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

Effect of simvastatin on high glucose- and angiotensin II-induced activation of the JAK/STAT pathway in mesangial cells

In the current study, we investigated the effect of simvastatin on the ability of high glucose (HG) and ANG II to activate the JAK2-STAT signaling cascade and induce glomerular mesangial cell (GMC) growth. We found that pretreatment with simvastatin significantly inhibited HG- and ANG II-induced collagen IV production, JAK2 activation, and phosphorylation of STAT1 and STAT3 in GMC. We also found that the activation of JAK2 by HG and ANG II was dependent on the Rho family of GTPases. Consistent with these in vitro results, both albumin protein excretion and phosphorylation of JAK2, STAT1, and STAT3 were attenuated in renal glomeruli by administration of simvastatin in a streptozotocin-induced rat model of HG diabetes. This study demonstrates that simvastatin blocks ANG II-induced activation of the JAK/STAT pathway in the diabetic environment, in vitro and in vivo, and, thereby, provides new insights into the molecular mechanisms underlying early diabetic nephropathy.

Simultaneous determination of metformin and gliclazide in human plasma by liquid chromatography-tandem mass spectrometry: application to a bioequivalence study of two formulations in healthy volunteers

A rapid and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated to simultaneously determine gliclazide and metformin in human plasma using huperzine A as the internal standard (IS). After acetonitrile-induced protein precipitation of the plasma samples, gliclazide, metformin and the IS were subjected to LC/MS/MS analysis using electro-spray ionization (ESI). Chromatographic separation was performed on a Hypersil BDS C18 column (50 mm x 2.1 mm, i.d., 3 microm). The method had a chromatographic running time of 2.0 min and linear calibration curves over the concentration ranges of 10-10,000 ng ml(-1) for gliclazide and 7.8-4678.9 ng ml(-1) for metformin. The recoveries of the method were found to be 71-104%. The lower limits of quantification (LOQ) of the method were 10.0 and 7.8 ng ml(-1) for gliclazide and metformin, respectively. The intra- and interday precision was less than 15% for all quality control samples at concentrations of 100, 500, and 2000 ng ml(-1). The validated LC/MS/MS method has been used to study bioequivalence in healthy volunteers. These results indicate that the method was efficient with a very short running time (2.0 min) for metformin and gliclazide compared to the methods reported in the literature. The presented method had acceptable accuracy, precision and sensitivity and was used in clinical bioequivalence study.

Antihypertensive drugs and incidence of type 2 diabetes: Evidence and implications for clinical practice

The major antihypertensive drug classes appear to exert differing effects on glycemic control and diabetes incidence. Thiazide diuretic and beta-blockers are potentially diabetogenic, whereas calcium channel blockers appear neutral. Inhibitors of the renin-angiotensin system are associated with improvements in glycemic control and may lower diabetes incidence, but it is not clear if this represents a truly preventive effect. Also, it should be noted that previous studies have reported inconsistent results, and the data to date are not definitive. We suggest that inhibitors of the renin-angiotensin system be used as first-line agents in uncomplicated hypertensive patients who are at high risk for developing type 2 diabetes. Thiazides and beta-blockers should not be avoided in patients with compelling indications for these drugs. Many hypertensive patients (particularly those who are obese or have prediabetes) require several agents to achieve target blood pressure levels. Therefore, the choice of initial agent is far less important than ensuring that target blood pressure goals are reached.

Issues in minority health: atherosclerosis and coronary heart disease in African Americans

