rr&d center of excellence for the medical consequences of spinal cord injury william a. bauman,...
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RR&D Center of Excellencefor the
Medical Consequencesof Spinal Cord Injury
William A. Bauman, M.D.Director
Ann M. Spungen, Ed.DCo-Director
January 21, 2010Rancho Los Amigo National Rehabilitation Hospital
Program Lines of Study
1. Endocrine ProgramWilliam A. Bauman, MD
2. Pulmonary ProgramGregory J. Schilero
3. Automomic Program Jill M. Wecht, EdD
4. Gastrointestinal Program Mark A. Korsten, MD
5. Molecular ProgramChristopher P. Cardozo, MD
Anabolic Hormones
Disuse Osteoporosis
Carbohydrate Metabolism
Lipid Metabolism
Endocrine Program
Coronary Heart Disease
Osteoporosis in SCI
• SCI is a nonweight bearing condition.
• Bone is lost rapidly with acute SCI.– goal is to preserve bone architecture & mass
• Bone continues to be lost years after SCI– goal is to replace bone mass
Endocrine Program
Disuse Osteoporosis• Pharmacological intervention:
Acute SCI: pamidronate & zoledronate Chronic SCI: Hectoral (1-α-hydroxyvitamin D2)
• Low amplitude, high frequency mechanical stimulation
• Evaluation of DXA vs. other imaging modalities
• Vitamin D replacement therapy
Bauman et al. Metabolism. 44:1612-1616, 1995.
• Absolute vitamin D deficiency state:32 of 100 (32%) in SCI 8 of 50 (16%) Cont
In Persons with SCI:
• Negative Correlation: PTH & 25 (OH) vitamin D levels
• Positive Correlation: PTH & 1,25 (OH)2 vitamin D levels
Calcium Metabolism in Chronic SCI
Relationship between Serum PTH and Urinary NTx Levels
Ledger et al., J Clin Endocrinol Metab 80:3304-3310, 1995.
Vitamin D Replacement: 2000 IU per Day for 3 Months
Baseline Month 1 Month 30
1
2
3
4
5
6
7
8Absolute Deficiency < 16 ng/mlRelative Deficiency < 30 ng/mlNo Deficiency ≥ 30 ng/ml
Nu
mb
er
of
Su
bje
cts
Bauman et al., Unpublished observation.
Endocrine Program
Anabolic Hormones• Baclofen to increase IGF-1• Anabolic steroid agents• Testosterone replacement therapy
Testosterone Replacement Therapy (TRT)
Intervention: 12 months of TRT
Endpoints: • Body composition• Muscle strength• Resting energy expenditure• Glucose tolerance• Autonomic function• Psychological assessment
CountAge (yrs)
Height (cm)Weight (kg)BMI (kg/m2)
Duration of InjuryPara/TetraComplete/
Incomplete
TRT 6
43±5180±7
87.8±15.726.8±3.1
13±102/94/2
Control 9
37±9174±4
83.2±6.0
27.4±2.2
11±92/67/2
Characteristics of Subjects for theTestosterone Replacement Study
Baseline Testosterone Washout
4042444648505254565860
TO
TA
L B
OD
Y LT
M (
kg
)
52.2
54.8 55.0
52.753.4
51.1
P<0.05
P<0.05
800900
10001100120013001400150016001700
REE (K
cal/
d)
1,386
Baseline Testosterone
1,508
1,341 1,349
P<0.05
122 Kcal/d
Testosterone Replacement Therapy
Design:TRT for 12 moWashout for 6 mo
Testosterone
Control
Bauman et al., Unpublished observation.
Endocrine Program
Carbohydrate Metabolism• IV GTT• Oral GTT• Relationship to:
- Soft tissue (total & regional)
- Activity (V02max)
Total Body Percent Lean Tissue & Age: Able-Bodied vs. SCI
Spungen et al., J Appl Physiol. 95:2398-2407, 2003.
TO
TAL
BO
DY
% L
EA
N
AGE (y)
25
35
45
55
65
75
85
95
10 20 30 40 50 60 70 80
SCI slope (-0.341, P<0.0001)
AB slope (-0.175, P<0.0001)
Spungen et al., J Appl Physiol. 95:2398-2407, 2003.
