March 1986 Vol 40 No 1

Journal of

Epidemiology and

Community Health

BRITISH M E D I C A L ASSOCIATION TAVISTOCK S Q U A R E L O N D O N WC1

Editorial Committee J R T C O L L E Y ( E d i t o r ) J O H N F O X

R M A C H E S O N \ ( A s s o c i a t e E d i t o r s ) P E T E R G E N T L E

R E M I D W I N T E R / G E O F F R E Y R O S E

J M E L W O O D E S T L I N W A T E R S

P C E L W O O D

E D I T O R B r i t i s h M e d i c a l J o u r n a l

J O C E L Y N C H A M B E R L A I N 1 " P « * n t i n g the . A N L E C K [SOCIETY FOR

J S O C I A L M E D I C I N E

B E R Y L F L I T T O N ( T e c h n i c a l E d i t o r )

It is the policy of this Journal to publish original work in the field of epidemiology and Community health which relates to a total defined population and which shall be numerically rated. The field of interest includes studies of the distribution and behaviour of disease in human populations; the definition of the agents responsable for the patterns observed; the modifying effect of social or environmental conditions on disease evolution; and the assessment of the health and efficiency of people exposed to various external circumstances. Linked with these subjects is the design of measures intended to control or prevent disease and the field assessment of their value in public health practice. Epidemiology and Community health also encompasses the objective study of the Organisation and functioning of medical Services with particular emphasis on the measurement of their efficiency. Papers are accepted on their scientific originality and general interest, and ethical considerations will be taken into account.

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J o u r n a l o f E p i d e m i o l o g y a n d C o m m u n i t y H e a l t h , Department of Epidemiology and Community Medicine, University of Bristol, Canynge H a l l , Whiteladies Road, Bristol BS8 2PR. Papers will be considered in accordance with the terms of the uniform requirements. Papers will be acknowledged if a stamped addressed envelope or an international postal coupon is enclosed. Papers will not be returned whether accepted or not, so copies should be retained by authors.

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JOURNAL OF EPIDEMIOLOGY

AND COMMUNITY HEALTH

E D I T O R I A L B O A R D

J R T C O L L E Y ( E d i t o r )

R M A C H E S O N and R E M I D W I N T E R ( A s s i s t a n t E d i t o r s )

J M ELWOOD PETER GENTLE GEOFFREY ROSE P C ELWOOD D MORRELL ESTLIN WATERS JOHN FOX

EDITOR B r i t i s h M e d i c a l J o u r n a l

representing the SOCIETY FOR SOCIAL MEDICINE

BERYL FLITTON (Technical Editor)

JOCELYN CHAMBERLAIN \ IAN LECK J

VOLUME 40 1986

B R I T I S H M E D I C A L A S S O C I A T I O N T A V I S T O C K S Q U A R E L O N D O N W C 1 H 9JR

Contents

N o 1 M a r c h 1 9 8 6

The demand for health: theory and applications A D A M W A G S T A F F page 1 Comparison of chiropractic and hospital outpatient management of low back pain: a feasibility study R E P O R T O F A W O R K I N G

G R O U P page 12 The Port Pirie cohort study: maternal blood lead and pregnancy outcome A N T H O N Y J M C M I C H A E L , G R A H A M V V I M P A N I , E V E L Y N F

R O B E R T S O N , P E T E R A B A G H U R S T , A N D P E T E R D C L A R K page 18 Testicular cancer mortality in England and Wales 1971 -80: variations by occupation M E M C D O W A L L A N D R B A L A R A J A N page 26 Parental occupations and cancer: a review of the literature s E A R U N D E L A N D L M K I N N I E R - W I L S O N page 30 Diet and coronary heart disease in England and Wales during and after the second world war D J P B A R K E R A N D C O S M O N D

page 37 Effect of a lactation nurse on the success of breast-feeding: a randomised controlled trial D E E A J O N E S A N D R O B E R T R W E S T

page 45 Social and family factors in childhood hospital admission D M F E R G U S S O N , L J H O R W O O D , A N D F T S H A N N O N page 50 Illness, disability, and drugs among 25 to 75 year olds living at home H E D L E Y P E A C H A N D J O H N R H C H A R L T O N page 59 Breast Screening clinic versus health education Session as outlets for B S E education c F L A H E R T Y , J P H I L I P , W G H A R R I S , A N D

c A F J O S L I N page 67 Psychiatric morbidity after Screening for breast cancer C H R I S T I N E D E A N , M M A U R E E N R O B E R T S , K A T E F R E N C H , A N D S U S A N

