Adrenocortical response of Bantus and Europeans to surgical stress

360 "I'RAN>.\¢'TION:¢ ,)~- Tile I'((.'YAL ~O(ilETY ( l i TROPICAl. MEDICINE AND l l Y ( ; I E N ' .

\%!. 54.

N,~ a

July, 1960.

A D R E N O C O R T I C A I , R E S P O N S E OF B A N T U S A N D E U R O P E A N S T O S U R G I C A L STRESS BY

L. PARKINSON, E. GHYOOT, R. VAN VLIERBERGHE AX'D G. BONE ~ Institut pour la Recherche Scientzifique eu A])'ique CentraIe ( I R S A C ) et Service ~VIgdica[, Elisabe:h.J:e, Belgia, Congo

Surgeons working in the Belgian Congo have noticed that the reaction of Bantus v) surgical conditions and especially to acute abdominal emergencies (peritonitis, strangulated hernia, intestinal obstruction) seems milder than the reaction of European subjects. T h e y are often surprised bv the discrepancy observed in Bantus between the serious condition found on operation and the relative lack of symptoms such as shock, fever, pain or rigidity. But this is a clinical observation, and difficult to assess unless some measurable criterion can be found. In the past 10 years, much work has been done on the response of the adrenal cortex to surgical stress. It occurred to us that a comparison of the adrenal reaction of Europeans and Bantus to surgery might provide a material basis for this clinical difference, and a possible hint as to the mechanism involved. After surge W, the adrenal secretes an increased amount of 17-hydroxycorticosteroids (17(OH)CS), which results in a transient rise of blood corticosteroids (FRANKSSON et al., 1954 ; SANDBER¢et al., 1954 ; STEEXBURGet al., 1956). This rise concerns at first tlm free 17(OH)CS and is followed, after a 2 to 4 hour time-lag, by a rise of the conjugated steroids derived from the free steroids (HELMREICH et al., 1957). Repeated estimations of plasma 17-hydroxycorticosteroids would therefore give a curve reflecting the adrenal response to surgery. But, as 17(OH)CS are excreted in urine (for 90 per cent. to 95 per cent. under conjugated forms), estimations of the daily urinary 17(OH)CS output will provide an easier way to study the adrenal response during an extended post-operative period. In fact, MOORE et al. (1955) have shown that the magnitude and duration of the rise in total urinary 17(Ott)CS is in close relation with the degree of trauma and the patient's course. T h e highe:;t figures are encountered on the 1st and 2nd day after operation and by the 4th day, in cases of soft tissue trauma, the daily excretion of 17(OH)CS has usually returned to normal. We therefore selected the 17(OH)CS urinary output in the 72 post-operative hours as a valid criterion of adrenal response to surgical stress. Changes in the eosinophil count, which have been shown to bear an inverse correlaton with 17(OH)CS excretion, have also been followed. T h e y are known to drop to low or * This work has been done with the aid and a grant of the Institut pour ]a Recherche Scientifique We are indebted to Prof. Z. Bacq for his stimulating advice. We wish to thank the medical laboratory for the numerous eosinophil counts performed and the stali" of both hospitals for their help in collecting specimens.

en Afrique Centrale (I.R.S.A.C.).

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zero values a few hours after operation, to remain low for 2 to 3 days, and to sx~'ing back r~) p r e - o p e r a t i , e levels about the time 1 7 ( O H ) C S excretion retur~qs to ~,~o,rmal. But these changes, as pointed out by HARDY et al. (1954), are only directional changes. Total eosip,> phil counts provide only a qualitative, but not a quantitati\c, indcx of cortical reactior,. O u r c o m p a r i s o n of the adrenal reaction to surgical stress ~f Europeans ami Bant~Is i,based on those two tests (with the stress laid o+, IT(OIl+C.'; ,'\cretion) carried <)tit i;: t',w~ similar grolJps of patiev.ts, livi!:e i,l the san/e clhnatc.