Cross-Sectional Study: Chronic SCI
SCI
Control
0
5
10
15
20
25
30
35
40
< 40 y 40 y
Tota
l Bo
dy
Pe
rcen
t F
at
*
P<0.0001
*
* P<0.05 for Control vs. SCI
Body Mass Index Criteria for Normal, Overweight and Obesity
Expert Panel on the Identification , Evaluation and Treatment of Overweight and Obesity in Adults. NIH NHLBI. 1998
UnderweightNormalOverweightObese
BMI (m/kg2)<18.5
18.5-24.925-29.9
>30
Spungen et al., J Appl Physiol 95:2398-2407, 2003.
Tot
al B
ody%
Fat
Body Mass Index (kg/m2)
0
10
20
30
40
50
60
10 15 20 25 30 35 40 45
The Relationship of Percent Fat With Body Mass Index
SCIControl
Ruderman NB, et al. The “metabolically-obese,” normal-weight individual. Am J Clin Nutr 34:1617-1621, 1981
Premise: Persons with metabolic disorders (type 2 DM, HTN, hypertriglyceridemia) who are not obese by standard weight tables or other readily available criteria, but who respond favorably to caloric restriction.
It is proposed that such individuals might be characterized by hyperinsulinism and an increase in fat cell size. Inactivity may be a contributing factor. As such, these individuals may benefit from exercise therapy.
St-Onge MP, et al. Metabolic syndrome in normal-weight Americans: new definition of the metabolically obese, normal-weight individual. Diabetes Care. 27:2222-2228, 2004.
Prevalence rates MONW syndrome were determined in 7,602 adult participants of the Third National Health & Nutrition Examination Survey.
BMI 21-22.9 23-24.9
Men 4.13 5.35
Women 4.34 7.77
Odds ratios (OR) compared with those with BMI=18.5-20.9
Effects of Spinal Cord Injury on the Determinants of Insulin Resistance
Muscle mass ↓Fat mass ↑
Activity ↓
Oral Glucose Tolerance by Neurological Deficit
Complete Tetraplegia
Incomplete Tetraplegia
Complete Paraplegia
Incomplete ParaplegiaDM
IGT
NL
27%
50%
23%
56%24%
20%
69%
76%
17 %
14 %
6 %
18 %
Bauman et al., Spinal Cord. 37:765-771, 1999.
Frequency of Impaired Glucose Tolerance and/orDiabetes Mellitus by Neurological Deficit
Neurological Subgroup
Complete Tetra
Incomplete Tetra
Complete Para
Incomplete Para
Percent
73*
44
24
31*p<0.0001
Bauman et al., Spinal Cord. 37:765-771, 1999.
Frequency of Hyperinsulinemia
Group
Tetra
Para
Percent
53*
37*P<0.05
Bauman et al., Spinal Cord. 37:765-771, 1999.
Ser
um
Glu
cose
(m
g/d
L)
0
25
50
75
100
125
150
175
200
225
250
0 30 60 90 120
NGT
IGT
DM
Time (minutes)
Serum Glucose Results from a 75 g OGTT in SCI
Bauman et al., Unpublished observation.
Pla
sm
a In
sulin
(U
/ml)
0
20
40
60
80
100
120
140
160
180
0 30 60 90 120
NGT
IGT
DM
Time (minutes)
Plasma Insulin Results from a 75 g OGTT in SCI
Bauman et al., Unpublished observation.
Percent of Subjects by SCI Group and FPI Category
0
5
10
15
20
25
30
35
40
0-5 5-9 10-14 15-19 20-100
TETRA
PARA
Per
cen
t
FPI CategoryBauman et al., Unpublished observation.
Percent of Subjects by Group & 2-Hour Insulin Category
After a 75 g OGTT
0-49 50-99 100-150 > 1500
5
10
15
20
25
30
35
40
45 TETRA
PARA
Per
cen
t
Two-Hr Insulin CategoryBauman et al., Unpublished observation.
Endocrine Program
Lipid Metabolism• Descriptive data• Relationship to body fat• Intervention with Niaspan
Protective Effect of HDL Cholesterol
• Reverse cholesterol transport
• Anti-oxidant• Anti-inflammatory• Direct vascular• Anti-platelet• Anti-coagulant
Bauman et al., Metab. 43:749-756, 1994.