R O B I N S O N page 71 Increase in hospital admissions for torsion of testis M N E L M S A N D D C O G G O N page 76 Reduction of tar, nicotine, and carbon monoxide intake in low tar smokers M A H R U S S E L L , M J J A R V I S , C F E Y E R A B E N D A N D

Y S A L O O J E E page 80 Prevalence of goitre and hypothyroidism in Southern Tanzania: effect of iodised oil on thyroid hormone deficiency w W Ä C H T E R , M M V U N G I , A K Ö N I G , C R P I C K A R D T , A N D P C S C R I B A page 86 Cerebral palsy—is it a seasonal disorder? L A L I T K A N T , S A R O J I N I D E W A N , A N D B K J A I N page 92 Society for Social Medicine page 94 Letter to the Editor page 70 Corrections page 96

N o 2 June 1 9 8 6

Mortality ratios, life expectancy, and causes of death in patients with Turner's Syndrome w H P R I C E , J F C L A Y T O N , S C O L L Y E R ,

R D E M E Y , A N D J W I L S O N page 97 Lifestyle changes in long term survivors of acute myocardial infarction R R W E S T A N D D A E V A N S page 103 Phlegm production and lung function among cigarette smokers changing tar groups during the 1970s H E D L E Y P E A C H ,

D M H A Y W A R D , D R E L L A R D , R W M O R R I S , A N D D S H A H page 110 Community hospitals in Oxfordshire: their effect on the use of specialist inpatient Services J A M E S E B A K E R , M I C H A E L G O L D A C R E ,

A N D J A M U I R G R A Y page 1 17 The natural history of asthma in childhood H R A N D E R S O N , J M B L A N D , S P A T E L A N D C P E C K H A M page 121 Distribution of episodes of mental illnes in general practice: results from the Second National Morbidity Survey N C S M E E T O N

page 130 Provision of Services for incontinent elderly people at home C A T H E R I N E W M C G R O T H E R , C H R I S T O P H E R M C A S T L E D E N , H I L A R Y

D U F F I N A N D M I C H A E L C L A R K E page 134 The elderly at home: indices of disability C A R O L J A G G E R , M I C H A E L C L A R K E , A N D R I C H A R D A N D R E W D A V I E S page 139 A n evaluation of Screening policies for cervical cancer in England and Wales using a Computer Simulation model D M P A R K I N

A N D s M M O S S page 143 Family building in parents with Down's Syndrome children A R B O O N page 154 Services for stroke patients one year after stroke J U L I A L E G H - S M I T H , D E R I C K T W A D E , A N D R I C H A R D L A N G T O N - H E W E R page 161 Use of the Nottingham Health Profile with patients following a stroke S H A H E B R A H I M , D A V I D B A R E R , A N D F I O N A N O U R I page 166 Repetition of accidents in young children c J A N E E M I N S O N , H A R J I N D E R J O N E S , A N D M I C H A E L G O L D A C R E page 170 Factors influencing participation in health surveys. Results from the prospective study " M e n born in Malmö, Sweden, 1914" L A R S J A N Z O N , B E R T I L S T E E N , B E R T I L H A N S O N , S V E N - O L O F I S A A C S O N , A N D S V E N - E R I C L I N D E L L page 174 Further evidence of a fall in blood lead in Wales P E T E R C E L W C O D A N D C O L I N T O O T H I L L page 178 Methylmercury exposure and mortality in southern Japan H I D E H I K O T A M A S H I R O , M I K I O A R A K A K I , M A K A T O F U T A T S U K A , A N D E U N

S U L L E E page 181 Blood pressures higher in the home than in the clinic in rural Kenya N R P O U L T E R , J D L U R Y , A N D A v T H O M P S O N page 186 Blood pressure and salt in Malawi: an urban rural study D S I M M O N S , G B A R B O U R , J C O N G L E T O N , J L E V Y , P M E A C H E R , H S A U L , A N D

T S O W E R B Y page 188

N o 3 September 1 9 8 6

Perinatal mortality Standards: construction and use of a health care Performance indicator E G K N O X , R L A N C A S H I R E , A N D

E H A R M S T R O N G page 193 Congenital cytomegalovirus infection: predisposing maternal factors P H I L I P M P R E E C E , P A T T O O K E Y , A N T H O N Y A D E S , A N D

