A systematic review of drug therapy to delay or prevent type 2 diabetes

The effect of saffron (Crocus sativus L.) on glycemia, lipid profile, and antioxidant status in patients with type-2 diabetes mellitus: A randomized placebo-controlled trial

In the current study, we aimed to investigate the effect of saffron supplementation on glycemic status, lipid profile, atherogenic indices, and oxidative status in patients with type-2 diabetes (T2DM). In a randomized, double-blind controlled trial, 70 patients were randomly allocated into two groups (n = 35, each) and received 100 mg/day of saffron or placebo for eight weeks. Dietary intake, weight, body mass index (BMI), waist and hip circumferences (WC and HC), waist to hip ratio (WHR), fasting blood sugar (FBS), hemoglobin A1c (HbA1c), insulin, and Homeostatic model assessment for insulin resistance (HOMA-IR), lipid profile, atherogenic indices, oxidative status, and liver enzymes were determined before and after the intervention. At the end of the eighth week, saffron intervention could significantly reduce FBS (7.57%), lipid profile (except high-density lipoprotein cholesterol [HDL-C]), atherogenic indices, and liver enzymes (p < .05). Moreover, saffron could improve oxidative status (nitric oxide [NO] and malondialdehyde [MDA] reduced by 26.29% and 16.35%, respectively). Catalase (CAT) concentration remained unchanged. Saffron supplementation may alleviate T2DM by improving glycemic status, lipid profile, liver enzymes, and oxidative status. Further investigation is necessary to assess possible side effects and confirm the positive effect of saffron as a complementary therapy in clinical recommendations for T2DM.

Preventive Medication Use among Adults Aged 40 and over in the United States: National Health and Nutrition Examination Survey, 2015-2018

OBJECTIVES

1. To estimate the prevalence of preventive medication use among adults in the United States (US); 2. To identify the socioeconomic, demographic and clinical factors associated with preventive prescription medication use; 3. To identify the diagnoses associated with preventive prescription medication use.

METHODS

Data from two cycles of the National Health and Nutrition Examination Survey, 2015-2016 and 2017-2018, are analyzed.

RESULTS

Among US adults aged 40 years or older (N = 7634), 31% use a preventive medication. Specifically, 27% of them use aspirin and 9% use other preventive prescription medications. Among those who use other preventive prescription medications, 27% report using one of the cardiovascular agents and 24% reported using anticoagulants and/or antiplatelet agents. High percentages of preventive prescription medication users report using medications to prevent heart attacks/myocardial infarctions (25%) or blood clots (23%). Uninsured adults are less likely to use preventive medications (OR: 0.656; p-value = 0.009) as compared with their counterparts with private insurance. On the other hand, older adults and those with diabetes, heart disease, arthritis and hypertension are more likely to use preventive medications. Furthermore, past smokers and adults who never smoked are more likely to use preventive medications as compared with those who currently smoke.

CONCLUSION

Policies are needed to increase access to preventive care for uninsured adults. Further research needs to review the benefits and harms of the chronic use of preventive medication among older adults in the US.

Association of diuretic use with increased risk for long-term post-transplantation diabetes mellitus in kidney transplant recipients

Background

Post-transplantation diabetes mellitus (PTDM) is a major clinical problem in kidney transplant recipients (KTRs). Diuretic-induced hyperglycaemia and diabetes have been described in the general population. We aimed to investigate whether diuretics also increase PTDM risk in KTRs.

Methods

We included 486 stable outpatient KTRs (with a functioning graft ≥1 year) without diabetes from a prospective cohort study. Participants were classified as diuretic users and non-users based on their medication use verified by medical records.

Results

At the baseline study, 168 (35%) KTRs used a diuretic (thiazide, n = 74; loop diuretic, n = 76; others, n = 18) and 318 KTRs did not use a diuretic. After 5.2 years [interquartile range (IQR) 4.0‒5.9] of follow up, 54 (11%) KTRs developed PTDM. In Cox regression analyses, diuretic use was associated with incident PTDM, independent of age, sex, fasting plasma glucose (FPG) and haemoglobin A_1c (HbA_1c) {hazard ratio [HR] 3.28 [95% confidence interval (CI) 1.84–5.83]; P <0.001}. Further adjustment for potential confounders, including lifestyle, family history of cardiovascular disease, use of other medication, kidney function, transplantation-specific parameters, BMI, lipids and blood pressure did not materially change the association. Moreover, in Cox regression analyses, both thiazide and loop diuretics associated with the development of PTDM, independent of age, sex, FPG and HbA_1c [HR 2.70 (95% CI 1.24–5.29); P = 0.012 and HR 5.08 (95% CI 2.49–10.34); P <0.001), respectively].

Conclusions

This study demonstrates that diuretics overall are associated with an increased risk of developing PTDM in KTRs, independent of established risk factors for PTDM development. The association was present for both thiazide and loop diuretics.

MPEG-PCL Nanomicelles Platform for Synergistic Metformin and Chrysin Delivery to Breast Cancer in Mice

BACKGROUND

Metformin (MET) is a well-known anti-diabetic drug that also has anti-cancer effects. However, high therapeutic doses of MET on cancer cells and the low efficacy of combinatory therapeutic approaches limit its clinical application. Recent studies have shown that chrysin (CHR) can improve the pharmaceutical efficacy of MET by suppressing human telomerase reverse transcriptase (hTERT) and cyclin D1 gene expression.

OBJECTIVE

This study aimed to develop different ratios of methoxy poly(ethylene glycol)-b-poly(e-caprolactone) (MPEG-PCL) micelles for breast cancer to co-deliver a synergistic CHR/MET combination.

METHODS

CHR/MET drug-loaded micelles were prepared by modified thin-film hydration. Fourier infrared spectrum, gel permeation chromatography, transmission electron microscopy, and high-performance liquid chromatography were used to evaluate the physicochemical properties of nanostructures. Cell proliferation and cell apoptosis were assessed by MTT and Annexin V-FITC/PI double staining method. The gene expression of hTERT and cyclin D1 was measured by real-time PCR assay. A subcutaneous mouse T47D xenograft model was established to evaluate the in vivo efficiency.

RESULTS

When the ratio of MPEG-PCL was 1:1.7, the highest drug loading rate and encapsulation efficiency of CHR (11.31±0.37) and MET (12.22±0.44) were observed. Uniform MPEG-PCL micelles of 51.70±1.91 nm allowed MET to incorporate with CHR, which were co-delivered to breast cancer cells. We demonstrated that CHR/MET co-delivery micelles showed a good synergistic effect on inhibiting proliferation in T47D cells (combination index=0.87) by suppressing hTERT and cyclin D1 gene expression. Compared with the free CHR/MET group, the apoptosis rate on T47D cells by CHR/MET nano-micelles significantly improved from 71.33% to 79.25%. The tumour volume and tumour weight of the CHR/MET group increased more slowly than that of the single-drug treatment group (P<0.05). Compared with the CHR/MET group, the tumour volume and tumour weight of the CHR/MET nano-micelle group decreased by 42% and 59%, respectively.

CONCLUSIONS

We demonstrated that ratiometric CHR/MET micelles could provide an effective technique for the treatment of breast cancer.

