5. Introduction
Pathogenesis
Normal Bone Remodeling
Hyperparathyroidism
Classifications of bone disease
Diagnosis of bone disease
Treatment of bone disease in CKD
6. Stage Description GFR
(ml/min/1.73 m2)
1 Kidney damage with normal or
GFR
90
2 Kidney damage with mild GFR 60-89
3 Moderate GFR 30-59
4 Severe GFR 15-29
5 Kidney failure < 15
(or dialysis)
KDOQI: CKD Staging
7.
8. KI (2007) 71, 31-38. Levin et. al.
Prevalence of Abnormal Mineral Metabolism in CKD
>4.6
10. EU1 KDIGO Japan2
PTH
pg/mL (pmol/L)
85–170
(9–18)
150–300
(16.5–33)
60–180
Ca
mg/dL (mmol/L)
8.8–11
(2.2–2.7)
<10.2 pref: 8.4–9.51
(<2.54 pref: 2.10–2.37)
8.4–10
(2.1–2.5)
Pi
mg/dL (mmol/L)
2.5–5.5
(0.8–1.8)
3.5–5.5
(1.1–1.8)
3.5–6.0
(1.1–2)
Ca x P
mg2/dL2
<55 mg2/dL2 <55 mg2/dL2 (not specified)
11.
12. 0.01
100
10
1
0.1
Annualmortality(%)
25–34 45–54 65–74 8535–44 55–64 75–84
Age (years)
Cardiovascular Mortality in the General
Population and in Dialysis Patients
General population
Male
Female
Black
White
Dialysis population
Male
Female
Black
White
13. The term renal osteodystrophy (ROD)
should be used exclusively to define the
bone pathology associated with CKD.
The clinical, biochemical, and imaging
abnormalities should be defined more
broadly as a clinical entity or syndrome
called Chronic Kidney Disease-Mineral
and Bone Disorder (CKD-MBD).
14. A systemic disorder of mineral and bone
metabolism due to CKD manifested by either
one or a combination of the following:
◦ Abnormalities of calcium, phosphorus, PTH, or
vitamin D metabolism
◦ Abnormalities in bone turnover, mineralization,
volume, linear growth, or strength
◦ Vascular or other soft tissue calcification
Moe et al Kidney International June 2006
15. A Framework for Classification of CKD-MBD
Type
*
Laboratory
Abnormalities
Bone Disease
Calcification of
Vascular or Other
Soft Tissue
L + - -
LB + + -
LC + - +
LBC + + +
* L = laboratory abnormalities (of calcium, phosphorus, PTH,
alkaline phosphatase or vitamin D metabolism); B = bone disease
(abnormalities in bone turnover, mineralization, volume, linear
growth, or strength); C = calcification of vascular or other soft
tissue.
17. 17
Elevated:
• FGF-23
• PTH
• Phosphorus
Decreased:
• Calcitriol
• Calcium
• Coronary calcification
• Aortic calcification
• Calciphylaxis
• Abnormal bone
– Mineralization
– Turnover
– Volume
KDIGO = Kidney Disease: Improving Global Outcomes.
KDIGO® is a registered trademark of Kidney Disease: Improving Global Outcomes, Inc.
Moe S, et al. Kidney Int. 2006;69:1945-1953.
KDIGO® Overview slide presentation at: http://www.kdigo.org/pdf/KDIGO%20Overview%20Slide%20Set.ppt
18. Traditionally classified according to degree
of abnormal bone turnover
High Turnover (osteitis fibrosa)
◦ Hyperparathyroidism
Low turnover
◦ Adynamic - Osteomalacia
Beta 2 MG amyloidosis
Osteoporosis
◦ Post-menopausal - Post-transplant
19. Kidney failure disrupts systemic calcium and
phosphate homeostasis and affects the bone, GIT and
parathyroid glands.
In kidney failure there is decreased renal excretion of
phosphate and diminished production of calcitriol
(1,25-dihydroxyvitamin D)
◦ Calitriol increases serum calcium levels
The increased phosphate and reduced calcium,
feedback and lead to secondary hyperparathyroidism,
metabolic bone disease, soft tissue calcifications and
other metabolic abnormalities
20.
21.
22.
23. • 4 or more small glands on
the posterior surface of
the thyroid gland.
• Can function without
neural control so can
transplant to another part
of the body
• 2 types of cells
– Chief cells – produce
parathyroid hormone
– Oxyntic cells – function
unknown
24. Responsible for maintaining serum calcium
in a normal range preventing hypocalcemia.
Does this by;
1. acting directly on the distal tubule of the kidney
to increase calcium reabsorption
– Increases calcitriol production (D3)
– D3 increases GIT absorption of Ca and Phos and
promotes osteoclast formation.
2. Acting on bone to increase calcium and
phosphate efflux
25. Can occur once eGFR < 60
PTH levels increase progressively as renal function declines and
by CKD stage 5(<15) most pt’s expected to have this.
