1. Physical Function: Overview
Definition: ability to perform physical activities without assistance.
Dependent on:
physical fitness (strength & stamina)
functional ability (coordination, balance)
Measured by:
1.)performance-based tests: “functional performance”
lab-based, objective
Grip strength, timed walking
2.) self report
Ability within home environment and social context

2. Make 4 bar graphs for gair speed and chair stand, check how cutoffs defined
Functional Performance Predicts Mortality and Hospitalization In HIV Negative Elderly Adults
Health, Aging and Body Composition Study, N= 3,079, aged 70-79
Cesari M, JAGS, 2009

3. Comparison of Functional Performance in HIV + vs Healthy Men
N= 346 (Lindle RS, J Appl Physiol 1997)
mean age, 52; median= same, 30-81
Oursler, KK, 2006

4. Functional Performance (N=56) Correlates with VACS Risk Index Score
table score_cat, contents( mean _6MWm mean gpdomin mean AGE )
1,<30; |
2,30-49; |
3, |
50-64;4, |
| mean(_6MWm) mean(gpdomin) mean(AGE)
1 |
2 |
3 |
4 |
for VO2peak, r= -0.31, p=0.02
Lowest quartile of grip strength associated with 7.5 point higher median score than highest quartile
Decrease of 50 meters associated with 33 point increase in score

5. Mild anemia is associated with reduced 6-MWD
add data values and p values, walking speed ref
. ttest vo2_kg if study==1, by( hct35)
Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval]
0 |
1 |
combined |
diff |
Pr(T < t) = Pr(|T| > |t|) = Pr(T > t) =
. ttest _6MWm if study==1, by( hct35)
0 |
1 |
combined |
diff |
Ha: diff < Ha: diff != Ha: diff > 0
Pr(T < t) = Pr(|T| > |t|) = Pr(T > t) =

6. Comparison of Survey Items

7. Self-reported Function in MACS 1994-1996
Hiv neg: hiv +
42 yrs(37-47) 39 (35-45)
median (range)
white 89% 83%
jacobson and fried looked at self -reported measures…
they found that hiv infected more likley to have each one of the characteristics of fraily than hiv negative men , and when frailty was defined as presence of 3 or more characteristics, 10 fold increase in the hiv-infected men
since wasting can be important manifestation of AIDS, separate models that excluded subjects with weight loss, and still found that hiv-infected had 4 fold increased risk frailty
prevalence-
Increased by duration of HIV infection
Increased by age, OR 1.6 (1.2, 2.2)
55 yo men with HIV for < 4 years have an est. prevalence of frailty of 3.4% = 65+ yo men without HIV
* age, ethnicity, education
Total number frail: HIV-infected (n=245) vs. HIV-negative men (n=1905)
Update ref
Check time parameters &if have survival
Desquilbert, Jacobson, Fried, et al, in press, J Gerontology Med Sci

8. Self-reported Physical Function in VACS: Limitations and Mean VACS Index Score by Item
HIV + Only, N= 2772
Yes
Slowly No

9. VACS Physical Function Score
Sum of 12 survey items
Transformed to 100 scale
Ceiling effect: /3 subjects no limitations %
Histogram for HIV +
N= 2772

10. VACS Physical Function Score
Sum of 12 survey items
Transformed to 100 scale
Ceiling effect: /3 subjects no limitations
 Three groups:
Severe limitations base on Lowest quintile (<67) %
Histogram for HIV +
N= 2772

11. VACS Physical Function Score
Sum of 12 survey items
Transformed to 100 scale
Ceiling effect: /3 subjects no limitations
 Three groups:
Severe limitations base on Lowest quintile (<67)
Intermediate limitations (68-99) %
Histogram for HIV +
N= 2772

12. VACS Physical Function Score
Sum of 12 survey items
Transformed to 100 scale
Ceiling effect: /3 subjects no limitations
 Three groups:
Severe limitations base on Lowest quintile (<67)
Intermediate limitations (68-99)
No limitations (=100) %
Histogram for HIV +
N= 2772

13. Level of Function Associated with VACS Index
VACS Risk Index Score 40 35 30 25 20 15
Small note on distribution, cut off of 67 in this limited dataset (hiv = only and those with the vacs index score available, actually is 23%, not 20%
N =3280 BACS-8 HIV + function group
N =2772 for sub-set with index available 10 5
severe limitations
intermediate limitations
no limitations
N = 650
N = 1094
N = 1028
need p value?