Combined in silico and in vitro studies to identify novel antidiabetic flavonoids targeting glycogen phosphorylase

Novel pharmacological strategies for the treatment of diabetic patients are now focusing on inhibiting glycogenolysis steps. In this regard, glycogen phosphorylase (GP) is a validated target for the discovery of innovative antihyperglycemic molecules. Natural products, and in particular flavonoids, have been reported as potent inhibitors of GP at the cellular level. Herein, free-energy calculations and microscale thermophoresis approaches were performed to get an in-depth assessment of the binding affinities and elucidate intermolecular interactions of several flavonoids at the inhibitor site of GP. To our knowledge, this is the first study indicating genistein, 8-prenylgenistein, apigenin, 8-prenylapigenin, 8-prenylnaringenin, galangin and valoneic acid dilactone as natural molecules with high inhibitory potency toward GP. We identified: i) the residues Phe285, Tyr613, Glu382 and/or Arg770 as the most relevant for the binding of the best flavonoids to the inhibitor site of GP, and ii) the 5-OH, 7-OH, 8-prenyl substitutions in ring A and the 4'-OH insertion in ring B to favor flavonoid binding at this site. Our results are invaluable to plan further structural modifications through organic synthesis approaches and develop more effective pharmaceuticals for Type 2 Diabetes treatment, and serve as the starting point for the exploration of food products for therapeutic usage, as well as for the development of novel bio-functional food and dietary supplements/herbal medicines.

Characteristics and Early Hypoglycemic Medications of Patients at Risk of Progression to Type 2 Diabetes in Japan: A Retrospective Cohort Study of Health Checkup and Claims Data

Medication therapy management by tracking patients with risk of progression to type 2 diabetes has not been investigated in Japan. We aimed to assess the characteristics of these patients and their early medications. Claims (n = 190507) and health checkup data (n = 106984) between April 2005 and March 2015 in Japan were selected. We selected patients aged ≥40 years with fasting plasma glucose levels of 100-125 mg/dL or glycated hemoglobin A1c values of 5.7-6.4%. The early-medication group comprised patients who received hypoglycemic medications within 6 months after their first clinic visit, while the no-medication group comprised patients who did not receive any hypoglycemic medications. Main outcome measures were characteristics and early hypoglycemic medications of patients at risk of progression to type 2 diabetes. Of 5676 individuals, hypoglycemic medications were initiated in 276 (5%). The early-medication group had a higher proportion of individuals with a body mass index ≥25 kg/m² and current smokers and drinkers than the no-medication group. Approximately 83% of patients in the early-medication group were prescribed a single hypoglycemic medication, and since 2010, dipeptidyl peptidase-4 inhibitors were prescribed to one-third of these patients. In our population, early hypoglycemic medication was initiated within 6 months of the first clinic visit, indicating that initiation took place earlier than recommended by current guidelines. Early hypoglycemic medications, especially dipeptidyl peptidase-4 inhibitors with low risks of hypoglycemia, might be prescribed based on patient characteristics. Further epidemiological studies are needed to confirm the suitability of early hypoglycemic medication.

Pharmacokinetic Interaction of Green Rooibos Extract With Atorvastatin and Metformin in Rats

An aspalathin-rich green rooibos extract (Afriplex GRT™) has demonstrated anti-diabetic and hypolipidemic properties, while also moderately inhibiting CYP3A4 activity, suggesting a potential for herb-drug interaction. The present study, therefore, evaluated the effects of orally administered GRT on the pharmacokinetics of atorvastatin and metformin in Wistar rats. Wistar rats were orally treated with GRT (50 mg/kg BW), atorvastatin (40 mg/kg BW) or metformin (150 mg/kg BW) alone or 50 mg/kg BW GRT in combination with 40 mg/kg BW atorvastatin or 150 mg/kg BW metformin. Blood samples were collected at 0, 10, and 30 min and 1, 2, 4, 6, and 8 h and plasma samples obtained for Liquid chromatography-mass spectrometry (LC-MS/MS) analyses. Non-compartment and two-compartment pharmacokinetic parameters of atorvastatin and metformin in the presence or absence of GRT were determined by PKSolver version 2.0 software. Membrane transporter proteins, ATP-binding cassette sub-family C member 2 (Abcc2), solute carrier organic anion transporter family, member 1b2 (Slco1b2), ATP-binding cassette, sub-family B (MDR/TAP), member 1A (Abcb1a), and organic cation transporter 1 (Oct1) mRNA expression were determined using real-time PCR expression data normalized to β-actin and hypoxanthine-guanine phosphoribosyltransferase (HPRT), respectively. Co-administration of GRT with atorvastatin substantially increased the maximum plasma concentration (C_max) and area of the plasma concentration-time curve (AUC_0-8) of atorvastatin by 5.8-fold (p = 0.03) and 5.9-fold (p = 0.02), respectively. GRT had no effect on the plasma levels of metformin. GRT increased Abcc2 expression and metformin downregulated Abcb1a expression while the combination of GRT with atorvastatin or metformin did not significantly alter the expression of Slco1b1 or Oct1 did not significantly alter the expression of Sclo1b2 or Oct1. Co-administration of GRT with atorvastatin in rats may lead to higher plasma concentrations and, therefore, to an increase of the exposure to atorvastatin.

Effect of metformin on all-cause and cardiovascular mortality in patients with coronary artery diseases: a systematic review and an updated meta-analysis

BACKGROUND

Metformin is the most widely prescribed drug to lower glucose and has a definitive effect on the cardiovascular system. The goal of this systematic review and meta-analysis is to assess the effects of metformin on mortality and cardiac function among patients with coronary artery disease (CAD).

METHODS

Relevant studies reported before October 2018 was retrieved from databases including PubMed, EMBASE, Cochrane Library and Web of Science. Hazard ratio (HR) was calculated to evaluate the all-cause mortality, cardiovascular mortality and incidence of cardiovascular events (CV events), to figure out the level of left ventricular ejection fraction (LVEF), creatine kinase MB (CK-MB), type B natriuretic peptide (BNP) and to compare the average level of low density lipoprotein (LDL).

RESULTS

In this meta-analysis were included 40 studies comprising 1,066,408 patients. The cardiovascular mortality, all-cause mortality and incidence of CV events were lowered to adjusted HR (aHR) = 0.81, aHR = 0.67 and aHR = 0. 83 respectively after the patients with CAD were given metformin. Subgroup analysis showed that metformin reduced all-cause mortality in myocardial infarction (MI) (aHR = 0.79) and heart failure (HF) patients (aHR = 0.84), the incidence of CV events in HF (aHR = 0.83) and type II diabetes mellitus (T2DM) patients (aHR = 0.83), but had no significant effect on MI (aHR = 0.87) and non-T2DM patients (aHR = 0.92). Metformin is superior to sulphonylurea (aHR = 0.81) in effects on lowering the incidence of CV events and in effects on patients who don't use medication. The CK-MB level in the metformin group was lower than that in the control group standard mean difference (SMD) = - 0.11). There was no significant evidence that metformin altered LVEF (MD = 2.91), BNP (MD = - 0.02) and LDL (MD = - 0.08).

CONCLUSION

Metformin reduces cardiovascular mortality, all-cause mortality and CV events in CAD patients. For MI patients and CAD patients without T2DM, metformin has no significant effect of reducing the incidence of CV events. Metformin has a better effect of reducing the incidence of CV events than sulfonylureas.

Precision medicine in diabetes prevention, classification and management

Diabetes has become a major burden of healthcare expenditure. Diabetes management following a uniform treatment algorithm is often associated with progressive treatment failure and development of diabetic complications. Recent advances in our understanding of the genomic architecture of diabetes and its complications have provided the framework for development of precision medicine to personalize diabetes prevention and management. In the present review, we summarized recent advances in the understanding of the genetic basis of diabetes and its complications. From a clinician's perspective, we attempted to provide a balanced perspective on the utility of genomic medicine in the field of diabetes. Using genetic information to guide management of monogenic forms of diabetes represents the best-known examples of genomic medicine for diabetes. Although major strides have been made in genetic research for diabetes, its complications and pharmacogenetics, ongoing efforts are required to translate these findings into practice by incorporating genetic information into a risk prediction model for prioritization of treatment strategies, as well as using multi-omic analyses to discover novel drug targets with companion diagnostics. Further research is also required to ensure the appropriate use of this information to empower individuals and healthcare professionals to make personalized decisions for achieving the optimal outcome.

