1. Complications in Type 1 Diabetes: Nephropathy Peter A. Gottlieb, MD Barbara Davis Center University of Colorado Health Sciences Center Denver, CO

2. Why do complications occur? Insulin hypothesisInsulin hypothesis Glucose hypothesisGlucose hypothesis DCCT and many other studies support glucose hypothesisDCCT and many other studies support glucose hypothesis

3. EDIC: Long Term Benefit of Intensive Treatment -The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Research Group. N Engl J Med 2000;342:381-9.

4. EDIC: Long Term Benefit of Intensive Treatment -The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Research Group. N Engl J Med 2000;342:381-9.

5. EDIC: Long Term Benefit of Intensive Treatment - The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Research Group. N Engl J Med 2000;342:381-9.

6. Transient hyperglycemia leads to oxidative stress which increases complications Testing of this hypothesis is needed to determine if this is indeed true

8. Diabetic Nephropathy: Pathogenesis Increased intraglomerular pressure Mesangial cell expansion Reactive Oxygen Species (ROS) Endothelial cell dysfunction Increased Glomerular Basement Membrane Thickness and Interstitial Fibrosis

9. DETAIL Study: Head to Head Comparison of ACE vs. ARB in Type 2 DN 5 yr, prospective, multicenter, randomized study in T2DM with HTN and early DN 120 subjects onTelmisartan 40-80 mg/day vs. 130 subjects on Enalapril 10-20 mg/day Primary endpoint: Change in GFR Secondary endpoints: Change in albuminuria, BP, CR, other CV outcome measures

11. DETAIL: Baseline Characteristics

12. DETAIL: Equivalent Protection from ACE and ARB in Change GFR

13. DETAIL: Key Points Use of ACE or ARB slows down loss of GFR in T2DM with nephropathy Confirms previous shorter term studies Additional protection seen for CV complications

14. ACE and ARB Lower Proteinuria better than ACE alone in T2DM Small 24 week study with 26 pts demonstrated that combination therapy of Losartan with Enalapril reduced proteinura greater than increased dose of Enalapril alone Blood pressure was similarly lowered in both groups CRP levels were lowered in combined treatment group, unchanged in ACE alone Other parameters measured were not significantly different between groups Igarashi, et al, Endocrine Journal, 2006, epub

15. Prevention and Treatment of Diabetic Nephropathy in T1DM Periodic screening for microalbuminuria – timed overnight samples beginning at 5 years from diagnosis Treatment of either microalbuminuria or HTN (to 120/80 or age-matched target) with ACE or ARB Use ACE or ARB, ACE with ARB and Diuretics, then consider other therapies based on clinical considerations

16. How do complications occur? Activation of Polyol PathwayActivation of Polyol Pathway Accumulation of Advanced Glycosylation End ProductsAccumulation of Advanced Glycosylation End Products Protein Kinase C PathwayProtein Kinase C Pathway Flux Through the Hexosamine PathwayFlux Through the Hexosamine Pathway Oxygen Radicals and Enhanced Oxidative StressOxygen Radicals and Enhanced Oxidative Stress Altered Expression of Growth Factors and Vasoactive MediatorsAltered Expression of Growth Factors and Vasoactive Mediators

17. Aldose Reductase and Polyol Pathway - Brownlee, M. Nature 2001 414:13 813-820.

18. AGE Pathway - Brownlee, M. Nature 2001 414:13 813-820.

19. How can we intervene? Polyol Pathway – Sorbinil, ZenarestatPolyol Pathway – Sorbinil, Zenarestat Advanced Glycosylation End Products – Aminoguanidine, sR RAGEAdvanced Glycosylation End Products – Aminoguanidine, sR RAGE Protein Kinase C Pathway – Selective PKC inhibitors such as LY333531Protein Kinase C Pathway – Selective PKC inhibitors such as LY333531 Flux through Hexamine – ?Flux through Hexamine – ? Oxidative Stress – Vitamin C, Vitamin E,  lipoic acidOxidative Stress – Vitamin C, Vitamin E,  lipoic acid Altered Expression of Growth Factors – VEGF inhibitorsAltered Expression of Growth Factors – VEGF inhibitors

20. Effect of  -lipoic acid on experiemental diabetic retinopathy Lin, et al, Diabetologia, 2006, 49:1089-1096

21. Do they work? Sorbinil, Zenarestat - Toxicity, IneffectiveSorbinil, Zenarestat - Toxicity, Ineffective Aminoguanidine, sR RAGE - ?Aminoguanidine, sR RAGE - ? PKC inhibitors - LY333531 - MaybePKC inhibitors - LY333531 - Maybe Flux through Hexamine – ?Flux through Hexamine – ? Oxidative Stress – Vitamin C, Vitamin E,  lipoic acid – Small effect?Oxidative Stress – Vitamin C, Vitamin E,  lipoic acid – Small effect? Altered Expression of Growth Factors – VEGF inhibitors - UnknownAltered Expression of Growth Factors – VEGF inhibitors - Unknown

22. Why have our best efforts not succeeded? ToxicityToxicity Drug Development – EfficacyDrug Development – Efficacy Need to target multiple pathways at onceNeed to target multiple pathways at once Or something else?Or something else?

23. PKC Pathway - Brownlee, M. Nature 2001 414:13 813-820.

24. Unified Theory of Complications - Brownlee, M. Nature 2001 414:13 813-820.

25. Inhibition of GAPDH Affects Multiple Complication Pathways - Du X, et al. J. Clin. Invest. 112:1049–1057 (2003).

26. New Therapeutic Approaches Glyceraldehyde-3-phosphate and fructose- 6-phosphate are major substrates for complication pathwaysGlyceraldehyde-3-phosphate and fructose- 6-phosphate are major substrates for complication pathways Benfotiamine, is a derivative of the B vitamin thiamineBenfotiamine, is a derivative of the B vitamin thiamine Activates the thiamine dependent pentose phosphate enzyme transketolase which converts these compounds away from these pathwaysActivates the thiamine dependent pentose phosphate enzyme transketolase which converts these compounds away from these pathways Affecting this pathway changes substrate availability for polyol, hexosamine, diacylglycerol (PKC), AGE pathway and NF-  B signalingAffecting this pathway changes substrate availability for polyol, hexosamine, diacylglycerol (PKC), AGE pathway and NF-  B signaling

27. MMF and ACE synergize to Reverse Experimental DN Wu, et al. Inflamm res. 2006. 192-199

28. MMF and ACE synergize to Reverse Experimental DN Wu, et al. Inflamm res. 2006. 192-199 TGF  ED1 MCP-1

29. Unified Theory of Complications - Brownlee, M. Nature 2001 414:13 813-820. Benfotiamine PARP inhibitors

30. New Therapeutic Approaches Molecules which can affect GAPDH activity Superoxide Dismutase Poly(ADPribose)polymerase (PARP) inhibitors, PJ34

31. Summary Tight control of blood sugars is the best means to prevent and reverse complications of diabetesTight control of blood sugars is the best means to prevent and reverse complications of diabetes Reducing glycemic variability may also contribute to the development of complications and can be achieved with CGMSReducing glycemic variability may also contribute to the development of complications and can be achieved with CGMS Therapies such as PKC inhibitors which attack single pathways may be of benefitTherapies such as PKC inhibitors which attack single pathways may be of benefit New therapeutic approaches which can target multiple pathways simultaneously may offer the best chance to prevent complicationsNew therapeutic approaches which can target multiple pathways simultaneously may offer the best chance to prevent complications

32. Thank you