Relationships between Insulin Sensitivity with VO2 max & HDL Cholesterol
HDL as a Risk Factor in Persons with SCIDecreased plasma HDL cholesterol Elevated Total Cholesterol : HDL ratioHDL cholesterol < 40 mg/dL: 63%
HDL cholesterol < 35 mg/dL: 44%HDL cholesterol < 30 mg/dL: 19%
Bauman et al., Spinal Cord, 1998Bauman et al., Metabolism, 1994Bauman et al., Spinal Cord, 1999Bauman et al., Topics in Spinal Cord Injury Rehab, 2008
30
35
40
45
50
TetraComplete
TetraIncomplete
ParaComplete
ParaIncomplete
Average Risk
Morbidity risk ratio(age-adjusted)
HDL (mg/dl)
20 40 60 80
0
1.0
2.0
HDL-Cholesterol & CHD Risk(Men in Framingham, MA)
HD
L C
ho
lest
ero
l (m
g/d
L)
HDL Cholesterol by Ethnicity
Bauman et al., Arch Phys Med Rehabil. 79:176-180, 1998.
National Cholesterol Education Program (NCEP)Expert Panel on Detection, Evaluation and TreatmentOf High Blood Cholesterol in Adults
» 1988 Adult Treatment Panel (ATP) I» 1993 ATP II» 2001 ATP III
Guidelines for Assessment of Risk for CHD
2004 Implications of Recent Clinical Trials for the National Cholesterol Education Program Adult Treatment Panel III Guidelines
Over the years, the “target values” for LDL cholesterolhave become more conservative.
Subjects: 41 subjects with paraplegia
• ASIA A & B: T6 to L1• Age: 34±11 years
Nash MS, et al. A guideline driven assessment of need for cardiovascular disease risk intervention in persons with chronic paraplegia. Arch Phys Med Rehabil. 88:751-757, 2007
Main Outcome Measure: % of subjects qualifying for intervention • Based on ATP III guidelines
Results: 63% of subjects qualified for intervention » 76% had HDL cholesterol <40 mg/dL » ~1/3 had hypertension » 34% had the metabolic syndrome
Nash et al. Arch Phys Med Rehabil. 88:751-757, 2007.
Conclusion: A high percentage of young, healthy persons with SCI are at risk for CVD & qualify for lipid-lowering intervention.
Nash MS, et al. Arch Phys Med Rehabil. 88:751-757, 2007
Risk Assessment for Coronary Heart Disease in a Veteran Population with Spinal Cord Injury. Topics in Spinal Cord Injury Rehabilitation. 12:35-53, 2007.
Purpose: » To determine the conventional risk factors for CHD & calculate risk for CHD to determine the target level for serum LDL cholesterol.
Population: » 224 outpatients with SCI associated with the VA Medical Center, Bronx, NY
Method: » Conventional risk factors for CHD were defined by the ATP III guidelines.
Characteristics of the Study Group
Bauman et al., Topics in Spinal Cord Inj Rehabil. 12:35-53, 2007.
Table 2
Major Risk Factors for CHD
Tetra (n=103) Para (n=119)
Bauman et al. Topics in Spinal Cord Inj Rehabil. 12:35-53, 2007.
Table 3
Ten-Year Risk Assessment
Bauman et al. Topics in Spinal Cord Inj Rehabil. 12:35-53, 2007.
Major Risk Factors for CHD
• Cigarette Smoking
• Hypertension (>140/90 mm Hg or on anti-hypertensive medications
• Low HDL cholesterol (<40 mg/dL)
• Family history of premature CHD (male first degree relative < 55 years; female first-degree relative < 65 years)
• Age (men > 45 years; women > 55 years
Serum HDL Cholesterol Levels in the ATP III Stratification of Risk for CHD
HDL cholesterol has a dual function:
(1) Counted as a Major Risk Factor that serves to modify LDL goals
(2) Used to estimate the 10-year risk for developing CHD (using the Framingham
risk scoring system)
Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. JAMA. 2001;285:2486-2497.
Nash MS, et al. Extended-Release Niacin for Treatment of Dylipidemia in Chronic Tetraplegia
Subjects: 54 persons with chronic tetraplegia and low HDL cholestrol
Results: ↑ HDL (24.5%)
↓ LDL
↓ TC
↓ TC:HDL
↓ LDL:HDL
Conclusion: Extended-release niacin is safe, tolerated, and effective for most persons with chronic tetraplegia.