Cardioprotection by Metformin: Beneficial Effects Beyond Glucose Reduction

Metformin is a biguanide that is widely used as an insulin-sparing agent to treat diabetes. When compared with the general population, diabetics are twice as likely to die from fatal myocardial infarction and congestive heart failure (CHF). There has been a significant concern regarding the use of metformin in patients with CHF because of their higher tendency to develop lactic acidosis. However, large epidemiological trials have reported better cardiovascular prognosis with metformin compared to other glucose-lowering agents among diabetics. Additionally, metformin has reduced the risk of reinfarction and all-cause mortality in patients with coronary artery disease and CHF, respectively. The protection against cardiovascular diseases appears to be independent of the anti-hyperglycemic effects of metformin. These effects are mediated through an increase in 5' adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and by increased phosphorylation of endothelial nitric oxide synthase (eNOS) in cardiomyocytes with an increased production of nitric oxide (NO). Metformin preconditions the heart against ischemia-reperfusion injury and may improve myocardial remodeling after an ischemic insult. The preponderance of evidence currently suggests that metformin is safe in patients with CHF, prompting the Food and Drug Administration to remove CHF as a contraindication from the package insert of all generic metformin preparations. In this narrative, along with a limited meta-analysis of available studies, we have reviewed the pleiotropic (non-glucose-lowering) effects of metformin that potentially contribute to its cardioprotective properties. Additionally, we have reviewed issues surrounding the safety of metformin in patients with cardiac diseases.

[Enteral failure and metabolic syndrome: Common neurohormonal mechanisms of development, possibilities of their rational therapy]

The paper deals with small bowel (SB) functional disorders in metabolic syndrome (MS). The main components of a cascade of metabolic abnormalities in MS are closely due to SB functional changes. This is associated to some extent with the presence of common neurohormonal mechanisms in the development of enteropathy and MS. The paper gives the physical, laboratory and instrumental methods for identifying SB dysfunctions in patients with MS. Therapy for the latter is of particular interest in the context of SB functional recovery. The authors discuss the possibilities of enteropathy therapy in patients with MS; thus there is not only SB functional recovery, but also improved overall metabolic processes.

Prevention of type 2 diabetes with the traditional Chinese patent medicine: A systematic review and meta-analysis

AIM

Early interventions in prediabetes can prevent or delay the incidence of type 2 diabetes mellitus (T₂DM). The aim of this review was to assess the efficacy and safety of traditional Chinese patent medicine (TCPM) on the prevention of T₂DM.

METHODS

Seven electronic databases were searched to identify eligible trials published until June 1, 2016. Randomized controlled trials (RCTs) that compared TCPM plus lifestyle modification (LM) versus LM alone were included for in the. RCTs that used TCPM plus LM compared with placebo plus LM were also included. Methodological quality was assessed using the Cochrane Collaboration Risk of Bias tool. A random- or fixed-effect model was used to analyze outcomes that were expressed as risk ratios (RRs) or mean differences (MD), and the I² statistic was used to assess heterogeneity.

RESULTS

Twenty-six trials with a total of 4169 participants met the inclusion criteria. Subgroup analysis confirmed that, compared with LM alone, TCPM and LM together were significantly better at reducing diabetes (RR, 0.47; 95% CI, 0.38-0.59) and normalizing blood glucose (RR, 0.76; 95% CI, 0.69-0.85). They also caused a greater reduction in fasting plasma glucose (FBG) (MD, -0.37; 95% CI, -0.62 to -0.13), 2-h plasma glucose (2h PG) (MD, -0.91; 95% CI, -1.35 to -0.47) and body mass index (BMI) (MD, -0.45; 95% CI, -0.76 to -0.14). Compared with placebo plus LM, TCPM plus LM was superior at reducing diabetes (RR, 0.55; 95% CI, 0.45-0.68) and normalizing blood glucose (RR, 0.62; 95% CI, 0.50-0.76). The interventions were also associated with a decline in FBG levels (MD, -0.68; 95% CI, -1.25 to -0.11) and 2h PG levels (MD, -1.07; 95% CI, -1.85 to -0.29). There were no significant differences in adverse events in either group. Subgroup and sensitivity analyses found no significant difference in overall effects among all study characteristics, indicating that the overall effects were stable. Generally, the quality of evidence was low for the effect of TCPM on the incidence of diabetes and normalization of blood glucose, and was very low for the effects of TCPM on FBG, 2h PG, and BMI.

CONCLUSIONS

Based on this systematic review, TCPM may reduce the risk of progression to T₂DM and increase the possibility of regression toward normoglycemia. As a result of the methodological drawbacks of the included studies, more rigorously designed RCTs are required to more reliably assess the efficacy of TCPM and long-term follow-up is needed before TCPM can be recommended for prediabetic patients.

Verapamil Use Is Associated With Reduction of Newly Diagnosed Diabetes Mellitus

OBJECTIVE

The mechanism of the beneficial effect of calcium-channel blockers (CCBs), especially verapamil, on the development of type 2 diabetes mellitus (T2DM) has been described. This study compared the incidence of T2DM in adults prescribed oral verapamil and propensity score-matched adults prescribed other oral CCBs.

METHODS

This retrospective population-based cohort study used Taiwan's National Health Insurance Research Database from 2000 to 2011. T2DM was defined according to the International Classification of Diseases, Ninth Revision, Clinical Modification.

RESULTS

During follow-up periods of 41,958 and 42,118 person-years, 269 of 4930 patients in the verapamil cohort and 340 of 4930 patients in the matched cohort, respectively, developed T2DM. The incidence rates were 6.41 and 8.07 per 1000 population per year among verapamil and other CCB users, respectively. The adjusted hazard ratio (HR) for T2DM associated with use of verapamil (vs. other CCBs) was 0.80 [95% confidence interval (CI), 0.68 to 0.94; P = 0.006]. After exclusion of patients followed for <180 days or <365 days (to avoid bias derived from delayed diagnosis), adjusted HRs remained significant [0.79 (95% CI, 0.67 to 0.93; P = 0.005) and 0.77 (95% CI, 0.65 to 0.91; P = 0.002), respectively]. Only the interaction term for age was significant (P = 0.009). Verapamil had a more prominent effect on patients aged older than 65 years (P < 0.001).

CONCLUSIONS

In patients with no known history of diabetes mellitus, oral verapamil use was associated with a decreased incidence of T2DM compared with other CCBs.

The Metabolic Syndrome in Women

The clustering of metabolic risk factors, overweight and hypertension is of particular importance in postmenopausal women due to the negative effect of menopause on bodyweight, glucose metabolism and the development of hypertension. Menopause acts directly as a risk factor by reducing the direct beneficial effect of ovarian hormones on cardiovascular functions, and indirectly by negatively influencing traditional risk factors for coronary artery disease. All changes occurring after the menopause must be regarded under a unifying mechanism that induces unfavorable changes in cardiovascular risk factors and vascular functions, which interact with each other, amplifying the effect of ovarian hormone deficiency and aging.

Chrysoeriol and other polyphenols from Tecoma stans with lipase inhibitory activity

ETHNOPHARMACOLOGICAL RELEVANCE

Tecoma stans is traditionally used by several ethnical groups in Mexico and Central America to treat diabetes. This species is mentioned in the majority of the ethnopharmacological studies compiled in Mexico focused in medicinal plants used as anti-diabetic treatment.

