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Pershadsingh HA. Dual Peroxisome Proliferator-Activated Receptor-alpha/gamma Agonists : In the Treatment of Type 2 Diabetes Mellitus and the Metabolic Syndrome. ACTA ACUST UNITED AC 2016; 5:89-99. [PMID: 16542049 DOI: 10.2165/00024677-200605020-00003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The metabolic syndrome consists of a combination of cardiovascular risk factors that include hyperglycemia with or without type 2 diabetes mellitus, visceral obesity, elevated blood pressure, and atherogenic dyslipidemia. These interrelated disorders and their associated lipotoxicity, oxidative stress, and inflammatory state predispose to a constellation of cardiovascular conditions leading to high risk of heart attack, stroke, renal failure, blindness, and lower extremity amputation. Visceral obesity, a prime risk factor for type 2 diabetes and a major component of the metabolic syndrome, potentiates atherogenesis, atherosclerosis, organ lipotoxicity, and oxidative tissue damage.Peroxisome proliferator-activated receptors (PPARs) are relatively recently discovered nuclear transcription factors that are modulated by dietary fatty acids, including the essential polyunsaturated fatty acids, arachidonic acid and its metabolites, and are essential to the control of energy metabolism. Of the three PPAR isoforms (alpha, gamma, and delta), synthetic pharmaceutical ligands that activate PPARalpha (the antidyslipidemic fibric acid derivatives ['fibrates']) and PPARgamma (the antidiabetic thiazolidinediones) have been studied extensively. Recently developed dual PPARalpha/gamma agonists may combine the therapeutic effects of these drugs, creating the expectation of greater efficacy, and perhaps other advantages in the treatment of type 2 diabetes and the metabolic syndrome. However, thiazolidinediones are hampered by adverse effects related to increased weight gain and fluid overload. It remains to be seen whether the dual PPARalpha/gamma agonists currently under development have similar limitations. Nevertheless, existing clinical data imply that the combined effects of thiazolidinediones and fibrates are likely to be emulated by dual PPARalpha/gamma agonists, providing superior efficacy to these classes for the treatment of type 2 diabetes, the metabolic syndrome, and their cardiovascular and other end-organ complications.
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Jiang M, Strand DW, Franco OE, Clark PE, Hayward SW. PPARγ: a molecular link between systemic metabolic disease and benign prostate hyperplasia. Differentiation 2011; 82:220-36. [PMID: 21645960 DOI: 10.1016/j.diff.2011.05.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 05/02/2011] [Accepted: 05/04/2011] [Indexed: 11/26/2022]
Abstract
The emergent epidemic of metabolic syndrome and its complex list of sequelae mandate a more thorough understanding of benign prostatic hyperplasia and lower urinary tract symptoms (BPH/LUTS) in the context of systemic metabolic disease. Here we discuss the nature and origins of BPH, examine its role as a component of LUTS and review retrospective clinical studies that have drawn associations between BPH/LUTS and type II diabetes, inflammation and dyslipidemia. PPARγ signaling, which sits at the nexus of systemic metabolic disease and BPH/LUTS through its regulation of inflammation and insulin resistance, is proposed as a candidate for molecular manipulation in regard to BPH/LUTS. Finally, we introduce new cell and animal models that are being used to study the consequences of obesity, diabetes and inflammation on benign prostatic growth.
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Affiliation(s)
- Ming Jiang
- Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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Derosa G, Maffioli P. Thiazolidinediones plus metformin association on body weight in patients with type 2 diabetes. Diabetes Res Clin Pract 2011; 91:265-70. [PMID: 20832133 DOI: 10.1016/j.diabres.2010.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 02/28/2010] [Accepted: 08/01/2010] [Indexed: 01/23/2023]
Abstract
There are different studies about the efficacy and safety and tolerability of thiazolidinediones added to metformin. The reported improved glycemic control with thiazolidinediones use seems to be associated with an increase in weight with an estimated 2-3 kg weight gain suggesting that maybe thiazolidinediones are not safe for the clinical use. Other authors reported that thiazolidinediones give an improvement in the glycemic without giving weight gain. With our review, we want to evaluate the effects of thiazolidinediones plus metformin combination in diabetic patients on the body weight. From the data emerged from our review we can conclude that even if a small increase in mean body weight was observed in patients treated with thiazolidinediones plus metformin therapy, the weight gain was less than previously reported and it was also considerably less than what might have been expected given the large improvements in glycemic control. For these reasons we can safely say that thiazolidinediones in combination with metformin are effective and well tolerated in patients with type 2 diabetes.
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Affiliation(s)
- G Derosa
- Department of Internal Medicine and Therapeutics, University of Pavia, 27100 Pavia, Italy.
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Fukuda D, Enomoto S, Hirata Y, Nagai R, Sata M. The angiotensin receptor blocker, telmisartan, reduces and stabilizes atherosclerosis in ApoE and AT1aR double deficient mice. Biomed Pharmacother 2010; 64:712-7. [DOI: 10.1016/j.biopha.2010.09.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Accepted: 09/10/2010] [Indexed: 12/12/2022] Open
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Derosa G, Tinelli C, Maffioli P. Effects of pioglitazone and rosiglitazone combined with metformin on body weight in people with diabetes. Diabetes Obes Metab 2009; 11:1091-9. [PMID: 19765050 DOI: 10.1111/j.1463-1326.2009.01087.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Currently, pioglitazone and rosiglitazone are the thiazolidinediones available for clinical use. In the literature, there are different studies concerning the efficacy, safety and tolerability of thiazolidinediones as add-on therapy to metformin in patients with type 2 diabetes inadequately controlled with metformin alone. Metformin and thiazolidinediones are both antihyperglycaemic drugs, both lower blood glucose concentrations in type 2 diabetes without causing overt hypoglycaemia and both require the presence of insulin to generate their therapeutic effects, but act without stimulating insulin secretion. Some authors reported that the improved glycaemic control obtained with thiazolidinediones is associated with an increase in body weight with an estimated 2-3 kg weight gain for every 1% decrease in HbA(1c) which could negate some of the benefits of the improved metabolic control. Some other authors, instead, reported that thiazolidinediones give a better improvement in the glycaemic control compared with metformin alone without giving weight gain. The emerging discrepancies from these studies could be because of the study design, the patient selection, the degree of glycaemic control and/or the methods to measure body weight. We have undertaken a thorough literature search on Medline and Embase to evaluate the effects of thiazolidinediones plus metformin combination in people with diabetes on the body weight.
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Affiliation(s)
- G Derosa
- Department of Internal Medicine and Therapeutics, University of Pavia, Fondazione IRCCS, Policlinico S. Matteo, 27100 PAVIA, Italy.
