The statistical analysis of neonatal TSH results from congenital hypothyroidism screening programs provides a useful tool for the characterization of moderate iodine deficiency regions.
TSH data from the congenital hypothyroidism screening program were analyzed in a mild to moderate iodine deficiency region. Neonatal TSH levels were measured at day 4-5 of life in 22,384 infants (99% coverage; 51.1% males, 48.9% females). The cut off TSH value for recall was established at 20 microUl/ml whole blood. TSH values > 20 microUl/ml were excluded from further analysis of the data. The frequency distribution analysis showed that the median neonatal TSH level was 2 microUl/ml and the mode (28% of newborns) corresponded to neonatal TSH values < 1 microUl/ml. TSH levels above 5 microUl/ml were observed in 14.4% children and the 97% cut off was 11 microUl/ml. When examined in relation to the areas of newborn origin, the individual 97% cut off values varied from 8 to 14 microUl/ml. Accordingly, the frequency of TSH levels above the 97% cut off value calculated for the entire newborn series (> 11 microUl/ml) ranged from 2.1% to 4.6%. A significant correlation was found between the frequency of neonatal TSH levels > 11 microUl/ml and both goiter prevalence (r2 = 0.88; p = 0.0019) and median urinary iodine excretion (r2 = 0.86; p = 0.0077) observed in those areas for which epidemiological data were available (n = 7). The results indicate that neonatal TSH data from the congenital hypothyroidism screening programs can be used for monitoring mild to moderate iodine deficiency regions.
Costante
G
G
Dipartimento di Medicina Sperimentale e Clinica, Università di Reggio Calabria, Catanzaro, Italy.
Grasso
L
L
Ludovico
O
O
Marasco
M F
MF
Nocera
M
M
Schifino
E
E
Rivalta
L
L
Capula
C
C
Chiarella
R
R
Filetti
S
S
Parlato
G
G
D015415:Biomarkers / Q000097:blood; D003409:Congenital Hypothyroidism; D005260:Female; D006042:Goiter / Q000453:epidemiology*; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000175:diagnosis*; D007231:Infant, Newborn; D007455:Iodine / Q000172:deficiency* / Q000652:urine; D007558:Italy / Q000453:epidemiology; D008297:Male; D008403:Mass Screening; D015995:Prevalence; D011446:Prospective Studies; D013972:Thyrotropin / Q000097:blood*
D015415:Biomarkers; D013972:Thyrotropin; D007455:Iodine