Unpublished observation.Supported by NIDRR, Department of Education
HDL LDL TC-20
-10
0
10
20
30
2000 mg
500 mg
1000 mg
1500 mg
Per
cent
Cha
nge
● High-sensitivity CRP● Interleukin-6● Fibrinogen● Tumor Necrosis Factor-α● Increased concentration of small, dense LDL particles● Lp(a)● Homocysteine● Apolipoprotein A1 and B● Postprandial lipemia● Vitamin D
● Visceral fat
Emerging Risk Factors For Coronary Heart Disease
Lee MY, et al. C-reactive protein, metabolic syndrome, and insulin resistance in individuals with spinal cord injury. J Spinal Cord Injury. 28:20-25, 2004.
C-reactive protein levels and IR C-reactive protein levels and Dyslipidemia
Mortality Ratios for Plasma Homocysteine Levels for Men and Women with SCI
Bauman et al. J Spinal Cord Med. 24:81-86, 2001.
Orakzai SH, et al. Measurement of coronary arterycalcification by electron beam computerized tomographyin persons with chronic spinal cord injury: evidencefor increased atherosclerotic burden. Spinal Cord. 2007
Subjects:
» 91 persons (76 men & 15 women) with chronic SCI matched 3:1 for age, gender, ethnicity & risk factors for CHD
Conclusions:
» Patients with SCI have greater atherosclerotic burden than able-bodied controls. This finding is beyond that explained by the traditional risk factors for CHD.
Results:
» The mean calcium score of the SCI group was significantly greater than the control group (75±218 versus 28±104, P<0.001)
» The prevalence of any CAC score was greater in the SCI population than the control population (51 versus 39%, P<0.05).
● What factors best predict risk for CHD?
Questions to be Addressed
● Are the guidelines for treatment decisions to reduce risk for CHD transferable from the able-bodied population to persons with SCI?
Are there studies that have stratified persons with SCIfor risk of CHD on evidenced-based guidelines?
Is there a study that has determined CHD in personswith SCI compared with matched, able-bodied controls?
● Are persons with SCI at increased risk for CHD?
These questions have not been answered.
Pulmonary Program
PI: Gregory J. Schilero MD
Study of the pathophysiology of spinal cord injury & the lung
Intervention(s) to increase expiratory muscle strength
Markers of lung inflammationInhibition of lung nitric oxide & effects on airway tone
Fitted Values for FVC Percent Predicted by Vertebral Level for Complete Motor Lesions
4249
5560 64 67 70 73 76 79 81 83 86 88 89 91 93 94 96 97 99 100
0
20
40
60
80
100
120
C3 C4 C5 C6 C7 C8 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 L1 L2 L3 L4
Pe
rce
nt
Pre
dic
ted
FV
C Normal Range
Lin & Spungen et al., Spinal Cord. 2001; 39:263-268.
LUNG VOLUMES
ICTVERVRV
Normal Tetraplegia
FRC
FVC
Restrictive Findings Slight TLC FVC ERV RV
- Correlates with level of injury
Pulmonary: Obstructive Disease in Individuals with Tetraplegia
Bronchodilators “unmask” obstruction
Increased airway tone
Hyperreactive airways to standard provocative testing
Effects of Nitric Oxide Synthase Inhibition on Levels of Exhaled NO and Airway Tone in Subjects with Chronic Cervical SCI
• Measurement of exhaled levels of nitric oxide offers a non-invasive methodology to indirectly assess the degree of airway inflammation.
Background● Asthma and spinal cord injury have similar findings of
reversible obstructive airway disease.
● In asthma, airway inflammation is present.
● The presence and/or role of airway inflammation in individuals with tetraplegia has not been reported.
● Airway inflammation may be a consequence of: (1) a systemic inflammatory response after acute SCI; (2) chronic underlying systemic inflammation; and/or (3) repetitive pulmonary infections 2º to ineffective cough.
Baseline Values of Exhaled Nitric Oxide (NO)
*P= 0.0109#P= 0.0045
8-Isoprostane Levels in Exhaled Breath Condensate (EBC)
8-isoprostane levels in tetraplegia (n=6), asthma (n=6) and control group (n=6). †p <0.05 vs. control group; *p <0.02 vs. control group
8-Isoprostane Levels
● 8-isoprostane levels represent pathways of inflammation seen in models of inflammation (e.g., COPD and asthma).
