0.3%), RR 2.21 (95% CI 0.74 to 6.58); 4 trials; 5093 participants; very low-certainty evidence; non-fatal MI 15/2989 (0.5%) versus 13/3885 (0.3%), RR 1.45 (95% CI 0.69 to 3.07); 6 trials; 6874 participants; very low-certainty evidence; one trial in 64 participants reported no microvascular complications were observed (very low-certainty evidence).Eleven trials compared M+S (N = 3626) with metformin plus a thiazolidinedione (N = 3685): all-cause mortality was 123/3300 (3.7%) versus 114/3354 (3.4%), RR 1.09 (95% CI 0.85 to 1.40); 6 trials; 6654 participants; low-certainty evidence; cardiovascular mortality 37/2946 (1.3%) versus 41/2994 (1.4%), RR 0.78 (95% CI 0.36 to 1.67); 4 trials; 5940 participants; low-certainty evidence; SAE 666/3300 (20.2%) versus 671/3354 (20%), RR 1.01 (95% CI 0.93 to 1.11); 6 trials; 6654 participants; very low-certainty evidence; NFS 20/1540 (1.3%) versus 16/1583 (1%), RR 1.29 (95% CI 0.67 to 2.47); P = 0.45; 2 trials; 3123 participants; very low-certainty evidence; non-fatal MI 25/1841 (1.4%) versus 21/1877 (1.1%), RR 1.21 (95% CI 0.68 to 2.14); P = 0.51; 3 trials; 3718 participants; very low-certainty evidence; three trials (3123 participants) reported no microvascular complications (very low-certainty evidence).Three trials compared M+S (N = 462) with metformin plus a glinide (N = 476): one person died in each intervention group (3 trials; 874 participants; low-certainty evidence); no cardiovascular mortality (2 trials; 446 participants; low-certainty evidence); SAE 34/424 (8%) versus 27/450 (6%), RR 1.68 (95% CI 0.54 to 5.21); P = 0.37; 3 trials; 874 participants; low-certainty evidence; no NFS (1 trial; 233 participants; very low-certainty evidence); non-fatal MI 2/215 (0.9%) participants in the M+S group; 2 trials; 446 participants; low-certainty evidence; no microvascular complications (1 trial; 233 participants; low-certainty evidence).Four trials compared M+S (N = 2109) with metformin plus a sodium-glucose co-transporter 2 inhibitor (N = 3032): all-cause mortality was 13/2107 (0.6%) versus 19/3027 (0.6%), RR 0.96 (95% CI 0.44 to 2.09); 4 trials; 5134 participants; very low-certainty evidence; cardiovascular mortality 4/1327 (0.3%) versus 6/2262 (0.3%), RR 1.22 (95% CI 0.33 to 4.41); 3 trials; 3589 participants; very low-certainty evidence; SAE 315/2107 (15.5%) versus 375/3027 (12.4%), RR 1.02 (95% CI 0.76 to 1.37); 4 trials; 5134 participants; very low-certainty evidence; NFS 3/919 (0.3%) versus 7/1856 (0.4%), RR 0.87 (95% CI 0.22 to 3.34); 2 trials; 2775 participants; very low-certainty evidence; non-fatal MI 7/890 (0.8%) versus 8/1374 (0.6%), RR 1.43 (95% CI 0.49 to 4.18; 2 trials); 2264 participants; very low-certainty evidence; amputation of lower extremity 1/437 (0.2%) versus 1/888 (0.1%); very low-certainty evidence.Trials reported more hypoglycaemic episodes with M+S combination compared to all other metformin-antidiabetic agent combinations. Results for M+S versus metformin monotherapy were inconclusive. There were no RCTs comparing M+S with metformin plus insulin. We identified nine ongoing trials and two trials are awaiting assessment. Together these trials will include approximately 16,631 participants.

AUTHORS' CONCLUSIONS

There is inconclusive evidence whether M+S combination therapy compared with metformin plus another glucose-lowering intervention results in benefit or harm for most patient-important outcomes (mortality, SAEs, macrovascular and microvascular complications) with the exception of hypoglycaemia (more harm for M+S combination). No RCT reported on health-related quality of life.