),I.VI'FI{IM. AND METHOI'):. ~i) ,3"election of parle,Its W e tried to confine ourselves to cases frequently e n c o u n t e r e d in both races and in which ~he a m o u n t of t r a u m a was comparable, such as gynaecological operations, gastrectomies, h e r n i o r r h a p h i e s and thyrnidectomies. O t h e r types of operation have also been inchlded, b u t r e p r e s e n t only a b o u t o n e - t e n t h of the h u n d r e d odd cases followed. Bone cases were ruled out on account of the d u r a t i o n of the m e t a b o l i c a n d h o r m o n a l changes, w h i c h exceeded 3 days and interfered with the chartin< ot results. O w i n g to the f r e q u e n c y of gynaecological operatior:~, \v~maen represent a hiah p r o p o r t i o n of the cases selected : 39 females for 14 males in b o t h series. O u r cases were chosen from those of the Prince L&)pold ]Iospital for Africans and the Reme Elisabeth H o s p i t a l fl~r E u r o p e a n s , at Elisabethville, Belgian Congo. "Fo avoid errors due to differences of surgical t e c h n i q u e , the same surgeon (E.G.) p e r f o r m e d m o s t of the operations in b o t h hospitals. U n f o r t u n a t e l y , it was n o t possible to eliminate differences of anaesthesia, spinal anaesthesia b e i n g used in the m a j o r i t y of cases in the African hospital, whilst general i,~halation anaesthesia with p e n t o t h a l induction was the rule in the Eurc~pean hospital. di) M e t h o d s a) t7-hydroa3'corticosteroids : T h e collection of urine ~\as, as m u c h as possible, started 24 i~.ours before operation. It was c o n t i n u e d on tile day of operation and on the following days to cover a 72 hours post-operative period. T w e n t v - f n u r h o u r s p e c i m e n s of urine were collected withmat preservative in a bottle kept in an ice-box at tl~e bed-side a n d delivered to the laboratory within an h o u r of the completion of the collection. If the estimations were not carried out immediately, the urine was kept in the deep-freeze and processed ~m the next day. T h e d e t e r m i n a t i o n of 17(()1{)CS were done according to the priuciple of RrDDY, Jvx},:I,'t'.r kn<)wledge o~l? after the b e g i n n i n g of this work. F o r the sake of keeping results comparable, we decided to adhere >, tim m e t h o d previously chosen. W e tested several modifications of REDDY'S m e t h o d (S.X~ITH, M1..L= 'f.{N(HZI!a n d PATTI, 1954 ; BROWN, 1954), b u t finally adopted, as giving the best results, the m,>dificati~m p u b l i s h e d by DEVIS a n d VANF~; in 1954. In the REDDY, JENKINS a n d r t t o R x ' s m e t h o d , the free and c o r r u g a t e d steroids are extracted frtm~, acidified urine at pI l 1 with n - b u t a n o l a n d are estimated by the P o r t c r - S i l b e r reaction, which is specific for the 17-21-dihydroxy 20-keto side chain. T h e strongly acid m e d i u m , in which this reaction is carried out, hydrolyses the conjugated forms and allows tlne estimation of the total, i.e. free and conjugatcd 17-hydroxycorticosteroids. I)EVIS a n d VANEK noticed t h a t the readings o b t a i n e d after the reaction of the extract ',~ith [:]eSO~ alone were often h i g h e r t h a n with P o r t e r - S i l b e r reagent ( p h e n y l h y d r a z i n e h y d r o c h l o r i d e + lieSO;). T h i s was ()wing to the f o r m a t i o n of coloured substances u n d e r the action of s u l p h u r i c acid, f~:,rmatiop i n h i b i t e d b y the r e d u c i n g properties of p h e n y l h y d r a ~ i n e . T h e addition ~,t: a n o t h e r r e d u c i n g age:;t. thiour,_.a, greatly i m p r o v e d the results. k s the t e c h n i q u e of DEvIs and \:axv.K was strictly a d h e r e d to, a detailed account will not be given he:'e. It is -vorth noting, however, that all the n - b u t a n o l tried had to be purified to avoid high blanks. T h e b u t a n o l was first treated with 20 p e r cent. N a O H , washed free of the alkali and left in contact for a week with P o r t e r - S i l b e r reagent before b e i n g redistilled (RI
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4 a n d 6 h o u r s after o p e r a t i o n , s~ tha~ two e s t i m a t i o n s ¢cotm~ing :ixe spt.cimcn o b t a i n e d t h e n e x t m o r n i n g ) -,veto m a d e in t h e first 24 pos~-ope'rativ¢ h o u r s . T h e c o t m t s xvcx d o n e a c c o r d i n g to t h e meth~>d (ff ~)t'xi,~-!~ (1910) an(! ~i!c r e s ~ h s ~:F.ressed as n u m b e r ~,f e,~.sir~p.~/~ per c . m m . o( bb~(~d.