AIM OF THE STUDY

Recently, this plant was found to display a high level of pancreatic lipase inhibitory activity, in addition to the several action mechanisms already described. Here we show the phytochemical and in vitro pharmacological characterization of some of the compounds responsible for the antilipase activity.

MATERIALS AND METHODS

Starting with a hydroalcoholic extract, fractions were obtained by liquid-liquid separation and successive processes of column chromatography purifications. Lipase inhibitory activity was measured employing a spectrophotometric analysis. For structural elucidation (1)H and (13)C NMR experiments were used. HPLC was used to quantify and confirm the identity of the bioactive compounds.

RESULTS

Bio-guided chemical purification of the hydroalcoholic extract produced an organic fraction (ethyl acetate, TsEA), flavone fractions (TsC1F13), (TsC1F15), (TsC1F16) and isolated compounds (chrysoeriol, apigenin, luteolin, and verbascoside) with the capability to inhibit the activity of pancreatic lipase. The most active fraction (TsC2F6B) was constituted by a mixture of Chrysoeriol (5,7-dihydroxy-2-[4-hydroxy-3-methoxyphenyl]chromen-4-one, 96% ) and Apigenin (4%). This flavone mixture displayed a percentage of inhibition of 85% when it was eavaluated at 0.25mg/mL. Luteolin and chrysoeriol produced a noncompetitive and mixed inhibition with values of IC50=63 and 158µM respectively. The content of chrysoeriol was also quantified in the hydroalcoholic extract (TsHAE) and organic fraction (TsEA) as 1% and 7% respectively. All of this confirms that high proportion of both flavones produce an increase of the biological activity due to they show the highest inhibition of lipase enzyme in a concentration dependant way.

CONCLUSIONS

These results evidence that the medicinal use of T. stans could be in part because of its lipase inhibitory activity allowing to adapt the administration of this plant before meals. Also this data could help to develop a novel phytopharmaceutical drug (standardized in luteolin, chrysoeriol, and apigenin) auxiliary for the Type 2 Diabetes mellitus.

Chromium level in prediction of diabetes in pre-diabetic patients

BACKGROUND

Chromium supplementations (Cr) have been shown to exert beneficial effects in the management of type-2 diabetes. Prevalence of Cr deficiency in pre-diabetic patients is not well-understood, therefore, the aim of this study was to evaluate the extent of this prevalence.

MATERIALS AND METHODS

In this cross-sectional descriptive study, 132 pre-diabetic patients were recruited. The participants were randomly selected from those who referred to the Shariati Hospital in Isfahan, Iran. Blood samples are collected for measurement of Cr, insulin, fasting blood sugar (FBS), and two-hour post-load plasma glucose. The body mass index (BMI) was calculated. Determination of Cr was carried out by atomic absorption spectrometry.

RESULTS

Thirty-four (31.5%) patients had Cr deficiency and 74 (68.5%) patients had normal Cr. There was no significant difference between sex, age groups (<50 years and ≥50 years) and between patients with and without a family history of diabetes in both the groups. No significant differences in age, BMI, FBS or insulin were observed between two groups. In the group with a normal level of Cr, there was a significant reversed correlation between the Cr level and age, but no significant correlation existed between the Cr level and other factors in both groups.

CONCLUSION

The levels of Cr deficiency are relatively common in patients with pre-diabetes, and it is necessary to screen patients with diabetes and pre-diabetes according to the American Diabetes Association guidelines, with regard to the Cr level and action should be taken to eliminate the Cr deficiency in these patients.

Prevention of type 2 diabetes in obese at-risk subjects: a systematic review and meta-analysis

Different intervention strategies can prevent new cases of type 2 diabetes (T2DM) in obese subjects. The present systematic review and meta-analysis evaluates the effectiveness of different strategies in prevention of type 2 diabetes in obese subjects. Studies were grouped into five different strategies: (1) physical activity ± diet; (2) anti-diabetic drugs (glitazones, metformin, glinides, alfa-glucosidase inhibitors); (3) antihypertensive drugs (ACE inhibitors, ARB); (4) weight loss-promoting drugs and lipid-lowering drugs (orlistat, bezafibrate, phentermine/topiramate controlled release); and (5) bariatric surgery. Only controlled studies, dealing with subjects BMI ≥ 30 kg/m(2), were included in the analysis, whether randomized or non-randomized studies. Appropriate methodology (PRISMA statement) was adhered to. Publication bias was formally assessed. Eighteen studies (43,669 subjects, 30,774 with impaired glucose tolerance and/or impaired fasting glucose), published in English language as full papers, were analyzed to identify predictors of new cases of T2DM and were included in a meta-analysis (random-effects model) to study the effect of different strategies. Intervention effect (new cases of diabetes) was expressed as odds ratio (OR), with 95 % confidence intervals (CIs). In obese subjects, non-surgical strategies were able to prevent T2DM, with different effectiveness [OR from 0.44 (0.36-0.52) to 0.86 (0.80-0.92)]; in morbidly obese subjects, bariatric surgery was highly effective [OR = 0.10 (0.02-0.49)]. At meta-regression analysis, factors associated with effectiveness were weight loss, young age and fasting insulin levels. Publication bias was present only when considering all studies together. These data indicate that several strategies, with different effectiveness, can prevent T2DM in obese subjects.

Prevention of type 2 diabetes; a systematic review and meta-analysis of different intervention strategies

AIM

Different intervention strategies can prevent type 2 diabetes (T2DM). Aim of the present systematic review and meta-analysis was to evaluate the effectiveness of different strategies.

METHODS

Studies were grouped into 15 different strategies: 1: diet plus physical activity; 2: physical activity; 3-6: anti-diabetic drugs [glitazones, metformin, beta-cell stimulating drugs (sulphanylureas, glinides), alfa-glucosidase inhibitors]; 7-8: cardiovascular drugs (ACE inhibitors, ARB, calcium antagonists); 9-14 [diets, lipid-affecting drugs (orlistat, bezafibrate), vitamins, micronutrients, estrogens, alcohol, coffee]; 15: bariatric surgery. Only controlled studies were included in the analysis, whether randomized, non-randomized, observational studies, whether primarily designed to assess incident cases of diabetes, or performed with other purposes, such as control of hypertension, of ischemic heart disease or prevention of cardiovascular events. Appropriate methodology [preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement] was used. Seventy-one studies (490 813 subjects), published as full papers, were analysed to identify predictors of new cases of T2DM, and were included in a meta-analysis (random-effects model) to study the effect of different strategies. Intervention effect (new cases of diabetes) was expressed as odds ratio (OR), with 95% confidence intervals (C.I.s). Publication bias was formally assessed.

RESULTS

Body mass index was in the overweight range for 13 groups, obese or morbidly obese in lipid-affecting drugs and in bariatric surgery. Non-surgical strategies, except for beta-cell stimulating drugs, estrogens and vitamins, were able to prevent T2DM, with different effectiveness, from 0.37 (C.I. 0.26-0.52) to 0.85 (C.I. 0.77-0.93); the most effective strategy was bariatric surgery in morbidly obese subjects [0.16 (C.I. 0.11,0.24)]. At meta-regression analysis, age of subjects and amount of weight lost were associated with effectiveness of intervention.

CONCLUSIONS

These data indicate that several strategies prevent T2DM, making it possible to make a choice for the individual subject.