Usually the 1st sign and occurs before lab tests pick up
phosphatemia, ↓ Vit D3 and ↓ calcium
Unless treated, progresses and frequency of parathyroidectomy
proportional to yrs on dialysis
26. Primary
Adenoma 80%
Multiple adenomas 4% (10% in elderly women)
Hyperplasia 15%
Carcinoma <1%
Secondary MEDICAL TTT
CRF, Malabsorption
Tertiary Surgical TTT
In long standing cases
27.
28. In renal failure driven by
◦Hypocalcaemia
◦Decreased vitamin D
◦hyperphosphataemia
29.
30.
31.
32. Due to excess PTH
Increased bone turnover activity (greater
number of osteoclasts and osteoblasts) and
defective mineralization.
Associated with bone pain and increased risk
of fractures.
33. Formally linked to aluminium toxicity
◦ From aluminium based phosphate binders
◦ From contamination of water in dialysate solutions
unmineralised osteoid
34. Characterized by low osteoblastic activity and bone
formation rates
Seen in up to 30% HD
May be due to excess suppression of the
parathyroid gland with therapies, particularly
calcium-containing phosphate binders and vitamin
D analogues.
Typically maintain a low serum intact PTH
concentration, which is frequently accompanied by
an elevated serum calcium level.
Felt to represent a state of relative
hypoparathyroidism
NORMAL diseased
35. Adapted from Goodman WG. In: Bilezikian JP, et al, eds. Principles of Bone Biology. 3rd Ed. San Diego, CA: Academic Press;
2008:1478-1510; Adapted from Moe SM, et al. In: Brenner BM, ed. The Kidney. 8th ed. Philadelphia, PA: Saunders Elsevier;
2008:1784-1813.
Mixed
Lesion
Osteitis FibrosaNormal Bone
Formation
High
Low
turnov
er
High turnover
Adynamic
Osteomalacia
Low PTH
36. Most with CKD and mildly elevated PTH are
asymptomatic
When present classified as either
1. Musculoskeletal
2. Extra-skeletal
37. Fractures, tendon rupture and bone pain
from metabolic bone disease, muscular pain
and weakness.
Most clinically significant is hip fracture and
fracture neck of femur , seen in CKD 5 (and is
associated with increase risk of death)
◦ NB. In dialysis pts there is already a 4.4 x increase
risk of hip fracture.
38. Important to recognise disordered bone and
mineral metabolism is a systemic disorder
affecting soft tissues, particularly vessels,
heart valves and skin.
CVD accounts for around half of all deaths of
dialysis patients.
Coronary artery and vascular calcifications
occur frequently in CKD 5 (and increase each
year on dialysis)
39. • A, Confluent calf plaques
(borders shown with
arrows). Parts of the skin
are erythematous, which is
easily confused with simple
cellulitis. B, Gross
ulceration in the same
patient 3 months later. The
black eschar has been
surgically débrided. C,
Calciphylactic plaques, a
few of which are beginning
to ulcerate. (Photographs
courtesy of Dr. Adrian Fine. Up
To Date)
40.
41.
42.
43. A. Zerbi S, et al. J Clin Endocrinol Metab. 2008;93:1121-1122; B. London GM, et al. Nephrol Dial Transplant.
2003;18:1731-1740.
B
A
45. Calcification of the Lung
Sanders C, et al. Am J Roentgenol. 1987;149:881-887.
Kuzela DC, et al. Am J Pathol. 1977;86:403-424.
Slide courtesy of E. Slatopolsky.
CalcifiedNoncalcified
50. Vascular calcification was present in 63–
69% of incident dialysis patients
1Block GA, et al. Kidney Int. 2005;68:1815-1824.
2Raggi P, et al. J Am Coll Cardiol. 2002 39:695-701.
53. Pts on dialysis for 7- 10 years can develop
osteoarticular amyloid deposits.
May present with carpel tunnel syndrome and
arthritis
54. Introduction
Pathogenesis
Normal Bone Remodeling
Hyperparathyroidism
Classifications of bone disease
Diagnosis of bone disease
55. Blood
◦ PTH
Random circulating PTH (1/2 life 2-4 mins)
Excreted renally so present for longer in RF
◦ Calcium
◦ Phosphate
Bone biopsy
◦ no longer frequently performed
Imaging
◦ In general not indicated
56. CKD Stage KDIGO
3 Every 6–12 months
4 Every 3–6 months
5 or D Every 1–3 months
Phosphate and Calcium
57. CKD Stage KDIGO
3 Every 6–12 months
4 Every 6–12 months
5 or D Every 3–6 months
PTH
58. Pathogenesis
Normal Bone Remodeling
Hyperparathyroidism
Classifications of bone disease
Diagnosis of bone disease
Treatment of bone disease in CKD
60. Phosphorus is unevenly distributed in the body
The major portion of phosphorus removed by HD is from
cell cytoplasm. The rate of phosphorus removal is slowed
by rate of transfer from within cells to plasma
◦ haemodialysis (HD) removes ~800 mg Pi/treatment
◦ peritoneal dialysis (PD) removes 150–200 mg Pi/PAK
Average phosphorus absorption = 600 mg/day or 4,200
mg/week
3 x weekly HD (4-hour sessions) removes 2,400 mg
phosphorus leaving 1,800 mg or 257 mg/day1
61. Aluminium used historically but now rarely used as concerns re
bone/CNS toxicity. May not be an issue if water quality good for
dialysis
Calcium based binders but concerns about about exacerbating
hypercalcaemia and thereby promoting vascular calcification.
