The Role Of Dıetary Tryptophan Intake In Fıbromyalgıa Syndrome

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---Beslenme ve Diyet Dergisi / J N u i r and Diet 32(l):61-65/2003

THE ROLE OF DIETARY TRYPTOPHAN INTAKE IN

FIBROMYALGIA SYNDROME

- Dr. Hakan GENÇ*, Dr. Meryem SARAÇOĞLU*, Dr. Burcu DUYUR*, Dr. H. Rana ERDEM*—1

A B S T R A C T

Fibrom yalgia Syndrom e (FS) is a common disea- se characterized by diffuse, w idespread pain and m ultiple tender points. Syndrome was sııbclassifı- ed as p r im a ıy fibrom ya lg ia (PFS) and secondaıy fib ro m yalgia (SFS). The a im o f this study was to e v a lu a te the role o f d ieta ry tryptophan in FS. Twenty fe m a le p a tie n ts w ith PFS, 20 with SFS and 20 fe m a le Controls, m atched by age and body m a ss index, p a r tic ip a te d in this study. D ietary tryptophan intakes o f the F S and control subjects were assessed with "total nutrition sc o re ” (TNS) prepared f o r this study. Average daily consumpti- on o f tıyptophan (ADCT) values were also calcu- lated b ased on this scoring system. A signifıcant difference w as obsen>ed between TNS and A D C T values o f F S p a tien ts and control subjects. TNS and AD CTs were signifıcantly lo\ver in botlı PFS and S F S groups. A s a result, tryptophan rich diet can be recom m ended to these p atients as a p a rt o f treatm ent regimen.

Key yvords: Fibromyalgia, diet, tryptophan Ö Z E T

F ibrom iyalji sendrom u (FS) diffüz, yaygın ağrı ve çok sayıda hassas noktalarla karakterize, sık gözlenen bir hastalıktır. Sendrom p rim e r F S ve seko n der F S olarak a lt gruplara ayrılmaktadır. Bu çalışm an ın am acı d iyet triptofan içeriğinin F S ’daki rolünü araştırm aktır. Yaşları ve beden kitle indeksleri açısından eşleştirilmiş 20 primer, 20 sekonder kadın F S hastası ve 20 kadın kontrol birey çalışm aya alınmıştır. Fibrom iyaljik hasta * M in is tr y o f H e a lth , A n k a ra E d u c a tio n a n d R e s e a r c h H o sp ital

2 n d D e p a r tm e n t o f P h y s ic a l M e d ic in e a n d R e h a b ilita tio n , A n k a r a - T U R K E Y

lar ve kontrol bireylerinin diyetlerinin triptofan i- çerikleri, bu çalışma için hazırlanmış olan “total beslenm e s k o r u ” (TBS) ile değerlendirilm iştir. Ortalama günlük triptofan alımları (OGTA) yine bu skorlama sistemi baz alınarak hesaplanmıştır. F S hastası ve kontrol bireyleri arasında TBS ve OGTA açısından anlamlı fa rk lılık gözlenmiştir. TBS ve OGTA prim er ve sekonder F S hastaların da kontrol bireylerine oranla belirgin olarak dü şük bulunmuştur. Sonuç olarak F S hastalarına, tedavi rejiminin bir parçası olarak triptofandan zengin diyet önerilmesinin yararlı olacağı belir lenmiştir.

Anahtar kelimeler: Fibromiyalji, triptofan, diyet

IN T R O D U C T IO N

Fibromyalgia Syndrome (FS) is a common disease characterised by widespread m usculosceletal pain and tendemess on palpation o f spesific ten- dinomusculoskeletal sites, called “tender points . FS was subclassifıed as prim ary fibrom yalgia (PFS) and secondary fibromyalgia (SFS). Patient with prim ary fibromyalgia have diffuse, widespread pain and multiple tender points in the ab- sence o f underlying, cau sativ e, or sig n ifıcan t concomitant condition. In the presence o f these conditions it is classifıed as secondary fibromyal gia. Studies have shown that the clinical characteristics o f FS in these patients are not signifı- cantly different from those o f primary fibromyal gia (1,2).

The most common characteristics o f the syndro me are nonrestorative sleep, tensiontype headache, subjective soft tissue swelling, m om ing stiffness and paresthesias. In addition anxiety,

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dep-62 G E N Ç H., SA R A Ç O Ğ L U M ., D U Y U R B ., E R D E M R.

ression, dysm enorrhea, irritable bowel syndrome, S icca sy n d ro m e, R a y n a u d ’s p henom enon and w om an urethral syndrom e m ay be seen in fıb- ro m y alg ia. C hronic fatique syndrom e, restless legs syndrom e, hypermobility, noctum al myoclo- nus, psychogenic pain are conditions sim ilar or related to fıbromyalgia (1,3).

