Acta Medica Scandinavica. Vol. CLIII, fasc. VI, 1956.

From the Medical Department of the Maria Hospital, Helsingfors. Head : Professor Guitio Totterman, M. D.

The Age Distribution in Pernicious Tapeworm Anemia

and Addisonian Pernicious Anemia. BY

G. TOTTERMAN and P. AHRENBERG

(Submitted for publication October 20, 1955.)

Introduction.

A quarter of a century ago, E. Lindstrom published his work on the incidence of pernicious anemia in four hospitals in Helsingfors, covering the years 1898-1927. His investigation shows that Addisonian pernicious anemia is definitely a disease of the aged. The same view had previously been expressed by Schauman, contrary to the prevailing conception that the disease occurred mainly at the.>best> age of man. This erroneous statement was due to no consideration having been taken as to the size of the age groups in the total population when working out the frequency tables.

The age distribution among patients with pernicious tapeworm anemia has been studied both by Lindstrom, Schauman and Saltzman. In their graphs, not only does the fact that the disease appears at a considerably lower age than Addisonian pernicious anemia seem astounding, but two peaks occur, the first one at the age of thirty in both studies, the second, in Lind- strom’s graph, in the sixth decade, and, in Schauman’s and Saltzman’s graph, in the fifth. Based on 457 cases from the literature, Birkeland drew his own graph for the ag6 distribution among patients with tapeworm anemia. It coincides, almost identically, with Schauman’s and Saltzman’s graph. Thus, the age distribution in pernicious tapeworm anemia and Addisonian pernicious anemia would differ considerably.

The difference seems rather surprising since investigations of recent years reveal an increasing similarity in the clinical picture of the two diseases. A renewed study of the age distribution among patients with pernicious tapeworm anemia, therefore, seemed to be indicated and, for purposes of comparison, a series of cases of Addisonian pernicious anemia was as- sembled.

422 G. TOTTERMAN AND P. AHRENBERG

The material.

The material comprises 400 cases of the first group and 930 cases of the latter, all froin the I1 Medical Clinic, Helsingfors (1912-1950, 178 and 388 cases), the Maria Hospital (1912-1952, 129 and 484 cases), and the Provincial Hospital, Milikeli (1947-1951, 93 and 58 cases). The piling up

of cases in the atter years is due to the increased turnover in the hospitals and the improved facilities for examination.

In figure 1, the unbroken line indicates the age distribution among 930 patients with Addisonian pernicious anemia. The broken line in the same figure is Lindstrom’s corresponding graph. Comparing the two graphs, it is seen that Lindstrom’s graph rises earlier, and at the age of 50-70 years there

THE AGE DISTRIBUTION IN PERNICIOUS ANEMIA 423

is almost no rise, but in the eighth decade, a rapid fall occurs. Our graph reveals n remarkably low incidence in the 10-30 year group and a steep rise from the age of 40 up to 70, and no particular decrease at a later age. A peak is seen in both graphs at the age of i 0 . In our series of cases, Addisonian pernicious anemia is a inore typical disease of the aged than is

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Fig. 2.

found to be the case in Lindstrom’s series. This is probably due to increased possibilities for laboratory examination and to the fact that diseases of the old now attract greater interest. As a result, an increasing number of cases of pernicious anemia is being diagnosed in the aged.

The unbroken line in figure 2 represents the 400 cases of pernicious tape- worm anemia in our series, and the broken line Lindstroni’s 299 cases of

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the same disease. Our graph lacks the two peaks observed in Lindstrom’s, Schauman’s and Saltzman’s, and Birlteland’s graphs. As already mentioned, the first peak occurs in the third decade in all the three series, the second peak, in Lindstrom’s graph, is in the sixth decade, and in the other two studies in the fifth. Our graph shows n moderate rise in the fourth decade and a steep rise with a definite maximum in the seventh decade-as is seen also in our graph for Addisonian pernicious anemia. Later, there is a con- sjderable decrease in the incidence of the disease. To give a rough summary of our graph it may be said that it resembles the graph for Addisonian per- nicious anemia but is considerably lower and less steep, and there is a rapid fall at a more advanced age.