Thiazolidinediones versus metformin on improving abnormal liver enzymes in patients with type 2 diabetes mellitus: a meta-analysis

Background

Liver enzyme abnormalities are common in patients with type 2 diabetes. Currently, the inverse relationship between elevated liver enzymes and antidiabetics intake may be explained by rigorous treatment and good control. However, few studies have directly explored the influence of antidiabetics on abnormal liver function, especially the comparison between two insulin sensitizers—thiazolidinediones and metformin.

Materials And Methods

Databases, including PubMed, Cochrane, CNKI, Wanfang and VIP were searched. Two reviewers performed independently. Meta-analysis was used when studies were homogeneous enough.

Results

Six studies, including 4726 patients with type 2 diabetes, were involved in this systematic review. Compared with metformin, thiazolidinediones significantly reduced the alanine transaminase, aspartate aminotransferase and gamma-glutamyl transpeptidase. Further subgroup analysis suggested that pioglitazone-treated participants showed vast improvement in decreasing alanine transaminase (MD = -13.70; 95% CI = -16.91 to -10.52; P < 0.00001; I² = 1%), aspartate aminotransferase (MD = -3.51; 95% CI = -5.74 to –1.28; P = 0.002; I² = 0%) and gamma-glutamyl transpeptidase (MD = -5.41; 95% CI = -9.40 to -1.42; P = 0.008; I² = 0%), while rosiglitazone exhibited no difference in lowering corresponding liver enzyme levels. Besides, thiazolidinediones similarly decreased fasting plasma glucose. However, thiazolidinediones were inferior to metformin in lowering HbA1C and alkaline phosphatase. Additionally, no significant publication bias was seen.

Conclusions

Thiazolidinediones may confer modest biological improvement of liver function in people with type 2 diabetes than metformin. But owing to the limited methodological quality, more clinical researches are warranted in the future.

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.

[The effectiveness of the spa and health resort-based treatment with the application of Essentuki-type drinking mineral waters for the management of non-alcoholic fatty liver disease in the patients presenting with type 2 diabetes mellitus]

The objective of the present study was to estimate the effectiveness of the spa and health resort-based treatment of non-alcoholic fatty liver disease in 40 patients at the mean age of 48,8 ± 5.7 years suffering from type 2 diabetes mellitus. All of them received combined therapy including the application of potable Essentuki-Novaya mineral water (20 patients) or Essentuki No 4 water (20 patients). This therapeutic modality resulted in positive dynamics of clinical symptoms of the disease, the functional liver tests, and parameters of intra-hepatic hemodynamics, lipid peroxidation homeostasis, and the hormonal status. It is concluded that the spa and health resort-based treatment with the application of local drinking Essentuki-type mineral waters for the management of non-alcoholic fatty liver disease in the patients presenting with type 2 diabetes mellitus leads to the improvement of the main functions of the liver, stabilizes carbohydrate and lipid metabolism, and prevents progression of the pathological process.

Pioglitazone: an antidiabetic drug with cardiovascular therapeutic effects

The antidiabetic compound pioglitazone, an activator of the intracellular peroxisome proliferator-activated receptor-gamma, and decreases metabolic and vascular insulin resistance. The drug is well tolerated, and its metabolic effects include improvements in blood glucose and lipid control. Vascular effects consist of improvements in endothelial function and hypertension, and a reduction in surrogate markers of artherosclerosis. In a large, placebo-controlled, outcome study in secondary prevention, PROactive study, the use of pioglitazone in addition to an existing optimized macrovascular risk management resulted in a significant reduction of macrovascular endpoints within a short observation period that was comparable to the effect of statins and angiotensin converting enzyme inhibitors in other trials. These results underline the value of pioglitazone for managing the increased cardiovascular risk of patients with a metabolic syndrome or Type 2 diabetes mellitus.

Prevalence of abnormal plasma liver enzymes in older people with Type 2 diabetes

AIMS

To determine the prevalence and distribution of abnormal plasma liver enzymes in a representative sample of older adults with Type 2 diabetes.

METHODS

Plasma concentrations of alanine aminotransferase, aspartate aminotransferase and γ-glutamyltransferase were measured in a randomly selected, population-based cohort of 1066 men and women aged 60-75 years with Type 2 diabetes (the Edinburgh Type 2 Diabetes Study).

