graves’ disease and bone metabolism sun wook cho & young joo park department of internal...
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Graves’ Disease and Bone Metabolism
Sun Wook Cho & Young Joo Park
Department of Internal Medicine
Seoul National University College of Medicine
Seoul, Korea
Untreated or persistentGraves’ Ds
Increasedbone turn-over
Fractures
Normal → Osteopenia Osteporosis
Changes of Bone in Graves’ Patients
Resorption > Formation
BMD was low in Graves’ patients, especially more in aged over 50 or postmenopausal subjects
- Studies in East-Asia -
J Clin Endocrinol Metab 1990;70:766–770
• Seoul National University Hospital, Korea
Changgeng Yi Xue Za Zhi 1990;13:274-281• Chang Gung Memorial Hospital, Taiwan
• University of Yamanashi Medical School, Japan
Zhonghua Yi Xue Za Zhi. 1998 Sep;78(9):682-4• Beijing Tongren Hospital, China
Clin Endocrinol (Oxf). 1993 Mar;38(3):283-6
The decrement of BMD or the increment of fracture risk in Graves’ disease is larger in aged or post-
menopausal subjects
- A meta-analysis about the risk of osteoporosis in Graves’ patients -
Vestergaard & Mosekilde, Thyroid, 2003:13:585
Bone mineral density (Z-score) Fracture risk (relative risk)
Age (years) Age (years)
The decreased BMD or the increased fracture riskin Graves’ patients is normalized after treatment
A meta-analysis, Vestergaard & Mosekilde, Thyroid, 2003:13:585
Clin Endocrinol, 2004:61:466 Thyroid, 2002:12:585
Bone mineral density (Z-score) Fracture risk (relative risk)
Dx Dx
The increased risk of fracture persists for at least 3~5 years after initial diagnosis and treatment of Graves’
disease
A large population-based study in DenmarkCalcif Tissue Int 2005:77:139
BMD was normalized in patients who reached euthyroid sta-tus after treatment, but decreased in persistently hyperthy-
roid patients
Oikawa, Hamamatsu University School of Medicine, Japan. Clin Endocrinol 1999:50:171
Hyper
Eu
Bone resorption > formationNormal → Osteopenia → Osteporosis
What induces the changes of bone in thyroid disease?
?TSH
Thyroid H Fractures
Both in osteoblasts & osteoclasts
Bone, 2008:43:418
Thyroid hormone (T3) increases both oesteoblasto-genesis and osteoclastogenesis
The osteoclastogenesis is greater than the osteoblastogenesis, and the uncoupling of osteoclast and osteoblast activitiesresults in a ~10% net loss of bone per remodeling cycle
TSH itself may play a role in the preservation of bone
Bone 2007:40:1128Clin Endocrinol 2006:64:86
3172 postmenopausal womenHealth Promotion CentreAsan Medical Centre, Korea
• Positive association between serum TSH and BMD in euthyroid sub-jects : 2 large scaled cross sectional studies
581 postmenopausal womenSubsamples of National Health and Nutrition Exam-ination Survey, NHANES III, US
• Increased risk for fracture in women with low serum TSH levels
686 women older than 65 years of age from a cohort of 9704 womenStudy of Osteoporotic Fractures Research Group. US Ann Intern Med 2001:134:561
Hyperthyroid-associated osteoporosis can be exacer-bated by the loss of TSH signaling
J Clin Invest 2012
TSHR-knockout mice have greater bone loss than wild-type mice with in-tact TSH signaling after thyroxine treatment, which induces hyperthyroid
status.
TSH inhibits osteoclastogenesis, while increases osteoblastogenesis in several in vitro studies.
>>>>
WT TSHR KO
Euthyroid
Hyperthyroid
Graves’ disease ; a condition of disruption of an inverse relationship between thyroid hormone and TSH
If TSH is an important negative regulator of bone remodeling,the presence of TSAb in Graves' disease would
protect against bone loss!
Effects ?TSHR
stimulatingantibody
Thyroid hormone + TSH + TSHR stimulating Ab (TSAb)
Net TSH action may be increased
Osteoblast & osteoclast
Is there any association between serum TSAb activities and serum os-teoblastogenic or osteoclastogenic ac-
tivities in Graves’ patients?
Rakuwakai Otowa Hospital, Japan, Osteoporos Int, 2006:17:1103
• Positive association between TSAb activities and urine N-telopeptide levels
J Clin Endocrinol Metab1990;70:766–770
• The other few reports showed that TSAb or bone turn-over markers were negatively association with BMD.
• It is hard to discriminate the effects of TSAb from those of thyroid hormone on BMD.
