AGE (yrs.)

FRWI
(4) __ 25-29 30-34 35-39 40-44 45-49 50-54 All Ages
<iooo} 195? | aes | ci | ast | tte | 28° | 888

100.0-]} 89.3 978 97.8 ag 976 | 100.0 97.6

19.9 | @) | G24 | be | a (16) (2) (216)
97.9 97.4 95.2 97.1 96.2 104.3 96.2
<l20.0 (9) (271) (103) (28) (27) (7) (445)
104.0 91.2 101.0 106.0 104.0 101.7
21200 | (0) (18) (8) (2) (2) (i) (28)
All 97.9 97.9 95.0 973 96.9 104.3 97.2
FRWIs jl (9) | (289) | (ios) | (30) | (9) | (e) (473)

Table 9-Exercise HR-IL

Taste 9. Tabulation of mean exercise HR versus age and FRWI categories. ‘These data represent the 1970
period. Each Table cell contains the mean resting HR value (in beats/min.) and immediately below it
(in parentheses) the number of data used in its calculation.

12


II. Methods.

1960-1968 Data—Utilizing date of birth, age
was calculated and expressed as the nearest com-
pleted year on the day of biodynamic testing.
Unclothed height and weight were measured to
the nearest quarter inch and quarter pound re-
spectively. The SBP and DBP were measured
under seated, resting conditions using standard
equipment and technique? MVO./Kg bw was
determined by any one of four equivalent
methods and converted to standard conditions
of temperature and pressure, dry (STPD). A
detailed description of the 1960-1963 data
acquisition methods has been previously re-
ported.t

1970 Data—ANl 1970 data were obtained from
the active medical certification files as they ex-
isted in May of 1970. Age was expressed as the
nearest completed year on the day of the medical
examination. As recorded in the medical cer-
tification files, height and weight are stated
rather than measured quantities. Since directly
measured height is far more accurate than stated
height, the 1970 heights were calculated from the
measured 1960-1963 heights and an anthro-
pometric correction factor for the expected height
decrement over an eight-year interval.%? Stated
weight, as obtained and recorded in the medical
certification files, is subject to error. Two com-
prehensive studies “7° have reported that heavy
men tend to underestimate their weights while
light ones tend to overestimate theirs. Because
neither corroboration of a stated weight error
nor appropriate correction factors are available
at this time for this specifie ATO population
segment, the uncorrected stated weights were used
as the best available data. However, because of
the nature of the age versus FRWI tables, the
quantitation of any parameter which changes in
direct proportion to the FRWI will tend to yield
conservative estimates at the polar FRWI
extremes.

The 1970 resting SBP and DBP data were
presumably obtained under standard conditions
of accuracy comparable with those of the 1960-
1963 period. As described in the ATC medical
examination procedure, the resting HR is meas-
ured immediately following cessation of a stand-
ard submaximum exercise and the recovery HR
is measured two minutes following exercise
termination.

The 1965 revised pathology codes of the avia-
tion medical service list all cardiovascular
pathology under the 400 series. This series con-
tains designated critical and non-critical pathol-
ogies. Once documented and coded, critical
items are permanently retained in the individual’s
medical certification file. Non-critical items may
be found in the individual’s current file only if
they are currently present. In this analysis, no
distinction was made between critical and non-
critical code items. However, it appears reason-
able to assume that the presence of any 400
series item would generally confer a greater
cardiovascular susceptibility than its absence.

Age Versus FRWI Tables—The general
rationale of this table format has been presented.
Five-year age brackets were arbitrarily chosen as
serving best the purposes of this analysis. The
FRWI brackets were limited arbitrarily to three
ranges (and two combinations thereof) which
were grossly representative of the total spectrum
of this parameter. The three separate FRWI
ranges chosen were: less than 100.0%, 100.0—
119.9% and 120% or greater. An FRWI of
100.0% indicates that the weight of the in-
dividual is equal to the median weight of the
FHS males of his height at the 1950 inception
of the FHS.° The rationale and formulae for
the calculation of the FRWI have been reported
previously.° The use of the FRWI for this
present analysis is based on the assumption of
population segment similarity at study inception.

Because many of the individual cells in the age
versus FRWT tables of analysed parameters were
represented by too few numbers of data, and
because the total number of 1970 data was not
always equal to that of the 1960-1963 data used
for each parametric analysis, the testing of inter-
cell differences for statistical significance was
not warranted. Therefore, inter-cell comparisons
were restricted to an examination of the overall
trend of the individual parametric changes with
respect to increases in age and FRWI.

HI. Results.

An average age increase of 8.3 years had oc-
curred in the 475 ATC personnel between the
1960-1963 and 1970 time periods respectively.
Over the 8.3 year interval, this group had mani-
fested an average weight gain of 9.7% even
though ten percent of the group had lost: weight
in the same time period, The youngest age





AGE (yrs.)

