Table 7.
Results of serum analyses in exposed Marshallese subjects
with at least two TSH assays >6 W/mi (1980).
Subject
No. & sex
Date of
sample
Serum TSH
( WU/m1)
3M
5M
4m
1977
1963
1972
1974
1969
1979
1974
1979
1974
69
500
6.0
7.0
6.3
6.5
6.3
8.3
10
2.5
0.5
7.3
5.4
4.4
4.9
7.1
8.0
4.2
1979
1980
8.8
7.3
7.6
5.1
16M
34F
71F
1977
1977
78F
32M
7
6.6
Normal control range:
0-6.0
Serum Ty,
(te /dl)
5.2
6.1
5.0-10.2
TBGI
(units)
Age at
exposure
Estimated
thyroid dose
(rads)
0.95
0.71
-0.82
0.89
0.91
-0.74
--
1
1
38
1150
1150
335
39
135
45
335
27
335
37
335
3
1050
0.98
0.82
0.68
0.89
0.85-1.10
observation of elevated 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 Ty, 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 patient had surgery subsequent to the test and is therefore categorized sepa-
rately (Table 8). Subjects No. 4, 71, and 78 all were hyperresponsive to TRH
stimulation, with serum TSH values at 20 min >22 WU/ml, which is the 97.5% confidence interval for mean normal responses in the Marshallese.
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BASAL AFTER
TRH
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 Ug TRH.
The upper limits of the normal range
are indicated by the shaded bars.
—~72-