Osteoporos Int 2006:17:1103
A few studies has been reported about the associa-tion between TSAb and bone markers
Study about an association between serum TSAb activ-ities and serum bone markers
• Subjects– 139 newly diagnosed Graves’ patients at SNUH
• 127 patients had TSHR Ab with stimulating activity (TSAb)
• 12 patients had TSHR Ab with blocking activity (TBAb)• Blocking activities were defined according to the clinical courses; sponta-
neously developed hypothyroid status with persistent high serumTBII levels.
• Measurements– T3, free T4, TSH– TSAb : 1st generation TBII methods– Serum Bone-specific alkaline phosphatase(ALP), osteocal-
cin, C-telopeptide– PTH, Ca/P, Prot/alb, 25-OH Vit. D3
TBII with stimulating activity (TSAb)TBII with block-
ing activityMen Premenopausal women
Postmenopausal women
n 25 83 19 12 (all female)
Age (years) 40±12 32±9 56±6 46±14
T3 (ng/dl) 395.9±205.1 430.9±183.0 343.4±123.8 209.7±122.7
Free T4 (ng/dl) 3.17±1.09 3.63±1.54 3.08±1.02 1.56±0.93
TBII (%) 48.2±25.6 53.7±23.5 41.3±24.6 75.0±22.0
Calcium (mg/dl) 9.7±0.4 9.6±0.4 9.5±0.4 9.6±0.7
Phosphrous (mg/dl) 4.3±1.1 4.4±1.0 4.6±0.5 4.2±1.2
25-OH Vit D3 (ng/ml) 18.4±10.8 16.7±8.7 17.3±9.0 17.0±6.9
PTH (pg/ml) 14.9±8.2 12.8±7.9 15.8±6.7 14.3±7.5
BS-ALP (U/L) 59.4±28.7 58.2±27.2 67.7±33.7 41.2±15.7
Osteocalcin (ng/ml) 54.0±29.5 45.9±19.6 41.1±27.4 31.8±18.5
C-telopeptide (ng/ml) 0.87±0.44 0.78±0.35 0.85±0.42 4.22±13.29
Clinical characteristics and serum parameters related with bone metabolism in subgroups
TB
II (%
) :
Sti
mu
lati
ng
=0.305 P<0.001
=0.184 P=0.038
=0.329 P<0.001
* P-value are from Partial correlation adjusting free T4
Serum C-telopeptideOsteocalcinBone specific ALP
TSAb activities show a positive correlation with serum bone turnover markers indepen-
dent of thyroid hormone levels
The correlation seems stronger in osteoblst makers than in osteoclast marker
* P-value are from Partial correlation adjusting free T4
Serum C-telopeptideOsteocalcinBone specific ALP
=0.253 P=0.453
=-0.541 P=0.086
=-0.555 P=0.076
TB
II (%
) :
Blo
ckin
g
No correlation or borderline negative correla-tion between TSHR blocking antibody and
serum bone turnover markers
Serum obsteoblastic activities were positively associated with TSAb activities in premenopausal female and male
Graves’ patients
Log-transformed value was usedCorrelation efficient (Pearson, Spearman); age, TSAb, T3, and FT4 were used for multivariate analysis.
Bone turn-over
markerMen
Premenopausal women
Postmenopausal women
Age 40±12 yrs 32±9 yrs 56±6 yrs
Univariate Multivariate Univariate Multivariate Univariate Multivariate
Bone specific ALP 0.360 0.491 0.313 0.362 0.259 0.376
Osteocalcin 0.466 0.680 0.296 0.443 0.380 0.380
C-telopeptide 0.348 0.348 0.107 0.392 0.082 0.469
• The positive association suggests that TSAb may have osteoblastogenic ef-fects.
• TSAb has little osteoblastogenic effects, thus little protective effects in post-menopausal women.
• The difference of TSAb effects on osteoblast among subgroups could be a pos-sible reason why the risk of osteoporosis is larger in postmenopausal women.
How can the effects of thyroid hormone levels be excluded from the effects of TSAb on bone
turn-over markers?
TSAb MenPremenopausal
womenPostmenopausal
women
Univariate Multivariate Univariate Multivariate Univariate Multivariate
T3 0.392 0.392 0.339 0.427 0.173 0.173
FT4 0.192 0.027 -0.006 0.427 0.152 0.173
• No association between thyroid hormone levels and TSAb
The correlation of TSAb with bone turn-over markers are different from those of thyroid
hormone levels• Different association with bone markers of TSAb with T3 or free T4
MenPremenopausal
womenPostmenopausal
women
TSAb Univariate Multivariate Univariate Multivariate Univariate Multivariate
Bone specific ALP 0.360 0.491 0.313 0.362 0.259 0.376
Osteocalcin 0.466 0.680 0.296 0.443 0.380 0.380
C-telopeptide 0.348 0.348 0.107 0.392 0.082 0.469
T3
Bone specific ALP 0.384 0.384 0.277 0.362 0.218 0.074
Osteocalcin 0.381 0.006 0.410 0.401 0.027 0.055
C-telopeptide 0.279 0.033 0.388 0.388 0.072 0.145
Free T4
Bone specific ALP 0.126 0.068 0.084 0.002 0.079 0.077
Osteocalcin 0.100 0.008 0.177 0.003 0.200 0.014
C-telopeptide 0.177 0.001 0.246 0.001 0.236 0.236
13 Graves’ patients, Greece, J Clin Endocrinol Metab 2000;85:1099
Changes in bone turn-over markers during therapy for hyperthyroidism
Osteoblast markers decreased very slowly contrast to the osteoclast marker
TSAb?
