Evaluation of the results of active diagnostics and treatment of coeliac disease in a high-prevalence area - a special focus on dietary compliance, quality of life and associated complications

Abstract

Keliakian tehostetun diagnostiikan vaikutukset Pirkanmaan sairaanhoitopiirin alueella

Keliakian aktiivinen diagnostiikka näyttää olevan kannattavaa. Asiaa tutkittiin väitöskirjassa Pirkanmaan sairaanhoitopiirin alueella, jossa tautia on diagnosoitu ja hoidettu aktiivisesti jo 1980-luvulta.

Keliakian taudinkuva on laaja ja tauti on yleinen; jopa 1 prosentti (Suomessa n. 50 000) väestöstä sairastaa sitä - suuri osa tietämättään. Gluteeniton ruokavalio on keliakian hoidon kulmakivi ja parantaa keliakiassa esiintyvän suolivaurion. Tiedetään, että keliakiaa esiintyy tietyissä riskiryhmissä, kuten lähisukulaisilla ja autoimmuunitauteja sairastavilla, 5-10-kertaisesti muuhun väestöön verrattuna. Nämä potilaat ovat keliakian suhteen usein varsin vähäoireisia tai jopa oireettomia, eikä hoidon pitkäaikaisvaikutuksista ole tutkimustietoa. Ei myöskään tiedetä, noudattavatko diagnoosihetkellä oireettomat potilaat gluteenitonta ruokavaliota jatkossa.

Väitöskirjatyössä selvisi, että pitkän seuranta-ajan jälkeenkin yli 80 prosenttia keliakiapotilaista noudattaa tarkkaa gluteenitonta ruokavaliohoitoa. Hoitomyöntyvyys oli hyvä huolimatta siitä, oliko keliakiasta diagnoosihetkellä oireita vai ei. Elämänlaatu oli keliakiapotilailla yhtä hyvä kuin väestössä yleensä, riippumatta siitä, oliko tauti todettu oireiden perusteella vai riskiryhmien seulonnassa.

Hoitamattomaan keliakiaan liittyy usein luuntiheyden aleneminen, mitä gluteeniton ruokavalio parantaa. Tutkimus osoitti, että riskiryhmien seulonnassa todetuilla potilailla luuntiheys oli yhtä hyvä kuin väestössä. Oireiden perusteella todetuilla potilailla luuntiheys oli hieman alentunut hoidosta huolimatta. Keliakian varhainen diagnoosi tuntuu siten estävän luustokomplikaatioita.

Aiemmissa tutkimuksissa todettua kohonnutta kokonaissyöpäriskiä ei tässä tutkimuksessa keliakiapotilailla todettu. Ainoastaan non-Hodgkinin imusolmukesyövän riski oli 3-kertainen väestöön verrattuna, mikä on samankaltainen tulos kuin muissa viimeaikaisissa tutkimuksissa. Kuolleisuus oli hieman lisääntynyt ensimmäiset 5 vuotta keliakian diagnoosista, mutta sen jälkeen samanlainen kuin väestössä yleensä. Kuolleisuus oli tässä tutkimuksessa alhaisempi kuin monissa muissa maissa tehdyissä tutkimuksissa, joissa keliakian esiintyvyys on alhaisempi ja siten diagnostiikka todennäköisesti tehottomampaa kuin meillä.

Keliakian yleisyyden ja hoidettavuuden vuoksi keliakian väestöseulonnasta keskustellaan, mutta sen kustannus-hyötysuhteesta ei ole vielä tietoa. Keliakiaa ei siksi seulota väestöstä. Väitöstutkimus osoitti, että jo tehostetulla diagnostiikalla saadaan keliakiaan liittyvien komplikaatioiden riskiä pienennettyä. Myös oireettomana todetuilla potilailla elämänlaatu säilyy hyvänä huolimatta siitä, että he noudattavat gluteenitonta ruokavaliohoitoa erittäin hyvin. Kun keliakiaa diagnosoidaan aktiivisesti, on syöpäriski väestötasolla ja kuolleisuus aiemmin oletettua pienempi. Tehokas keliakian diagnostiikka, jossa keskitytään myös vähäoireisten potilaiden ja keliakian riskiryhmiin kuuluvien potilaiden löytämiseen, on kannattavaa toimintaa.

The clinical spectrum of coeliac disease is wide: patients may suffer from malabsorption and evince various gastrointestinal or extraintestinal symptoms, or be totally asymptomatic. Osteoporosis and lymphoma are the most well-known complications of coeliac disease and many autoimmune diseases are more common in patients with coeliac disease than in non-coeliac populations.

