at
Table 7.
Results of serum analyses in exposed Marshallese subjects
with at least two TSH assays >6 \/ml (1980).
Age at
exposure
Est imated
thyroid dose
(rads)
0.95
0.71
—
1
1
38
1150
1150
335
0.89
0.91
39
135
_
45
335
_
27
335
37
335
3
1050
Subject
No. & sex
Date of
sample
Serum TSH
(10/m1)
Serum Ty,
Cg/d1)
3M
5M
4M
1977
1963
1972
69
500
6.0
2.5
0.5
7.3
16M
1969
1979
6.3
6.5
4.4
4.9
1979
8.3
8.0
0.74
5.2
6.1
7.6
5.1
0.98
0.82
0.68
0.89
34F
7iF
78F
32M
1974
7.0
1974
6.3
1974
10
1977
1977
1979
1980
7
6.6
8.8
7.3
Normal control range:
0-6.0
5.4
7.1
4.2
5.0-10.2
TBGI
(units)
0.82
0.85-1.10
observation of elcvated TSH in the individuals Listed in Table 7 cannot be
attributed to age alone. No. 4 and No. 78 were among those in whom TSH stimu-
lation tests had been performed earlier. Both had Tyg increments of “1 Hg/dl
24 hours following 10 units TSH administration, a clearly subnormal response
showing that these thyroids had no capacity to respond to increased demand.
To evaluate the pituitary/thyroid axis more completely, TRH studies were
done in some individuals. Results on subjects No. 4, 71, and 78 are given in
Figure 5. Data from subject No. 74, discussed below, are also shown. ‘This pa~tient had surgery subsequent to the test and is therefore categorized separately (Table 8). Subjects No. 4, 71, and 78 all were hyperresponsive to TRH
stimulation, with serum TSH values at 20 min >22 W/ml, which is the 97.52 con-
fidence interval for mean normal responses in the Marshallese.
.
"|
,
*
40
5
=
en
g 20
<
ret
Inq
,,
* 10
o &
BASAL AFTER
Figure 5.
Basal plasma TSH and TRH-
stimulated TSH in euthyroid Marshallese
and in four exposed subjects with
biochemical evidence of impaired thyroid function. Plasma was obtained
20 min after infusion of 500 | TRH.
The upper limits of the normal range
are indicated by the shaded bars.
TRH
-72-