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Chiarelli F, Di Marzio D. Peroxisome proliferator-activated receptor-gamma agonists and diabetes: current evidence and future perspectives. Vasc Health Risk Manag 2008; 4:297-304. [PMID: 18561505 PMCID: PMC2496982 DOI: 10.2147/vhrm.s993] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Since their initial availability in 1997, the thiazolidinediones (TZDs) have become one of the most commonly prescribed classes of medications for type 2 diabetes. In addition to glucose control, the TZDs have a number of pleiotropic effects on myriad traditional and non-traditional risk factors for diabetes. TZDs may benefit cardiovascular parameters, such as lipids, blood pressure, inflammatory biomarkers, endothelial function and fibrinolytic state. In this review, we summarise the experimental, preclinical and clinical data regarding the effects of the TZDs in conditions for which they are indicated and discuss their potential in the treatment of other conditions.
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Tordjman KM, Semenkovich CF, Coleman T, Yudovich R, Bak S, Osher E, Vechoropoulos M, Stern N. Absence of peroxisome proliferator-activated receptor-alpha abolishes hypertension and attenuates atherosclerosis in the Tsukuba hypertensive mouse. Hypertension 2007; 50:945-51. [PMID: 17909121 DOI: 10.1161/hypertensionaha.107.094268] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Peroxisome proliferator-activated receptor-alpha is widely distributed in the vasculature where it is believed to exert pleiotropic antiatherogenic effects. Its role in the regulation of blood pressure is still unresolved; however, some evidence suggests that it may affect the renin-angiotensin system. We investigated its role in angiotensin II-induced hypertension in the Tsukuba hypertensive mouse (THM). This is a model of hypertension and atherosclerosis because of high angiotensin II and aldosterone levels as a result of the transgenic expression of the entire human renin-angiotensin system. Making the THM animals deficient in Peroxisome proliferator-activated receptor-alpha (THM/PPARKO) totally abolished hypertension and myocardial hypertrophy. This was accompanied by a reduction in plasma human active renin in THM/PPARKO mice compared with THM animals from 3525+/-128 mU/L to 1910+/-750 mU/L (P<0.05) and by a normalization of serum aldosterone (1.6+/-0.29 nmol/L versus 3.4+/-0.69 nmol/L; P=0.003). In the THM/PPARKO mice, the extent of atherosclerosis at the aortic sinus after a 12-week period on an atherogenic diet was decreased by >80%. In addition, the spontaneous formation of foam cells from peritoneal macrophages, a blood pressure-independent event, was reduced by 92% in the THM/PPARKO mice, suggesting protection from the usual oxidative stress in these animals, possibly because of lower prevailing angiotensin II levels. Finally, chronic fenofibrate treatment further elevated blood pressure in THM animals but not in THM/PPARKO animals. Taken together, these data indicate that peroxisome proliferator-activated receptor-alpha may regulate the renin-angiotensin system. They raise the possibility that its activation may aggravate hypertension and hasten atherosclerosis in the context of an activated renin-angiotensin system.
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Affiliation(s)
- Karen M Tordjman
- Institute of Endocrinology, Metabolism and Hypertension, Aviv Sourasky Medical Center, Sackler Faculty of Medicine Tel Aviv University, Tel Aviv, Israel.
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Caldwell SH, Patrie JT, Brunt EM, Redick JA, Davis CA, Park SH, Neuschwander-Tetri BA. The effects of 48 weeks of rosiglitazone on hepatocyte mitochondria in human nonalcoholic steatohepatitis. Hepatology 2007; 46:1101-7. [PMID: 17661371 DOI: 10.1002/hep.21813] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
UNLABELLED Rosiglitazone, a thiazolidinedione peroxisome proliferator-activated receptor gamma ligand, reduces disease activity in nonalcoholic steatohepatitis (NASH), a disease associated with hepatocyte mitochondrial crystalline inclusions that are not seen in animal models of NASH. In human and animal studies of adipose tissue, thiazolidinediones may induce mitochondrial biogenesis and associated morphological changes. To determine if rosiglitazone alters the hepatocyte mitochondrial morphology in human NASH, we prospectively and systematically examined liver biopsies from human subjects with NASH before and after 48 weeks of rosiglitazone by transmission electron microscopy. Twenty patients (body mass index = 34 +/- 7) were studied. Four coded sections from each of 20 pretherapy biopsies and each of 20 posttherapy biopsies were examined by transmission electron microscopy. The total hepatocyte mitochondria and crystal-containing mitochondria were counted, and semiquantitative scoring was performed for macrosteatosis, microsteatosis, dilated endoplasmic reticulum, apoptosis, Mallory bodies, and hepatocyte enlargement. The total mitochondria count was unchanged after therapy, but there was a significant increase in crystal-containing mitochondria from 4.0% (95% confidence interval = 1.8-8.8) to 7.2% (95% confidence interval = 3.9-12.6; odds ratio = 1.80; P = 0.04) after the treatment with rosiglitazone. Macrosteatosis (P < 0.001) and Mallory bodies (P = 0.05) significantly decreased, but no change was evident in microsteatosis, cellular enlargement, dilated endoplasmic reticulum, or apoptosis. CONCLUSION Rosiglitazone therapy of NASH is associated with increased crystalline inclusions in hepatocyte mitochondria. Whether these are adaptive or pathological remains unknown, and further studies are warranted to assess hepatic mitochondrial function during thiazolidinedione therapy for NASH.
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Affiliation(s)
- Stephen H Caldwell
- Gastrointestinal/Hepatology Division, Digestive Health Center of Excellence, University of Virginia, Charlottesville, VA 22908, USA.
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Kovanecz I, Ferrini MG, Vernet D, Nolazco G, Rajfer J, Gonzalez-Cadavid NF. Ageing-related corpora veno-occlusive dysfunction in the rat is ameliorated by pioglitazone. BJU Int 2007; 100:867-74. [PMID: 17662078 DOI: 10.1111/j.1464-410x.2007.07070.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To determine whether ageing-related changes in the penile corpora cavernosa, namely corporal veno-occlusive dysfunction (CVOD), loss of smooth muscle cells (SMCs), and excessive collagen deposition, can be ameliorated by the peroxisome proliferator-activated receptor gamma (PPARgamma) agonist pioglitazone, in a rat model of ageing as we have shown in a rat model of type 2 diabetes. MATERIALS AND METHODS Male Fischer 344 rats (16-18 months old) were fed chow containing 0%, 0.001% or 0.02% pioglitazone for 2 or 4.5 months, using 5 month old rats as 'young' controls. Functional changes were determined by dynamic-infusion cavernosometry (DIC). Histological changes were assessed by histochemistry and immunohistochemistry followed by quantitative image analysis and/or quantitative Western blot. Reactive oxygen species were estimated in blood. RESULTS Pioglitazone at both doses reduced the high DIC 'drop rate' present in the untreated aged groups to the level seen in the young rats. The papaverine response was increased to young control levels by short-term high-dose pioglitazone and the long-term low-dose treatment, but not by the short-term low-dose treatment. Pioglitazone at all doses and durations of treatment failed to reverse the decreased corporal SMC/collagen ratio and SMC content, oxidative stress, or the elevated contents of collagen, or transforming growth factor beta1, seen in the aged penis, but did reduce the collagen III/I ratio, and at a high dose increased apoptosis. Both treatments inhibited the Rho-kinase system, by increasing Src homology region 2-containing protein tyrosine phosphatase and reducing Vav. PPARgamma were detected in corporal SMCs. CONCLUSIONS Pioglitazone ameliorated ageing-related CVOD, possibly by a PPARgamma-mediated inhibition of Rho-kinase and not by a protective effect on the corporal smooth muscle.