(Poly)peptide-based therapy for diabetes mellitus: insulins versus incretins

Insulin therapy remains the standard of care for achieving and maintaining adequate glycemic control, especially in hospitalized patients with critical and noncritical illnesses. Insulin therapy is more effective against elevated fasting glycaemia but less in the reduction of postprandial hyperglycaemia. It is associated with a high incidence of hypoglycemia and weight gain. Contrary, GLP-1 mimetic therapy improves postprandial glycaemia without the hypoglycaemia and weight gain associated with aggressive insulin therapy. Moreover, it has the potential to reduce cardiovascular related morbidity. However, its increased immunogenicity and severe gastrointestinal adverse effects present a huge burden on patients. Thus, a right combination of basal insulin which has lowering effect on fasting plasma glucose and GLP-1 mimetic with its lowering effect on postprandial plasma glucose with minimal gastrointestinal adverse effects, seems the right therapy choice from a clinical point of view for some diabetic patients. In this article, we discuss the pros and cons of the use of insulin analogues and GLP-1 mimetics that are associated with the treatment of type 2 diabetes.

Independent and combined effect of diet and exercise in adults with prediabetes

Prediabetes is defined as impaired fasting glucose and/or impaired glucose tolerance. Impaired fasting glucose is usually defined as fasting blood glucose between 5.6 mmol/L and 6.9 mmol/L (100.8-124.2 mg/dL), and impaired glucose tolerance is the 2-hour oral glucose tolerance test of 7.8-11.0 mmol/L (140.4-198.0 mg/dL). Most individuals with prediabetes are overweight or obese and are at greater risk of type 2 diabetes (T2D). The first line of treatment for individuals with prediabetes is lifestyle modification, including diet and exercise. The aim of this review, through the revision of primarily randomized control trials, is to discuss the independent and combined effect of diet and exercise on the incidence of T2D, glycemic control, and weight loss in adults with prediabetes. Based on the available literature, lifestyle modification combining both diet and exercise is effective at reducing the incidence of T2D and improving glycemic control, even without a significant reduction in body weight. Thus, it is unclear whether weight loss, through lifestyle modification, is a cornerstone for improving glycemic control in individuals with prediabetes. The independent effect of diet or exercise alone on the improvement in glycemic control and/or reduction in body weight in individuals with prediabetes still requires more studies to draw a clear conclusion, considering the quality and quantity of available studies. As of now, the best diet and/or exercise program to improve glycemic control and body weight in adults with prediabetes is unknown.

Pitavastatin ameliorated the progression of steatohepatitis in ovariectomized mice fed a high fat and high cholesterol diet

AIM

Many studies indicate an accelerated progression of non-alcoholic steatohepatitis (NASH) in postmenopausal women. Very recently, we reported that estrogen deficiency enhanced the progression of steatohepatitis in mice fed a high fat and high cholesterol (HFHC) diet. Hypercholesterolemia is often observed in postmenopausal women, and recent studies indicate it to be an important risk factor for the progression of NASH. Statins can slow NASH progression in the estrogen-deficient state but the precise mechanisms of their effects are still unclear.

METHODS

We investigated the effects of pitavastatin on steatohepatitis progression using ovariectomized (OVX) mice fed a HFHC diet or HFHC + pitava diet (containing 5 p.p.m. pitavastatin) for 6 weeks.

RESULTS

Serum alanine aminotransferase and cholesterol levels significantly decreased in mice fed the HFHC + pitava diet compared with mice fed the HFHC diet. Real-time reverse transcription polymerase chain reaction representing hepatic inflammatory gene expressions significantly decreased in mice fed the HFHC + pitava diet compared with the HFHC-fed mice. Pitavastatin treatment also decreased both hepatic macrophage infiltration and hepatocyte chemokine (C-C motif) ligand 2 expression and improved the liver fibrosis condition when compared with the mice fed the HFHC diet. In addition, the enhanced spleen monocyte chemokine (C-C motif) receptor 2 expression in ovariectomized mice fed the HFHC diet was also decreased by pitavastatin administration.

CONCLUSION

Our study demonstrated that the exacerbated steatohepatitis progression in OVX mice fed a HFHC diet could be attenuated by pitavastatin treatment at least through inhibition of hepatic macrophage infiltration. We concluded that statins should be useful for treating NASH in postmenopausal women.

Incretin-based Therapies for Type 2 Diabetes

There is a growing interest in developing therapeutic strategies for type 2 diabetes based on the actions of the hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). These hormones are the major incretins released from the intestine in response to nutrient ingestion, and they stimulate insulin secretion in a glucosedependent manner. Both peptides are degraded by the enzyme dipeptidyl peptidase-4 (DPP-4), thus terminating their actions. Studies in animal models of diabetes have shown that the incretins also exert a number of additional actions that improve glucose disposal. GLP-1 reduces food intake and gastric emptying, as well as inhibiting glucagon secretion. Injectable formulations of DPP-4-resistant GLP-1-related peptides (incretin mimetics) that are now in clinical use (exenatide) or undergoing trials (e.g. liraglutide) have been shown to reduce fasting and postprandial glucose and glycosylated hemoglobin (A1C) levels and induce weight loss. Oral administration of DPP-4 inhibitors potentiates the actions of incretins released during a meal. Clinical trials have demonstrated that DPP-4 inhibitors are weight-neutral drugs that also effectively reduce plasma glucose and A1C levels. One inhibitor, sitagliptin, is now available in Canada and the United States, and another, vildagliptin, has recently been approved by the European Union. Other inhibitors are under development. Preclinical studies indicate that treatment with incretin mimetics or DPP-4 inhibitors also preserves beta cell mass by exerting mitogenetic and prosurvival effects. It is not known whether similar effects occur in humans.

Simultaneous determination of atorvastatin, metformin and glimepiride in human plasma by LC-MS/MS and its application to a human pharmacokinetic study

A simple, rapid and sensitive liquid chromatography-tandem mass spectrometric (LC–MS/MS) assay method has been developed and fully validated for the simultaneous quantification of atorvastatin, metformin and glimepiride in human plasma. Carbamazepine was used as internal standard (IS). The analytes were extracted from 200 μL aliquots of human plasma via protein precipitation using acetonitrile. The reconstituted samples were chromatographed on a Alltima HP C18 column by using a 60:40 (v/v) mixture of acetonitrile and 10 mM ammonium acetate (pH 3.0) as the mobile phase at a flow rate of 1.1 mL/min. The calibration curves obtained were linear (r²≥0.99) over the concentration range of 0.50–150.03 ng/mL for atorvastatin, 12.14–1207.50 ng/mL for metformin and 4.98–494.29 ng/mL for glimepiride. The API-4000 LC–MS/MS in multiple reaction monitoring (MRM) mode was used for detection. The results of the intra- and inter-day precision and accuracy studies were well within the acceptable limits. All the analytes were found to be stable in a battery of stability studies. The method is precise and sensitive enough for its intended purpose. A run time of 2.5 min for each sample made it possible to analyze more than 300 plasma samples per day. The developed assay method was successfully applied to a pharmacokinetic study in human male volunteers.