Fey 20-24 25-29 30-34 35-39 40-44 45-49 All Ages
<1000} Mee | tir | fer | ee | Ho | Ao | Gey
100.0-}| 76.7 81.2 85.0 80.5
19.9 (6) (13) (3) (0) (0) (0) (22)
<l200 | WF | Bat | Be | P| HO | PO | dai
2120.0 ie 4a) mi (0) (0) (0) ve)
FAwis| eat | 998 | a | 9°] ao] aR° | TBR

Taste 5. Tabulation of mean DBP versus age and FRWI categories.

period.
theses) the number of data used in its calculation.

general concentration of the lower values of this
parameter in the combined older/obese categories
are relatively stronger evidences for directionally
commensurate CHD susceptibility in light of the
relatively poor initial physical fitness levels.**
The 1970 HR data appear to corroborate the
MVO,/Kg bw indication of decreased physical
fitness with age and obesity, The HR data may
possibly indicate a further decrease in physical
fitness over the 8.3 year period in light of the
concomitant increases which occurred in the
FRWI. Decreased physical fitness is usually
associated with increased obesity. Evidence of
a further decrease in physical fitness would serve
to strengthen the notion of increased relative sus-
ceptibility to CHD as reflected by the FHS re-
ports empirically linking poor physical fitness to
increased CHD susceptibility.’ 7 **

The strongest evidence for increasing relative
CHD susceptibility is, of course, provided by the

Table 5- OBP-I

These data represent the 1960-1963

Each Table cell contains the mean DBP value (in mm Hg) and immediately below it (in paren-

400 pathology code incidence. Although only 13
of the 475 ATC personnel manifested 400 code
pathologies, the overall pattern relating percent
incidence to age and obesity was rather re-
markable. The inherent strength of this evidence
is not subject to conjecture, for the presence of a
400 coded item in the individual’s record is based
on a documented medical diagnosis. Therefore,
based on all the parameters analyzed, an overall
consistent pattern has emerged which relates rela-
tively increasing CHD susceptibility to advanced
age and obesity in this ATC population segment.
Since this pattern is based on a relatively small
population sample of 475 individuals, statements
stronger than those describing general directional
trends are not presently warranted. However,
since age, height, weight, SBP, DBP, the 400
pathology code, as well as resting, exercise and
recovery HRs are routinely obtained and re-
corded in all ATC medical examinations, and


AGE (yrs.)

FRWI
(%) 25-29 30-34 35-39 40-44 45-49 50-54 _ All Ages

905 925 91.4 90.8 93.2 94.7 92.2
<1000 | fey | daa) | (a7) | 03) | a | ts) | (230)
100.0-|] 103.9 | 107.4 | 108.9 | 107.2 | 108.2 | 102.7 107.7
19.9 | (3 | c24 | Ger | cs) | G6) | (2) | (zie)
94.9 99.3 100.9 99.6 102.1 97.0 99.7
<120.0 || (3) | 272) | cos) | (28) | (27) | (7) | (446)
128.8 128.5 129.6 128.5 121.0 128.5

21200 |} co) | ts) (6) | (2) (2) ( (29)
All 949 | 101.1 | 102.4| 101.6 | 103.9 | 100.0 | 101.5
FRWIs || (9) | (290) | (ios) | (30) | (29) | (8) | (475)

TaBLe 2.

‘Tabulation of mean FRWI versus age and FRWI categories.

Table 2- FRWI-IL
These data represent the 1970 period.

Each Table cell contains the mean FRWI value (in percent) and immediately below it (in parentheses)

the number of data used in its calculation.

total spectrum of these mean SBP values lies
within norm range* and the type and general
degree of increases with both age and obesity are
not unusual,*® it is of salient interest to point out
that the highest of these SBP values, proceeding
in the direction of undesirable elevation, tend
to be concentrated in the combined older/obese
categories.

‘The age versus FRWI tabulation of mean DBP
for the 1960-1963 period is shown in Table 5 and
its counterpart for 1970 is shown in Table 6. The
entire spectrum of DBP values in both of these
tables lies within the norm range for the general
population of the United States.7 In parallel
behavior with the mean SBP, a general trend of
increase in mean DBP with both age and obesity
is also apparent in these two tables. In further
similarity, the increase in mean DBP with obesity
is generally manifested in each of the segmental
age-range columns. Also warranted is the same

point of interest that, despite the overall norm
range of these DBP values** and overall norm
range of increase with age and obesity,'* the
highest DBP values, in the direction of undesir-
able elevation, again tend to be concentrated in
the combined older/obese categories.

The tabulation of mean MVO,/Kg bw in the
age versus FRWI format for the 1960-1963
period is shown in Table 7. According to the
Balke rating scale, for United States males,'* all
the values of MVO,/Kg bw in this table lie
within the Poor and Average categories of
physica] fitness. As previously stated,* ° decreas-
ing MVO,/Kg bw reflects decreasing physical
fitness. FHS studies have also reported that de-
creased physical fitness is associated with in-
creased CHD susceptibility..? Examination of
the All FRWIs and All Ages columns in Table
7 reveals a general trend of decrease in MVO2/
Kg bw with age and obesity. The possibility



group (20-29 years in 1960-1963) manifested the
largest average weight gain of 10.7% in the 8.3
year interval. In a 1960-1962 United States
population study,” the average weight gain of a
comparable age group of males over the same

time interval was 6.9%. This information may
be useful in martialling an age-focused educa-
tional effort against excessive weight gain since
the 20-29 year old group constituted 80.6% of
the 475 ATC personnel.

AGE (yrs.)