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Affiliation(s)
- Istvan Kovanecz
- Urology Research Laboratory, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
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Park JS, Cho MH, Lee KY, Kim CS, Kim HJ, Nam JS, Ahn CW, Cha BS, Lim SK, Kim KR, Lee HC. The effects of pioglitazone on cerebrovascular resistance in patients with type 2 diabetes mellitus. Metabolism 2007; 56:1081-6. [PMID: 17618953 DOI: 10.1016/j.metabol.2007.03.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 03/20/2007] [Indexed: 11/25/2022]
Abstract
Atherosclerosis is one of the major causes of morbidity and mortality in patients with type 2 diabetes mellitus. Pioglitazone has been reported to have antiatherogenic effects. The aim of this study was to investigate whether pioglitazone affects pulsatility index (PI) of the cerebral arteries and the carotid intima-media thickness in type 2 diabetic patients. A total of 40 type 2 diabetic patients were included in this study. They were divided into 2 groups: the pioglitazone-treated group (pioglitazone 15 mg/d with gliclazide 80-320 mg/d for 12 weeks) and the gliclazide-treated group (gliclazide 80-320 mg/d for 12 weeks). Transcranial Doppler ultrasonography was performed for each cerebral artery, and PI was calculated as (systolic velocity-diastolic velocity)/mean velocity. The pioglitazone treatment significantly increased high-density lipoprotein cholesterol and decreased triglyceride levels and insulin resistance. This study revealed that the change in mean intima-media thickness was not significant in both groups, but the change in PI was significantly decreased with pioglitazone compared to gliclazide. In conclusion, pioglitazone decreased PI and improved cerebrovascular resistance in type 2 diabetic patients.
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Affiliation(s)
- Jong Suk Park
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
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Spears M, McSharry C, Thomson NC. Peroxisome proliferator-activated receptor-gamma agonists as potential anti-inflammatory agents in asthma and chronic obstructive pulmonary disease. Clin Exp Allergy 2007; 36:1494-504. [PMID: 17177672 DOI: 10.1111/j.1365-2222.2006.02604.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Inhaled corticosteroids are the most effective therapy for chronic persistent asthma and have a role in the treatment of chronic obstructive pulmonary disease (COPD). However, corticosteroids have reduced efficacy in some patients with asthma and fail to halt the progressive deterioration in lung function characteristic of COPD. Additional or alternative drug treatments to corticosteroids are required to improve control of inflammation in patients with therapy resistant airway disease. Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonists have displayed potent anti-inflammatory properties in experimental models of asthma and other airway diseases and as a result have the potential to become an additional treatment for asthma and COPD. We review the evidence from these experimental models and their applicability to asthma and COPD and the requirements for future clinical and experimental research.
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Affiliation(s)
- M Spears
- Department of Respiratory Medicine, Division of Immunology, Infection and Inflammation, University of Glasgow, Glasgow, UK
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Affiliation(s)
- K Kiryluk
- Division of Nephrology, Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, New York 10033, USA.
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Berhanu P, Perez A, Yu S. Effect of pioglitazone in combination with insulin therapy on glycaemic control, insulin dose requirement and lipid profile in patients with type 2 diabetes previously poorly controlled with combination therapy. Diabetes Obes Metab 2007; 9:512-20. [PMID: 17587394 DOI: 10.1111/j.1463-1326.2006.00633.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM The aim of this randomized placebo-controlled study was to evaluate the safety and efficacy of pioglitazone administered alone or in combination with metformin in reducing insulin dosage requirements for improved glycaemic control in patients with type 2 diabetes previously poorly controlled with combination therapy. METHODS In this multicentre, double-blind study, 222 patients with haemoglobin A1c (HbA(1c))>8.0% at screening treated with combination therapy initially were given titrated insulin therapy (to fasting plasma glucose <140 mg/dl) and then were randomly assigned to 20-week treatment with pioglitazone or placebo in combination with insulin, with or without concurrent metformin therapy. More than 98% of patients were taking metformin prior to and during the study. RESULTS Pioglitazone significantly reduced (p < 0.05) insulin dose requirements 2 weeks after treatment initiation. At study end relative to baseline, pioglitazone reduced daily insulin dosages by 12.0 units (p < 0.001), a 21.5% (12.0/55.8 units at baseline) group mean average reduction. Relative to placebo, pioglitazone reduced daily insulin dosages by 12.7 units [95% confidence interval [CI]: -17.5, -8.0], while improving mean HbA(1c) levels [adjusted mean HbA(1c) change: pioglitazone, -1.6% vs. placebo, -1.4% (not statistically different)]. Pioglitazone also significantly increased high-density lipoprotein cholesterol levels [adjusted mean difference: +4.5 (95% CI: 2.6-6.5) mg/dl], decreased triglyceride levels [-43.9 (-69.2, -18.6) mg/dl], shifted low-density lipoprotein (LDL) particle concentrations from small [pattern B, -13.6% (-17.7%, -9.5%)] to large [pattern A, +15.1% (10.8%, 19.5%)] and increased mean LDL particle size [+3.8 (2.6, 4.9) A]. More pioglitazone-treated patients experienced oedema (9.0 vs. 4.5%) and weight gain (9.1 vs. 2.7%) than placebo patients. CONCLUSIONS Pioglitazone in combination with insulin therapy improved glycaemic control, reduced insulin dose requirements and improved lipid profiles in patients with type 2 diabetes previously poorly controlled with combination therapy.
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Affiliation(s)
- P Berhanu
- Division of Diabetes, Endocrinology and Metabolism, Wayne State University School of Medicine, Detroit, MI, USA
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Moulin P. Les traitements à visée métabolique: «de la biochimie à la paroi». Rev Med Interne 2007; 28 Suppl 1:S12-3. [PMID: 17466416 DOI: 10.1016/j.revmed.2007.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- P Moulin
- Fédération d'endocrinologie diabétologie maladies métaboliques nutrition, hôpital cardiovasculaire Louis-Pradel, 69677 Bron, France.