One o f the most important pathophysiologic theories o f FS is combination o f Central and perip- heral m echanism s based on “central neurohormo- n al d y s fu n c tio n ” . D e c re a se d se ro to n in level w h ich m ay be trig gered by nonspesifıc stress from traum a, viral infection or mental stress is thought to be a causative factor (3).

The aim o f this study was to evaluate the role of dietary tryptophan which is a precursor o f seroto nin in FS. We also assessed the most common characteristics o f FS in our patients.

MATERIALS AND METHODS

Tvventy female patients vvith PFS, 20 with SFS (due to type2 diabetes m ellitus (DM )) and 20 woman Controls, matched by age and body mass index (BMI), participated in the study. Ali pati ents fulfilled the classifıcation criteria for fibrom y alg ia pro posed by A m erican C o llege o f Rheumatology (ACR) (4). First, demographic fe- atures o f the patients were noted and clinical cha racteristics o f FS such as nonrestorative sleep, tensiontype headache, m om ing stiffness, subjective sofit tissue swelling and paresthesias were as- ked. Then ali patients undenvent detailed loco- motor and systemic examination.

Tender point (TP) and control point (CP) exami- nations w ere perform ed w ith F is c h e r’s tissue compliancemeter which may be used as a pressure pain algom eter (5-7). Eighteen TP and 4 CP (mid forearm and thumbnail on the left and right sides o f the body) (8) were evaluated respectively. Compliancemeter was applied to these spe- sifıc points and the amount o f pressure causing pain (pain pressure treshold PPT) were recorded as kg/cm 2 . Points that vvere painful w ith less than 4 kg/cm2 pressure vvere accepted as tender

points. Severity o f fıb ro m y a lg ia w as a sse sse d vvith total myalgic score (TM S) and control point score (CPS). The sum o f the PPTs o f 22 points (1 8 T P a n d 4 C P ) w e re c a l c u l a t e d a s T M S (kg/cm2) and the sum o f the PPTs o f the control points were recorded as CPS (kg/cm 2) (6,7). We used “total nutrition score (T N S)” , prepared for th is study, fo r th e a s s e s s m e n t o f d ie ta ry tryptophan intakes o f the FS and control subjects. Tryptophan rich fo od in tak e (an im al p ro te in s; meat, egg, offal, m ilk, cheese, vegetable proteins; dry beans, chickpeas, lentils, oily seeds; sesam - me, black cumin, sunflow er seed, pum pkin seed, almond, walnut, peanut, flour; bread and chocolate) (9) was scored 0 to 4 according to consum p- tion frequency o f each food (0: none or rare, 1: once a mounth, 2: once a w eek, 3: m ore than ön ce a week, 4: everyday; at least for one m eal). The sum o f the scores w ere calculated as TN S. Average daily consum ption o f tryptophan values (ADCT) o f FS patients and control subjects also calculated according to co n su m p tio n freq uen cy and am ount o f each food based on this scoring system. The am ount o f tryptophan w hich w as ta- ken with food for 30 days w as calculated and divided to 30. Final value w as recorded as A D C T (g/day).

SPSS 10.0 for w indow s w as used for statistical analysis. C hisquare an d onevvay A N O V A tests vvere selected for analysis and po sth o c analysis were perform ed vvith B o n ferro n i test. P values less than 0.05 were accepted as significant.

RESULTS

The m ean age o f the 20 fem ales w ith PFS w as 51.25 ± 8.82 years (betw een 34-70), 20 fem ales with SFS vvas 55.65 ± 11.06 years (betvveen 36- 78) and 20 female control w as 51.40 ± 7.68 years (betvveen 40-65). D em o g rap h ic fea tu re s o f fıb- rom yalgia and control groups and m ean disease durations are given in Table 1. T here w as no sta- tistic a lly sig n ific a n t d iffe re n c e betvveen th e 3 groups vvith respect to m ean age, height, vveight, body m ass in d ex a n d d u ra tio n o f th e d is e a s e (p>0.05). The m ean DM duration vvas 9.8 ± 5.27

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T h e R o le o f D ietary T ry p to p h a n in ta k e in F ib ro m y alg ia S y ndrom e ₆₃

y ears and m ean fasting blood glucose level was 193.5 ± 63.42 m g/dL in SFS group.

P a tie n ts w ith PFS w ere not differen t than SFS g roup in any o f clinical param eters (p>0.05). N o n rc s to ra tiv e sleep, su b jective jo in t svvelling, m o rn in g stiffn e ss and p a re sth esias w ere found m o re in P F S a n d SF S g ro u p s th a n C ontrols (p< 0.001).