FRWI
(%) 20-24 25-29 30-34 35-39 40-44 45-49 All Ages
86.8 87.4 89.4 90.6 94.6 93.0 87.6
<1000 | igay | con) | ser | ten | 3 ay} (370)
100.0-]] 106.9 | 106.3 | 105.5 | 106.5 | 105.3 | 106.0 106.4
19.9 |} (5) (35) qa) (7) (5) a) (94)
89.8 92.1 93.2 94.6 99.0 99.5 91.4
<l20.0 | (233) | (iaz) | ca7) | (28) | (2) | (2) | caea)
122.6 123.9 122.5 121.3 123.0
21200 |} (3) 6) | @ | a | (0) (ity
All 90.2 93.2 94.4 | 955 99.0 99.5 92.1
FRWIs | (236) | (147) | (49) | (29) (12) (2) (478)

Taste 1.

Tabulation of mean FRWI versus age and FRWI categories.

Table I- FRWI-T

‘These data represent the 1960-1963 period.

Each Table cell contains the mean FRWI value (in percent) and immediately below it (in parentheses) the

the number of data used in its calculation.

Table 1 presents the age versus FRWI compila-
tion of mean FRWI for the 1960-1963 period and
Table 2 presents its counterpart for the 1970
period. Over the 8.3 years, the mean FRWI of
the entire group increased from a value of 92.1 to
101.5. Visual examination of the data in both
tables reveals that, over the 8.3 year period, a
general trend of, increasing FRWI toward
obesity had apparently occurred, as well as an
increase in the number of individuals manifesting
the greater FRWI increases.

The age versus FRWI tabulation of mean
SBP representing the 1960-1963 period is pre-
sented in Table 3 and its 1970 counterpart is

presented in Table 4. The entire spectrum of
SBP values in both of these tables lies within the
norm range for the general population of the
United States.* An examination of the AIL
FRWIs category in both tables reveals a general
trend of increase in mean SBP with age. This
type and degree of increase is not unusual.’®
Scrutiny of the All Ages column in both tables
reveals a more defined trend of increase in mean
SBP as the FRWI increases toward obesity.
This increase in SBP with obesity cannot be at-
tributed to age alone, for the same general trend
of increase is revealed in each of the segmental
age-range columns of both tables. Although the




AGE (yrs.)

FRWI
(%) 2529 30-34 35°39 40-44 45-49 50-54 All Ages
120.0 | 121.4 19.0 | 122.5 | 115.6 | 1220 | 120.6
<i000 (6) (148) (47) (13) an (5) (230)
100.0-|] 113.3 | 123.4 | 124.9 | 126.7 | 133.0 | 129.0} 1247
119.9 (3) (124) (56) (15) (16) (2) (216)
uzs | 122.3 | 122.2 | 124.8 | 125.9 | 1240 | 122.6
<120.0 |] “(sy | (272) | clos) | (ae) | (27) | (7) | (446)
131.1 131.3 | 128.0 |] 149.0 | 110.0 | 131.4
21200 || (oy | tis) (6) (2) (2) W) (29)
All 78 | 122.7 | 1228 | 125.0 | 1275] 122.3 123.2
FRWis || ts) | (90) | (os) | Go) | (2s) | (i (475)

—_ Table 4- SBP-IL.

Tante 4. ‘Tabulation of mean SBP versus age and FRWI categories. These data represent the 1970 period.
Fach Table cell contains the mean SBP value (in mm Hg) and immediately below it (in parentheses) the

number of data used in its calculation.

in each Table cell represents the percent incidence
of 400 code pathology. Because eliminative oc-
currences of 400 code pathologies are not docu-
mented in the data repository of this population
segment, a total incidence number of only 13 in
these 475 ATC personnel is not surprising. De-
spite this small absolute incidence of only 13,
Table 11 reveals a general trend of increase in the
percent incidence of cardiovascular pathology
with age and obesity in the All FRWIs and All
Ages columns, as well as in their respective
smaller segmental categories. The directional
trend of this parameter appears to be consistent
with the trends of the other parameters similarly
analyzed.

Iv.

The general trends of all the parameters ex-
amined in the age versus FRWI table format
appear to support the presence of a relatively

Discussion.

increasing CHD susceptibility with age and
obesity in this ATC population segment. Fur-
ther, there appears to be a consistent general con-
centration of those parametric values reflecting
the greatest relative susceptibility to CHD in
the combined older/obese categories. Over the
8.8 year period, the quantitative increases in the
FRWI as well as the increased number of in-
dividuals in the obese category appears to be
evidence reflecting an advancing relative sus-
ceptibility to CHD.

Although the spectra of SBP and DBP values
were well below the hypertensive thresholds of
marked CHD susceptibility,! the actual values
indicated a general increase with age and obesity,
the higher values were generally concentrated in
the combined older/obese categories and both
spectra shifted upwards over the 8.3 year period.

The appearance of a general trend of decrease
in MVO./Kg bw with age and obesity, and a



TECHNICAL REPORT STANDARD TITLE PAGE

T, Report No. 2. Government Accession No. 3. Recipient's Catalog No.
FAA-AM-71-19

4. Title and Subtitle 5. Report Date

CHANGES IN CARDIOVASCULAR HEALTH PARAMETERS OVER AN April 1971
EIGHT-YEAR INTERVAL IN AN ATC POPULATION SEGMENT 6. Performing Organization Code

7. Author! s)

@. Performing Organization Report No.