RESULTS

Overall, 29.1% (95% CI 26.1-31.8) of patients had one or more plasma liver enzymes above the upper limit of the normal reference range. Only 10.1% of these patients had a prior history of liver disease and a further 12.4% reported alcohol intake above recommended limits. Alanine aminotransferase was the most commonly raised liver enzyme (23.1% of patients). The prevalence of abnormal liver enzymes was significantly higher in men (odds ratio 1.40, 95% CI 1.07-1.83), in the youngest 5-year age band (odds ratio 2.02, 95% CI 1.44-2.84), in patients with diabetes duration < 5 years (odds ratio 1.38, 95% CI 1.01-1.90), plasma HbA(1c) ≥ 58 mmol/mol (7.5%) (odds ratio 1.43, 95% CI 1.09-1.88), obese BMI (odds ratio 2.84, 95% CI 1.59-3.06) and secondary care management for their diabetes (odds ratio 1.40, 95% CI 1.05-1.87). However, all these factors combined accounted for only 7.6% of the variation in liver enzyme abnormality.

CONCLUSIONS

The prevalence of elevated liver enzymes in people with Type 2 diabetes is high, with only modest variation between clinically defined patient groups. Further research is required to determine the prognostic value of raised, routinely measured liver enzymes to inform decisions on appropriate follow-up investigations.

Which is the eligible patient to be treated with pioglitazone? The expert view

Pioglitazone has an important role in the treatment of patients with Type 2 diabetes. The drug can help patients to achieve sustained glycemic control and may delay the requirement for insulin. Pioglitazone may provide benefits beyond its effects on glycemia, with data suggesting it may confer anti-atherosclerotic and cardioprotective properties. Attention should be given to possible side effects relating to class effects of TZD, and selection of appropriate patients to be prescribed pioglitazone will enable optimum benefits to be derived from pioglitazone treatment.

Comparison of the effects of long-term pioglitazone and rosiglitazone therapy on liver enzymes in type 2 diabetes

Aims

Insulin resistance is a major factor influencing the progression of non-alcoholic fatty liver disease (NAFLD). Hence, insulin sensitisers such as thiazolidinediones (TZDs) are a potential treatment for NAFLD although their long-term benefits remain unknown.

Methods

We retrospectively studied 396 and 364 type 2 diabetes patients who received pioglitazone and rosiglitazone therapy respectively from diabetes clinics between May 2001 and November 2007.

Results

One hundred and seventy-seven pioglitazone-treated and 152 rosiglitazone-treated patients were included. After a year of treatment, significant improvement in glycated haemoglobin A1C (HbA1C), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) was observed in both groups despite weight gain. Changes in HbA1C and liver function test (LFT) were positively correlated in pioglitazone-treated (ALT p=0.01; GGT p<0.001; ALP p=0.006) and rosiglitazone-treated (GGT p= 0.01, ALP p=0.002) groups. Multiple regression showed no significant difference in the changes in ALT (p=0.43) and GGT (p=0.13) between the groups but a larger reduction in ALP (p=0.03) was noted in rosiglitazone-treated patients. Sixty patients remained on pioglitazone and 46 patients continued on rosiglitazone after four years. Sustained improvement in ALT, GGT and HbA 1C was observed in both groups despite weight gain over four years.

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.

Lifestyle modification as the primary treatment of NASH

This article reviews the rationale and data behind recommending lifestyle changes to prevent and reverse NASH, focusing specifically on changes that lead to increased physical activity in sedentary patients, changes in dietary habits, and decreased calorie consumption to achieve gradual and sustained weight loss in those who are overweight or obese. In a culture that values avoiding even minimal exertion these are not easy changes to make. Ultimately, the success of care providers in helping patients to recognize and overcome these barriers depends on a patient's motivation, but clinicians can be more persuasive and able to bolster this motivation when armed with a conviction based on data that establish this to be the best course of action for patients with NASH.

Earlier triple therapy with pioglitazone in patients with type 2 diabetes

AIMS

This study assessed the efficacy of add-on pioglitazone vs. placebo in patients with type 2 diabetes uncontrolled by metformin and a sulphonylurea or a glinide.