Cardiovascular disease (in particular, CHD) is the leading cause of death in the United States for Americans of both sexes and of all racial and ethnic backgrounds. African Americans have the highest overall CHD mortality rate and the highest out-of-hospital coronary death rate of any ethnic group in the United States, particularly at younger ages. Contributors to the earlier onset of CHD and excess CHD deaths among African Americans include a high prevalence of coronary risk factors, patient delays in seeking medical care, and disparities in health care. The clinical spectrum of acute and chronic CHD in African Americans is the same as in whites; however, African Americans have a higher risk of sudden cardiac death and present clinically more often with unstable angina and non-ST-segment elevation myocardial infarction than whites. Although generally not difficult, the accurate diagnosis and risk assessment for CHD in African Americans may at times present special challenges. The high prevalence of hypertension and type 2 diabetes mellitus may contribute to discordance between symptomatology and the severity of coronary artery disease, and some noninvasive tests appear to have a lower predictive value for disease. The high prevalence of modifiable risk factors provides great opportunities for the prevention of CHD in African Americans. Patients at high risk should be targeted for intensive risk reduction measures, early recognition/diagnosis of ischemic syndromes, and appropriate referral for coronary interventions and cardiac surgical procedures. African Americans who have ACSs receive less aggressive treatment than their white counterparts but they should not. Use of evidence-based therapies for management of patients who have ACSs and better understanding of various available treatment strategies are of utmost importance. Reducing and ultimately eliminating disparities in cardiovascular care and outcomes require comprehensive programs of education and advocacy(Box 4) with the goals of (1) increasing provider and public awareness of the disparities in treatment; (2) decreasing patient delays in seeking medical care for acute myocardial infarction and other cardiac disorders; (3) more timely and appropriate therapy for ACSs; (4) improved access to preventive, diagnostic, and interventional cardiovascular therapies; (5) more effective implementation of evidence-based treatment guidelines; and (6) improved physician-patient communications.

Long-term pharmacotherapy for obesity and overweight

BACKGROUND

Worldwide prevalence rates of obesity and overweight are rising and safe and effective treatment strategies are urgently needed. A number of anti-obesity agents have been studied in short-term clinical trials, but long-term efficacy and safety need to be established.

OBJECTIVES

To assess/compare the effects and safety of approved anti-obesity medications in clinical trials of at least one-year duration.

SEARCH STRATEGY

MEDLINE, EMBASE, the Cochrane Controlled Trials Register, the Current Science Meta-register of Controlled Trials, and reference lists of original studies and reviews were searched. Date of last search was December 2002. Drug manufacturers and two obesity experts were contacted in to detect unpublished trials. No language restrictions were imposed.

SELECTION CRITERIA

Double-blind, randomised controlled weight loss and weight maintenance trials of approved anti-obesity agents that 1) enrolled adult overweight or obese patients, 2) included a placebo control group or compared two or more anti-obesity drugs 3) used an intention-to-treat analysis, and 4) had a minimum follow-up period of one year. Abstracts and pseudo-randomised trials were not included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed all potentially relevant citations for inclusion and methodological quality. The primary outcome measure was weight loss.

MAIN RESULTS

Of the eight anti-obesity agents investigated, only orlistat and sibutramine trials met inclusion criteria. Eleven orlistat weight loss studies (four of which reported a second year weight maintenance phase) and five sibutramine studies (three weight loss and two weight maintenance trials) were included. Attrition rates averaged 33% during the weight loss phase of orlistat trials and 43% in sibutramine studies. All patients received lifestyle modification as a co-intervention. Compared to placebo, orlistat-treated patients lost 2.7 kg (95% CI: 2.3 kg to 3.1 kg) or 2.9% (95% CI: 2.3 % to 3.4%) more weight and patients on sibutramine experienced 4.3 kg (95% CI: 3.6 kg to 4.9 kg) or 4.6% (95% CI: 3.8% to 5.4%) greater weight loss. The number of patients achieving ten percent or greater weight loss was 12% (95% CI: 8% to 16%) higher with orlistat and 15% (95% CI: 4% to 27%) higher with sibutramine therapy. Weight loss maintenance results were similar. Orlistat caused gastrointestinal side effects and sibutramine was associated with small increases in blood pressure and pulse rate.

REVIEWERS' CONCLUSIONS

Studies evaluating the long-term efficacy of anti-obesity agents are limited to orlistat and sibutramine. Both drugs appear modestly effective in promoting weight loss; however, interpretation is limited by high attrition rates. Longer and more methodologically rigorous studies of anti-obesity drugs that are powered to examine endpoints such as mortality and cardiovascular morbidity are required to fully evaluate any potential benefit of such agents.