Michael T. Lategola, Ph.D.

9. Performing Organization Name and Address 10, Work Unit No.
FAA Civil Aeromedical Institute
P, 0. Box 25082 TT. Contract or Grant No.

Oklahoma City, Oklahoma 73125

13. Type of Report and Period Covered

12. Sponsoring Agency Nome and Address

Office of Aviation Medicine OAM Report
Federal Aviation Administration
800 Independence Avenue, S.W. 14. Sponsoring Agency Code

Washington, D.C. 20590

15. Supplementary Notes

This work was done under Tasks AM-D-67-PHY-1 and AM-B-71-PHY-2.

16, Abstract
Dirise'{960-1963, the Civil Aeromedical Research Institute (CAML) conducted @ broad

spectrum of biomedical evaluations ona large number of air traffic control (ATC)
students. Approximately 1270 of these students (20-50 years of age) underwent bio-
dynamic evaluation of physical fitness. From these data, the relationships of maxi-
mum oxygen uptake (MVO9/Kg bw), resting SBP and DBP to age and the FRWI (an obesity
indicator) were examined. General data trends indicated an increase in SBP and DBP
with age and the FRWI. The MY¥O2/Kg bw showed a general trend of decrease as both age
and the FRWI increased.

In 1970, approximately 475 of the original 1270 ATC students possessed current airman
medical certificates, An average age increase of 8.3 years had occurred. Relevant
data from the current aeromedical certification files were examined. The average
weight gain was approximately nine percent. The 1970 resting SBP and DBP also in-
creased with both age and the FRWI. The percent incidence of the 400 pathology code,
as well as resting exercise and recovery heart rates, increased with age and the FRWI.

An overall pattern has emerged which indicates an advancing relative susceptibility
to coronary heart disease (CHD) in those individuals with a combination of advanced
age and obesity. Corroboration in a larger population sample is being pursued. If
corroborated, this pattern waild have direct use in the areas of mass aeromedical
screening, early detection, susceptibility reversal and preventive maintenance
aspects of CHD.

17. Key Words. ATC personnel; cardiovascular | 18. Distibution Statement

health; preventive maintenance; coronary Availability is unlimited. Document may

heart disease; aeromedical screening, be released to the National Technical

early detection; susceptibility reversal;| Information Service, Springfield,

age; obesity; blood pressure; maximum Virginia 22151, for sale to the public.

oxygen uptake; heart rate; cardiovascular

patholog’

“9. Security Classif. (of this report) 20. Security Classif. (of this page) 2i- No. of Pages | 22. Price
Unclassified Unclassified 15 $3.00

Form DOT F 1700.7 (8-69)



AGE (yrs.)

FRWI
(%) 20-24 25-29 30-34 35-39 40-44 45-49 All Ages

39.4 38.2 37.1 35.5 35.8 34.5 38.5

<l000} F345 | dén | 3) | Bo | Te] WP] Bea
100.0-}| 370 36.8 348 35.8 37.9 36.6
19.9 |} @&3) (34) (i) (7) (4) (0) (89)
39.0 37.9 365 35.6 36.6 34.5 38.1

<l20.0 | a7) | cai) | tea | 7 | a (i) | (as)
> 35.2 31.0 33.0 33.5 32.7
2120.0 | (3) (5) (2) (iy (0) (0) tt)
All 390 | 376 | 363 | 355 | 366 | 345 | 38.0

FRWIs il (230) | (146) | (46) | (28) | an ay | (462)

Table 7- MVO2 /Kg bw-T

Taste 7, Tabulation of mean MVO:/Kg bw versus age and FRWI categories. These data represent the 1960-
1963 period. Each Table cell contains the mean MVO:/Kg bw value (in ml/min./Kg) and immediately be-
low it (in parentheses) the number of data used in its calculation.

simple parameters as age, height, weight, SBP,
DBP, and HR would seem to be highly desirable.
A more focused effort could be afforded to the
aviation medical examiner for the detection of
any form of CHD which would be incompatible
with the safe conduct of airman/ATC activities.
Such focused efforts could include the assessment
of any or all of the remaining documented indices
from the FHS coronary profile’ This could
provide an enhanced capability for early detec-
tion of incipient CHD.

Where a strong indication of CHD sus-
ceptibility appeared to be present, but no form
of CHD, per se, were diagnosed, educational
options could be exercised in the direction of
susceptibility reversal for return to a fully
optimum state of cardiovascular health. Finally,

if absolute threshold values for susceptibility
parameters were delineated for all the segments
of the airman population, an extension of educa-
tional efforts would be logical in order to fully
establish the concept of preventive maintenance
of optimum cardiovascular health. An educa-
tional effort aimed at the reversal of CHD sus-
ceptibility and at preventive maintenance of
optimum cardiovascular health would be of par-
ticular relevance for ATC personnel as an in-
tegral portion of FAA Order 9480.2A which
established a specific program of health main-
tenance on their behalf. The degree to which
this is achieved in all the major segments of the
airman population should be reflected in the
enhancement of aviation safety.