17-hydroaTcorticosteroid t.vcrtti(m The hydroxycorticosteroid excretion \~as first de~ermined in normal suhjects. ()ur results for Europeans agreed fairly well with those of other authors (Table I). In spite of subtropical living conditions, the fig~res were the sam-- for males but slightly lower for females. T h e comparison between normal Europeans and Bantus showed practically n . difference in female values whils:~ Ii~ropean maIe val-~es v, ere about 25 per cent. higher th~u~ normal Bantu mate values. TABLE I.

E x c r e t i o n ~: ~ 7 - h y d r o x y c o r t i c o s t e r o i d s (rr~: 24h.) in n o r m a l subjects.

.

Race

No. cases

Bantu European European European

I0 (, 15

Iak"

[emale

.~.tean

I~.ange

5..:.e~ 5.b

1 '-9.3 4.I-7.5 2.~-I2.0

No. ca,~es i M e a n 33 ~,(~ t5 1~

5.0 5.2 3.8 4.8

P,ange 0.5-9.4 0.7-7.5 1 .I-8.6 1.6-8.7

Reference Present paper Present paper R e d d v et al. I)evis et al.

After surgical operauon, the excretion of 17(OH)CS was much higher in Europeans than in Africans. This is shown in the frequency histogram obtained by plotting the mlmber of cases against the total 17(OH)CS excretion during the 3 days following the operatio;, (Figure). Our results, based on a suad) of 53 Africans and 53 L'uropeans, are summarized in Table 1[ : the types of surgicaI operation are given with the number of cases operated on, the mean post-operative 17(OH)CS urinary excretion in rag./72 hours and the minimal and maximal values observed in each group. The casts have been carefully matched in both racial groups. T h e lack of information for African patients prevented us from considering the age factor, but a close parallelism exists as regards other factors such as sex and type of ~,peration. As can be seen from the Table, the excretion of 17-hydroxycorticosteroid after surgery was always higher in the European group. For a given type of operation, the mean wdue for the Europeans was usually equal to, or higher than. the maximal individual response i;; ~he corresponding Banu; group. When all the cases are taken together, the excretion (,f IT(OH)CS during the 3 post-operative days was about 3! per cent. lower in Bantus, and this i~q males as well as i~ females. This difference is statistically highly significant (P<0.0I)I).

E,silzopki/ co,rots 'Fhe average Bar..tu si~ev, ed ~. r<]atR-e c,sinopi'dii~ : ~hcrca.~ three-quarters of ti-:z' t]wropca~l pro-operative xai,aes fell ',~ithin limits ¢,t 5U :,, 400 cosinophils per c.mm., ti,c .-ame proportion of Banzu pr~--opei-a~ivc iigur,:~ ~:~;~ec(i ir, ::~ ~00 to 800 eosinophils per c..m::,. Owing to this differer, ce {n :h.- ~\, o races, cx,~"~>-&,r: of the eosinophi~ response as pe~c.tnta'g~c reduction (,:~ tLc h-{:i~! cuu~!t ('['ii(,!<.: ~t :{.. ~,53'I seemed i,~appropriate. \',~

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}%c. l " r e q u e n c y h i s t o g r a m of t h e 1 7 - h y d r o x y c o r t i c o s t e r o i d e x c r e t i o n in Europeans and Bantus and surgical stress. The figures represent the e u m u l a t i ~ e e x c r c ' d o n in t h e 72 h o u r s f o l l o w i n g o p e r a t i o n .