METHODS

This multicentre, double-blind, parallel-group study randomized 299 patients with type 2 diabetes to receive 30 mg/day pioglitazone or placebo for 3 months. After this time, patients continued with pioglitazone, either 30 mg [if glycated haemoglobin A1c (HbA(1c)) <or=6.5%] or titrated up to 45 mg (if HbA(1c) >6.5%), or placebo for a further 4 months. The primary efficacy end-point was improvement in HbA(1c) (per cent change). Secondary end-points included changes in fasting plasma glucose (FPG), insulin, C-peptide, proinsulin and lipids. The proinsulin/insulin ratio and homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of beta-cell function (HOMA-B) were calculated.

RESULTS

Pioglitazone add-on therapy to failing metformin and sulphonylurea or glinide combination therapy showed statistically more significant glycaemic control than placebo addition. The between-group difference after 7 months of triple therapy was 1.18% in HbA(1c) and -2.56 mmol/l for FPG (p < 0.001). Almost half (44.4%) of the patients in the pioglitazone group who had a baseline HbA(1c) level of <8.5% achieved the HbA(1c) target of < 7.0% by final visit compared with 4.9% in the placebo group. When the baseline HbA(1c) level was >or= 8.5%, 13% achieved the HbA(1c) target of < 7.0% in the pioglitazone group and none in the placebo group. HOMA-IR, insulin, proinsulin and C-peptide decreased and HOMA-B increased in the pioglitazone group relative to the placebo group.

CONCLUSIONS

In patients who were not well controlled with dual combination therapy, the early addition of pioglitazone improved HbA(1c), FPG and surrogate measures of beta-cell function. Patients were more likely to reach target HbA(1c) levels (< 7.0%) with pioglitazone treatment if their baseline HbA(1c) levels were < 8.5%, highlighting the importance of early triple therapy.

Safety and tolerability of pioglitazone in high-risk patients with type 2 diabetes: an overview of data from PROactive

People with type 2 diabetes mellitus have an excess risk of macrovascular disease and a poorer prognosis. PROactive (PROspective pioglitAzone Clinical Trial In macroVascular Events) was a landmark study of secondary cardiovascular disease (CVD) prevention in type 2 diabetes that suggested a beneficial effect of pioglitazone therapy on macrovascular outcomes. Previous studies have already shown that pioglitazone has a good safety and tolerability profile in people with type 2 diabetes, but PROactive provided an opportunity to assess tolerability and safety associated with long-term exposure in a vulnerable subpopulation at very high cardiovascular risk. This review discusses all the key safety and tolerability characteristics associated with pioglitazone therapy in PROactive. As in previous studies, pioglitazone was associated with typical, but manageable, increases in oedema (26.4% vs 15.1% for placebo) and weight gain (mean change of +3.8 kg vs -0.6 kg for placebo). Increased hypoglycaemia with pioglitazone was consistent with improved glycaemic control. Despite more reports of serious heart failure in the pioglitazone group (5.7% vs 4.1% for placebo), there was a proportional improvement in macrovascular outcomes among patients developing heart failure, and absolute rates of macrovascular events and mortality were similar to those in the placebo group. Liver function tests confirmed the hepatic safety of pioglitazone with long-term use and revealed a tendency to improved hepatic function, which may reflect reductions in liver fat. The comparative incidence of malignancies was similar; however, more cases of bladder neoplasm (14 vs 5) and fewer cases of breast cancer (3 vs 11) were observed in the pioglitazone versus placebo arms of the study. A higher rate of bone fractures observed among pioglitazone-treated female patients (5.1% vs 2.5%) warrants further investigation. Overall, safety and tolerability was predictable, and adverse events were not treatment limiting. These results suggest that any beneficial effects of pioglitazone on macrovascular outcomes are accompanied by good long-term tolerability in this population of very high-risk patients with type 2 diabetes and established CVD.