10


AGE (yrs)

FRWI

(%) 25-29 30-34 35-39

40-44 45-49 50-54 _All Ages

vio | 738 | 75.7 | 772 | 724 | 792 | 743
100.0] TEP | daar | (ae (13) cD) (5) (230)
100.0-]] 72.0 | 77.1 77.8 80.7 84.6 81.0 78.0
119.9 | @) | c24 | fer | (5) (16) (2) (216)
71.3 | 753 | 769 | 790 | 796 | 797 | 76.1
<120.0 | fey | 272) | cos | (es) | (27) | 7) | (4408)
s28 | 787 | 805 | 975 | 640] 82.1
21200 |} (oy | ts) (6) (2) (2) () (28)
All 713 757 77.0 | 79.1 80.8 778 76.5
FRWIs |] (9) | (290) | (109) | (30) (29) (8) (475)
Table 6 DBP-1L

Tape 6. Tabulation of mean DBP versus age and FRWI categories, These data represent the 1970 period.
Each Table cell contains the mean DBP value (in mm Hg) and immediately below it (in parentheses) the

number of data used in its calculation.

since the total ATC population currently num-
bers in excess of 20,000 personnel, a similar
analysis of the whole ATC population would
statistically test the general validity of the inter-
parametric relationships reported here. If such
an analysis should confirm the general pattern
observed here, only the consistency of these inter-
parametric relationships will have been corrobo-
rated. The general pattern could also be
statistically tested in other major segments of the
airman population. The corroborated presence of
relatively increasing CHD susceptibility for the
whole ATC population would still not delineate
the actual degree of susceptibility in concrete
terms such as mortality and/or morbidity ratios.
In order to obtain definitive information of this
nature, a prospective study would be necessary.
An initial population sample of statistically ap-
propriate size and composition, initially free of
CHD, would have to be followed temporally for

the actual incidence rate of subsequently docu-
mented occurrences of CHD. If, following a
reasonable time period, an examination of the age
versus FRWI tabulation of percent CHD in-
cidence revealed an age versus obesity relation-
ship consonant with the parametric trends of this
report, then corroboration and quantification
would have been achieved simultaneously. Cor-
roboration of this general pattern could be of
extreme practical value.

Tf actual CHD susceptibility of a significant
degree were clearly delineated by a combination
of quantitative threshold values of the parameters
in this report, the delineation of the susceptible
portion of each major segment of the airman
population would have major relevance to avia-
tion safety. In terms of CHD screening in an
airman population currently numbering ap-
proximately 725,000,** a delineation of such sus-
ceptibility based on the measurement of such



AGE (yrs.)

FRW
(%) 20-24 25-29 30-34 35-39 40-44 45-49 All Ages
122.0 118.5 123.4 1225 134.0 110.0 121.2
<l000 1 ep | Nair | ter | ow a (78)
100.0-}} 121.8 122.7 | 126.3 123.0
19.9 (6) (13) (3) (0) (0) (0) (22)
122.0 120.1 124.2 (22.5 134.0 110.0 121.6
<!20.0 | say | (3a) | ain (2) () Ww | don
> 130.0 132.8 110.0 128.5
=120.0 ff tn (4) W) (0) (0) | (0) (6)
All 122.1 121.5 123.0 1225 134.0 110.0 122.0
FRWIs |} (53) | (38) | (12) (2) a) Ww) (107)

Table 3- SBP-TI

Taste 8. Tabulation of mean SBP versus age and FRWI categories. These data represent the 1960-1963

period.
theses) the number of data used in its calculation.

that age and obesity may be making separate
contributions to the decrease in MVO./Kg bw is
suggested by the general presence of the same
trend within each of the segmental age and
FRWI categories. The point of paramount in-
terest is the general tendency of an overall con-
centration of the lower MVO./Kg bw values
(lower physical fitness) in the combined older/
obese categories.

In the 1970 period, the only available data
having relevance to the 1960-1963 MVO./Kg bw
data were the resting, exercise and recovery HRs.
As previously indicated,'' physical fitness is
inversely related to the HR at rest, at fixed-levels
of submaximum exercise and at fixed-intervals
of post-exercise recovery. The age versus FRWI
tabulations of mean resting HR, mean exercise
HR and mean recovery HR for the 1970 period
are presented in Tables 8, 9, and 10 respectively.
In these tables, there appears to be a general

Each Table cell contains the mean SBP value (in mm Hg) and immediately below it (in paren-

trend of increase in all three HR parameters with
age and, obesity. In concordance with the 1960-
1963 MVO./Kg bw data, these HR data appear
to indicate a general trend of decreasing physical
fitness with age and obesity, as well as a tendency
for a concentration of this condition in the older/
obese categories. These trends may bear addi-
tional importance if considered from the view-
point that the 1960-1963 MVO,/Kg bw data
already indicated undesirably low physical fitness
baselines *® from which further decreases in
physical fitness may have occurred. The direc-
tional relation of these three HR parameters to
decreasing physical fitness is well estab-
lished.* 9°22 The inverse relationship of physical
fitness to CHD susceptibility has been clearly
established by the FHS.****