14. intermediate limitations
no limitations
intermediate limitations
severe limitations
HR= 1.8
(1.4,2.2)
HR= 3.0
(2.4,3.8)
2,<67, | 0, censured; 1, died
20%centile | | Total
0 | 1, | 1,144
1 | | 1,222
2 | |
Total | 2, | 3,107
. xi: stcox i.functlevel if HIV==1
i.functlevel _Ifunctleve_ (naturally coded; _Ifunctleve_0 omitted)
failure _d: death
analysis time _t: time_yrs
Refining estimates:
Iteration 0: log likelihood =
Cox regression -- Breslow method for ties
No. of subjects = Number of obs =
No. of failures =
Time at risk = LR chi2(2) =
Log likelihood = Prob > chi2 =
_t | Haz. Ratio Std. Err z P>|z| [95% Conf. Interval]
_Ifunctlev~1 |
_Ifunctlev~2 |
adjusted for agebl, sex, raceg
level (1.3, 2.0)
level (2.2, 3.4)

15. HIV and Pulmonary Disease Together Severely Affect Function65 70 75 80 85 90 35 40 45 50 55 60
Function
Score
HIV- Pulm-
HIV+ Pulm-
HIV- Pulm+
HIV+ Pulm+
Age (yr)

16. Take Home Points Self-reported measures need to:
have wider dynamic range
Functional performance measures need to:
measure different parameters
endurance rather than slowing
lower extremity muscle wasting + central obesity ?
be adapted for impact of specific comobidities
anemia, lung disease, diastolic dysfunction

17. Ongoing Physical Function Research in VACS
Change in function score over time
Cardiac and pulmonary predictors of performance in 6 MWD
INHALE (PI, Crothers)
VACS ABC (PI, Freidberg)
Proposal to study relationship of cardiac function and exercise performance

18. Reference slides

19. 6MWD appears to be sensitive measure of exercise capacity
add data values and p values, r value b/w 2
. ttest vo2_kg if study==1, by( hct35)
Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval]
0 |
1 |
combined |
diff |
Pr(T < t) = Pr(|T| > |t|) = Pr(T > t) =
. ttest _6MWm if study==1, by( hct35)
0 |
1 |
combined |
diff |
Ha: diff < Ha: diff != Ha: diff > 0
Pr(T < t) = Pr(|T| > |t|) = Pr(T > t) =

20. Change in Physical Function with Aging: a Moving Target
VO2peak (ml/kg/min)
Aerobic Capacity
Injury
Age (yrs) 50 60 70 80
Rehabilitation
Nursing Home
Death
Normal Aging 40 30
Recovery 20
Chronic Disability 
HIV  
Stroke
CHF

21. Implications for Life Expectancy
Beyond Survival:
Implications for Life Expectancy
Adapted from theory of compression of morbidity theory from
James F. Fries
Stanford University, Palo Alto, California
Fries, NEJM 1980
(his theory - ave period disabled life will decrease)
Oursler, 2007

22. Frailty Phenotype in Elderly HIV uninfected
Relatively uncommon. Among 70-79yo:
12% of Cardiovascular Health Study (CHS)
11.3% of WHAS (Women’s Health and Aging Study) I & II cohort
A Clinical Syndrome, present if 3/5 +:
Exhaustion (self- report)
Slowed walking speed (4-8 m walk)
Low activity (self-report)
Weakness (lowest quintile grip strength)
Weight loss (self-report and measured)
Check refs
Fried L, et al. J of Gerontology, 2001
Newman, et al. J of Gerontology, 2001
Bandeen-Roche et al. , J of Gerontology, 2006

23. Mean VACS Index Score by Survey Item

24. Self reported physical limitations VACS 8 (N =3280)
Yes
Slowly No
Response