Hepatic dysfunction and insulin insensitivity in type 2 diabetes mellitus: a critical target for insulin-sensitizing agents

The liver plays an essential role in maintaining glucose homeostasis, which includes insulin-mediated processes such as hepatic glucose output (HGO) and uptake, as well as in clearance of insulin itself. In type 2 diabetes, the onset of hyperglycaemia [itself a potent inhibitor of hepatic glucose output (HGO)], alongside hyperinsulinaemia, indicates the presence of hepatic insulin insensitivity. Increased HGO is central to the onset of hyperglycaemia and highlights the need to target hepatic insulin insensitivity as a central component of glucose-lowering therapy. The mechanisms underlying the development of hepatic insulin insensitivity are not well understood, but may be influenced by factors such as fatty acid oversupply and altered adipocytokine release from dysfunctional adipose tissue and increased liver fat content. Furthermore, although the impact of insulin insensitivity as a marker of cardiovascular disease is well known, the specific role of hepatic insulin insensitivity is less clear. The pharmacological tools available to improve insulin sensitivity include the biguanides (metformin) and thiazolidinediones (rosiglitazone and pioglitazone). Data from a number of sources indicate that thiazolidinediones, in particular, can improve multiple aspects of hepatic dysfunction, including reducing HGO, insulin insensitivity and liver fat content, as well as improving other markers of liver function and the levels of mediators with potential involvement in hepatic function, including fatty acids and adipocytokines. The current review addresses this topic from the perspective of the role of the liver in maintaining glucose homeostasis, its key involvement in the pathogenesis of type 2 diabetes and the tools currently available to reduce hepatic insulin insensitivity.

PPARalpha regulates the hepatotoxic biomarker alanine aminotransferase (ALT1) gene expression in human hepatocytes

In this work, we investigated a potential mechanism behind the observation of increased aminotransferase levels in a phase I clinical trial using a lipid-lowering drug, the peroxisome proliferator-activated receptor (PPAR) alpha agonist, AZD4619. In healthy volunteers treated with AZD4619, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were elevated without an increase in other markers for liver injury. These increases in serum aminotransferases have previously been reported in some patients receiving another PPARalpha agonist, fenofibrate. In subsequent in vitro studies, we observed increased expression of ALT1 protein and mRNA in human hepatocytes after treatment with fenofibric acid. The PPAR effect on ALT1 expression was shown to act through a direct transcriptional mechanism involving at least one PPAR response element (PPRE) in the proximal ALT1 promoter, while no effect of fenofibrate and AZD4619 was observed on the ALT2 promoter. Binding of PPARs to the PPRE located at -574 bp from the transcriptional start site was confirmed on both synthetic oligonucleotides and DNA in hepatocytes. These data show that intracellular ALT expression is regulated by PPAR agonists and that this mechanism might contribute to increased ALT activity in serum.

Effect of pioglitazone on heart function and N-terminal pro-brain natriuretic peptide levels of patients with type 2 diabetes

We assessed the effect of the addition of pioglitazone on metabolic control and heart function of patients with type 2 diabetes already receiving sulfonylurea plus metformin. Forty-four patients were given 30 mg of pioglitazone for 3 months. Physical examination, laboratory tests including N-terminal pro-brain natriuretic peptide (NT-proBNP), and echocardiography, were performed at baseline and at study completion. Target HbA(1c) levels were achieved by 44.2% of the patients. Pioglitazone ameliorated lipid profile and lowered liver enzymes and C-reactive protein. Significant increases in NT-proBNP by 39% (P < 0.005) were noticed, but echocardiographic parameters were not altered, even in high-risk subgroups (patients older than 60 years, with diabetes for more than 10 years, with hypertension, with elevated baseline NT-proBNP levels, with left ventricular hypertrophy). In patients with a greater than 60% increase in NT-proBNP levels, a significant increase in left ventricular ejection fraction (P < 0.05) and in fractional shortening (P < 0.05) was found. None of the patients developed edema or signs or symptoms of heart failure. Triple oral combination antidiabetic treatment is an effective therapeutic strategy and weight gain does not abrogate its beneficial actions. Pioglitazone does not affect heart function and even though it increases NT-proBNP, this appears to represent a reaction to volume overload.