TA~.: ,~" I[.

17-ic,'drox.veortic~sterc, id excreti~m in Bantu's a n d E u r o p e a n s after s u r a e r y . e x c r e t e d in 72 h o u r s . Bantus

.

Kuropeans

T y p e e,f i , p ( r a t i o n

No. of cases i

7xfean

( ~t:served range

N,,. of c a s e s

Hysteropexy Hysterectomy'* Ablation of adnexa Ruptured ectopic Gastrectomy Laparotomy (various; Iternia Goitrt. (Y,*.her

4 23 4

~q 4 24.4 24- I

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5-.7

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Observed range "2o 9-46 .S 13.6-54.3 ,~)_.<-45.4

!~

37 8 3t~.7 25 {; 4 7 {~ 53 4

43.,%{,7.':~

t 5

33.7 24 4

24,(>67.;~ 1~, 5-31 ,~i

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SURGICAL

S'FI/li:;:"

ad,)ptcd instead N.u~am~o's (1954) criteria. \Vhe~ intcrweting the results of the eosinophil ~est after A C T t t gel injection, he rates ~/s a normal response a fall to less than l!) cosiuophils c.mm., provided the initial c~,)unt is ldgher than 5i) cosiv.ophils/c.mm, We therefore compared the percentage of cases of hoth races in ~ hich the eosinophil count, initially hi~zher than 50 eosinophils c.mm., dropped to less tha,.1 li) eosii:ophils/'c.mm. Thirty-six of our Bantu and 37 of ()tar European cases x\.cre studied as regards eosinophits. Ii~ the 24 hours following operation, 75 per cent. of the Europeans showed a fall ()f the eosinophil count to less than 10 eosin.~c.mm., but only 55 per cent. of the Bantus showed a similar drop. Thus, the results of the eosinophil counts also showed a lesser response to surecry ~m the part of Bantus, and confirmed the data obtained by 17(OH)CS estimations. DISCUSSION

Excretion of 17-hvdro½'cortieosteroid in normal subjects Our results agree with those of POLn'ZER and '['ucKv_r~ (1958) who used N~rymberski's method to compare the normal 17 ketogenic steroids excretion in Bantu and European subjects of South Africa : he found, as we did, a higher average normal excretion in the male European than in the male Bantu, but very little difference as far as females were concerned. These findings might also be correlated with ALLUROOK'S data (1956) from East Africa. He observed that the average size of the suprarenals in East African Bantu males is smaller than in white North American subjects, and demonstrated that this is due to a difference in cortical weight, unrelated to total body weight.

Post-operatA'e t 7-kydroxycorticosteroid excretion T h e difference observed in the post-operative urinal" excretion of total 17(OH)CS in Europeans and Bantus living in the same climate confirmed tile impression of surgeons concerning the relative lack of clinical response of Bantus to surgical conditions. However, an experimental factor likely to influence the results must be examined first, i.e., the type of anaesthesia used. T h e influence of anaesthesia is controversial. SAND~R(~ et al. (1954) describe a rise of the plasma 17(OH)CS after ~urgery under spinal anaesthesia as well as under general anaesthesia. On the c(mtrary, in a recent paper, VH~TUW et al. (1957) found a normal increase after surgery under general anaesthesia, but not under spinal anaesthesia. This observation may have important implications in our study, as there is a marked difference in the type of anaesthesia currently used in each of the two hospitals : practically all the Europeans were operated on under geaeral anaesthesia whereas 75 per cent. of the Bantus were operated on under spinal anaesthesia. We were unable to avoid this difference which was inherent in the conditions of work. It is difficult, however, to weigh the implications of the work of VIRTUe"et al., as in their study, the 17(OH)CS estimations were carried out in plasma 1 hour after the start of operation, whereas in ours the estimation:s concern the total t~rinary excretion of 17(OH)CS during the 72 hours following operation, thus for a period of time extending long after the effects of anaesthesia. With our method of estimation, it seems that the type of anaesthesia has no influence on the 17(OH)CS excretion. In a comparison of the 13 Bantu patients ia~ our series who were operated on under general or local anaesthesia, and of the 38 operated on under spinal anaesthesia, the mean 72 hours post-operative 17(OH)CS excretions were

L.