C A T H E R I N E S P E C K H A M page 205 Seasonal variations in cryptorchidism M A R K B J A C K S O N A N D A N T H O N Y J S W E R D L O W page 210 Month of birth of men with malignant germ cell tumours of the testis L B E R N S T E I N , C L A I R C H I L V E R S , T M U R R E L L S , A N D M C P I K E

page 214 Recent trends in mortality due to testicular cancer in Ireland: a comparison with England and Wales J O H N A T H O R N H I L L , R O N A N

M C O N R O Y , D A N I E L G K E L L Y , A N T H O N Y W A L S H , J A M E S J F E N N E L L Y , A N D J O H N M F I T Z P A T R I C K page 218 Maternal smoking and low birthweight: implications for antenatal care R O G E R J S I M P S O N A N D N G A R M A N D S M I T H page 223 Why did postperinatal mortality rates fall in the 1970s? R S U N D E R L A N D , A G A R D N E R , A N D R R G O R D O N page 228 Research in epidemiology and Community health in the medical curriculum: students' opinions of the Nottingham experience J M E L W O O D , J C G P E A R S O N , R J M A D E L E Y , R F A L O G A N , M W B E A V E R , P A G I L L I E S , J L I T T L E , A N D A L A N G H A M page 232 Epidemiology of rotavirus gastroenteritis Y S E N T U R I A page 236 Insulin-dependent diabetes in a Scottish region: incidence and urban/rural differences N R W A U G H page 240 Trends in blood lead levels in Christchurch (NZ) and environs 1978-85 D A P H N E H I N T O N , P A T R I C I A A C O O P E , W I L L I A M

A M A L P R E S S A N D E D W A R D D J A N U S page 244 The Tromso heart study: alcoholic beverages and coronary risk factors T O R M O D B R E N N page 249 Mortality from alcohol related disease in Italy C A R L O L A V E C C H I A , A D R I A N O D E C A R L I , G U E R R I N O M E Z Z A N O T T E , A N D C E S A R E

C I S L A G H I page 257 Ethnic group differences in low birthweight of live singletons in Singapore, 1981-3 K E N N E T H H U G H E S , N A L L A R T A N , A N D

K W O K - C H A N L U N page 262 Who responds to postal questionnaires? A N N C A R T W R I G H T page 267 Letters to the Editor page 274

N o 4 December 1 9 8 6

Health and disease: two philosophical perspectives L E N N A R T N O R D E N F E L T page 281 Is there seasonal Variation in the prescribing of antidepressants in the Community? K E R E N S K E G G , D C S K E G G , A N D B w M C D O N A L D page 285 Early oral contraceptive use and breast cancer: theoretical effects of latency K L I M M C P H E R S O N , P A C O O P E R , A N D M P V E S S E Y

page 289 The nature of mycobacterial disease in south east England, 1977-84 M A L C O L M D Y A T E S , J O H N M G R A N G E , A N D C H R I S T O P H E R H

C O L L I N S page 295 Perinatal outcomes and related factors: social class differences within and between geographica! areas D I A N A E L B O U R N E , C O L I N

P R I T C H A R D , A N D M A R J O R I E D A U N C E Y page 301 Breast feeding and smoking hygiene: major influences on cotinine in urine of smokers' infants A L I S T A I R W O O D W A R D , N I C K

G R G U R I N O V I C H A N D P H I L I P R Y A N page 309 A case-control study of acute appendicitis and diet in children M N E L S O N , J M O R R I S , D J P B A R K E R A N D S S I M M O N D S page 316 Distribution of body weight and height: comparison of estimates based on self-reported and observed measures W A Y N E J

M I L L A R page 319 Association of serum lipids with coffee, tea, and egg consumption in free-living subjects M A N F R E D S G R E E N A N D E L I E Z E R J U C H A

page 324 Heart rate, employment Status, and prevalent ischaemic heart disease confound relation between cereal fibre and blood pressure M I C H A E L J L I C H T E N S T E I N , M I C H A E L L B U R R , A N N M F E H I L Y , A N D J O H N W G Y A R N E L L page 330 A randomised controlled trial to investigate the effect of a high fibre diet on blood pressure and plasma fibrinogen A N N M F E H I L Y , M I C H A E L L B U R R , B A R B A R A K B U T L A N D , A N D R O B E R T D E A S T H A M page 334 Edinburgh breast education campaign on breast cancer and breast self-examination: was it worth while? M M A U R E E N R O B E R T S ,