Similar changes with osteoblast
marker
The changes of NTx are very similar to those of T3.
Osteoclast markerOsteoblast marker
Relation between TSAb and osteoblast marker
Relation between T3 and osteoclast marker
Osteoclast marker is correlated with thyroid hormone levels, while osteoblat markers is more with TSAb activities
T3 MenPremenopausal
womenPostmenopausal
women
Univariate Multivariate Univariate Multivariate Univariate Multivariate
Bone specific ALP 0.384 0.384 0.277 0.362 0.218 0.074
Osteocalcin 0.381 0.006 0.410 0.401 0.027 0.055
C-telopeptide 0.279 0.033 0.388 0.388 0.072 0.145
TSAb MenPremenopausal
womenPostmenopausal
women
Univariate Multivariate Univariate Multivariate Univariate Multivariate
Bone specific ALP 0.360 0.491 0.313 0.362 0.259 0.376
Osteocalcin 0.466 0.680 0.296 0.443 0.380 0.380
C-telopeptide 0.348 0.348 0.107 0.392 0.082 0.469
TSAb shows a positive correlation with osteoblast markers
T3 shows a positive correlation both with osteoclast marker and osteoblast marker
Calcium Corrected Ca Intact PTH 25OH-VitD3
TSAb
Total 0.041 -0.046 0.057 0.166
Men 0.100 -0.189 0.031 0.037
PreMP women 0.060 0.090 0.113 0.211
PostMP women -0.179 -0.103 0.062 0.230
PTH MenPremenopausal
womenPostmenopausal
women
Univariate Multivariate Univariate Multivariate Univariate Multivariate
Bone specific ALP 0.006 0.003 0.011 0.009 0.015 0.015
Osteocalcin 0.087 0.050 0.130 0.117 0.322 0.367
C-telopeptide 0.919 0.932 0.732 0.634 0.328 0.241
Multivariate analysis: Age, TSI, T3, FT4, PTH is in-volved.
* Log-transformed value was used.
The effects of TSAb on bone metabolism is not re-lated with PTH, a osteoblastogenic factor
• No correlation between TSAb and PTH
• No correlation between PTH and bone turn-over markers
• Serum TSAb activities were associated with an increased bone
turn-over (osteoblastogenesis >> osteoclastogenesis), indepen-
dent of thyroid hormone levels in Graves’ patients.
• The TSAb-related increments of osteoblastic activities were ob-
served in premenopausal women and men, but not in post-
menopausal women. These findings might explain the lower BMD
and the higher fracture risk in postmenopausal Graves’ women.
• Even though a low TSH level may contribute to the bone loss of
hyperthyroidism that has been attributed traditionally to high thy-
roid hormone levels, the presence of TSAb in Graves' disease
would protect against bone loss.
Summary
Inhibition No physiologic effect Stimulation
Cell, 2003:115:151
JBMR, 2007:22:849Mol Endocrinol, 2008:22:501
Is it real that TSH/TSAb can increase the os-teoblastogenesis?