Also concerns about promoting hypercalcaemia in adynamic low
turnover) bone disease
Sevelamer Hydrochloride and Lanthanum Carbonate are the
current non-calcium based binders used in clinical practice. May
avoid problems associated with calcium based binders but more
expensive
62. Brand Compound /form Dose (mg/day) Type Manufacturer
Alu-cap® Aluminium hydroxide capsule 4–20 x 475 mg/day
(2–10 g)
Metal Meda Pharmaceuticals (UK)
Calcichew® Calcium carbonate tablet 2–3 x 1250 mg/day Calcium Shire Pharmaceuticals
Calcium 500® Calcium carbonate tablet 1–2 x 1250 mg/day Calcium Generic (Twinlab, etc)
Phosex® Calcium acetate tablet 3–6 x 250 mg/day Calcium Vitaline Pharma (UK)
Titralac® Calcium carbonate tablet Up to 20 x 420 mg/day Calcium 3M Health Care
PhosLo® Calcium acetate (generic) 9–12 x 667 mg/day Calcium Generic (Fresenius Medical Care)
Fosrenol® Lanthanum carbonate tablet 750–3750 mg/day Metal Shire Pharmaceuticals
RenaGel® Sevelamer hydrochloride
capsule
3–9 x 800 mg/day Non-metal Genzyme
Renvela® Sevelamer carbonate film-
coated tablet
3–6 x 800 mg/day Non-metal Genzyme (USA)
OsvaRen® (EU)
Rephoren (UK)
Calcium acetate/ magnesium
carbonate tablet
3–12 x 435/235 mg/day Metal Fresenius
63. Class of phosphate binder Advantages Disadvantages
Al-based
(Al hydroxide)
Effective across wide pH range,
inexpensive1
Absorption of Al can lead to long-term toxicity resulting in
neurological damage and possible death1
Ca-based
(Ca acetate, Ca carbonate)
Effective, inexpensive, well tolerated,
well established, widely available
Likely to increase hypercalcaemia, and risk of arterial
calcification, function over a narrow gastric pH range,
high tablet burden
Sevelamer (hydrogel
polymer/resin)
Metal-free, low toxicity, lowers lipids and
arterial calcification – does not affect Ca
Acidosis due to HCl, expensive. Benefits in controlling Pi
levels and reduced calcification not sufficiently evaluated
in comparison with other treatments.2 Not effective over
wide pH range
La-based
(La carbonate)
Effective, well tolerated, low toxicity, low
tablet burden Ca-free, reasonable cost
Efficacy similar to Ca-based binders. Possible tissue
accumulation not ruled out but refuted by some authors
64. Rationale: elevated PTH may increase Ca and Pi thereby
promoting vascular calcification
Vitamin D analogues 1st line therapy as PTH driven by lack of
activated vitamin D
Calcimimetics avoid adverse effects on Ca and Pi
Low PTH associated with adynamic bone disease
65. Vitamin D
- decreases PTH secretion but increases Ca uptake from intestine
- vitamin D sterols include calcitriol, alfacalcidol, doxercalciferol, paricalcitol
Calcimimetics
- increase sensitivity of parathyroid Ca receptor thereby reducing PTH – without
increasing Ca2
- also reduce Phosphate
Surgery
• permanently reduces PTH secretion in patients unresponsive to medication
• BUT may result in adynamic bone disease
Phosphate binders are also used to manage hyperphosphataemia associated with
SHPT
66. Calcitriol directly suppresses PTH secretion
Vitamin D receptor on PTH gland down regulated
as hyperplasia of the gland is advanced
67. Intravenous or oral pulses are equally
effective
Equal efficacy of daily versus equivalent pulse
doses
Hypercalcaemia remains a complication
Hyperphosphatemia also a complication
68.
69.
70.
71. Therapy Advantages Disadvantages
Cinacalcet Effective in reducing PTH
levels
No hypercalcaemia
Phosphate levels may improve
Lack of good outcome data
showing reductions in CV
events
and bone effects
Expensive
Vitamin D and
analogues
Effective in reducing PTH
levels
Studies show improved
survival
Can cause hypercalcaemia
Can cause
hyperphosphataemia
Surgery Permanent/irreversible Can cause adynamic bone
disease
Can injure local nerve tissue
72.
73. Autonomous hypersecretion which
continues despite of correction of the
underlying renal disease by
transplantation
