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Bellini-Peterson et al., Sao Paulo, Brazil, investigated prospectively lipid profiles in
124 patients with subclinical hypothyroidism (mean TSH 15 ± 10.9 mU/l ) and compared results with
80 matched healthy controls (mean TSH 1.7 ± 1.0 mU/l). They found elevated total cholesterol in
79% of patients vs 20% of controls (p < 0.0001). LDL were elevated in 64.5% vs 41.2% (p < 0.001),
VLDL 73.4% vs 28.7% (p < 0.001) and serum triglycerides 57.2% vs. 13.7% (p < 0.01). No differences
were present for HDL levels. Also mean levels of total cholesterol, VLDL and triglycerides were
higher in patients. A positive correlation was present between TSH levels and these three
parameters and this was also true for TPO-Ab values with total cholesterol and triglycerides.
(Comment: Again this study shows an increase in risk factors for cardiovascular diseases in
subclinical hypothyroidism nowadays termed mild hypothyroidism. See also Meier et al., JCEM,
86, 4860, 2001, showing that treating subjects with mild thyroid failure with L-thyroxine not
only normalizes risk factors but also improves clinical symptomatology. In the same issue of the
JCEM a debate is being published between pro- and opponents of thyroxine therapy in mild thyroid
failure. My personal opinion (despite the results in the next report) is in favor of treatment
in persistent subclinical hypothyroidism.) Duntas et al., Athens, Greece, investigated an other
aspect of risk factor development in subclinical hypothyroidism by measuring plasma levels of
oxi-LDL in 29 patients with subclinical hypothyroidism, 33 with overt hypothyroidism and 57
healthy controls. They found a significant mean increase of oxi-LDL of 34.5% in overt
hypothyroidism but an insignificant elevation of 7.2% in subclinical hypothyroidism.
Two communications were related to perinatal thyroid hormone deficiency and brain development in humans. Thus, Rovet et al., Ontario, Canada, assessed visual processing deficits in perinatal and neonatal thyroid hormone deficiency. They studied 48 three months-old infants: 17 offspring of hypothyroid women, 9 with early-treated congenital hypothyroidism (CH) and 22 normal controls. They found visual deficits in 45% of pre- and neonatal thyroid hormone deficiency and in 17% of controls (p = 0.02). The same group also reported a study with regard to development of memory, in 79 children in the age from 7-12 years, 44 of whom had congenital hypothyroidism and 35 controls. They tested episodic-, semantic- and recognition memory. Selective memory disturbances were found more in the thyroid hormone deficient group, suggesting hippocampal damage. The authors plan to further study neuro-imaging of the hippocampus in this type of children. |