S U S A N E R O B I N S O N , K A T E F R E N C H , A N N P R O U D F O O T , H E L E N T A L B O T , A N D R O B E R T A E L T O N page 338 Motor neurone disease in the Lothian Region of Scotland, 1961-81 S U S A N M H O L L O W A Y A N D J D O U G L A S M I T C H E L L page 344 Epidemiology in Antarctica H I L A R Y K I N G page 351 Changes in annual tuberculosis notification rates between 1978/79 and 1983 for the population of Indian subcontinent ethnic origin resident in England A J N U N N , J A N E T H D A R B Y S H I R E , W A L L A C E F O X , D E B O R A H A J O H N S O N , A N D v H S P R I N G E T T page 357 What's in a name? Accuracy of using surnames and forenames in ascribing Asian ethnic identity in English populations A N G U S

N I C O L L , K A R E N B A S S E T T , A N D S T A N L E Y J U L U A S Z E K page 364 Index to volume 40 page 369

J o u r n a l o f E p i d e m i o l o g y a n d C o m m u n i t y H e a l t h , 1986, 40, 86-91

Prevalence of goitre and hypothyroidism in Southern Tanzania: effect of iodised oil on thyroid hormone deficiency* W W Ä C H T E R 1 , M M V U N G I , 2 A K Ö N I G , 3 C R P I C K A R D T , 3 A N D P C S C R I B A 4

F r o m 6 2 9 6 M e n g e r s k i r c h e n ; 1 L u t h e r a n H o s p i t a l , 2 I l e m b u l a v i a I r i n g a , T a n z a n i a ; M e d i z i n i s c h e K l i n i k I n n e n s t a d t der Universität München* Ziemssenstrasse 1 , D - 8 0 0 0 München 2, West G e r m a n y ; K l i n i k für I n n e r e M e d i z i n der Universität,4 R a t z e b u r g e r A l l e e 1 6 0 , D — 2 4 0 0 Lübeck 1 , West G e r m a n y

SUMMARY In the Southern Highlands of Tanzania the prevalence of endemic goitre due to iodine deficiency is in the ränge of 90% and hypothyroidism in the ränge of 50% of schoolchildren. The present study confirms these data and documents the beneficial effect of Lipiodol injections on thyroid function in children around the age of puberty compared with untreated children from the same villages. On the other hand, a decrease in the prevalence of goitre could not be shown. A beneficial effect is shown for infants of mothers who received iodine during pregnancy. It seems that this form of supplementation is sufficient for breast fed children for more than three years, even when a second child has been delivered in the meantime. In contrast, older siblings of these babies may become hypothyroid when breast feeding is stopped. The determination of thyroid autoantibodies in iodine treated and untreated children and in young adults showed no increasing prevalence of positive findings thus excluding iodine induced chronic thyroiditis at least in the young target population.

The southern highlands of Tanzania are known to be an area with a high prevalence of endemic goi t re 1 2

and hypothyroidism 2 due to iodine deficiency. Therefore, in 1979, privately initiated iodine supplementation was undertaken regionally in order to motivate" the local medical establishment into continuing this programme.

A reinvestigation was performed in 1982 in order to

1 reestablish the persistence of a high prevalence of goitre in untreated schoolchildren;

2 make a comparison between treated and untreated children from the same villages, which differed only with respect to their age;

3 study the beneficial effect of iodised pi l , given to pregnant women, by investigation of mothers and infants three years later; and

4 exclude harmful thyroiditis 3 4 induced by iodised oil by investigation of thyroid autoantibodies in untreated and treated children and adults.

The data are presented to draw the attention of the local authorities to the iodine deficiency problems.

*Supported by Berliner Missionswerk, Division for World Mission, Berlin, West Germany

Methods

Thyroid enlargement was determined by palpation a n d c l a s s i f i e d a c c o r d i n g to the W H O recommendations. 5 6 Thyroid palpations were performed by three different investigators.

Thyroid hormone levels, thyroxine binding globulin ( T B G ) and serum T S H levels were determined by radioimmunoassay, as described elsewhere. 7 - 9 Thyroid antibodies were determined using commercial test Systems (Fa Welcome, Burgwedel, F R G ) . Blood spot T S H from filter paper was determined as previously described. 2 Blood samples were drawn from a cubital vein. Samples were centrifuged, and serum was stored at 4°C for up to 10 days and thereafter frozen at - 2 0 ° C until determinations were performed. Blood samples for blood spot T S H analysis were taken from fingerprick from 30 infants. Filter papers were thoroughly dried and stored in the same way as serum samples.