Prevention of cardiovascular complications of the metabolic syndrome: focus on pharmacotherapy

The metabolic syndrome increases the risk of atherothrombotic cardiovascular disease (CVD) and diabetes. In turn, diabetes promotes the development of atheroma and is regarded as a coronary heart disease risk equivalent. A multifactorial therapeutic strategy is advocated for patients with the metabolic syndrome to improve cardiovascular risk factor profiles and to reduce the chances of developing type 2 diabetes. Individual components of the syndrome must be addressed using safe, efficacious, and cost-effective measures. There is general agreement that lifestyle modifications, including control of body weight, avoidance of central adiposity, adoption of an antiatherogenic diet, and regular physical activity, are crucial. However, as the magnitude of the individual components of the metabolic syndrome increases with time, lifestyle measures are often insufficient. An individual with metabolic syndrome will often require drug treatment for hyperglycemia, atherogenic dyslipidemia, and high blood pressure, together with antiplatelet therapy. Reducing the need for polypharmacy is an increasingly important consideration for clinicians and the pharmaceutical industry; to date, no single therapy has emerged that targets the root cause(s) of the syndrome. HMG-CoA reductase inhibitors are important agents that reduce CVD morbidity and mortality, in people with impaired fasting glucose or metabolic syndrome. Selective cannabinoid receptor antagonists appear promising because they improve or attenuate several key defects of the syndrome. Thiazolidinediones and metformin are presently licensed for treatment of type 2 diabetes but may prove to have a broader role in future. Novel insulin-sensitizing drugs are under investigation. Drugs that act to prevent or reverse endothelial dysfunction may be of particular utility in preventing cardiovascular disease, especially if initiated before tissue damage has become irreversible. Insulin therapy, which has antiinflammatory and endothelial protective properties, has been shown to reduce morbidity and mortality in high-risk nondiabetic patients during critical illness. Potential synergy between different classes of drugs with metabolic and/or cardiovascular protective properties merits further investigation.

An outpatient-based clinical program for diabetes prevention: an update

OBJECTIVE

To update outcomes of the Diet-Exercise-Activity-Lifestyle (DEAL) program, a clinic-based diabetes prevention intervention.

METHODS

Changes in weight, fasting blood glucose, and 2-hour glucose after a 75-g oral glucose tolerance test were evaluated in patients who enrolled in the DEAL program between January 2007 and August 2009.

RESULTS

The 221 qualified participants had a mean age of 62 years, weight of 87.4 kg, body mass index of 31.2 kg/m², fasting glucose level of 109 mg/dL, and 2-hour glucose value of 138 mg/dL. Among the program participants, 67% were women and 88% were white; 56% had isolated impaired fasting glucose, 5% had impaired glucose tolerance only, and 39% had both. The 6-month follow-up medical appointment was kept by 72% of program participants, but only 56% attended the 12-month visit. By 6 months after baseline, 59% had significantly lower fasting glucose concentrations, 59% had improvement in 2-hour glucose levels, and 61% had weight loss. Nearly 40%, however, were nonresponders and had increased fasting glucose, 2-hour glucose, and weight by 6 months. By the 12-month visit, significant declines in fasting glucose (P<.001), 2-hour glucose (P<.001), and weight (P = .008) occurred in comparison with baseline values; however, no significant changes occurred in these measures between the 6- and 12-month visits (P>.30 for all).

CONCLUSION

Most DEAL participants showed improvement in glucose levels and weight, but some patients exhibited worsening glucose intolerance. Factors underlying nonresponse need to be identified. Ongoing experience and analysis should help revise the DEAL program so that outcomes for all participating patients will improve.

GIP-overexpressing mice demonstrate reduced diet-induced obesity and steatosis, and improved glucose homeostasis

Glucose-dependent insulinotropic polypeptide (GIP) is a gastrointestinal hormone that potentiates glucose-stimulated insulin secretion during a meal. Since GIP has also been shown to exert β-cell prosurvival and adipocyte lipogenic effects in rodents, both GIP receptor agonists and antagonists have been considered as potential therapeutics in type 2 diabetes (T2DM). In the present study, we tested the hypothesis that chronically elevating GIP levels in a transgenic (Tg) mouse model would increase adipose tissue expansion and exert beneficial effects on glucose homeostasis. In contrast, although GIP Tg mice demonstrated enhanced β-cell function, resulting in improved glucose tolerance and insulin sensitivity, they exhibited reduced diet-induced obesity. Adipose tissue macrophage infiltration and hepatic steatosis were both greatly reduced, and a number of genes involved in lipid metabolism/inflammatory signaling pathways were found to be down-regulated. Reduced adiposity in GIP Tg mice was associated with decreased energy intake, involving overexpression of hypothalamic GIP. Together, these studies suggest that, in the context of over-nutrition, transgenic GIP overexpression has the potential to improve hepatic and adipocyte function as well as glucose homeostasis.

Effects of preventive acupuncture on streptozotocin-induced hyperglycemia in rats

BACKGROUND

Diabetes prevention has received increasing attention recently. Clinical and experimental studies showed that acupuncture could produce hypoglycemic effect. However, little is known about the effectiveness of acupuncture in diabetes prevention.

AIM

To investigate the preventive effects of acupuncture on streptozotocin (STZ)-induced hyperglycemia in rats.

METHODS

Hyperglycemia was induced by a single intraperitoneal injection of STZ (60 mg/kg). Rats were randomly divided into six groups (no.=8 each group): control, diabetes, preventive acupuncture plus STZ injection, STZ injection plus therapeutic acupuncture, STZ injection plus preventive and therapeutic acupuncture, and preventive and therapeutic acupuncture control. Body weight, blood glucose, serum insulin, lipid peroxidation, and antioxidant enzymes were measured by routine standard methods. Histological analysis of pancreatic islets was conducted.

RESULTS

Preventive acupuncture significantly relieved hyperglycemia, insulin deficiency, weight loss, and pancreatic islet damage in rats with STZ injection; it also significantly reduced serum lipid peroxidation and enhanced superoxide dismutase in the serum and the pancreas without significantly affecting serum glutathione peroxidase and catalase. Therapeutic acupuncture exhibited a hypoglycemic effect in the late stage, but did not significantly improve other parameters.

CONCLUSIONS

These results indicate that preventive acupuncture is beneficial to the control of STZ-induced hyperglycemia in rats.

Effect of mulberry leaf extract with enriched 1-deoxynojirimycin content on postprandial glycemic control in subjects with impaired glucose metabolism

Aims/Introduction:  The glucose analogue, 1-deoxynojirimycin (DNJ), found in mulberry (Morus alba) leaves, is a promising α-glucosidase inhibitor. We evaluated the effect of the ingestion of mulberry leaf extract with enriched DNJ content on postprandial hyperglycemia in subjects with impaired glucose metabolism.

MATERIALS AND METHODS

  In study 1, we carried out a randomized, double-blind, crossover trial to assess the effects of single ingestion of mulberry leaf extract (3, 6 or 9 mg DNJ) or placebo on blood glucose and insulin concentrations during 2 h after a carbohydrate (200 g boiled white rice) challenge in 12 subjects with fasting plasma glucose (FPG) in the range of 100-140 mg/dL. Study 2 was a randomized, double-blind, placebo-controlled trial to assess the efficacy of 12-week extract supplementation (6 mg DNJ, t.i.d.) for long-term glycemic control in 76 subjects with FPG in the range of 110-140 mg/dL.

RESULTS

  In study 1, ingestion of the mulberry leaf extract led to attenuated postchallenge acute glycemia in a dose-dependent manner (P = 0.006, group × time interaction, two-way anova). In study 2, the serum 1,5-anhydroglucitol concentration, a sensitive indicator of postprandial glycemic control, in the extract group increased and was higher than that in the placebo group over the 12-week treatment period (P < 0.001, group × time interaction, two-way anova); no differences in FPG, glycated hemoglobin and glycated albumin concentrations were observed between the groups.

CONCLUSIONS

  Long-term ingestion of mulberry leaf extract with enriched DNJ content could result in improved postprandial glycemic control in individuals with impaired glucose metabolism. These trials were registered with UMIN (no. UMIN000003154 and UMIN000003155). (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00101.x, 2011).

Oral anti-diabetic drugs for the prevention of Type 2 diabetes

AIM

To determine the comparative efficacy of oral anti-diabetic drugs in preventing the development of Type 2 diabetes.

