Renal Failure and the diabetic Foot Andrew J M Boulton, MD, DSc, - PowerPoint PPT Presentation

Renal Failure and the diabetic Foot Andrew J M Boulton, MD, DSc, FACP, FICP,FRCP Universities of Manchester, UK and Miami, FL, USA President, Worldwide Diabetes Educational Initiative “The art of medicine consists of Complications of Diabetes Affect Every amusing the patient while Part of the Body nature cures the disease” Microvascular Complications Macrovascular Complications Voltaire Diabetic Retinopathy Stroke NOT now Leading 2- to 4-fold increase in cause of blindness in cardiovascular mortality working-age adults and stroke Heart Diabetic Nephropathy Disease Leading cause of end-stage renal disease Diabetic Neuropathy Leading cause of Peripheral nontraumatic Vascular Disease lower extremity amputations Harris MI. Clin Invest Med . 1995;18:231-239. Nelson RG, et al. Adv Nephrol Necker Hosp . 1995;24:145-156. World Health Organization. Diabetes Mellitus Fact Sheet 138 .2002.

The Harsh Reality of Diabetes Diabetes... an affliction that is not very frequent…being a melting down of the • Most common cause of ESRD in Europe/USA flesh and limbs into the urine…life is short, 140 per million in diabetes disgusting and painful…thirst 15-42 per million in non-diabetes unquenchable…the kidneys and bladder never stop making water…it may be • Once on dialysis poor survival if diabetic something pernicious, derived from other 5 year survival 30.2% if diabetic diseases, which attack the bladder and 5 year survival 62.2% if non-diabetic kidneys Areteus of Cappadocia (early 2nd century ad) Proteinuria Is an Independent Risk Incidence of End Stage Renal Disease Factor for Mortality in Type 2 Diabetes diabetes ACEi 1.0 Normoalbuminuria hypertension 0.9 (n = 191) P <.01 Microalbuminuria 0.8 glomerulonephritis Survival (n = 86) P <.05 (all-cause cystic kidney disease mortality) 0.7 Macroalbuminuria* (n = 51) 0.6 0.5 0 1 2 3 4 5 6 Years * P < 0.001 normoalbuminuria vs macroalbuminuria. Gall MA et al. Diabetes . 1995;44:1303-1309. Rossing P Diabetologia 2005;48:1439-1444

Annual Transition Rates Causal Pathways for Foot Through Stages of DN Ulceration No nephropathy 1.4% • Neuropathy most important component 2.0% (1.3% to 1.5%) (1.9% to 2.2%) cause (78%) Microalbuminuria • Critical triad: neuropathy, deformity, 3.0% and trauma present in 63% 2.8% (2.6% to 3.4%) (2.5% to 3.2%) • Ischemia component cause in 35% Macroalbuminuria • >80% of ulcers potentially preventable 4.6% 2.3% (3.6% to 5.7%) (1.5% to 3.0%) Elevated plasma creatinine or Renal replacement therapy 19.2% (14.0% to 24.4%) DN = diabetic nephropathy. Adler et al . Kidney Int. 2003;63:225-232. Reiber, Vileikyte et al, 1999. Risk Factors for foot ulceration in Risk Factors for foot ulceration Diabetic Nephropathy: in Diabetic Nephropathy Results • VPT, NCV and foot pressures 84 patients studied significantly reduced in all 3 groups – • 4 groups: Microalbuminuria (MA), eg., VPT: MA=21, A=28, CRF=39V. Albuminuria (A); Chronic Renal • Past history of ulcers in 5% NN, 10% Failure(CRF) and non-nephropathic MA and A, and 40% CRF. diabetes (N) • Patients at all stages of nephropathy • VPT, NCVs and dynamic foot pressures have increased DFU risk. assessed Fernando DJ et al, Diabetic Med 1991;8:223. Fernando DJ et al, Diabetic Med 1991;8:223.

Other Associations with Incidence of Foot Ulcers & Amputation in ESRD Foot Ulceration End-stage Renal Disease • Association between start of dialysis and incidence of foot ulceration • Up to 40% of dialysis patients have past or current ulceration • ? Related to lack of diabetes follow-up • ? Ethnic protection lost Game et al 2006, 2010; Ndip et al 2010 Game FL, Jeffcoate WH et al. Nephrol Dial Transplant 2006 CKD associated risk independent of PAD Life on Dialysis 9 8 Nicholas Evans, BMJ 2012;345:e5262 : “Being on dialysis isn’t really a life: it’s not even half a 7 life.” 6 5 ≥ 60 ml/min Renata Carey, BMJ 2012:345:e4492 : 4 ≥ 30 to < 60 ml/min < 30 ml/min ”Dialysis is brilliant, of course, but deeply horrendous.” 3 2 Renata Carey, BMJ 2012:345:e4492 1 “On the dialysis unit, patients suddenly appear with 0 amputations: and often before that with heavily bandaged No PAD PAD Total No PAD PAD Total population population feet, rapidly followed by crutches and then wheelchairs.” Foot Ulcer Amputation Margolis DJ, Hofstad O, Feldman HI. Diabetes Care 2008