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Park KG, Lee KM, Chang YC, Magae J, Ando K, Kim KB, Kim YN, Kim HS, Park JY, Lee KU, Lee IK. The ascochlorin derivative, AS-6, inhibits TNF-alpha-induced adhesion molecule and chemokine expression in rat vascular smooth muscle cells. Life Sci 2006; 80:120-6. [PMID: 16989870 DOI: 10.1016/j.lfs.2006.08.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Revised: 07/03/2006] [Accepted: 08/23/2006] [Indexed: 10/24/2022]
Abstract
Vascular inflammation induced by the proinflammatory cytokine/NF-kappaB pathway is one of the key mechanisms in the development of atherosclerosis. Peroxisome proliferators-activated receptor-gamma (PPARgamma) plays an important role in the prevention of arterial inflammation and formation of atherogenesis. Herein we examine the effects of a newly identified synthetic PPARgamma ligand, ascochlorin-6 (AS-6), on TNF-alpha-stimulated NF-kappaB activity and inflammatory molecule expression in vascular smooth muscle cells (VSMCs). AS-6 successfully inhibited TNF-alpha-stimulated NF-kappaB activity and inflammatory molecule expression, including vascular cell adhesion molecule-1 (VCAM-1), monocyte chemotactic protein-1 (MCP-1), and fractalkine (CX3CL1). Transient transfection with an [NF-kappaB]x4 luciferase reporter construct showed that AS-6 inhibition of TNF-alpha-stimulated NF-kappaB activation was PPARgamma-dependent. The effects of AS-6 on TNF-alpha-stimulated VCAM-1 and CX3CL1 expression were abolished in cells transfected with an adenovirus expressing dominant-negative PPARgamma and in cells treated with a PPARgamma specific inhibitor, GW9662, confirming again that the anti-inflammatory effect of AS-6 was PPARgamma-dependent. The inhibitory effects of AS-6 on TNF-alpha-stimulated inflammatory gene expression and NF-kappaB activation were more potent than those of rosiglitazone and pioglitazone. This study shows that AS-6 reduces the inflammatory response to TNF-alpha in VSMCs. The data suggest the possibility that AS-6 can be used to prevent the development and progression of atherosclerosis.
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Affiliation(s)
- Keun-Gyu Park
- Department of Internal Medicine and Institute for Medical Science, Keimyung University School of Medicine, Daegu, South Korea
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Hampel JKA, Brownrigg LM, Vignarajah D, Croft KD, Dharmarajan AM, Bentel JM, Puddey IB, Yeap BB. Differential modulation of cell cycle, apoptosis and PPARgamma2 gene expression by PPARgamma agonists ciglitazone and 9-hydroxyoctadecadienoic acid in monocytic cells. Prostaglandins Leukot Essent Fatty Acids 2006; 74:283-93. [PMID: 16647253 DOI: 10.1016/j.plefa.2006.03.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Revised: 02/15/2006] [Accepted: 03/12/2006] [Indexed: 12/22/2022]
Abstract
We sought to compare the effects of the thiazolidinedione ciglitazone with the endogenous fatty acid PPARgamma agonists 9- and 13-hydroxyoctadecadienoic acid (9- and 13-HODE), in U937 monocytic cells. Ciglitazone and 9-HODE inhibited cell proliferation and all three agonists increased cellular content of C18:0 fatty acids. Ciglitazone and 13-HODE resulted in an increased percentage of cells in S phase and ciglitazone reduced the percentage of cells in G2/M phase of cell cycle, whilst 9-HODE increased the percentage of cells in G0/1 and reduced the fraction in S and G2/M phases. 9-HODE selectively induced apoptosis in U937 cells, and increased PPARgamma2 gene expression. Induction of apoptosis by 9-HODE was not abrogated by the presence of the PPARgamma antagonist GW9662. Synthetic (TZD) and endogenous fatty acid ligands for PPARgamma, ciglitazone and 9- and 13-HODE, possess differential, ligand specific actions in monocytic cells to regulate cell cycle progression, apoptosis and PPARgamma2 gene expression.
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Affiliation(s)
- Jade K A Hampel
- School of Medicine and Pharmacology, University of Western Australia, Fremantle and Royal Perth Hospitals, Australia
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Pershadsingh HA. Treating the metabolic syndrome using angiotensin receptor antagonists that selectively modulate peroxisome proliferator-activated receptor-γ. Int J Biochem Cell Biol 2006; 38:766-81. [PMID: 16298156 DOI: 10.1016/j.biocel.2005.08.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Revised: 07/17/2005] [Accepted: 08/10/2005] [Indexed: 11/15/2022]
Abstract
The metabolic syndrome, defined as a cluster of visceral obesity, insulin resistance, dyslipidemia and elevated blood pressure, is associated with pro-thrombotic, pro-atherogenic and inflammatory risk factors that predispose to cardiovascular disease. Although activators of the peroxisome proliferator-activated receptors (PPARalpha,gamma,delta) in various combinations are under development for treating the metabolic syndrome, they are hampered by adverse effects related to increased adipogenesis, weight gain, fluid overload and carcinogenesis. The recent discovery that telmisartan and irbesartan, antihypertensive angiotensin II type 1 receptor (AT1-R) blockers (ARBs), were uniquely capable of activating PPARgamma, has provided a novel approach to addressing the multifactorial components of the metabolic syndrome. Both drugs have established favorable safety profiles and can activate PPARgamma at concentrations potentially achievable at therapeutic doses. Emerging studies have revealed that both these drugs have beneficial metabolic profiles. This information provides a strategic rationale and pharmacological platform for the development of novel dual ARB/PPARgamma agonists to target the metabolic syndrome and its cardiovascular sequelae, for which therapy is presently insufficient or non-existent. Beneficial effects of these agents include increased energy expenditure, improved lipid profile, increased insulin sensitivity, blood pressure reduction, and amelioration of the associated pro-inflammatory and pro-atherogenic risk profiles. The potential benefit for treatment of the metabolic syndrome, cardiovascular protection, and prevention of related end-organ complications could be of immense clinical value.
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Abstract
Patients at risk for diabetes development have been recently characterized as those presenting higher baseline serum glucose concentration, increased body mass index, elevated systolic blood pressure, reduced serum high-density lipoprotein-cholesterol and those with history of prior use of antihypertensive drugs. Little is known, however, about the long-term outcome of patients at high risk for diabetes development, so-called 'prediabetic' patients. Prediabetes state has been defined as the presence of either impaired glucose tolerance or impaired fasting glucose, and accumulating evidence suggests that individuals with a non-diabetic range of hyperglycaemia (prediabetic) are already at risk for cardiovascular diseases. This short review analyses the need of targeting 'prediabetic' hypertensive patients in order to develop strategies for cardiovascular protection intended to diminish the consequences of precipitating the development of diabetes and its cardiovascular and renal deleterious effects.
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Affiliation(s)
- Julián Segura
- Hypertension Unit, Hospital 12 de Octubre, Madrid, Spain.