N u m b e r o f t e n d e r p o in ts w a s f o u n d h ig h e r (p < 0 .0 0 1 , p < 0 .0 1 ) and total m yalgic score and co n tro l point scores w ere low er (p<0.001) in PFS and SFS g roup s than in control subjects (Table

2).

A s ig n ifıc a n t d ifferen ce w as o bserved betw een to ta l n u tritio n sc o re s (T N S ) and av erage daily co n su m p tio n o f tryptophan (A D C T) values o f FS patien ts an d control subjects. TN S was found to be s ig n ific a n tly lo w e r in PFS and SFS groups (p< 0 .05 , p<0.01 respectively) than control group. A D C T w as fo u n d to be sig n ifican tly low er in PFS and SFS g roups too (p<0.05, p<0.01 respec tively). M ean T N S and A D TC values and statistical a n a ly sis are show n in Table 3.

D IS C U S S IO N

P a th o p h y sio lo g ic th eories o f FS can be divided into the three groups b ased on the follow ing pro- p o s e d m e c h a n is m s . (1) P rim arily Central: This th e o r y b a s e d on c o m o rb id ity o f fib ro m y a lg ia w ith m a jö r dep ressio n , m igraine, irritable bowel s y n d ro m e , c h ro n ic fatiq u e syndrom e, panic di- s o rd e rs an d the a lp h a e le c tro e n c ep h a lo g ra p h ic sle e p an o m aly . (2) C o m b in atio n o f Central and p e rip h e ra l m ech an ism s based on “central neuro- h o n n o n a l d y sfu n c tio n ” . D ecreased serotonin le vel w h ic h m ay be triggered by nonspesifıc stress fro m traum a, viral infection or m ental stress is o- ne o f the po ssible m echanism s. (3) Prim arily pe ripheral: T h is theory focused on localised ische- m ia due to distu rb ed m icrocirculation that causes m u sc le pain. To explain w idespread pain at rest, c h a ra c te ristic o f FS, this theory invokes disturbed p a in m o d u la tio n in the cen tral nerv o us system

(CNS) (3).

One o f the A C R criterion for the diagnosis o f FS is the existence o f “sensitive points”. W hile for- m er data indicated pain only in these described points, recent studies have shown an increase in the sensitivity throughout the body (10). M oreo- ver, it is stated in the recent studies that a central hyperexcitability exists in FS patients and as a consequance o f this, the afferent input originated from periphery is am plifıed and continued by the central nervous system (11-13).

Tryptophan, which is an amino acid and a precursor o f serotonin, not only inhibits the descending pain pathw ays, but also is an im portant neurot- ransm itter in stage 4 sleep. D ecrease in restorati- ve nonREM sleep, occurence o f somatic com pla- ints, depression and an increase in the perceived pain ensues as a consequence o f its decrease in the brain. Decreased serotonin level is one o f the most studied m echanism s in the etiopathogenesis o f fibromyalgia (13,14). 5 Hydroxy-L-tryptophan is used per oral in the treatment o f patients w ith fib ro m y a lg ia and is rep o rted to have su c ce ss (15).

A num ber o f studies have reported the effects o f diet on the symptom s o f rheum atic disease, but alm ost ali have dealt with rheumatoid arthrıtıs, so very little inform ation on fibrom yalgia is available (16,17). K aartinen et al.(17), assessed the effect o f uncooked vegan diet on symptoms in 18 FS patients. They concluded that vegan diet had benefıcial effects on fibrom yalgia symptom s. Vi tamin B6 plays a role in the synthesis o f seroto nin from try p to p h an . T ry p to p h a n m e ta b o lism was altered, with urinary excretions o f xanthure- nic acid after tryptophan loading. Pyridoxine rep- letion corrected ali o f the ab norm alities noted. Vitamin B6 in natural foods w as as available as crystalline pyridoxine (18). Futher studies w ere n ecessary ab o u t this issue. M ark u s et al. also show ed the effects o f w hey p ro tein on plasm a tryptophan levels. They reported that w hey prote in rich in ? la c ta lb u m in in c re a se d the ıa tio o f plasm a tryptophan to the sum o f other large

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neut-Table 1. D em ographic featu res o f FS and control groups and mean disease dıırations

6 4 G E N Ç H., S A R A Ç O Ğ L U M ., D U Y U R B., E R D E M R.

Age (year) H eight (m) W eight (kg) BMI (kg/m 2) D uration o f FS(year)

PFS 51.25±8.82 1.60±0.06 72.05±10.71 28.09±4.97 4 .0 0 İ2 .7 3

SFS (Type-2 DM) 55.65±11.06 1.56±0.07 73.55±10.87 30.1 2 i4 .4 3 4 .4 5 İ2 .3 7

Control 5 1.40±7.68 1.58±0.05 7 5 .5 0 il0 .6 9 30.00±4.39

P >0.05 >0.05 >0.05 >0.05 >0.05

FS: Fibrom yalgia, PFS: Prim ary Fibrom yalgia, SFS: Secondary Fibrom yalgia, DM : D iabetes M ellitus, BM I: Body Mass Index

Table 2. Clinical featu res o f prim ary, secondary F S and control groups.