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respectively 28.4 nag. and 24.3 rag. Tiicse figures do not differ significamiy. The slightly higher value of the mean for Bantus operated on under general anaesthesia could be duc t~ the large percentage of serious cases among this group. We may, therefore, assume that the difference obserxed between Europeans and Bantus is linked to the racial group, but at this stage wc can onh. make suppositions as to its origi:q. It may arise at any step in the metabolism of lhe steroids • secretion of the hormone in response to stimulus whether direct or mediated bv the pituitary, structural m,~dificati~,~ ~r conjugation of the free steroids and excretion by the kidney. \Ve shall only examine some obvious physiological or environmental particularities (~f the Bantus which could explain their lm~er rate of 17(Otl)CS excretion under stres's. 1) It is noticeable that African sub.}ects tend to ha~c a smaller daih- urine output tha,.q Europeans living in the same climate. Our pre-operative data give us an average of 7S(t ml./day 46 cases) for the Africans, and 95(1 ml./day (16 cases) for the t-uropeans. Similarly, urinary output in the 72-hour period, starting on the morning of operation, totals an average of 1630 ml. (53 cases) for the Africans, and 1860 ml. (5.3 cases) for the Europeans. BROWN and Asm.:R (1958) found :~ direct correlation between urine output and steroid excretion in normal human subjects. ~tou:ever, I,AZO-\V.~,S~':M and HI~I~ (1958), working on guinea-pigs, found that this correlation held true ouiv for resti_ng subjects but did not appl 3 after A C T H stress. In our study, ~e could lind no relationship between post-operative urine volume and steroid excretion iln either race. Therefore it seems unlikely that the racial difference in post-operative excretion of 17(Otl)CS should bc related to a difference in urinary output. 2) A poor nutritional state co,aid have an influence on the amount of adrenal secretion. Animal experiments showed that the adrenal cortex of rats fed on a protein-deficient diet recovers more slowly from artistically induced stress (GLAsSFR and I,~;aWm~M, 1955). As the diet of most Africans is usually poor in proteins, their adrenal reserve might conceivabh be low. Moreover, many suffer from parasitic diseases which may induce conditions of subclinical asthenia, and asthenic subjects, when submitted t~ corticotropin tests, have ~ low urinary steroid excretion (AI m~.~,~-x-l:rR.,,'~'r et al., I957). 3) Various authors have sho\vll ilia{ there is a relation between liver function, plasma levels of 17(OH)CS and rate of conjugation and excretion. TYLER and his co-workers (1954), correlating the results of liver function tests and of plasma 17(OH)CS estimations after surgery, came to the tentative conclusion that the raised post-operative plasma 17(Ott)CS levels were due partly to an increased adrenal secreti on, and partly to impaired hepatic removal of steroids from the blood. It has also been shown by EN(n.eRT et al. (1957) that the rate of clearance of cortisol is decreased in liver disease, and bv Buow~ et al. (1954) that hepatic patients have a lower daily excr~ti(m of corticosteroids. In Africans, owing to parasitic diseases and malnutrition, liver deficiencies arc liable to be frequent. As the liver is concerned with the hydrogenation and conjugation of the free plasma steroids, and as 90 per cent. t~ '~5 per cent. of the urinary steroids are conjugated, the exislence of liver deficiencies ill llant,,zs c(mld explain some of" our results. Vurther work is obviously, needed to localize the physiological mechanism imolved i~ , s • zhe difference of reaction of Arr:c~r;< and t:~ur¢*peans to stress, al~.d to, decide upon its environmental or t~ereditary origin.