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20
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Pershadsingh HA. New generation angiotensin II type 1 receptor antagonists that selectively modulate peroxisome proliferator-activated receptor-γ. Drug Dev Res 2006. [DOI: 10.1002/ddr.20142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Abstract
Insulin resistance underlies the pathogenesis of hyperglycaemia and cardiovascular disease in most people with type 2 diabetes. Metformin and thiazolidinediones (pioglitazone and rosiglitazone) counter insulin resistance by different cellular mechanisms and with complementary effects, making them suited for use in combination. Metformin exerts a stronger suppression of hepatic glucose output, while thiazolidinediones produce a greater increase in peripheral glucose uptake, enabling metformin-thiazolidinedione combinations to improve glycaemic control in type 2 diabetes with additive efficacy. Basal insulin concentrations are not raised by metformin or thiazolidinediones, so there is minimal risk of hypoglycaemia, and metformin can reduce the weight gain associated with thiazolidinediones. There are overlapping effects of metformin and thiazolidinediones against a range of athero-thrombotic factors and markers. These include decreased plasminogen activator inhibitor-1, reduced platelet aggregation, reductions of several vascular adhesion molecules, and reduced markers of low-grade inflammation such as C-reactive protein. Additionally, thiazolidinediones increase adiponectin and slightly reduce blood pressure. Both metformin and thiazolidinediones can improve components of the lipid profile: thiazolidinediones consistently reduce free fatty acid concentrations and decrease the proportion of small dense low-density-lipoprotein, and pioglitazone also decreases triglycerides. During co-administration, metformin and thiazolidinediones do not interfere with each other's pharmacokinetics, and lower doses of the two agents together can achieve efficacy with fewer side effects. Metformin-thiazolidinedione combinations require attention to the precautions for both agents, especially renal, cardiac and hepatic status. Thus, metformin and thiazolidinediones can be used in combination to address the hyperglycaemia and vascular risk in type 2 diabetes.
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Affiliation(s)
- C J Bailey
- School of Life and Health Sciences, Aston University, Birmingham, UK.
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22
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Revelo MP, Federspiel C, Helderman H, Fogo AB. Chronic allograft nephropathy: expression and localization of PAI-1 and PPAR-gamma. Nephrol Dial Transplant 2005; 20:2812-9. [PMID: 16221712 DOI: 10.1093/ndt/gfi172] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Chronic allograft nephropathy (CAN) is a major cause of loss of renal allografts. Mechanisms postulated to be involved include sequelae of rejection, warm ischaemia time, drug toxicity, ongoing hypertension and dyslipidaemia. Plasminogen activator inhibitor-1 (PAI-1) is implicated not only in thrombosis, but also in fibrosis, by inhibiting matrix degradation, and is expressed in renal parenchymal cells as well as in macrophages. Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a member of the steroid receptor superfamily, and plays a major beneficial role in lipid regulation, insulin sensitivity and macrophage function, factors that may play a role in CAN. We therefore studied the expression of these molecules in CAN. METHODS All renal biopsy/nephrectomy files from Vanderbilt and Nashville VAMC from a 6 year period were reviewed to identify all renal transplant biopsies or nephrectomies more than 6 months after transplant with CAN. CAN was defined as fibrosis in the graft, vascular, interstitial or glomerular. All cases were scored for severity of fibrosis in vasculature (0-3 scale), glomeruli (% affected with either segmental and/or global sclerosis) and interstitial fibrosis (% of sample affected). PAI-1 and PPAR-gamma immunostaining was assessed on a 0-3 scale in glomeruli, vessels and tubules. RESULTS Eighty-two patients with a total of 106 samples met entry criteria. The population consisted of 59 Caucasians and 23 African-Americans; 49 males, 33 females with average age 37.9+/-1.7 years. Average time after transplant at time of biopsy was 60.5+/-4.9 months (range 7-229). Glomerulosclerosis extent in CAN was on average 26.5+/-2.4% compared with 3.6+/-1.2% in normal control kidneys from native kidney cancer nephrectomies and 0% in transplanted kidney biopsies from patients obtained > or =6 months after transplantation without CAN. Native control kidneys showed mild interstitial fibrosis (8.0+/-1.2%), whereas transplant controls showed very minimal fibrosis (2.0+/-2.0%). Interstitial fibrosis in CAN kidneys was on average 47.9+/-2.4%. Glomerular PAI-1 and PPAR-gamma staining scores were markedly increased in CAN (1.8+/-0.1, 2.3+/-0.1, respectively) compared with normal control kidneys from native kidney cancer nephrectomies (PAI-1 0.2+/-0.2 and PPAR-gamma 0.4+/-0.2, P<0.001) and transplanted kidney biopsies from patients obtained > or =6 months after transplantation without CAN (PAI-1 0 and PPAR-gamma 0, P<0.001). Tubular PAI-1 and PPAR-gamma staining scores were 1.9+/-0.1 and 1.9+/-0.1, respectively, and also increased over both native and transplant kidney controls (0.8+/-0.2 for both categories for PAI-1, 1.2+/-0.2 for both categories for PPAR-gamma, respectively). Vascular sclerosis in CAN was 1.0+/-0.1 with increased PAI-1 and PPAR-gamma scores (1.7+/-0.1, 1.2+/-0.1, respectively) compared with controls. Infiltrating macrophages were increased in CAN, and were positive for both PAI-1 and PPAR-gamma. Biopsies with less sclerosis overall showed a trend for less PAI-1 and PPAR-gamma staining. CONCLUSION PAI-1 and PPAR-gamma are both increased in CAN compared with non-scarred native or transplant control kidneys. We speculate that altered matrix metabolism and macrophage function might be involved in the development of CAN.
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Affiliation(s)
- Monica P Revelo
- Department of Pathology, C3310 Medical Center North, Vanderbilt University Medical Center, Nashville, TN 37232-2561, USA
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Johns DG, Ao Z, Eybye M, Olzinski A, Costell M, Gruver S, Smith SA, Douglas SA, Macphee CH. Rosiglitazone Protects against Ischemia/Reperfusion-Induced Leukocyte Adhesion in the Zucker Diabetic Fatty Rat. J Pharmacol Exp Ther 2005; 315:1020-7. [PMID: 16123307 DOI: 10.1124/jpet.105.090993] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Increased susceptibility to atherosclerosis increases the risk of mortality in type 2 diabetic patients. Leukocyte adhesion to the endothelium is a critical step in atherogenesis. In addition to its insulin-sensitizing effects, rosiglitazone (RSG) possesses anti-inflammatory properties. However, the effects of RSG on the initial phase of leukocyte recruitment (rolling, adhesion) have not been studied in vivo. This study tested the hypothesis that RSG treatment of Zucker diabetic fatty (ZDF) rats inhibits ischemia/reperfusion-induced leukocyte adhesion to the endothelium. Male ZDF rats (16 weeks) were treated with RSG (3 mg/kg/day, p.o.) 7 days before experimentation. Leukocyte-endothelial interactions in cremaster venules were recorded using intravital microscopy prior to 30 min of ischemia and during a 90-min reperfusion period. Although blood pressure, plasma glucose, and insulin were not different between treatment groups, RSG treatment was associated with reduced leukocyte rolling and inhibition of leukocyte adhesion throughout the reperfusion period (P < 0.01). Cremaster mRNA expression of vascular cell adhesion molecule-1 (VCAM-1) was reduced by 35% in RSG-treated animals (P < 0.01), whereas P- and E-selectin and intercellular adhesion molecule-1 (ICAM-1) were unchanged. Immunostaining for P-selectin, E-selectin, and VCAM-1 was reduced by 21, 61, and 50%, respectively (for all, P < 0.05), in RSG-treated animals. Inhibition of ischemia/reperfusion-induced leukocyte adhesion might contribute to the utility of RSG as a therapy for vascular disease.