The age versus FRWI tabulation of the 400
pathology code incidence for the 1970 period is
presented in Table 11. The parenthesized value


of the Framingham Relative Weight Index
(FRWI) was assessable from directly measured
height and weight data. Our 1960-1963 determi-
nations of resting systolic blood pressure (SBP)
and diastolic blood pressure (DBP) were assess-
able in relation to the FHS finding of increased
CHD susceptibility conferred by elevated blood
pressure. The reported inverse relationship be-
tween level of physical activity and CHD
susceptibility’ was assessable in terms of our
1960-1963 measurements of MVO./Kg bw. The
directly proportional relation of this latter item
to physical activity capacity is well established.? §

According to one of the FHS reports, the
twelve-year incidence rate of CHD in their male
subjects with an entry age of 40-49 years was
2.33 times that of their comparable 30-39 year
old group. Another FHS report arbitrarily de-
fined frank obesity as an FRWI of 120% or
greater.” In this report covering males of 30-
59 years of age at study entry,® the twelve-year
risk of the 120% or greater FRWI group for
development of CHD was 1.78 times that of the
90-109% FRWI group. In the same report,
further comparisons of the same two FRWI

“ groups over the same twelve-year period revealed
that the risk of the obese group for development
of angina pectoris (AP) was 2.09 times that of
the non-obese group and the risk of those in the
obese category for sudden CHD death was 5.06
times that of the non-obese category. In an
earlier FHS report,® sudden death was defined
as a sub category of CHD in which death
occurred in a matter of minutes in persons ap-
parently well. Therefore, it is conservatively
apparent that age beyond 40 years and obesity
of an FRWI of 120% or greater are at least
associated with a substantially increased sus-
ceptibility to CHD. The possibility that obesity,
per sé, has a causal as well as an associative rela-
tion to the development of CHD and its sequelae
is strongly supported by the evidence that the
risk of CHD increases further when other risk
factors are superimposed upon obesity.‘

Since neither age nor obesity, per se, are dis-
qualifying according to aeromedical certification
standards, a wide distribution spectrum of each
of these two parameters in the ATC and/or any
other substantial segment of the airman popula-
tion is a reasonable expectancy. Because of the
expected wide distribution of these two factors
and because of their reported association with

CHD susceptibility,** it seemed reasonable to
examine the quantitative distributions of the
FRWI, SBP, DBP, and MVO,/Kg bw in an age
versus FRWI table format. This analysis could
expose CHD factorial interrelationships, if pres-
ent, in the 1960-1963 ATC student data.

Because height and weight (FRWI determi-
nants), age, as well as SBP and DBP data are
routinely obtained and recorded as an integral
part of the annual ATC medical certification
procedure, this affords an identical analysis of
current values of these same parameters obtained
during the current medical examinations of those
ATC students who had subsequently become
career ATC personnel. A current analysis of the
identical factors could reveal the temporal
progress, if any, of whatever CHD factorial in-
terrelationships existed in the 1960-1963 period.
Since MVO./Kg bw is inversely related to rest-
ing, fixed-level submaximum exercise and post
exercise recovery heart rates (HR), and since
these three HR measurements are also obtained
and recorded as a routine portion of the annual
ATC medical examination, the analysis of their
current values seemed warranted in relevance to
the 1960-1963 MVO,./Kg bw data.

Of the 1,270 ATC students who underwent
biodynamic testing in the 1960-1963 period, ap-
proximately 870 completed their ATC training
successfully. Of these 870 graduates, date of
birth (age determinant) along with height and
weight (FRWI determinants) were obtained on
only 653 of them in the 1960-1963 period. A
search of the active medical certification files in
1970 revealed 475 of the 1960-1963 graduates who
were currently ATC personnel and whose medical
certification records contained age, height, weight
and adjunct data. The age versus FRWI
parametric tabulations representing the 1960—
1963 and the 1970 time periods respectively were
restricted to the data obtained from the original
475 ATC students who were still present as
career personnel in 1970.

Because of its direct relevance and availability
from the current medical cetification files, an age
versus FRWI tabulation of the incidence of
cardiovascular pathology of the 400 series was
also included in the analysis of the 1970 data.
Although VC and MBC were measured in the
1960-1963 period,! these two parameters were
omitted from this analysis because data for the
1970 period were not available.


rRWI AGE (yrs.)
(%) 25-29 30-34 35-39 40-44 45-49 50-54_All Ages

< 75.7 74,3 73.9 75.7 75.1 768 74.4
100.0 (6) (147) (47) (13) ay (5) (229)

100.0-|) 82.0 | 746 76.6 75.0 75.1 73.0 75.0
119.9 (3) (124) (56) (15) (16) (2) (216)

7ze | 744 | 749 | 753 | 755 | 757 | 747
<I200 || ‘sy | a7 | cox | ca) | 7 | ai | 445)

77.9 70.4 77.0 88.0 86.0 77.5
21200 | (o | as) (5) (2) (2) WW (28)

All 779 | 746 | 747 | 75.4 | 76.0 | 77.0 | 749
FRWIs ji (9) | (289) | (os) | (30) | (29) (8) (473)

Table 10-Recovery HR-I

Taste 10. Tabulation of mean recovery HR versus age and FRWI categories. These data represent the 1970
period, Each Table cell contains the mean resting HR value (in beats/min.) and immediately below it
(in parentheses) the number of data used in calculation.

18



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REFERENCES

M. T.: Biodynamic Evaluation of Air
Traffic Control Students Between 1960-1963, FAA
Office of Aviation Medicine Report (in process).

