Surgery and Healing in the Developing World - Dartmouth-Hitchcock

Metabolic Maladaptation
Table 4. Goiter rates and impaired fertility in Zairian populations
Bas Uele Haut Uele Ituri Forest Nyankunde
People Examined 522 (%) 412 (%) 83 (%) 84 (%)
Primary Sterility 125 (23.9) 51 (12.4) 12 (14.5) 4 (4.8)
Secondary Sterility 150 (28.7) 27 (6.6) 2 (2.4) 14 (16.6)
Incidence of 83.3 73.2 55.4 12.5
Goiter in Female n = 1127 n = 621 n = 195 n = 168
Population (%)
297
Cassava is a New World product, and probably arrived in this area not long
before or with the Azande migration into it. Cyanide content of cassava is not unique
to this root crop, but its concentration in this species is higher. Exclusive or dominant
intake of this calorie source would accentuate the problem of iodine deficiency
but not create it. Those who are more affluent in this society and who may depend
less on cassava as a principle intake (for example, the ruling Azande families) still are
not free of goiter or cretinism, and in fact, Chief Sasa himself and the ancestral
portraits of the ruling chiefs before him exhibit very prominent displays of goiter.
The Chief’s brother, also bearing the royal name Sasa, is of comparable age, but
exhibits stunted stature, lumbar lordosis, splayed stance, clumsy gait and the other
features of congenital hypothyroidism. He is deaf-mute, retarded in intelligence,
capable of limmited self-care. His TSH is 718 IU/ml, T 4 0.2 and T 3 16; for comparison,
those values for the author serving as a control are: TSH 3.7 (Nl: 0.5-4.0
uIU/ml), T4 6.21 (Nl: 4.00-11.00 µg/ml), T3 125.7 (Nl: 70.0-220.0 ng/dl).
Hypothyroidism in the Uele endemia is due to iodine deficiency. This iodine
deficiency effects newborns severely in congenital cretinism and adults with acquired
goiter through the compensatory mechanisms of the pituitary’s TSH stimulation of
the thyroid gland hypertrophy. Despite compensatory efforts the iodine deficient
population remains hypothyroid, and even marginal iodine deficiency is made worse
by the cyanide content in the principle staple source of calories, the cassava, which
also acts as goitrogen compounding the effects of iodine deprivation.
Hypothyroidism—A Metabolic Disease
The effect of hypothyroidism is reflected differently in the adult or child, and
this clinical difference will be investigated in this area of very high endemic affliction
of both age groups.
In the human adult, hypothyroidism is characterized by low energy output, inactivity
and subnormal metabolism. The thyroid itself undergoes compensatory
hypertrophy into a goiter, an enlarged thyroid gland, sometimes enormously expanded
with grotesque disfiguration of the throat and neck. The development of a
goiter is a compensatory mechanism. In response to the effects of severe iodine
deficiency, the pituitary gland secretes excess thyroid stimulating hormone (TSH),
which partially mitigates the effects of the deficiency. Goiter may also result from
other concomitant stimuli that are called goitrogens, most of which act through
similar mechanisms by making what little iodine is available less so. Some goitrogens
exacerbate iodine deficiency that might otherwise be compensated for by the
mitigating hypertrophy of the thyroid gland. 29
29