Normal ranges for healthy controls from Miinich were: thyroxine (Ti) 4-5-10-0 /*g/dl; thyroxine binding globulin ( T B G ) 1-6-2-8 mg/dl; T . / T B G ratio 1-8-5-7 (arbitrary units); triiodothyronine (T3) 80-160 ng/dl; thyrotropin (TSH) 0-2-1 mU/1 .

P r e v a l e n c e o f g o i t r e a n d h y p o t h y r o i d i s m : effect o f i o d i s e d o i l o n t h y r o i d h o r m o n e d e f i c i e n c y 87

The T S H radioimmunoassay was performed using a low l abe l l ed 1 2 5 I - T S H tracer and a prolonged incubat ion time. T S H Standards were d i lu ted in human serum from volunteers during T3 suppression (100 /xg/d).Thelowerlimitof detection is 0-4 mU/1 7 ; the normal basal level in the Bavarian goitre region is below 2 1 mU/1; thus serum levels in the ränge 2-2-5-0 mU/1 were assumed to be borderline, whereas serum levels over 5 mU/1 are clearly indicative of hypothyroidism.

In euthyroid children more than 10 days old and in adults, blood spot T S H (lower limit of detection 12 mU/1) is undetectable. In a previous study 2 we showed that blood spot T S H levels below 12 mU/1 do not necessarily exclude moderate or mild hypothyroidism, because of a loss of T S H activity on the filter paper, presumably due to environmental humidity. In this study the transport time was less than two weeks and the filter papers were kept in a cool box during the time of sampling.

Study population

G R O U P I

Five hundred and sixty children f r o m seven different villages who had never received iodine Prophylaxis 2

were investigated for thyroid enlargement and thyroid function.

G R O U P I I I

For comparison, 124 children f r o m three different villages who had received iodine supplementation (1 ml L i p i o d o l R , Byck-Gulden Federal Republic Germany, im, containing 480 mg iodine bound to ethyl-ester of oleum papaveris) three years previously, were reinvestigated.

G R O U P 11

This special group was compared with 134 children of younger age, from the same three villages who had not yet received iodine.

The age was requested from the children but this information cannot be relied on, because the date of birth is not documented in the rural areas of Tanzania. It is obviously doubtful whether children attending primary school are more than 16 years o f age in groups I and III. Therefore, those who gave an age of 17-47 years (n = 30) were not eliminated.

In addition, 25 young women, who had received iodised oil during pregnancy in 1979, their babies born in 1979/80 (n = 25), and five younger babies born in 1981/82 were investigated. T S H levels of the children were determined by the filter paper method.

Thyroid autoantibodies were investigated in 138 untreated children and adults as well as in 174 treated children and adults to exclude a possible increase in

immunological reactions after a high dose of lipid bound iodine.

Wilcoxon Rank test was used for Statistical analysis.

Results

C H I L D R E N W I T H O U T I O D I N E P R O P H Y L A X I S

( G R O U P 1 )

A total of 560 schoolchildren, 6-19 years of age, were investigated before iodine supplementation.

© 4 0 - ,

* / • 20.

o-J

154

© 4 0 - .

°/o 2 0 -

9-11 12-14 15-17 Years

215

o-J

© n.d. -21 - 5 -10 - 2 0 -100 >100

m U / l T S H

4 0 - i

°/o 2 0 -

© O-J

n.d.-18 - 2 - 5 -3-5 - 4 5 - 5 5 T 4 / T 8 G

278 5 0 - | V Z

°/o 2 5 -

0 - » 160 -200 -300 >300

n g / d l T3

Fig 1 D i s t r i b u t i o n o f age ( A ) t T S H l e v e l s ( B ) , T A / T B G r a t i o ( C ) , a n d Tz l e v e l s ( D ) i n 5 6 0 s c h o o l c h i l d r e n from different v i l l a g e s i n U w a n j e . As i n d i c a t e d by t h e different numbers f o r t h e v a r i o u s p a r a m e t e r s , d a t a a r e n o t c o m p l e t e f o r t e c h n i c a l reasons.

88 W Wächter, M M v u n g i , A König, C R P i c k a r d t , a n d P C S c r i b a

The distribution of age, T S H levels, T 4 / T B G ratio, and T3 levels is given in figure 1.

The T4/TBG ratio was normal in only 67% (table 1) and normal T S H levels were found in only 31% of these children; 41% had moderately elevated T S H levels in the ränge 2-2-5-0 mU/1, whereas 28% of the T S H levels were in the ränge 5-1—745 mU/1, indicating frank hypothyroidism. There was a significant correlation between the T4/TBG ratios and basal T S H levels (p<0-01). No correlation was shown for T3 and T S H levels.