The effects of discontinuing pioglitazone in patients with nonalcoholic steatohepatitis

A pilot study of a 48-week course of pioglitazone demonstrated significant improvements in the biochemical and histological features of nonalcoholic steatohepatitis (NASH). The aim of the study was to assess the effects of stopping pioglitazone. Twenty-one patients with NASH were treated with pioglitazone (30 mg/day) for 48 weeks and underwent baseline and end-of-treatment evaluation including liver biopsy. Thirteen patients were followed for at least 48 weeks after stopping therapy and 9 underwent repeat liver biopsy. Statistical comparisons were made to evaluate whether discontinuation of pioglitazone resulted in a reversal of improvements seen on therapy. Stopping pioglitazone was associated with subsequent elevation in serum alanine aminotransferase levels (from 34 +/- 13 to 70 +/- 39 IU/l), decrease in adiponectin (from 9.7 +/- 9.1 to 5.1 +/- 4.5 microg/ml), worsening insulin sensitivity (HOMA Index: from 2.9 +/- 1.8 to 5.5 +/- 5.4), and increase in total hepatic fat (from 30% +/- 32% to 71% +/- 33%) despite no change in average body weight compared to the end of treatment. Repeat liver biopsy in 9 patients revealed significant worsening of parenchymal inflammation (from 1.2 +/- 0.7 to 2.9 +/- 1.1) and steatosis (from 0.9 +/- 0.6 to 2.1 +/- 1.3) but no change in fibrosis (from 1.1 +/- 1.2 to 1.2 +/- 1.3). NASH was again present on liver biopsy in 7 patients.

CONCLUSION

These findings suggest that long-term therapy with pioglitazone may be necessary to maintain improvements in disease activity in patients with NASH, although weight gain during treatment may ultimately limit its beneficial effects.

Hepatic safety profile and glycemic control of pioglitazone in more than 20,000 patients with type 2 diabetes mellitus: postmarketing surveillance study in Japan

The prospective observational study was designed to identify factors affecting glycemic control with pioglitazone and to confirm the hepatic safety of the drug in patients with type 2 diabetes. Baseline patient characteristics, changes in serum hemoglobin A1c (A1c) and alanine aminotransferase (ALT), other treatments for diabetes mellitus, and hepatobiliary adverse reactions were examined. In total, 24,993 patients, representing 28,008 patient-years, were included in the safety evaluation and 20,447 patients in the efficacy evaluation. No case of hepatic failure was reported, and neither temporal nor dose relations were found between pioglitazone and ALT abnormalities. Serum A1c was clearly reduced in patients with baseline body mass index <25 kg/m(2) or baseline fasting immunoreactive insulin <5.0 microU/mL. Among the patients treated for more than 6 months, the change in A1c was -1.0% at 6 months with both monotherapy and combination therapy and remained stable up to 18 months. The overall rate of achievement of A1c<7% in patients with baseline A1c above 7% was 34.1%; notably, the achievement rate of A1c<7% was approximately 30% even in patients with high baseline A1c (mean 8.8%) taking multiple antidiabetic medications, including sulfonylurea, for whom insulin therapy is usually indicated in Japan.

Pioglitazone for type 2 diabetes mellitus

BACKGROUND

Diabetes has long been recognised as a strong, independent risk factor for cardiovascular disease, a problem which accounts for approximately 70% of all mortality in people with diabetes. Prospective studies show that compared to their non-diabetic counterparts, the relative risk of cardiovascular mortality for men with diabetes is two to three and for women with diabetes is three to four. The two biggest trials in type 2 diabetes, the United Kingdom Prospective Diabetes Study (UKPDS) and the University Group Diabetes Program (UGDP) study did not reveal a reduction of cardiovascular endpoints through improved metabolic control. Theoretical benefits of the newer peroxisome proliferator activated receptor gamma (PPAR-gamma) activators like pioglitazone on endothelial function and cardiovascular risk factors might result in fewer macrovascular disease events in people with type 2 diabetes mellitus.

OBJECTIVES

To assess the effects of pioglitazone in the treatment of type 2 diabetes.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE and The Cochrane Library. The last search was conducted in August 2006.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials in adult people with type 2 diabetes mellitus and had a trial duration of at least 24 weeks.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Pooling of studies by means of random-effects meta-analysis could be performed for adverse events only.

MAIN RESULTS

Twenty-two trials which randomised approximately 6200 people to pioglitazone treatment were identified. Longest duration of therapy was 34.5 months. Published studies of at least 24 weeks pioglitazone treatment in people with type 2 diabetes mellitus did not provide convincing evidence that patient-oriented outcomes like mortality, morbidity, adverse effects, costs and health-related quality of life are positively influenced by this compound. Metabolic control measured by glycosylated haemoglobin A1c (HbA1c) as a surrogate endpoint did not demonstrate clinically relevant differences to other oral antidiabetic drugs. Occurrence of oedema was significantly raised. The results of the single trial with relevant clinical endpoints (Prospective Pioglitazone Clinical Trial In Macrovascular Events--PROactive study) have to be regarded as hypothesis-generating and need confirmation.