METHODS

A systematic literature search of MEDLINE, EMBASE and Cochrane CENTRAL was conducted for randomized controlled trials evaluating oral anti-diabetic drugs in patients at high risk for developing Type 2 diabetes. Mixed-treatment comparison meta-analysis methods were used to evaluate the relative risks and risk differences of developing Type 2 diabetes, along with associated 95% credible intervals.

RESULTS

Overall, 20 trials (n = 23 230 participants) were included. Upon mixed-treatment comparison meta-analysis, thiazolidinediones, alpha-glucosidase inhibitors and biguanides significantly reduced the relative risk of developing diabetes by 64, 40 and 27%, respectively, compared with control. Sulphonylureas and glinides showed no significant effect. Moreover, thiazolidinediones significantly reduced the relative risk of diabetes by 50% compared with biguanides and trended towards a 40% risk reduction vs. alpha-glucosidase inhibitors [relative risk 0.60 (95% credible intervals 0.34-1.02)]. None of the results were appreciably altered upon subgroup or sensitivity analyses. When evaluating risk differences compared with control, thiazolidinediones (-9%, number needed to treat = 11), alpha-glucosidase inhibitors (-7%, number needed to treat = 14) and biguanides (-7%, number needed to treat = 14) continued to show significant benefit.

CONCLUSIONS

Of the oral anti-diabetic drugs evaluated to prevent Type 2 diabetes, thiazolidinediones were associated with the greatest risk reduction compared with control and associated with greater risk reduction than biguanides. Alpha-glucosidase inhibitors and biguanides performed similarly, and better than control, while sulphonylureas and glinides provided no significant benefit.

Chromium effects on glucose tolerance and insulin sensitivity in persons at risk for diabetes mellitus

OBJECTIVE

To investigate the effects of daily chromium picolinate supplementation on serum measures of glucose tolerance and insulin sensitivity in patients at high risk for type 2 diabetes mellitus.

METHODS

We conducted a randomized, double-blind, placebo-controlled, modified cross-over clinical trial with 6-month sequences of intervention and placebo followed by a 6-month postintervention assessment. Adult patients with impaired fasting glucose, impaired glucose tolerance, or metabolic syndrome were enrolled. Participants received 6-month sequences of chromium picolinate or placebo at 1 of 2 dosages (500 or 1000 mcg daily). Primary outcome measures were change in fasting plasma glucose, 2-hour plasma glucose during oral glucose tolerance testing, fasting and 2-hour insulin, and homeostasis model assessment of insulin resistance (HOMA-IR). Secondary outcomes included anthropometric measures, blood pressure, endothelial function, hemoglobin A1c, lipids, and urinary microalbumin.

RESULTS

Fifty-nine participants were enrolled. No changes were seen in glucose level, insulin level, or HOMA-IR (all P>.05) after 6 months of chromium at either dosage level (500 mcg or 1000 mcg daily) when compared with placebo. None of the secondary outcomes improved with either chromium dosage compared with placebo (P>.05).

CONCLUSIONS

Chromium supplementation does not appear to ameliorate insulin resistance or impaired glucose metabolism in patients at risk for type 2 diabetes and thus is unlikely to attenuate diabetes risk.

Diabetes prevention: can insulin secretagogues do the job?

The recent Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial reported that nateglinide, a non-sulfonylurea insulin secretagogue, failed to prevent progression from impaired glucose tolerance to diabetes. In order to determine the beneficial effect of insulin secretagogues as a class in diabetes prevention, we performed a literature search for randomized controlled studies and review articles on diabetes prevention and use of sulfonylureas, nateglinide, and meglitinide in PubMed and Ovid Medline since 1950. Three studies were identified with none of them reporting success in preventing diabetes, indicating that insulin secretagogues should not be recommended for diabetes prevention.

Place of pitavastatin in the statin armamentarium: promising evidence for a role in diabetes mellitus

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, known as statins, have revolutionized the treatment of hypercholesterolemia and coronary artery disease prevention. However, there are considerable issues regarding statin safety and further development of residual risk control, particularly for diabetic and metabolic syndrome patients. Pitavastatin is a potent statin with low-density lipoprotein (LDL) cholesterol-lowering effects comparable to those of atorvastatin or rosuvastatin. Pitavastatin has a high-density lipoprotein (HDL) cholesterol raising effect, may improve insulin resistance, and has little influence on glucose metabolism. Considering these factors along with its unique pharmacokinetic properties, which suggest minimal drug–drug interaction, pitavastatin could provide an alternative treatment choice, especially in patients with glucose intolerance or diabetes mellitus. Many clinical trials are now underway to test the clinical efficacy of pitavastatin in various settings and are expected to provide further information.

Pharmacokinetics of verapamil in diabetic rats induced by combination of high-fat diet and streptozotocin injection

The aim of this study was to investigate effects of type 2 diabetes on the pharmacokinetics of verapamil after intravenous administration. Diabetes mellitus (DM) rats were induced by combination of high-fat diet (HFD) and streptozotocin. Plasma concentrations of verapamil in DM rats, rats fed with HFD, and control (CON) rats were measured after intravenous administration of 1 mg/kg verapamil and corresponding pharmacokinetic parameters were estimated. Area under the plasma concentration in DM rats was significantly smaller than that in CON rats. In vitro microsomal study showed that intrinsic clearance of verapamil in DM rats was significantly higher than those in CON rats. Compared to CON rats, higher intrinsic clearance was also observed in HFD rats. Western blot results demonstrated higher levels of CYP3A2 in DM and HFD rats, which was in line to activity of CYP3A. All the results gave a conclusion that diabetes may enhance metabolism of verapamil in rat, and the enhancement may partly result from induction of CYP3A.

An outpatient-based clinical program for type 2 diabetes prevention

OBJECTIVE

To review first-year results of a clinic-based type 2 diabetes prevention program.

METHODS

From January through December 2007, patients with a diagnosis of prediabetes participated in the Diet-Exercise-Activity-Lifestyle program for instruction in lifestyle changes. Physical therapy assessments were retrospectively reviewed to search for symptoms or findings of physical impairments. Changes in weight and 2-hour glucose tolerance test results were assessed at 6 months. Patient satisfaction with the program was evaluated.

RESULTS

Ninety-two patients qualified for the program. Mean baseline fasting glucose concentration was 108 mg/dL, and 2-hour glucose concentration was 134 mg/dL. Mean age was 62 years, and 66% were women. Review of physical therapy assessments demonstrated gait/balance disturbances in 47% of patients, peripheral neuropathy in 43%, and musculoskeletal problems in 63%. Among 47 patients who had 6-month follow-up visits, 72% lost weight. Fasting glucose levels improved in 58% in persons with impaired fasting glucose, and 2-hour glucose values decreased in patients who had impaired glucose tolerance. Seventy-eight percent graded the program as either "very good" or "excellent."

CONCLUSIONS

Programs geared toward type 2 diabetes prevention can be feasibly implemented on an outpatient basis. Preliminary data suggest that improvements in weight and glucose values can be achieved. As the prevalence of prediabetes increases, health care systems must gain further experience with effective outpatient diabetes prevention strategies.