PNAS, 2011:108:16277
Wnt (LRP-5) and VEGF (Flk) signaling
Wnt5a
• Many controversies about the effects of TSH/TSAb on osteoblast!• Recent data strongly suggest a stimulatory effect
C3H10T1/2 cell
ALP/GAPDH
Ost
eo
calc
in/G
AP
DH
• Osteoblast marker gene
VEHTSH
TSAbVEH
TSHTSAb
VEH
osteogenic medium
VEHTSH
TSAbVEH
TSHTSAb
VEH
osteogenic medium
VEHTSH
TSAbVEH
TSHTSAb
VEH
osteogenic medium
Osteocalcin/GAPDH Collagen type I /GAPDH
• Alkaline phosphatase (ALP) activity
none TSH M22 OM OM (+) TSH
OM (+) M22
0
0.1
0.2
0.3
0.4
0.5
0.6
AL
P a
ctiv
ity
VEH TSH TSAb VEH TSH TSAb
osteogenic medium
The expression of ostoeblastogenic gene or osteoblas-togenic activity was not increased by treatment of
TSH or TSAb
β-Catenin
γ-tubulin
γ-tubulin
Smad
VEHTSH
TSAbVEH
TSHTSAb
wnt3A
VEHTSH
TSAbVEH
TSHTSAb
BMP
• No change in Wnt- catenin signals
• No change in BMP-Smad signals
p-ERK
γ-tubulin
ERK
VEHTSH
TSAb
• Increased phosphorylation of ERK
Changes of the signals in ostogenic pathway after treatment of TSH/TSAb
Inhibition No physiologic effect
Cell, 2003:115:151 JBMR, 2007:22:849
Mol Endocrinol, 2008:22:501
The effects of TSH/TSAb on osteoclastogenesis
Thyroid, 2011:21:897 PNAS 2006:103:12849
TSAb Protective or compenstory effects
Correlation in Graves’ patients :Osteoblastogenic effect > osteoclastogenenic effect
In vitro data :? Osteoblastogenic effect, inhibitory effect on osteoclastogenesis
Possible therapeutic applicationof TSHR analogues
Summary
• Thyrotoxicosis is an established cause of high-bone-turnover osteoporosis, which results from a net increase in bone re-sorption.
• In untreated Graves’ patients, BMD was decreased and the risk of fracture was increased, especially more in aged or postmenopausal subjects.
• Treatment of Graves’ disease normalizes the levels of bone turnover markers rapidly, but the BMD after about 5 years.
• Recent in vitro or animal studies suggest the osteoblastogenic or anti-osteoclastogenic effects of TSH, and as well as thyroid hormone, TSH or TSAb itself may be an important regulator of bone remodeling.
• There remains a concern about that therapeutic suppression of TSH to very low levels may contribute to bone loss in some peatients.
• Serum TSAb activities are positively correlated with os-teoblastic activities in premenopausal female or male Graves’ patients.
• Even though a low TSH level and high thyroid hormone levels may contribute to the bone loss of hyperthyroidism, the pres-ence of TSAb in Graves' disease would compensatory protect against bone loss.
• These results implicate a possibe therapeutic application of TSH analogues for several diseases including osteoporosis.
Summary
Acknowledgements
• Prof. Bo Youn Cho• Prof. Jun-Key Chung
• Sun Wook Cho, MD, PhD
• Jae Hyun Bae, MD
• Sun Kyeong Han, BS
• Do Joon Park, MD, PhD
• Ka Hee Yi, MD, PhD
• Kyung Won Kim, MD, PhD
• Jae Hoon Moon, MD, PhD
• Hoon Sung Choi, MD, PhD
• Jung-A Lim, MD, PhD
Rev Endocr Metab Disord 2010:11:219–227
=0.006P=0.941
=0.245P=0.003
=0.320P<0.001
=0.069P=0.481
=0.325P<0.001
=0.363P<0.001
Fre
e T
4
Serum C-telopeptideOsteocalcinBone specific ALP
T3
Serum C-telopeptideOsteocalcinBone specific ALP
Correlation between thyroid hormone and serum bone turnover markers
Stimulating activityBlocking activityMen Normal
ref.PreMPwomen
Normal ref.
PostMPwomen
Normal ref.
Calcium (mg/dl)
9.7±0.4 8.8-10.5 9.6±0.4 9.5±0.4 9.6±0.7
Phosphrous (mg/dl)
4.3±1.1 2.5-4.5 4.4±1.0 4.6±0.5 4.2±1.2
Adjusted-Ca 9.5±1.4 9.8±0.4 9.7±0.4 9.6±0.7
25-OH Vit D3 (ng/ml)
18.4±10.8
9.0-37.6 16.7±8.717.3±9.
017.0±6.9
PTH (pg/ml) 14.9±8.2 10-66 12.8±7.915.8±6.
714.3±7.5
BS-ALP (U/L)59.4±28.
715.0-41.3
58.2±27.2
11.6-29.6
67.7±33.7
14.2-42.7
41.2±15.7
Osteocalcin (ng/ml)
54.0±29.5
14-4645.9±19.
611-43
41.1±27.4
15-49 31.8±18.5
C-telopeptide (ng/ml)
0.87±0.44
<0.5840.78±0.3
5<0.573
0.85±0.42
<1.0084.22±13.2
9• BS-ALP : men ≥25years 15.0-41.3• C-telopeptide : men 30-50 years <0.584, 50-70 years <0.704, >70 years <0.854• osteocalcin (ng/mL) ; 24–70 in men aged 18–30, 14–46 in men older than 30, 11–43 in pre-
menopausal women ,15–46 in postmenopausal women
Serum parameters related with bone metabo-lism in the subjects