AUTHORS' CONCLUSIONS

Until new evidence becomes available, the benefit-risk ratio of pioglitazone remains unclear. Different therapeutic indications for pioglitazone of the two big U.S. and European drug agencies should be clarified to reduce uncertainties amongst patients and physicians.

Pioglitazone: a review of its use in type 2 diabetes mellitus

Pioglitazone is an antihyperglycaemic agent that, in the presence of insulin resistance, increases hepatic and peripheral insulin sensitivity, thereby inhibiting hepatic gluconeogenesis and increasing peripheral and splanchnic glucose uptake. Pioglitazone is generally well tolerated, weight gain and oedema are the most common emergent adverse events, and there are no known drug interactions between pioglitazone and other drugs. In clinical trials in patients with type 2 diabetes mellitus, pioglitazone as monotherapy, or in combination with metformin, repaglinide, insulin or a sulphonylurea, induced both long- and short-term improvements in glycaemic control and serum lipid profiles. Pioglitazone was also effective in reducing some measures of cardiovascular risk and arteriosclerosis. Pioglitazone thus offers an effective treatment option for the management of patients with type 2 diabetes.

Pioglitazone: an antidiabetic drug with the potency to reduce cardiovascular mortality

Pioglitazone is an antidiabetic drug known to decrease peripheral, hepatic and vascular insulin resistance by the stimulation of PPARgamma. In clinical trials, pioglitazone as monotherapy or in combination with other oral antidiabetic drugs or insulin has demonstrated to effectively improve blood glucose levels, long-term glucose control and the lipid profile. The vascular effects of pioglitazone include improvement of endothelial function and microcirculation, reduction of blood pressure and inflammatory surrogate markers of atherosclerosis, and a reduction of a composite measure of macrovascular events (death, stroke and myocardial infarctions). The drug is well tolerated and has an acceptable side effect profile. Because of its additional microvascular and macrovascular effects, pioglitazone is an attractive and effective treatment option for the management of Type 2 diabetes mellitus.

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.

A fixed-dose combination of pioglitazone and metformin: A promising alternative in metabolic control

BACKGROUND

When type 2 diabetes is managed with glucose-lowering monotherapy, glycemic control ultimately deteriorates due to the inability of the beta-cell to overcome insulin resistance. Combining drugs with different complementary mechanisms of action improves long-term glycemic control and may lower the risk of vascular complications. A fixed-dose combination of pioglitazone (a thiazolidinedione) and metformin has been approved for use in the US (Actoplus met) and in Europe (Competact).

SCOPE

This review (based upon MEDLINE and EMBASE searches from January 1990 to April 2006) discusses the potential benefits of co-formulating metformin and pioglitazone with respect to compliance and targeting glycemia, as well as other metabolic parameters.

FINDINGS

Pioglitazone increases insulin sensitivity, while metformin reduces hepatic gluconeogenesis and improves peripheral glucose uptake. Both agents reduce hyperglycemia and hyperinsulinemia, and appear to protect beta-cell function. Their similar pharmacokinetic time profiles have facilitated a co-formulation bioequivalent to their separate administration. In randomized studies, pioglitazone and metformin administered separately provided significantly better glycemic control than metformin monotherapy or metformin plus gliclazide. Pioglitazone and metformin have complimentary benefits on diabetic dyslipidemia; pioglitazone primarily improves high-density lipoprotein cholesterol and triglyceride levels (to a greater extent than rosiglitazone does), while metformin mainly improves total cholesterol. Pioglitazone and metformin also modulate other atherosclerosis biomarkers, including inflammatory mediators, coagulation thrombosis components, and carotid intima media thickness. Together, these pleiotropic effects have the potential to confer a reduced risk of cardiovascular disease in patients with type 2 diabetes. Pioglitazone and metformin are well tolerated in combination, with low rates of hypoglycemia, and the convenience of a single tablet may be expected to aid dosing compliance.

CONCLUSION

The co-formulation of pioglitazone and metformin is a rational approach that maximizes the established, complimentary benefits of these agents, while potentially improving compliance.