The diagnostics of coeliac disease have been actively pursued in the Tampere University Hospital area ever since 1980, and patients with mild symptoms and coeliac disease risk groups have also been diagnosed and treated. Many patients are asymptomatic, but there are no long-term studies on compliance and quality of life in this group.

The aim of the study was to evaluate the dietary compliance, quality of life and coeliac disease complications after long-term follow-up in the area, where the clinical prevalence of the disorder is high, up to 0.3 per cent of the local population. Dietary compliance was evaluated in 703 coeliac disease patients by questionnaire and patient records and in 53 screen-detected and 44 symptom-detected treated coeliac disease patients by means of interview, 4-day food record and coeliac disease serology. According to these studies, as many as 77 to 83% of the patients adhered to strict gluten-free diet, which is a better result than in many other countries.

Quality of life was measured by Psychological General Well Being questionnaire in 53 screen-detected and 44 symptom-detected, long-term treated coeliac disease patients and was comparable to that in 110 non-coeliac controls. Also gastrointestinal symptoms (measured by Gastrointestinal Symptom Rating Scale questionnaire) were similar in treated coeliac patients and in non-coeliac controls. Quality of life was further evaluated in screen-detected treated patients by Short Form 36 Health Survey questionnaire and the results compared to a Finnish population sample of 2,060 persons. According to the results, mental health was significantly better in screen-detected patients than in the general population. In other items, there were similar trend which showed no significant differences. Bone mineral density (measured by Dual Energy X-ray Absorptiometry method) in 53 screen-detected long-term treated coeliac disease patients did not differ from the population in general, whereas bone mineral density in 44 symptom-detected patients was lower. The occurrence of fractures was inquired after, but there was no difference between the groups.

The occurrence of autoimmune diseases was studied in 703 treated coeliac disease patients by questionnaire and hospital records and the results compared to that in 299 non-coeliac patients undergoing gastroscopy. The duration of gluten exposure in relation to occurrence of autoimmune diseases in coeliac disease patients was evaluated in logistic regression analysis. Patients with coeliac disease had significantly more autoimmune diseases than controls. The duration of gluten exposure had no promotive effect on the occurrence of autoimmune diseases. Further, the prevalence of clinical and subclinical autoimmune thyroid diseases was studied in 79 treated coeliac disease patients and in 184 non-coeliac controls by measuring serum thyroid hormones and antibodies and by thyroid ultrasound examination. Hypothyreosis and subclinical autoimmune thyroid diseases were significantly more common in patients with coeliac disease than in controls. Coeliac disease patients were prone to atrophic thyroiditis. A hypoechoid pattern in ultrasound examination was even more common in those coeliac patients, whose coeliac disease was diagnosed later in life. This finding suggests that the late diagnosis of coeliac disease predisposes to the later development of manifest autoimmune thyroid disease.

The risk of cancer and mortality in 781 patients with coeliac disease and in 366 with dermatitis herpetiformis were compared to the age- and sex-matched Finnish population. In contrast to many earlier studies, the total cancer risk was not increased. The risk of non-Hodgkin lymphoma was 3-fold in patients with coeliac disease and 6-fold in patients with dermatitis herpetiformis, this risk being fairly similar to that observed in recent studies. The mortality rate was slightly but significantly increased in coeliac disease patients. Mortality in patients with dermatitis herpetiformis was significantly decreased the reason for this remaining unclear. This study showed that in a high prevalence area of coeliac disease where the diagnostic approach has been active, the majority of the patients are under gluten-free diet. The diagnosis of patients with mild symptoms and patients in coeliac disease risk groups seems justified in that dietary treatment does not worsen the quality of life of these patients. Also the risk of osteoporosis seems to be lower when coeliac disease is diagnosed at an early stage. Although osteoporosis was more common in patients with symptom-detected coeliac disease they did not experience more fractures than screen-detected patients. Fracture risk warrants further study in larger patient series. A gluten-free diet did not seem to affect the occurrence of autoimmune diseases. Interestingly, cancer risk in the patients with coeliac disease was not increased to that in the population in this high-prevalence area but in accordance to earlier studies, the risk of non-Hodgkin lymphoma was increased. In addition, the mortality risk in coeliac disease was lower than in many studies from other countries, where the clinical prevalence of coeliac disease is lower.