Implications of recently published trials of blood pressure-lowering drugs in hypertensive or high-risk patients

We reviewed 6 recent outcome trials of blood pressure (BP)-lowering drugs in 74,524 randomized hypertensive or high-risk patients. Over interpretation of nonsignificant or marginal probability values in large trials with overlapping end points, exclusion of patients not tolerating or not adhering to experimental treatments, labeling nonsignificant treatment effects as modest, and insufficient information on the quality of the BP measurements or on the BP changes early after randomization raise concern. From a clinical viewpoint, results should not be extrapolated to patients with characteristics dissimilar from those randomized. The benefit beyond BP lowering in cardiovascular prevention is tiny. Dual inhibition of the renin system should only be used in patients at high risk, in whom all drug combinations have been tried and who cannot be controlled by a single renin system inhibitor. Current evidence does not support BP lowering in normotensive patients or the use of renin system inhibitors for prevention of stroke recurrence. Because angiotensin-receptor blockers might offer less protection against myocardial infarction than angiotensin-converting enzyme inhibitors, the latter should remain the preferred renin system inhibitor for cardiovascular prevention in angiotensin-converting enzyme inhibitor-tolerant patients. In 2 trials, in which new-onset diabetes was a predefined end point, 1000 patients had to be treated for 1 year with an angiotensin-receptor blocker instead of placebo to prevent just 2 cases. From a design viewpoint, the time has come to revise the concept of large simple trials and to pursue research questions that serve patient interests more than showing noninferiority or highlight the ancillary qualities of marketable antihypertensive drugs.

Chinese herbal medicines for people with impaired glucose tolerance or impaired fasting blood glucose

BACKGROUND

Around 308 million people worldwide are estimated to have impaired glucose tolerance (IGT); 25% to 75% of these will develop diabetes within a decade of initial diagnosis. At diagnosis, half will have tissue-related damage and all have an increased risk for coronary heart disease.

OBJECTIVES

The objective of this review was to assess the effects and safety of Chinese herbal medicines for the treatment of people with impaired glucose tolerance or impaired fasting glucose (IFG).

SEARCH STRATEGY

We searched the following databases: The Cochrane Library, PubMed, EMBASE, AMED, a range of Chinese language databases, SIGLE and databases of ongoing trials.

SELECTION CRITERIA

Randomised clinical trials comparing Chinese herbal medicines with placebo, no treatment, pharmacological or non-pharmacological interventions in people with IGT or IFG were considered.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data. Trials were assessed for risk of bias against key criteria: random sequence generation, allocation concealment, blinding of participants, outcome assessors and intervention providers, incomplete outcome data, selective outcome reporting and other sources of bias.

MAIN RESULTS

This review examined 16 trials lasting four weeks to two years involving 1391 participants receiving 15 different Chinese herbal medicines in eight different comparisons. No trial reported on mortality, morbidity or costs. No serious adverse events like severe hypoglycaemia were observed. Meta-analysis of eight trials showed that those receiving Chinese herbal medicines combined with lifestyle modification were more than twice as likely to have their fasting plasma glucose levels return to normal levels (i.e. fasting plasma glucose <7.8 mmol/L and 2hr blood glucose <11.1 mmol/L) compared to lifestyle modification alone (RR 2.07; 95% confidence intervall (CI) 1.52 to 2.82). Those receiving Chinese herbs were less likely to progress to diabetes over the duration of the trial (RR 0.33; 95% CI 0.19 to 0.58). However, all trials had a considerable risk of bias and none of the specific herbal medicines comparison data was available from more than one study. Moreover, results could have been confounded by rates of natural reversion to normal glucose levels.

AUTHORS' CONCLUSIONS

The positive evidence in favour of Chinese herbal medicines for the treatment of IGT or IFG is constrained by the following factors: lack of trials that tested the same herbal medicine, lack of details on co-interventions, unclear methods of randomisation, poor reporting and other risks of bias.

Advancing therapy in type 2 diabetes mellitus with early, comprehensive progression from oral agents to insulin therapy

BACKGROUND

Early and intensive glycemic control is necessary to prevent or minimize the development of microvascular and macrovascular complications in individuals with type 2 diabetes mellitus. However, many patients are unable to attain glycemic control, partly due to protracted treatment with oral antidiabetic drugs (OADs) despite inadequate control and barriers to initiating insulin therapy. Patients at different stages of disease may benefit from the early introduction of intensive glycemic control.

OBJECTIVE

This article discusses some of the potential barriers to achieving and maintaining optimal glycemic levels in patients whose blood glucose is sub-optimally controlled with OADs and reviews the benefits of early introduction of intensive glycemic control in patients at various stages of disease, with an emphasis on insulin therapy.

METHODS

Relevant English-language articles published from 1996 to 2006 were identified through searches of the National Center for Biotechnology PubMed database. Search terms included insulin, insulin therapy, type 2 diabetes, insulin analogs, early insulinization, and diabetes prevention, among others. Studies were assessed regarding designs, primary and secondary efficacy parameters, glycosylated hemoglobin (HbAM(lc)), fasting plasma glucose, incidence of hypoglycemia, and other safety assessments. Inclusion criteria were multicenter, randomized, open-label, parallel-group trials, as well as retrospective observational studies, conducted in Europe or the United States. Additional analyses and guideline-based recommendations are included.

RESULTS

The landmark results of the United Kingdom Prospective Diabetes Study, which found that an intensive strategy in 3867 newly diagnosed patients with type 2 diabetes was associated with stricter glycemic control than was conventional care (HbA(lc) over 10 years, 7.0% vs 7.9%; P < 0.001), as well as a 25% reduction in the risk for microvascular complications (P = 0.01). Early initiation of insulin therapy concomitantly with OADs appeared well tolerated in the populations studied, was effective in recently diagnosed patients, and may also confer anti-inflammatory and antiatherogenic effects. Characteristics associated with newer formulations of insulin (eg, basal insulin analogues as well as rapid-acting insulin analogues, the insulin pump, or inhaled insulin) may help overcome barriers associated with initiating insulin therapy.

CONCLUSIONS

Based on the literature, early and persistent intensification of antidiabetic therapy is an approach that most likely will achieve optimal glycemic control in patients with type 2 diabetes and help prevent associated complications. Greater clinical experience with newer therapeutic approaches, including incretin mimetics and dipeptidyl peptidase-IV inhibitors, will provide insight into their place in the spectrum of diabetes treatments.

Health care costs and mortality for Canadian urban and rural patients with diabetes: population-based trends from 1993-2001

BACKGROUND

Recent reports suggest that the health status of individuals residing in rural areas (as much as one third of the Canadian population) may be inferior to those who live in urban areas.

OBJECTIVE

This study compared trends in mortality and in provincial health care system costs for individuals with diabetes, according to urban/rural residence in Saskatchewan, Canada.

METHODS

The Canadian National Diabetes Surveillance System criteria were applied to the linked administrative databases of Saskatchewan Health to identify all individuals with diabetes between 1991 and 2001. Annual health care costs across 5 categories of health care services (physician visits, prescription medications, hospitalizations, day surgeries, and dialysis) were identified over a 9-year period (1993-2001). Costs (in 2001 Can $) and mortality rates were directly age adjusted, and comparisons were made across individuals residing in large urban, small urban, and rural areas.

RESULTS

A total of 57,774 individuals with diabetes were identified, approximately half (n = 26,656) of whom resided in rural areas. In 2001, total per capita costs were $3454 for large urban, $3427 for small urban, and $3289 for rural dwellers. Per capita costs of most individual categories were highest in large urban centers over the follow-up period with the exception of hospitalizations, which were highest among rural residents ($1444 vs $1283 for large urban residents). Despite differences in the individual cost categories, overall health care costs according to place of residence were similar. Overall, the age-adjusted mortality rates increased substantially from 12 (1993) to 18 (2001) deaths per 1000 population, although rates were similar across geographic locations.

CONCLUSIONS

From 1993 to 2001, we observed systematic differences in costs of individual resource categories according to urban/rural residence in Saskatchewan, with urban dwellers with diabetes incurring greater costs in most categories. Age-adjusted total costs and mortality rates were similar, however, suggesting that rural populations with diabetes may not be as disadvantaged as commonly believed. Investing in better primary care access for all patients with diabetes may reduce downstream costs in Saskatchewan's provincial health care system.