● 8-isoprostane is a marker of oxidative stress.
● In the able-bodied population, there is good correlation of 8-isoprostane with small airway function and small airway inflammation.
*
Cardiovascular/Autonomic Program
PI: Jill M. Wecht, EdD
Chronic SCI• 24-hour monitoring of
hemodynamic parameters
• Interventions to reduce orthostatic hypotension
24-hour Heart Rate
65
70
75
80
85
90
95
100
105
24-h
ou
r H
eart
Rat
e
8am noon 4pm 8pm midnight 4am 8am
P<0.001 versus AB & tetraplegic groups
controlsparaplegictetraplegic
Wecht et al., Unpublished observation.
24 hour Systolic Blood Pressure
p<0.05 versus controls
tetraplegicparaplegicControl
95
100
105
110
115
120
125
130
135
24 H
ou
r S
BP
(m
mH
g)
8am noon 4pm 8pm midnight 4am 8am
Wecht et al., Unpublished observation.
Efficacy of Drug or Physical Maneuver on BP and Cerebral Perfusion
Interventions
•α1-agonist (midodrine)
•nocturnal head-up tilt
•nitric oxide synthase inhibitor
Sympathetic Cardiac Control
Grimm et al. Am J Physiol. 1997.
LF-RRI 0.04-0.15 Hz
0
1000
2000
3000
4000
5000
6000
7000
Control Para Tetra-Inc Tetra-Com
SUPINE
HUT
COLD PRESSOR
ISOMETRIC
Ab
solu
te L
F-R
RI (
mse
c2 /H
z)
Parasympathetic Cardiac Control
0
1000
2000
3000
4000
5000
Control Para Tetra-Inc Tetra-Com
SUPINE
HUT
COLD PRESSOR
ISOMETRIC
Grimm et al., Am J Physiol. 1997.
HF-RRI 0.15-0.40 Hz
Ab
solu
te H
F-R
RI (
mse
c2 /H
z)
ISOMETRIC
Sympathovagal Balance (LF/HF)
0
0.5
1
1.5
2
2.5
3
Control Para Tetra-Inc Tetra-Com
SUPINE
HUT
COLD PRESSOR
ISOMETRIC
Grimm et al., Am J Physiol. 1997.
Ab
solu
te L
F/H
F R
RI
(mse
c2 /H
z)
LF-RRI/HF-RRI
Gastrointestinal Program
PI: Mark A. Korsten, MD
Assessment of drug therapy for treatment of difficulty with evacuation
Evaluation of elective colonoscopy
Gastrointestinal MorbidityDifficulty with evacuation, especially
constipation and impaction, is common after SCI.
Bowel care requires regular use of laxatives, enemas and suppositories.
Bowel care is often time-consuming and labor intensive.
Is there a practical pharmacological approach to bowel care on our clinical horizon?
Placebo Neostigmine Neo+Glyco0
25
50
75
100
Complete
Most
Moderate
Some
None
Evacuation Rating
Per
cen
t o
f S
ub
ject
s
* *
*P < 0.01 compared to normal saline
Korsten et al., Amer J Gastroenterol. 2005.
Neostigmine and Glycopyrrolate on Bowel Evacuation in Persons with SCI
» To study the quality of bowel preparation for colonoscopy after oral cleansers, bowel prokinetic agents, mechanical lavage, or a combination.
» To compare polyp detection rates in persons with SCI and able-bodied controls.
Elective Colonoscopy in Persons with SCI
POLYP DETECTION RATE DURING COLONOSCOPY: ABLE- BODIED CONTROLS vs. SCI PATIENTS
Able bodied pa-tients (n=31)
SCI patients (n=32)
0
10
20
30
40
50
60 51.6
21.9
% c
olo
no
sco
pie
s w
ith
p
oly
ps
P = 0.02 by Fisher’s exact test
Molecular ProgramPI: Christopher P. Cardozo, MD
Transcriptional regulation of anabolic/ catabolic factors in muscle
Effect of anabolic/ catabolic agents on muscle after denervation or SCI
Effect of anabolic agents on functional recovery