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Affiliation(s)
- Douglas G Johns
- Department of Vascular Biology and Thrombosis, GlaxoSmithKline, 709 Swedeland Rd, UW2510, King of Prussia, PA 19406, USA.
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Chui PC, Guan HP, Lehrke M, Lazar MA. PPARgamma regulates adipocyte cholesterol metabolism via oxidized LDL receptor 1. J Clin Invest 2005; 115:2244-56. [PMID: 16007265 PMCID: PMC1172230 DOI: 10.1172/jci24130] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Accepted: 05/17/2005] [Indexed: 01/21/2023] Open
Abstract
In addition to its role in energy storage, adipose tissue also accumulates cholesterol. Concentrations of cholesterol and triglycerides are strongly correlated in the adipocyte, but little is known about mechanisms regulating cholesterol metabolism in fat cells. Here we report that antidiabetic thiazolidinediones (TZDs) and other ligands for the nuclear receptor PPARgamma dramatically upregulate oxidized LDL receptor 1 (OLR1) in adipocytes by facilitating the exchange of coactivators for corepressors on the OLR1 gene in cultured mouse adipocytes. TZDs markedly stimulate the uptake of oxidized LDL (oxLDL) into adipocytes, and this requires OLR1. Increased OLR1 expression, resulting either from TZD treatment or adenoviral gene delivery, significantly augments adipocyte cholesterol content and enhances fatty acid uptake. OLR1 expression in white adipose tissue is increased in obesity and is further induced by PPARgamma ligand treatment in vivo. Serum oxLDL levels are decreased in both lean and obese diabetic animals treated with TZDs. These data identify OLR1 as a novel PPARgamma target gene in adipocytes. While the physiological role of adipose tissue in cholesterol and oxLDL metabolism remains to be established, the induction of OLR1 is a potential means by which PPARgamma ligands regulate lipid metabolism and insulin sensitivity in adipocytes.
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Affiliation(s)
- Patricia C Chui
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6149, USA
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Abstract
Osteoporosis and atherosclerosis are both widely prevalent in an ageing population, and induce serious morbidities and death. There is growing evidence that in addition to their relationship to ageing, osteoporosis and atherosclerosis are also linked by biological associations. This article reviews their clinical interrelations, discusses the basic biology of bone and the arterial wall, and presents five examples that illustrate their biological linkages. Current therapeutic approaches emerging from these linkages, including statins, bisphosphonates, and the thiazolidinediones, have dual effects on bone and the vasculature. Additional therapies derived from experimental studies that enhance bone density and reduce atherogenesis hold further promise to diminish the morbidity and mortality of osteoporosis and atherosclerosis, with attendant benefits to society.
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Affiliation(s)
- D Hamerman
- Department of Medicine and Resnick Gerontology Center, Albert Einstein College of Medicine and Montefiore Medical Center, 111 East 210th Street, Bronx, NY 10467, USA.
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Singh N, Webb R, Adams R, Evans SA, Al-Mosawi A, Evans M, Roberts AW, Thomas AW. The PPAR-γ activator, Rosiglitazone, inhibits actin polymerisation in monocytes: Involvement of Akt and intracellular calcium. Biochem Biophys Res Commun 2005; 333:455-62. [PMID: 15950942 DOI: 10.1016/j.bbrc.2005.05.127] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Accepted: 05/18/2005] [Indexed: 11/15/2022]
Abstract
Monocyte hyperactivation as seen in diabetes results in increased cytoskeletal rigidity and reduced cell deformability leading to microchannel occlusions and microvascular complications. The thiazolidinediones (TZDs) are PPAR-gamma agonists that have been reported to exert beneficial non-metabolic effects on the vasculature. This study demonstrates that the TZD, Rosiglitazone, significantly reduces f-MLP-induced actin polymerisation in human monocytic cells (p < 0.05). Two of the key signalling processes known to be involved in the regulation of cytoskeletal remodelling were investigated: PI(3)K-dependent Akt phosphorylation and intracellular calcium concentration [Ca(2+)](i). The PI(3)K inhibitor, Wortmannin, ameliorated f-MLP-induced actin polymerisation (p < 0.05), while the Ca(2+) sequestration inhibitor, thapsigargin, induced actin depolymerisation (p < 0.05), confirming the involvement of both processes in cytoskeletal remodelling. Rosiglitazone significantly reduced f-MLP activation of Akt (p < 0.05), and significantly increased [Ca(2+)](i) in both resting and f-MLP-stimulated cells (p < 0.05). Therefore, Rosiglitazone interacts with signalling events downstream of occupancy of the f-MLP receptor, to modulate cytoskeletal remodelling in a PPAR-gamma-independent manner. To our knowledge, these results are the first to present evidence that a PPAR-gamma agonist can modulate actin remodelling in monocytes, and may therefore be protective against microvascular damage in diabetes.