The overall prevalence of goitre was 90% in 512 children of group I. For the difference in numbers of children in figs 1 and 2 see fig 1; 75% of these children (fig 2) had goitre grades I and IL Goitre grade III increased significantiy with age (p<001) .

C O M P A R I S O N O F C H I L D R E N W I T H A N D W I T H O U T

P R E V I O U S I O D I N E P R O P H Y L A X I S

The data for 124 children from three different villages, who had received iodised oil injections three years previously (group III), were compared with t hose of 134 c h i l d r e n w i t h o u t i o d i n e supplementation (group II) from the same villages.

According to the selection, the children forming group III were significantiy older than those in group II (fig 3), because only the younger ones, not yet attending school in 1979, had not received iodised oil injections. Thyroid function in group III was significantiy different in all parameters tested (p<0-01, table 2).

The most striking difference was found for the T S H levels. Mean T S H level was only slightly elevated in the iodine treated group but clearly elevated with a wide ränge of Variation in the untreated group. Out of 134 untreated children, 64 (48%) had basal T S H levels of 5 mU/1 and more, whereas in only 8 out of 123 (6-5%) treated children was T S H above 5 mU/1.

A s shown in table 1 (middle and right part) 45-5% of children without previous iodine supplementation in group II exhibited thyroxine deficiency. In group II

Table 1 C o m p a r i s o n o f t h y r o i d f u n c t i o n o f c h i l d r e n f r o m t h e same v i l l a g e s w i t h o u t ( g r o u p II) a n d w i t h ( g r o u p I I I ) i o d i n e P r o p h y l a x i s

Group I Group II Group III

T * I T B G ratio 7 V T B G ratio T«/TBG ratio TSH <l-8 >l-8 <l-8 >l-8 <l-8 >l-8

« 2 1 4-7 26-1 3 0 15-7 1-6 50-8 2-2-5-0 10-6 30-5 9 0 24-6 0-8 39-5 > 5 0 17-9 10-4 33-6 14-2 1-6 5-6

330 670 45-5 54-5 4-0 960

Group I. 512 children without iodine Prophylaxis Group II. 134 children without iodine Prophylaxis from three selected villages. Group III. 124 children from the same villages three years after 1 ml iodised oil im.

Table 2 R e l a t i v e d i s t r i b u t i o n o f n o r m a l , b o r d e r l i n e a n d c l e a r l y e l e v a t e d T S H l e v e l s i n r e l a t i o n t o decreased a n d n o r m a l 7 V T B G ratio

Group II Group III

n n

Age (yr) 133 9-4 ± 1-3 111 13-3 ± 1-8 Ta (ng/dl) 132 185 ± 52 123 160 ± 32 TVTBG 129 2-1 ± 1-0 124 3 0 ± 0-9 TSH (mU/1) 134 20-6 ± 70-6 123 2-6 2-4

Goitre grade (WHO)

Fig 2 D i s t r i b u t i o n o f g o i t r e s i n 512 c h i l d r e n w i t h o u t i o d i n e P r o p h y l a x i s .

P r e v a l e n c e o f g o i t r e a n d h y p o t h y r o i d i s m : effect o f i o d i s e d o i l o n t h y r o i d h o r m o n e d e f i c i e n c y 89

50n

• / . 25-

7 - 9 10-12 <12 Years

10-13 13-15 15-17 Years

Fig 3 Age d i s t r i b u t i o n o f c h i l d r e n from the same v i l l a g e s w i t h o u t (left) and w i t h ( r i g h t ) i o d i n e P r o p h y l a x i s .

only 15*6% were euthyroid in terms of both normal T4/TBG ratio and normal T S H level. In contrast, only 4% of children who had received iodised oil 3 years previously, showed a decreased T4/TBG ratio. In this group, 50*8% were euthyroid in terms of normal T4/TBG ratio and T S H levels.

Comparison of the different grades of goitre did not reveal significant differences between groups II and III.

R E I N V E S T I G A T I O N O F M O T H E R S R E C E I V I N G

I O D I N E D U R I N G P R E G N A N C Y A N D

I N V E S T I G A T I O N O F T H E I R C H I L D R E N

In one village, 25 mothers who had received iodine in 1979 during pregnancy and 25 children born in

1979/80 as well asfive children born in 1981/82 were reinvestigated. A l l mothers had serum T S H levels below 2-1 mU/1. The T S H levels as measured by the filter paper method were elevated in 7 out of 25 older babies (28%) (fig. 4) but in none of the younger babies. A l l of the latter were breast fed.