Dialysis vs No-dialysis Dialysis and Foot Ulceration Factor No-dialysis Dialysis OR (95% CI) P-value (n=187) α (n=139) α Prevalent foot ulcer (%) 4.8 21 5.1 (2.3 to 11) <0.0001 • Dialysis is an independent risk factor Prior amputation (%) 6.4 15 2.6 (1.2 to 5.6) 0.008 for foot ulceration PAD (%) 43 64 2.4 (1.5 to 3.8) <0.0001 • When compared to ESRD patients not Neuropathy (%) 65 79 2.0 (1.2 to 3.3) 0.006 on dialysis, 4.2x increased risk of foot Prior foot ulcer (%) 20 32 1.9 (1.1 to 3.1) 0.011 ulceration Deformity (%) 33 22 0.6 (0.4 to 1.0) 0.019 • Mortality after amputation - 290% IWGDF risk categories (%) Low vs High risk category 16 vs 85 7 vs 94 2.7 (1.2 to 5.8) 0.015 increase in hazard for those on dialysis Patient care • Need for foot care on dialysis units Use of bespoke footwear (%) 8 16 2.6 (1.2 to 4.3) 0.026 Walking barefoot at home (%) 28 43 2.0 (1.2 to 3.1) 0.004 Routine podiatry attendance (%) 70 44 0.3 (0.2 to 0.5) <0.0001 Ndip A et al, Diabetes Care 2010;33: 878-880 and 33;1811-1816 Daily inspection of foot (%) 70 29 0.2 (0.1 to 0.3) <0.0001 Lavery et al, Diabetes Care 2010;33:epub August 25 th . Ndip A et al. Diabetes Care 2010 ADA T A S K F O R C E R E P O R T Mortality after amputation in CKD & Haemodialysis Risk factors for foot ulcers � CKD and dialysis treatment are independent risk • Previous amputation factors for mortality after lower extremity • Past foot ulcer history amputation. • Peripheral neuropathy • Foot deformity • Peripheral vascular disease � 10-year mortality among patients on dialysis • Visual impairment who have an amputation X 3 greater than • Diabetic nephropathy (especially those on dialysis) patients that require amputation without CKD. • Poor glycemic control • Cigarette smoking � Mortality in this population is higher than many other disease processes such as coronary artery Boulton AJM et al, Diabetes Care 2008;31:1679. disease and cancer Lavery LA, Hunt NA, Ndip A et al. Diabetes care 2010

Mortality,Dialysis and Foot Cumulative survival post-amputation Ulceration • 192 diabetic dialysis patients followed for 2 years • Overall 2 yr mortality 53%: 59% if foot ulcer at baseline; 74% if amputation: p<0.001. • Mortality after amputation - 290% increase in hazard for those on dialysis • Need for foot care on dialysis units Lavery LA, Hunt NA, Ndip A et al. Diabetes care 2010 Ndip A et al, 2012 . Recommendations Recommendations 3. Vascular Assessment What about the ABI? • Foot pulse assessment – dichotomous • ADA/ACC recommend that all those patients >50 years old should have an IF ANY PULSE ABSENT or Hx of annual ABI PVD, then • Is this practical • Ankle Brachial Index if possible. • Could this give rise to a false sense of security?

Recommendations What about the ABI? • ADA/ACC recommend that all those patients >50 years old should have an annual ABI • Is this practical • Could this give rise to a false sense of security? Diabetes ESRD Vascular calcification Osteolysis/osteopenia Charcot RANKL/OPG ? Foot ulceration Charcot neuroarthropathy (CNA): Amputation The osteolysis/ vascular calcification paradox

Contrasting fortunes: Chalk or Cheese RANKL/OPG and Vascular Calcification • RANKL/OPG signaling pathway plays a role in vascular calcification • Human VSMCs cultured in serum from CN patients show accelerated osteoblastic differentiation • This pathway is a potential target for intervention Ndip A et al, Diabetes 2011;60:2187 Multidisciplinary team • Diabetologists • Interventional Radiologists For one mistake made for • Nurses not knowing, ten mistakes • Orthotist are made for not looking. • Patient • Podiatrist • Surgeons No conflicting advice J A Lindsay