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Affiliation(s)
- Neenu Singh
- School of Applied Science, University of Wales Institute Cardiff, Western Avenue, Cardiff CF5 2YB, UK
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Abstract
Type 2 diabetes mellitus is a progressive and complex disorder that is difficult to treat effectively in the long term. The majority of patients are overweight or obese at diagnosis and will be unable to achieve or sustain near normoglycaemia without oral antidiabetic agents; a sizeable proportion of patients will eventually require insulin therapy to maintain long-term glycaemic control, either as monotherapy or in conjunction with oral antidiabetic therapy. The frequent need for escalating therapy is held to reflect progressive loss of islet beta-cell function, usually in the presence of obesity-related insulin resistance. Today's clinicians are presented with an extensive range of oral antidiabetic drugs for type 2 diabetes. The main classes are heterogeneous in their modes of action, safety profiles and tolerability. These main classes include agents that stimulate insulin secretion (sulphonylureas and rapid-acting secretagogues), reduce hepatic glucose production (biguanides), delay digestion and absorption of intestinal carbohydrate (alpha-glucosidase inhibitors) or improve insulin action (thiazolidinediones). The UKPDS (United Kingdom Prospective Diabetes Study) demonstrated the benefits of intensified glycaemic control on microvascular complications in newly diagnosed patients with type 2 diabetes. However, the picture was less clearcut with regard to macrovascular disease, with neither sulphonylureas nor insulin significantly reducing cardiovascular events. The impact of oral antidiabetic agents on atherosclerosis--beyond expected effects on glycaemic control--is an increasingly important consideration. In the UKPDS, overweight and obese patients randomised to initial monotherapy with metformin experienced significant reductions in myocardial infarction and diabetes-related deaths. Metformin does not promote weight gain and has beneficial effects on several cardiovascular risk factors. Accordingly, metformin is widely regarded as the drug of choice for most patients with type 2 diabetes. Concern about cardiovascular safety of sulphonylureas has largely dissipated with generally reassuring results from clinical trials, including the UKPDS. Encouragingly, the recent Steno-2 Study showed that intensive target-driven, multifactorial approach to management, based around a sulphonylurea, reduced the risk of both micro- and macrovascular complications in high-risk patients. Theoretical advantages of selectively targeting postprandial hyperglycaemia require confirmation in clinical trials of drugs with preferential effects on this facet of hyperglycaemia are currently in progress. The insulin-sensitising thiazolidinedione class of antidiabetic agents has potentially advantageous effects on multiple components of the metabolic syndrome; the results of clinical trials with cardiovascular endpoints are awaited. The selection of initial monotherapy is based on a clinical and biochemical assessment of the patient, safety considerations being paramount. In some circumstances, for example pregnancy or severe hepatic or renal impairment, insulin may be the treatment of choice when nonpharmacological measures prove inadequate. Insulin is also required for metabolic decompensation, that is, incipient or actual diabetic ketoacidosis, or non-ketotic hyperosmolar hyperglycaemia. Certain comorbidities, for example presentation with myocardial infarction during other acute intercurrent illness, may make insulin the best option. Oral antidiabetic agents should be initiated at a low dose and titrated up according to glycaemic response, as judged by measurement of glycosylated haemoglobin (HbA1c) concentration, supplemented in some patients by self monitoring of capillary blood glucose. The average glucose-lowering effect of the major classes of oral antidiabetic agents is broadly similar (averaging a 1-2% reduction in HbA1c), alpha-glucosidase inhibitors being rather less effective. Tailoring the treatment to the individual patient is an important principle. Doses are gradually titrated up according to response. However, the maximal glucose-lowering action for sulphonylureas is usually attained at appreciably lower doses (approximately 50%) than the manufacturers' recommended daily maximum. Combinations of certain agents, for example a secretagogue plus a biguanide or a thiazolidinedione, are logical and widely used, and combination preparations are now available in some countries. While the benefits of metformin added to a sulphonylurea were initially less favourable in the UKPDS, longer-term data have allayed concern. When considering long-term therapy, issues such as tolerability and convenience are important additional considerations. Neither sulphonylureas nor biguanides are able to appreciably alter the rate of progression of hyperglycaemia in patients with type 2 diabetes. Preliminary data suggesting that thiazolidinediones may provide better long-term glycaemic stability are currently being tested in clinical trials; current evidence, while encouraging, is not conclusive. Delayed progression from glucose intolerance to type 2 diabetes in high-risk individuals with glucose intolerance has been demonstrated with troglitazone, metformin and acarbose. However, intensive lifestyle intervention can be more effective than drug therapy, at least in the setting of interventional clinical trials. No antidiabetic drugs are presently licensed for use in prediabetic individuals.
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Affiliation(s)
- Andrew J Krentz
- Southampton University Hospitals NHS Trust, Southampton, UK.
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Gouni-Berthold I, Giannakidou E, Müller-Wieland D, Faust M, Kotzka J, Berthold HK, Krone W. Peroxisome proliferator-activated receptor-??2 Pro12Ala and endothelial nitric oxide synthase-4a/b gene polymorphisms are not associated with hypertension in diabetes mellitus type 2. J Hypertens 2005; 23:301-8. [PMID: 15662218 DOI: 10.1097/00004872-200502000-00012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE AND DESIGN The Pro12Ala and the 4a/b polymorphisms of the peroxisome proliferator-activated receptor gamma (PPARgamma) and the endothelial nitric oxide-synthase (eNOS) genes, respectively, have been associated with hypertension in some but not all studies. The purpose of this study was to investigate the association between these polymorphisms and hypertension in patients with diabetes mellitus type 2 (DM2). METHODS We determined, by polymerase chain reaction (PCR), the Pro12Ala PPARgamma2 and the eNOS 4a/b gene polymorphisms in a total of 395 patients with diabetes mellitus 2 (DM2) (225 men and 170 women) from the LIANCO (Lipid-Analytic-Cologne) study. Hypertension was defined as known or newly diagnosed hypertension according to current national guidelines. Associations were determined using chi-square statistics. The influence of genotype and other parameters on blood pressure was determined by analysis of variance (ANOVA) and multivariate analyses. RESULTS The genotype frequencies of the Pro12Ala polymorphism were 3% AlaAla, 23% ProAla and 74% ProPro and of the eNOS 4a/b polymorphism 3% a/a, 25% b/a and 72% b/b. There were 65% patients with, and 35% without hypertension. A total of 77% of the patients with hypertension were under pharmacological treatment. The mean systolic and diastolic blood pressure (SBP, DBP) was 148 +/- 22 and 84 +/- 11 mmHg in patients with, and 131 +/- 12 and 79 +/- 8 mmHg in patients without, hypertension. There was no difference in the occurrence of hypertension among ProAla and AlaAla subjects compared with ProPro subjects (P = 0.98). There was also no difference between a-allele carriers and non-carriers of the eNOS polymorphism (P = 0.42). There were no differences between men and women in the associations. Analysis of variance did neither identify an influence on systolic or diastolic blood pressure by the presence of the Ala or the a-allele of the respective genotypes nor a significant interaction of the two. CONCLUSIONS In DM2 the Pro12Ala and 4a/b gene polymorphisms of the PPARgamma2 and eNOS genes, respectively, are not associated with systolic or diastolic blood pressure, either in men or in women. Our results in a large cohort fail to confirm reports of recent studies suggesting an association of lower blood pressure in patients with DM2 and carriers of Pro12Ala polymorphism.
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Affiliation(s)
- Ioanna Gouni-Berthold
- Department of Internal Medicine II, University of Cologne and Center of Molecular Medicine Cologne (CMMC), Cologne, Germany.