T H Y R O I D A U T O A N T I B O D I E S I N U N T R E A T E D A N D

I O D I N E T R E A T E D C H I L D R E N A N D A D U L T S

A s shown in table 3, microsomal antibodies were undetectable in 311 out of 312 treated and untreated subjects. One out of 156 treated children from group I had a low positive titre. Thyroglobulin antibodies were borderline positive in 2 out of 126 untreated and in another 2 out of 154 iodine treated children.

Discussion

The investigation of schoolchildren before iodine supplementation again demonstrates the high prevalence of endemic goitre in this area. 1 2 The high prevalence of overt and borderline hypothyroidism among the schoolchildren without supplementation was confirmed. Despite the fact that up to now no concise Information on the mental and somatic handicaps of these children is available, there is no doubt that the degree of biochemically confirmed hypothyroidism alone indicates the need for an

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Fig 4 T 4 / T B G r a t i o , Ts and TSH levels i n 25 young females, who received i o d i n e P r o p h y l a x i s d u r i n g pregnancy three years previously and TSH-levels o f the c h i l d r e n d e l i v e r e d s h o r t l y after i o d i n e i n j e c t i o n as w e l l as TSH levels o f c h i l d r e n b o r n 2-3 years after i o d i n e i n j e c t i o n . F o r I d e n t i f i c a t i o n o f i n d i v i d u a l t h y r o i d hormone levels, Symbols o f c h i l d r e n w i t h TSH levels above 20 mV II a r e r i n g e d .

90 W Wächter, M M v u n g i , A König, C R P i c k a r d t , a n d P C S c r i b a

Table 3 T h y r o i d a u t o a n t i b o d i e s i n u n t r e a t e d a n d i n L i p i o d o l t r e a t e d c h i l d r e n a n d a d u l t s

n

M a b

Pos Neg

Tgab

Pos Neg

Untreated children 128 0 128 2 126 Untreated adults with goitre 10 0 10 0 10 Treated children 156 1 155 2 154 Treated women 18 0 18 0 18

Totais 312 1 311 4 308

effective iodine supplementation programme in this area.

The comparison of untreated and iodine treated children from the same villages shows the beneficial long-term effect on thyroid function of 1 ml Lipiodol im in terms of lower T S H levels and higher T4/TBG ratios in the treated group. It could be shown that 96% of the treated children had noimal T4/TBG ratios. However, investigation of the more sensitive parameter of thyroid hormone deficiency, ie, T S H determination, shows that only 50% of these children were fully euthyroid when compared with basal T S H levels of normal controls from the mild iodine deficiency area in Southern Germany. 7 This finding is to be expected because urinary iodine excretion decreases exponentially with a half-life of 5-6 months after injection of iodised o i l . 5

M o r e o v e r c o m p a r i s o n reveals that this supplementation did not result in a sufficient decrease of thyroid enlargement. However, it cannot be excluded that the goitres of these children had exhibited a transient decrease during optimal iodine effect as described in other regions. 5

For these two reasons, the interval between iodine injections should probably be shorter than three years, at least for children in puberty and adolescence when euthyroid function, in terms of both normal T4 /TBG ratio and normal serum T S H level and a nearly normal thyroid volume, is the aim of such a supplementation programme.

In a previous study, 2 we showed that blood spot T S H levels below 12mU/l do not necessarily exclude moderate or mild hypothyroidism, because T S H activity is partly lost on the filter paper, but frank hypothyroidism may not be overlooked by using this kind of T S H measurement. Therefore, we judge that filter paper T S H from a finger prick of the 30 babies gives a rough insight into the protective effect of 1 ml iodised oil for mothers and newborns, when investigated three years after the mothers had received iodised oi l during pregnancy. A l l of the women had normal T S H levels three years after the injection, whether they had given birth to a second child in the meantime or not. A m o n g the older babies of these women, 28% were found to be hypothyroid after stopping breast feeding, whereas none of the

second children had elevated T S H levels. A l l o f the iatter were still breastfed. Thus, maternal milk seems to be a sufficient source of iodine for these children since it had been shown that there is a linear relation between iodine content in the milk and maternal iodine excretion, at least in borderline iodine deficiency. 1 0 This finding indicates that iodine Prophylaxis should be given to children as soon as breastfeeding is stopped.