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C;;~VN~)t ORTI(7~I. R~-.M'ON'@~ OF BAN'I';./'q \2x'.) ELRt)PE~N'4 ~ O SUR,;HCAL ~ T R ] : ~ ~ UNI.M ~i~3"

1) '~'he adre~tal response .:0 s~rgical stress of B':~atns and !2v,ropeans tivin:~ i,. :he ,,~iv 51! :,..:::cent. lower in Bantus tha~ in lSuropeans, m~:l this was irrespective of sex. 4) T h e eosinophilic response simwed the ~mw trend as the 1 7 ( O H ) C S cxcrcti~m. 5) Some possible causes of this difference ~f rcsp~mse to st:rgical stress arc disc~;~s:, i. REFERENCES

ALBEAUX-FERNET,~I., P,t'(;AaD, P. & R.:)sla×I, J. P. (1957}. .7. c/i,t. Emtocrim, 17, 51'). ALLBROOK, D. (1956). Lancet, 2, 778. APPLEBY, J. I., GIBSON, G.,NoRYMBERSKI,j. K. & Swt:.m~a, R. I). (1955}. Hiochem. J., 60, 455 ~i:~,J.t,>~ BROWN, H. (1954). Fed. Proc., 1:3, 18. - & ASHeR, H. (1958). Proc. Soc. exp. Biol., _\'. }'., 99, 642. , WILLARDSON,D. G., SAMUELS, L. T. & TYLEa, F. H. (t954). J. din. h, vest., 33, 1524 Davis, R. & VANEK, R. (1954). Ann. Endocr. Paris, 15, 196. DtJN(mR, R. (1910). ll/Iunch, reed. Wschr., 57, 1942. ENGLERT, E. JR., BROWN, H., WALLACH,S. & S[MONS, E. L. (19571). J. clin. F.ndocr:t¢., 17, ~." ~; FRANKSSON, C., GEMZELL, C. & VON EULEa, U. (1954). Ibid., 14, ~08. GLASSER, S. R. & LEATHEM, J. M. (1955). Endocrinology, 56, 420. IIARDY, J. D., RICHARDSON,E. _~,'I.&DOHAN, F. C. (1954). Surg. Gynec. Obstet, 98, 51It~LMRHCH, M. L., JENKINS, D. & SWAN, tt. (1957). Surgery, 14, 895. LAzo-WASEM, E. A. & HIER, S. W. (1958). Endocrinology, 62, 308. MOORE, F. D., S T E E N B U R G , R. \V., BALI., ~I. R., WH.SON, G. M. & .'XIYRDEN,J. A. 1955}. .4;ev d:,G,., 141, 173. NABARRO,J. D. N . (1954). Lancet, 2, 11(tl. POLITZER, W. M. & TL'CKER, B. (1958). Ibid., 2, 778. Pd~DDY, W. J. (1954). Metabolism, 3, 489 , JENKINS, D. & THORN, G. W. (1952). Ibid., 1, 51t. SANDBE~C, A. A., En~-NEs, K., SAMUH.S, L. T. & TYLER, F. ti. ~.1954). J. din. Invest., 33, 1309. S~1rrn, R. W., MELLIN{;E~, R. C. & PATTI, A. A. (1954). J. olin. Endocrin., 14, 336. STEeNBURC, P-. W., LEXNmaN, R. & MOORE, F. D. (1956). Ann. Surg., 143, 180. THORN, J. W., GOETZ, F. C., STReETEN, I). H. P., DINC.XIAX',J..~'. & ARONS, W. L. 41933}. .~. c/'.r< Endocrin., 13, 6{)4. TYLER, F. H., SCHMIDT, C. i)., EIK-NEs, K., BROWN, H. & SAMUELS, L. T. (1954). J. chn. ,M.vest., 33, 1502 and 1517. VIRTUE, R. W., t-]ELMREICH, .XI. 1~. ,~ GA1NZA, E. (1957). Surgery, 41, 549.