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Nakamura T, Matsuda T, Kawagoe Y, Ogawa H, Takahashi Y, Sekizuka K, Koide H. Effect of pioglitazone on carotid intima-media thickness and arterial stiffness in type 2 diabetic nephropathy patients. Metabolism 2004; 53:1382-6. [PMID: 15375799 DOI: 10.1016/j.metabol.2004.05.013] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Atherosclerosis is the major cause of morbidity and mortality in patients with type 2 diabetes, and pioglitazone has been reported to have anti-inflammatory and potential antiatherogenic effects. The aim of the present study was to determine whether pioglitazone, glibenclamide, or voglibose affects carotid intima-media thickness (IMT), pulse wave velocity (PWV), and urinary albumin excretion (UAE) in normotensive type 2 diabetic nephropathy patients. Forty-five normotensive type 2 diabetes patients with microalbuminuria were randomized to 12-month treatment with pioglitazone (30 mg/d, n = 15), glibenclamide (5 mg/d, n = 15), or voglibose (0.6 mg/d, n = 15). Pre- and posttreatment UAE, PWV, and IMT values were compared between treatment groups and a group of age-matched healthy control subjects (n = 30). Pretreatment PWV, IMT, and UAE values differed little between the 3 groups, but UAE was greater in the 45 type 2 diabetes patients (132.5 +/- 36.4 microg/min) than in the control subjects (6.2 +/- 1.8 microg/min, P < .001). IMT (0.76 +/- 0.12 mm) was significantly greater in the diabetics than in the controls (0.60 +/- 0.08 mm, P < .01). PWV (1,840 +/- 320 cm/s) was also significantly greater in the diabetics than in the controls (1,350 +/- 225 cm/s, P < .01). After 6 and 12 months, UAE, IMT, and PWV in the pioglitazone treatment group were significantly lower than those in the glibenclamide treatment group and voglibose treatment group (UAE: 6 months, P < .05 and 12 months, P < .01; IMT and PWV: 6 months, P < .05 and 12 months, P < .05). Pioglitazone, but not glibenclamide or voglibose, appears to be effective in reducing UAE, IMT, and PWV in normotensive type 2 diabetes patients with microalbuminuria.
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Affiliation(s)
- Tsukasa Nakamura
- Department of Medicine, Shinmatsudo Central General Hospital, Chiba, Japan
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Bailey CJ, Day C. Avandamet: combined metformin-rosiglitazone treatment for insulin resistance in type 2 diabetes. Int J Clin Pract 2004; 58:867-76. [PMID: 15529521 DOI: 10.1111/j.1742-1241.2004.00318.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Insulin resistance is a major endocrinopathy underlying the development of hyperglycaemia and cardiovascular disease in type 2 diabetes. Metformin (a biguanide) and rosiglitazone (a thiazolidinedione) counter insulin resistance, acting by different cellular mechanisms. The two agents can be used in combination to achieve additive glucose-lowering efficacy in the treatment of type 2 diabetes, without stimulating insulin secretion and without causing hypoglycaemia. Both agents also reduce a range of atherothrombotic factors and markers, indicating a lower cardiovascular risk. Early intervention with metformin is already known to reduce myocardial infarction and increase survival in overweight type 2 patients. Recently, a single-tablet combination of metformin and rosiglitazone, Avandamet, has become available. Avandamet is suitable for type 2 diabetic patients who are inadequately controlled by monotherapy with metformin or rosiglitazone. Patients already receiving separate tablets of metformin and rosiglitazone may switch to the single-tablet combination for convenience. Also, early introduction of the combination before maximal titration of one agent can reduce side effects. Use of Avandamet requires attention to the precautions for both metformin and rosiglitazone, especially renal, cardiac and hepatic competence. In summary, Avandamet is a single-tablet metformin-rosiglitazone combination that doubly targets insulin resistance as therapy for hyperglycaemia and vascular risk in type 2 diabetes.
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Affiliation(s)
- C J Bailey
- School of Life and Health Sciences, Aston University, Birmingham, UK.
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Pearce KH, Iannone MA, Simmons CA, Gray JG. Discovery of novel nuclear receptor modulating ligands: an integral role for peptide interaction profiling. Drug Discov Today 2004; 9:741-51. [PMID: 15450240 DOI: 10.1016/s1359-6446(04)03201-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There is currently a marketed drug for nearly every nuclear receptor for which the natural ligand has been identified. However, because of the complexity of signal transduction by this class of ligand-regulated transcription factors, few of these drugs have been optimized for pharmaceutical effectiveness. Over the past several years, structural and biochemical work has shed light on some of the ligand-induced features of nuclear receptors that enable them to trigger signal transduction cascades. This review will highlight the use of peptide interactions to cluster different classes of ligands and to identify novel nuclear receptor-modulating ligands as potential drug candidates. Phage display and a multiplexed peptide interaction assay are two of the technologies that are key to this approach. When used as part of a drug discovery platform, this type of biochemical characterization can bridge the gap between high-throughput chemical synthesis and disease model testing. Furthermore, the development of these methodologies is timely because there is a significant medical need for new and improved nuclear receptor drugs that retain beneficial effects but do not have undesired side effect activities.
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Affiliation(s)
- Kenneth H Pearce
- Department of Gene Expression and Protein Biochemistry, GlaxoSmithKline Discovery Research, Research Triangle Park, NC 27709, USA.
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Meyers CD, Kashyap ML. Pharmacologic elevation of high-density lipoproteins: recent insights on mechanism of action and atherosclerosis protection. Curr Opin Cardiol 2004; 19:366-73. [PMID: 15218398 DOI: 10.1097/01.hco.0000126582.27767.87] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE OF REVIEW Despite the best efforts in reduction of low-density lipoprotein cholesterol, most cardiovascular events are not being prevented. Because high-density lipoprotein (HDL) promotes reverse cholesterol transport and other antiatherogenic effects, interventions aimed at raising HDL cholesterol or mimicking its beneficial effects may greatly improve treatment and prevention of cardiovascular disease. This article reviews the antiatherogenic effects of HDL, recent insights into the mechanisms of action of currently available, and emerging HDL-based therapies. RECENT FINDINGS New insights into the basic science of HDL function and metabolism (such as the discovery of beta-chain ATP synthase as a hepatic catabolic HDL receptor) are further characterizing the importance of HDL in atheroprotection and identifying novel targets of drug development. Nicotinic acid, fibrates, statins, and thiazolidinediones not only increase HDL cholesterol but also alter HDL subpopulation size and composition. Furthermore, these drugs promote direct antiatherogenic effects of HDL (antioxidation, anti-inflammation, antithrombotic effects, endothelial stabilization). Emerging HDL-raising therapies (such as cholesteryl ester transfer protein inhibitors and 1,2-dimyristoyl-sn-glycero-phosphocholine) and novel interventions that mimic HDL's beneficial effects (such as apolipoprotein AImilano and apolipoprotein AI mimetic peptides) are proving beneficial in animal and human studies. SUMMARY An understanding of the atheroprotective mechanisms of HDL is essential for the rational use of currently available drugs and directed development of new drugs. Increasing total HDL cholesterol may not be as important as increasing the functional properties of HDL. Cardiovascular disease treatment and prevention can be improved by combining current low-density lipoprotein-based strategies with effective HDL-based interventions.
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Affiliation(s)
- C Daniel Meyers
- Atherosclerosis Research Center, VA Long Beach Healthcare System, Long Beach, California, USA
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