. Dawber, T. R., G. F. Meadors, and F. E. Moore, Jr.:

Epidemiological Approaches to Heart Disease: The
Framingham Study, AM. J. PUB, HEALTH, 41:279,
1951.

. Kannel, W. B., W. P. Castelli, and P, M. McNamara:

The Coronary Profile: 12-Year Follow-Up in the
Framingham Study, JOUR. OCCUP. MED., 9:611,
1967.

Kannel, W. B., T. R. Dawber, and P. M. McNamara:
Detection of the Coronary-Prone Adult: The Fram-
ingham Study, J. IOWA MED. SOG., 56:26, 1966.

. Kannel, W. B., E, J. LeBauer, T. R. Dawber, and

P. M. McNamara: Relation of Body Weight to
Development of Coronary Heart Disease, CIRC.,
35:734, 1967.

. Kagan, A. T. R. Dawber, W. B. Kanel, and N.

Revotskie: The Framingham Study: A Prospective
Study of Coronary Heart Disease, FED. PROC.,
21(4) Part 11:52, 1962.

. Dawber, T. R., W. B. Kannel, and G. D, Friedman:

Vital Capacity, Physical Activity and Coronary
Heart Disease, Ch, 81 in Prevention of Ischemic
Heart Disease, TWinois, C. C. Thomas, 1966.
Astrand, P. 0.: Human Physical Fitness with Special
Reference to Sex and Age, PHYSIOL. REVS., 36:307,
1956.

. Astrand, I.: Aerobic Work Capacity in Men and

Women, ACTA PHYSIOL, SCAND. SUPPL., 169:11,
1960.

Dawber, T. R., W. B. Kannel, and L. P. Lyell: An
Approach to Longitudinal Studies in a Community:
‘The Framingham Study, ANN. N.Y. ACAD. SCI.
107 :539, 1963.

Naughton, J.: Cardiorespiratory Endurance, MINN.
MED., 51:619, 1968.

Bordley, J., C. A. R, Connor, W. F. Hamilton, W. J.
Kerr, and C. J. Wiggers: Recommendations for

15

13.

14.

15.

16.

1.

18.

19.

. Lester, M., L.-T.

Blood Pressure Determinations by Sphygmonometers,
CIRC., 4:508, 1951.

‘Trotter, M., and C. G. Gleser: The Effective of Age-
ing on Stature, AM. J. PHYS. ANTHROPOL., 9:311,
1951a.

Damon, A.: Adult Weight Gain, Accuracy of Stated
Weight and Their Implications for Constitutional
Anthropology, AM. J. PHYS. ANTHROPOL, 23 :306,
1965.

Society of Actuaries: Build and Blood Pressure
Study, Volume I, Chicago, Society of Actuaries, 1959,
pp. 24.

Dawber, T. R., F. E. Moore and G. V. Mann:
Coronary Heart Disease in the Framingham Study,
J. PUB, HEALTH, 47 (Suppl): 4, 1967.

Weight, Height and Selected Body Dimensions of
Adults: United States, 1960-1962. Vital and Health
Statistics, Series 11, No. 8, p 6, 1965.

Balke, B., and R. W, Ware: An Experimental Study
of “Physical Fitness” of Air Force Personnel, U. 8.
ARMED FORCES MED. JOUR., 10:657, 1959.
Frick, M. H.: Significance of Bradycardia in Relation
to Physical Training, Ch. 3 in Physical Activity and
the Heart, Mlinois, C. C. Thomas, 1964.

. Grimby, G. and B. Saltin: Physiological Analysis

of Physically Well Trained Middle Aged and Old
Athletes, ACTA MED. SCAND., 179 :513, 1966.
Sheffield, P. Trammell, and T. J.
Reeves: The Effect of Age and Athletic Training
on the Maximal Heart Rate During Muscular Exer-
cise, AM, HEART J., 76:370, 1968.

. Hanson, J. S., and B. S. Tabakin: Comparison of

the Circulatory Response of Upright Exercise in 25
“Normal” Men and 9 Distance Runners, BRIT.
HEART J., 211, 1965.

. Kannel, W. B.: Habitual Level of Physical Activity

and Risk of Coronary Heart Disease, CANAD. MED.
ASSOC. J., 96:811, 1967.

. Aeromedical Certification Statistical Handbook, 1970.



CHANGES IN CARDIOVASCULAR HEALTH PARAMETERS OVER AN
EIGHT-YEAR INTERVAL IN AN ATC POPULATION SEGMENT

I. Introduction.

During 1960-1963, the Civil Aeromedical Re-
search Institute (CARI) conducted a broad
spectrum of biomedical evaluations on a large
number of air traffic control (ATC) students.
Approximately 1,270 of these students (20-50
years of age) underwent’ biodynamic testing of
physical fitness. This testing included adjunct
measurements of height, weight, pulmonary vital
capacity (VC) and maximum breathing capacity
(MBC) as well as maximum aerobic work
capacity in terms of the maximum oxygen uptake
per kilogram body weight (MVO./Kg bw).*
These data were collected as baselines for sub-
sequent evaluations of the students after they
had become career ATC personnel. The subse-
quent evaluations were planned as assessments of
longitudinal changes associated with chrono-
logical aging and health related aspects of job
performance.