In our study, there is no suspicion that intramuscular injection of iodised oil increases the rate of chronic thyroiditis in children and young adults, because thyroid antibodies did not increase compared with the untreated study population. This is in contrast to the Observat ion of Boukis et a l , 3 who found an increased rate of thyroglobulin and microsomal ant ibodies , up to 42-8%, three and six months after oil injection in their study population 19-60 years of age. Our finding is also in contrast to the O b s e r v a t i o n in regions with an effective Prophylaxis programme with iodised salt.4 Although we cannot exclude a transient increase in thyroid ant ibodies in our sample, we can conclude f r o m our data that this rough f o r m of iodine Prophylaxis does not induce harmful chronic thyroiditis in the young population, which is the main target for Prophylaxis programmes.

We thank the Berliner Mission for supporting D r M Mvungi and for donating the iodised oil (Lipiodol). We also thank Dr Kadete and his staff, of the Ilembula Lutheran Hospital who took part in the reinvestigation programme; the technical staff of the endocrine laboratories of the Medizinische Kl inik Innenstadt der U n i v e r s i t ä t M ü n c h e n for determination of the thyroid function parameters; and Mrs R Thomeier for her thorough preparation of the manuscript.

References

^ a t h a m M C . The aetiology, Prophylaxis and treatment of endemic goitre in Ukinga, Tanzania. East A f r i c a n M e d i c a l J 1965; 42: 489-501.

2 W ä c h t e r W, Mvungi M G , Triebel E , et a l . Iodine deficiency, hypothyroidism and endemic goitre in Southern Tanzania. A survey showing the positive effects of iodizhed oil injections by T S H determination in dried blood Spots. J E p i d e m i o l C o m m u n i t y H e a l t h , 1985, 39 (3) 263-270.

3 Bouki s M A , Koutras D A , Souvatzoglou A , e t a l . Thyroid hormone and immunological studies in endemic goiter.7 C l i n E n d o c r i n o l M e t a b 1983; 57: 859-62.

4 Harach H R , Escalante D A , Onativia A , et a l Thyroid Carcinoma and thyroiditis in an endemic goitre region before and after iodine Prophylaxis. A c t a E n d o c r i n o l 1985; 108: 55-60.

P r e v a l e n c e o f g o i t r e a n d h y p o t h y r o i d i s m : effect o f i o d i s e d o i l o n t h y r o i d H o r m o n e d e f i c i e n c y 91 5 Hetze l BS, Thil ly C H , Fierro-Benitez R, et a l . lodized oil

in the prevention of endemic goiter and cretinism. In: E n d e m i e g o i t e r a n d c r e t i n i s m — i o d i n e n u t r i t i o n i n h e a l t h a n d disease. J B Stanbury, BS Hetzel, eds. New York, Chichester, Brisbane, Toronto: John Wiley and Sons Inc. 1980; 513-32.

6 Perez C, Scrimshaw NS, Munoz J A . Technique of endemic goitre surveys. In: E n d e m i c g o i t r e . Monograph series no. 44 Geneva: Wor ld Health Organization, 1960; 369-84.

7 Erhard t F, Marschner I, Pickardt C R , et a l . Verbesserung und Qual i tä tskontrol le der radioimmunologischen Thyrotropin-Bestimmung. J C l i n Chem C l i n B i o c h e m 1973; 11: 381-7.

8 Gär tne r R , Kewenig M , Horn K , et a l . A new principle of t h y r o x i n e ( T 4 ) a n d t r i i o d o t h y r o n i n e ( T 3 ) radioimmunoassay in unextracted serum using antisera with binding optima ät extreme p H ranges.7 C l i n Chem C l i n B i o c h e m , 1980; 18: 571-7.

• 'Horn K , K u b i c z e k T h , P i c k a r d t C R , et a l . Thyroxin-bindendes Globu l in ( T B G ) : P räpa ra t i on , r a d i o i m m u n o l o g i s c h e B e s t i m m u n g u n d klinisch-diagnostische Bedeutung. K l i n Wschr 1977; 55: 881-94.

1 0 Heidemann P H . D i e S t r u m a i m N e u g e b o r e n e n - u n d K i n d e s a l t e r . Stuttgart-New Y o r k : Thieme, 1984.

n D u n n JT, Medeiros-Neto G A . E n d e m i c g o i t e r a n d c r e t i n i s m : C o n t i n u i n g t h r e a t s t o w o r l d h e a l t h . Pan American Health Organization Scientific Publication no 292, 1975.