P rim a ry FS S eco n d ary FS P P rim a ry FS C o n tro l P S e c o n d ary FS C o n tro l P (n:20) (% ) (n:20) (% ) (n:20) (% ) (n:20) (% ) (n :2 0 ) (% ) (n :2 0 ) (% ) NRS 16 (80) 18 (90) >0.05 16 (80) 6 (30) <0.001 18 (90) 6 (30) <0.001 SJS 19 (95) 15 (75) >0.05 19 (95) 9 (45) <0.001 15 (75) 9 (45) <0.05 MS 18 (90) 18 (90) >0.05 18 (90) 7 (35) <0.001 18 (90) 7 (35) <0.001 Paresthesia 15 (75) 16 (80) >0.05 15 (75) 5 (25) <0.001 16 (80) 5 (25) <0.001 Headache 18 (80) 18 (90) >0.05 18 (80) 17 (85) >0.05 18 (90) 17 (85) >0.05 NTP 14.70±2.27 14.65±1.87 >0.05 14.70±2.27 4.75±2.79 <0.001 14.65±1.87 4 .7 5 i2 .7 9 <0.01 TMS (kg/cm 2) 71.50±4.53 70.15±4.75 >0.05 71.50±4.53 102.30±4.34 <0.001 7 0 .1 5 i4 .7 5 1 0 2 .3 0 i4 .3 4 <0.001 CPS (kg/cm*) 14.78±2.60 14.93±2.14 >0.05 14.78±2.60 23.77±3.26 <0.001 1 4 .93i2.14 2 3 .7 7 i3 .2 6 <0.05

FS: F ıb ro m y alg ia, N R S: N o n -R esto rativ e Sleep, SJS: S u b jectiv e Jo in t Svvelling, M S: M o m in g StifTness, N T P : N u m b e r o f T e n d e r P o in ts , T M S : T otal M yalgic S core, C PS: C o n tro l P o in t S core,

Table 3. Total nutrition scores (TNS) and average daily consumption o f tryptophan (ADCT) values o f p rim a ry fibrom yalgia (PFS), secondary fıbrom yalgia (SFS) patients and control group.

P rim ary FS Secondary FS P P rim a ry FS C o n tro l P S e c o n d a ry FS C o n tro l P

(n:20) (n:20) (n:20) (n:20) (n :2 0 ) (n :2 0 )

TNS 15.40±2.95 ADTC (g/day) 1.06i0.39

14.15i3.46 0.98İ0.58 >0.05 >0.05 15.40i2.95 1.06i0.39 17.60±3.35 1.25*0.96 <0.05 <0.05 1 4 .15i3.46 0 .9 8 i0 .5 8 17 .60i3.35 1.25±0.96 <0.01 <0.01

mance in stressvulnerable subjects (19).

This is the fırst study to investigating the role o f dietary tryptophan intake in FS using TNS vvhich is prepared for this study. TNS is a simple and u- seful scoring system under lim ited laboratory conditions. We found using this scoring system that our patients vvith PFS and SFS had lovver di etary tryptophan intake as compared to the con trol group. We also found that our patients vvith PFS and SFS had lower average daily consumpti on o f tryptophan values (1.06±0.39 g/day and 0.98±0.58 g/day respectively) as com pared to control subjects. These values also lovver than the average daily consumption o f tryptophan in USA (1.2 g/day)(20).

M ultiple theories about the pathogenesis o f this disease dictates various therapy regimens. As the

diffıcult, current therapeutical ap p roaches seem to be inadequate. L edingham et al. (21) vvere re- ceived sev en ty tw o p a tie n ts vvith PFS in th e ir study and they reported a poor prognosis characterised by a high degree o f f'unctional im pairm ent and persistence o f symptom s.

In conclusion, considering the central hyperexci- tab ility exists in FS p a tie n ts, try p to p h a n m ay play an important role in fibrom yalgia as a causative factor and also plays a role in persistence o f fibromyalgia symptom s. Thus tryptophan rich diet (for exam ple ineluding w hey proteins, m ilk, meat, vegetable proteins, chocolate ete.) can be recom mended to these patients. The am ount and frequency o f dietary triptophan intake and also the effect o f tryptophan on sym ptom s in FS p ati ents should be confırm ed vvith further studies.

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T h e R o le o f D ictary T ry p to p h a n In tak e in F ib ro m y alg ia S yndrom e ₆₅

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