: Zt R ne we PY Fy ; e Boog | “iea eT sas 108 LARSEN et al. ’ TABLE LV BASELINE SERUM TSH CONCENTRATIONS AND RESPONSE 10 500 yg THYROTROPIN RELEASING HORMONE(TRH) IN CONTROL MARSHAL LESE SUBJECTS a9 Basal seruan TSH concenteations and response to TRE | Mean 1 SD Since the most sensitive index of aapaaed thyroid function ts an clevahion i scHin PSH which occurs through the hy potiadanie-pilunary diy cod feedback ants, scruin TSP concentrations aid then iespumse to PRED were measured: an both Wie conuol and tlie exposed Rongelep population. fa praunary by pothyronlisa, wu/ul Basal YSU [AEA-SM-224/607 the wesponse of the pituitary to PRED is cxcessively preat (8) Mea basal OSH Mean t SD 2020.75 was 2 U/l in 25 non-exposed cuthytou Marshallese, and dhe tauge was from Range U.5- 3.0 undetectable (0 05 pll/ial) to 3 pU final (Fable IV) Serta PSH 20 minutes folowing ERGE was ticdeascd an all control subjeots “Thre gncan increimcnt was OSH 20 san alter TRH absras Range 11.5 24.5 4¢SD) with a range of from 4 7 to 20 pU find Phese cesulls aie not 47-20 sigitlicantly different from these previously reported mn uther populations |9] Ohi the basis of Giese studies, celerta were established for clussiication of paticnts as having biochemical evidence of unpaued Unyroid function. Phese citleria ate subiaiized oo dable V, and include cither two basal PSEE dedermiiaations giculer thaa 5 pU find (> 4 stundaid deviaiions above he meuab or basal TABLE Vo CRITERIA FOR THE DIAGNOSIS OF BIOCHEMICAL THYROID BYSEUNCTION | Hasal plasina ISH > § pu/mi plasma VSOP > 3 wU/inl (but <5 gl/aid) aud piasmia V Std alterPRU 22 pU/md. Consistent observations ta Uhese tanges were requited On EWo Occasions fo mel the critenta fos bigchcamcab evidence of thyroid dysfunction While scrim Ty concentration is ao dmportant determin’ in the thyrout status of the todiidual, prewiods studies have indicated hat evidence Of mmipaimed dhytoul fuactioan can On (wo Occasions be ehemted by these lests belare serum Py comcentiaions dave fallen below the normal range FLO] Pheretore, the serum Py codceutiatior was nod used as a or 20a i) Basal plasina TSH ~ Phasing PSdlatler FRH > 22 pU/ml chilcion pt establishing dhe diagnosis Of panned thyroid bane tion JpUf/ul in Table Vitis shown the drequency of ul deust a single chewaled basal PSGL OU Iwo OLcusions coaccntiahion dn vatiows Maishalicse populations. Ing comlrot group of 115 why were nol exposed to cfadiation, § 1 sabpects ar 100 of tie population bad aseruin PUSH) greater thao 3 g/ml. dn ten of these, serui PSH wis only nuainally elevated (4 O pU/ial of less), the remuming value was oO | wU/il None of these patients had detectable clinical hypothyroidism of thyroid colargement, but serum Ty concentrations were generally ui the low normal range. le the exposed Unk population, }2 of 99 subjects tested had at least one TABLE VIO FREQUENCY OF AT LEAST A SINGLE ELEVATED BASAL SERUM [SH CONCENTRATION IN THLE MARSHALLESE POPULATION basal scrum TSU greater than 3 pU/nd, though none of Uiesc was in excess of Contra uncapused Utiusk exposed (thyroid dase <. 95 padss Kungclip aid Aiingnae ¢expused (Subjects without surgery Number Number lesied > 3.0 pU/ial * S aU/ind ‘ble ancidence of elevated TSiiin this population is not signiticantly different tron that of the unexposed group. dn the Rongelap wad Adingnae Lis Ml tO serum PSH greater than 3 wU/inb, and im two cases seruan VSEL was in excess of yy 12 43 fi ‘ populaion, EL uf 43 subjects were tound tu have al least a single elevated basal 7 wU fol, and in two causes scam PSU was in excess of 7 U/l 12 “Thus isa slentiicandly lugher prevaleace than inthe offer bwo groups pooled (p <0 05) Ia Fig. | ate shown the respomses to PRE of the tour midiviaduals who met the Zo criteria given in Table Vo The nociaal basal PSU) and response to TRIE ae shown and excluding Nus 3 & 9) tn the shaded burs. In these four individuals, the basal serum VSI was elevated, | ( aa \