In 1967, a five-year biomedical followup task
was initiated. The ATC students who had be-
come career personnel were somewhat randomly
distributed throughout the various tower and en-
route centers of the air traffic system. Two of
the largest concentrations of biomedical followup
candidates (14 apiece) were located at two Cali-
fornia enroute centers. The followup evaluations
of these two groups were to be conducted in-
house at the Civil Aeromedical Institute (CAMI)
in Oklahoma City. In very short order, it be-
came apparent that, because of combined dif-
ficulties in ATC leave scheduling, biorhythmic/
environmental displacements and travel logistics,
the return of these personnel to the Civil Aero-
medical Research Institute for followup evalua-
tions would be grossly inefficient in cost and time,
as well as biologically undesirable. The same
logic would apply to other personnel concentra-
tions with similarly distant geographic locations.

Serious consideration was given to field testing
at the geographic sites of substantial personnel

concentrations. This was deemed unfeasible
when considered in terms of the travel logistics of
in-house equipment and research personnel, as
well as the total time which would be needed to
process geographically a reasonable number of
followup candidates.

Further examination of the geographic distri-
bution of personnel revealed that a small but
useful number of followup candidates was located
at the Kansas City and Fort Worth enroute
centers. Of these candidates, a total of 20
volunteered to return to CAMI for the evalua-
tion. The evaluation of these 20 personnel in-
house was deemed feasible because of the rela-
tively short travel time between each of these
centers and Oklahoma City, and because of their
general biorhythmic/environmental compatibility
with the Oklahoma City area. When these 20
personnel were subsequently evaluated, ortho-
static tolerance (tilt table) as well as resting and
exercise electrocardiography testing were em-
ployed in addition to those procedures used in the
1960-1963 period. A segmental separate report
will cover the results of these 20 followup
evaluations.

In the 20 years since its 1950 inception,? the
Framingham Heart Study (FHS) has succeeded
in delineating an extensive battery of quantifiable
indicators of gradational susceptibility to
coronary heart disease (CHD). This battery of
indicators has become well known as the “coro-
nary profile”? In 1970, as a facet of in-house
research on early detection of cardiovascular
disease in aviation personnel, the data obtained
from the ATC students in the 1960-1963 period
were reviewed and found to contain several of
the FHS indices.

For males, the FHS data have clearly shown
that increased age and obesity each confer in-
creased susceptibility to CHD.*® In the 1960-
1963 ATC data, age was available as a directly
recorded item and the degree of obesity in terms



ACKNOWLEDGMENTS

The author sincerely acknowledges the sustained, intensive efforts of
Mrs. Peggy Lyne and Mrs. Paula Grape in the massive data processing in-
volved in this report. Mr. Charles Booze and Dr. Earl Folk are acknowl-
edged for their facilitation of access to the 1970 medical certification data
and adjunct consultation concerning data analysis.


-RWI AGE (yrs.)
(4) 25-29 30-34 35:39 40-44 45-49 50-54 All Ages

745 73.3 72.4 748 74.7 77.2 73.4
<l000 (6) (147) (47) (13) a) (5) (229)

100.0-]} 69.3 | 73.6 75.6 74.0 75.0 | 70.0 74.2
119.9 (3) (124) (56) | (15) (16) (2) (216)

72.8 73.4 74.2 74.4 74.9 75.1 73.8
<120.0 | (9) | ez | cos) | (ay | (27) | «7 | (44s)

> 75.6 | 70.0 | 750 | 870] 840 | 75.6
=120.0 |] (0) i)

(5) (2) (2) ( (28)
All 72.8 73.6 74.0 74.4 757 76.3 73.9
FRWIs |} (9) | (289) | (los) | (30) | (29) (8) | (473)

Table 8-Resting HR-IT

Taste 8. Tabulation of mean resting HR versus age and FRWI categories. These data represent the 1970
period, Each Table cell contains the mean resting HR value (in beats/min.) and immediately below it
(in parentheses) the number of data used in its calculation.

11



AGE (yrs.)

FRWI
(4), 25-29 30-34 35-39 40-44 45-49 50-54 All Ages
0/6 2/148 1/47 O/I3 Wu 0/5 4/230
<1000 1 Cyr [Paar | aay | fae | wen | (7)
100.0-]] 073 | 37124 | 1756 | 0715 1/16 172 6/216
19.9 | © | 4) | (er | cr | 3) | woo] @s)
0/9 5/272 2/103 0/28 2/27 \/7 10/446
<120.0 | oy | tied | iy | co | za | 4a) (2.2)
0/0 0/18 2/6 0/2 1/2 O/I 3/29
21200 || %o) tor | (333) ] 0) | (S00 | © (10.3)
All ove | 57290] 47109 | 0/30 | 3729] 178 | 137475
FRWIs |} (0) (7) | 7) | (0) (10.3) | (12.5) (2.7)

Table I!- 400 Path. Code - IT

Taste 11, Tabulation of 400 pathology code incidence versus age and FRWI categories. These data represent

the 1970 period.

Each Table cell contains the ratio of the 400 code incidence number to the total number

of cell individuals and immediately below it (in parentheses) the equivalent of the ratio in terms of percent

incidence,

14