The organs of the human body were created to perform ten functions among which is the function of the kidney to furnish the human being with thought.

Transcription

1 The organs of the human body were created to perform ten functions among which is the function of the kidney to furnish the human being with thought. Leviticus Rabba 3 Talmud Berochoth 6 1 b

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3 Nephrology an ancient specialty

4 Kidneys working! - How?

5 Structure of the renal corpuscle, looking into the Bowman s capsule at glomerular capillary tuft. 1 million nephrons in each kidney Pollak M R et al. CJASN 2014;9: by American Society of Nephrology

6 Normal Renal Physiology Receive a quarter of cardiac output. Filtration 180L/day + 25,200 mmol Na + /day urine output 2L/day with mmol Na + day. 80% reabsorption proximal tubule 15% reabsorption cortical collecting tubule 5% medullary collecting tubule

7 In the beginning the abundance of the sea Led to profligacy The ascent through the brackish waters of the estuary To the salt-poor lakes and ponds Made immense demands Upon the glands Salt must be saved, water is free. Maurice B Strauss Boston. Remember 252,000mM Na+/day

8 KIDNEY FUNCTION Filtration and excretory capacity urine. Salt + water homeostasis. Essential for blood pressure. Endocrine function hormones for blood pressure, erythropoietin - anaemia, vitamin D - bones. Metabolic function. How do we assess kidney function?

9 Blood pressure Blood test. Urine dipstick analysis

10 Chronic Kidney Disease (CKD) Australia or NZ Healthy Adult Community Data from AusDiab Increased risk 1:3 CKD 1:7 Dialysis or Transplant 1:1400

11 How much CKD in Australia or NZ? 16% of Adults >25yrs have protein or blood in urine or moderately severe reduction in kidney function* GFR <60mL/min 6.6% Albumin in urine 7.5% 2.5% Blood in Urine *MDRD based egfr

12 Estimated 1/3 adults at increased risk of CKD AusDiab Survey April 2001 Otago Southland Survey High risk subgroups: 1. Diabetes 7.5% diabetic (only ½ knew it) 23% abnormal GT 2. Hypertension 29% (only ½ knew it) 3. Smokers 23% 4. Age > 65 yrs 5. Maori and Pacific Islanders 6. Family history of kidney disease etc 7. Obese

13 Chronic Kidney Disease Stage Description GFR (ml/min) 1 Kidney damage (proteinuria) with normal or increased GFR 2 Kidney damage with mild decrease in GFR 3 Moderate decrease in GFR >90 60 to to 59 4 Severe decrease in GFR 15 to 29 5 Kidney failure < 15 or RRT

14 Similar risk for Cardiovascular disease.

15 'bubbles appearing on the surface of the urine indicate renal disease with a prolonged course'

16 Fig 1 Time to clinical outcomes by proteinuria and kidney dysfunction Tonelli, M. et al. BMJ 2006;332:1426 Copyright 2006 BMJ Publishing Group Ltd.

17 Chronic Kidney Disease Interventions to slow progression 1. Hypertension 2. Proteinuria 3. Salt & diet, Exercise What s good for the heart is good for your kidneys

18 Hypertension and the Kidney

19 Thickened media Reduplication of elastic lamina Intimal hyperplasia

20 Arteriolosclerosis Interstitial fibrosis glomerulosclerosis and tubular atrophy Compensatory glomerular hypertrophy

21 Arteriosclerosis and Pulse Wave Velocity Systole Diastole Remember: pulsatile flow to laminar flow. SE Greenwald J Pathol 2007

22 Young Arteries Laminar flow in tissues Older arteries Renal arterioles SE Greenwald J Pathol 2007

23 Pulse Wave Forms Shape force felt by artery. Older stiff vessel reflected wave early SBP DBP Increased pressure Heart brain kidney SE Greenwald J Pathol 2007

24 therefore if large amounts of salt are taken the pulse will stiffen and harden Chinese Physician Huang Ti Nei Ching SU Wein 1700BC Translation Wan Ping AD762

25 How is the Kidney linked into Hypertension We evolved in a low dietary salt (high potassium) environment (fruit cereals) Dietary salt < 1tsp salt or 2300mg Na+ Current intake 5-20g/day! (NZ 9g/day) Inability to excrete salt load leads to increased volume expansion - hypertension. Probable genetic inheritance

26 New Zealanders consume an average of 1.5 teaspoons of salt per day (NNS 1997) The recommended salt intake is mmol per day (WHO) 2300mg Na+ / day 75-85% of New Zealanders salt intake comes from processed foods eg. Bread, hard cheese, processed meats, soups, sauces, gravies, snack foods, frozen meals etc Salt Intake:

27 Low salt foods are those which contain less than 120mg of sodium per 100g of food Medium salt foods contain between 120 and 600mg of sodium per 100g of food High salt foods contain more than 600mg of sodium per 100g of food tion.org.nz/nutritionfacts/minerals/sodium Salt.

28 Impact of salt loading in hypertensive individuals

29 Non-drug interventions to lower blood pressure Exercise Diet salt Stop smoking

30 Assessment of Risk End organ involvement Proteinuria (elevated albumin/creatinine ratio or protein/creatinine ratio) present 30-40% hypertensive individuals at diagnosis 10x risk of cardiovascular event. Normal blood pressure less than 130/80.

31 Management Medications to lower blood pressure and reduce proteinuria. Will only work if they are actually taken.

32 The Evolution of Uroscopy Endre & Fernando Kidney International 2016

33 Chronic Kidney Disease

34 Progression of Kidney Disease.

35 Impact of CKD Prevention of chronic kidney disease is the key focus of the international Nephrology community. Globally we cannot sustain the rapidly increasing burden of end stage renal disease (ESRD) requiring dialysis and the high costs associated with renal replacement therapy. Exponential rise in renal disease, especially diabetic renal disease over the next 10 years.

36 Impact of CKD Global epidemic of diabetes Diabetes - 50% of new cases of ESRD. Cost of diabetic nephropathy estimated at $36 million per annum (Endre, Beavan, Buttimore NZMJ 2006) Disproportionately high incidence in Maori & Pacific Islanders.

37 Renal Replacement Therapy. Non-dialysis full supportive management. Haemodialysis. Continuous Ambulatory Peritoneal Dialysis (CAPD). Renal Transplantation.

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39 ANZDATA Registry 2015

40 Cause of ESKD

41 Figure 2.3 New Patients Age Specific Rates - New Zealand Year Total 0-19 yrs yrs yrs yrs yrs 85+ yrs ANZDATA Registry Annual Report 2013

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44 Dialysis Therapy Maintains a state of controlled renal failure. Clearance equivalent to GFR ml/min. If done well, can be very effective the more the better. Limitations. Metabolism and endocrine function. Large impact on individual lifestyle, family.

45 Renal Transplantation. Preferred therapy for suitable recipients. 800 (2500) on list. Full rehabilitation normal kidney function. Side effects of medications immunosuppression. Organ donors: Cadaveric vs. LRD

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47 Organ Donation A gift of life Many lives altered multi-organ donors (Kidney (2) heart (heart valves), liver, lung, pancreas, corneas, bone) Awareness discussion with family.

48 Take Home Points The Kidney is the key regulator of blood pressure. Hypertension major contributor to Heart disease Hypertension is a major component of Kidney disease Proteinuria and hypertension are major prognostic factors require more aggressive treatment. Contributes to progression of CKD. CKD increases the risk of cardiac disease 5 fold. Frequently requires medication Do not forget salt and exercise. Strong focus of research: & Kidney Health NZ.