Some Further Observations on Goiter in Lebanon

An incidence of goiter of 25.4 per cent was found among school children residing in a mountain village in Lebanon. This incidence was highest in girls between nine and twelve years of age; the incidence appeared to be related to socioeconomic status.Twenty-six families from the area were Selected to participate in a double-blind controlled salt supplementation program. For twelve months, half the families were given iodized salt and the other half plain salt. Clinical examinations were conducted and the urinary excretion of iodine was measured initially and at intervals through the study. In the group given iodized salt, the incidence of goiter decreased from 30 to 12 per cent, whereas in the control group there was a decrease from 41 to 36 per cent. Initial values for urinary iodine were low in all subjects of both groups; after the distribution of salt, excretion values increased significantly in the group given supplements.Studies of the thyroidal uptake of Il31showed high values in subjects with and without goiters in the control group; the mean values for the group given iodized salt were greatly decreased. The results of a thiocyanate test in a group of subjects with goiters were negative.Dietary information failed to reveal an unusually high consumption of goitrogenic foods. However, high salt intake was observed; this observation was supported by the finding, in general, of high levels of urinary chloride. The possible relationship of high salt intake to goiter in human subjects was examined, based on information from experiments with animals.It was concluded that iodine deficiency was the primary cause of goiter in the area in which the study was conducted. Other factors which may have contributed to the local problem of goiter are discussed.