The dotted line in the same figure refers only to the cases of tapeworm aneiliia from the Provincial Hospital in Mikkeli and covers a shorter period, 1947-1951. The number of cases is small, including only 93 cases, but more complete because one of us (P. Ahrenberg) followed-up all these patients. This graph bears a still greater resemblance to that of the Addisonian per- nicious anemia, but it, too, shows a definite decrease in the oldest age group.

G. TOTTERMAN AND P. AHRENBERG

Discussion.

Considering our series of cases of pernicious tapeworm anemia, we may say that the age distribution approaches that of the group of Addisonian pernicious anemia far closer than do Lindstrom’s, Schauman’s and Saltz- man’s, and Birkeland’s results. The cause of this discrepancy is difficult to explain, however. Statistically, the graphs are fully comparable. It is true that our series are larger than Lindstrom’s, Schauman’s and Saltzman’s, but Birlteland’s, assembled from the literature, are greater than ours. It might be thought that the lower incidence in the younger age groups of pernicious tapeworm anemia in our series was due to increased knowledge and greater vigilance among the people, followed by increased anthelmintic treatment, and to the decreased occurrence of tapeworm infestation in the younger age groups.

To shed some light on this question, the incidence of tapeworm infestation a t various ages was studied with the aid of notes made by the physicians in three communes in the north of Carelia. In these parts, the population is highly infested by the broad tapeworm. For this reason we assumed that an investigation of this kind would yield a fairly accurate picture of the tapeworiii infestation in the various age groups. About 10,000 outpatient records were studied and in 729 of these the occurence of Diphyllobothriulli 1 at u m was noted .

Figure 3 shows the age distribution among these tapeworni patients. The frequency of infestation is comparatively low below the age of 10. Later there is a distinct increase up to the age of 30. In the following decade,

THE AGE DISTRIBUTION IN PERNICIOUS ANEMIA 425

the graph runs fairly evenly but rises again, reaching its final niaxiiiiuni in the sixth decade. After this age the incidence decreases and in the eighth decade it is about the same as in the second. The reason for the decreased incidence in the older age groups is not known, but the phenomenon is

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Fig. 3.

statistically reliable in any case. Nevertheless, the decrease may be due to a less thorough examination of very old patients, or the incidence of infesto- tion niay truly be less. The reduced occurrence of pernicious tapeworm anemia, as observed in our graph for the oldest age groups, niay be due to the infestation being less and no doubt causing the considerable difference in the incidence of Addisonian pernicious anemia and tapeworm anemia in the oldest age group in our material.

426 G. TOTTERMAN A N D P. A H R E N B E R G

The assumption that the comparatively low incidence of tapeworm aneiiiia before the age of 40 might be due to a low incidence of infestation was found incorrect, however. The degree of infestation in the fourth decade was almost the highest, and very considerable as early as in the third decade. This discrepancy between the coniparatively prolific occurrence of tape- wornis and the low incidence of pernicious tapeworm anemia in the age group 20-40 may indicate t h a t a c e r t a i n l a t e n t p e r i o d i s r e q u i r e d b e f o r e a n e m i a d e v e l o p s o r , i n a y o u n g p e r s o n , t a p e w o r m i n f e s t a t i o n i s n o t l i a b l e t o c a u s e p e r n i c i o u s t a p e w o r m a n e m i a a s r e a d i l y a s i n t h e a g e d .

Summary.

Our investigation of the age distribution among patients with pernicious tapeworm anemia shows greater resemblance to the age distribution in Addisonian pernicious anemia than is shown by the results of previous research workers. Some differences appear, however, for instance, a some- what higher incidence of pernicious tapeworm aneinia in the younger age groups and a certain decrease in the very old age groups. The great similarity of the graphs is highly suggestive of the pathogenesis of the two forms of pernicious anemia being siiiiilar in many respects. The same trends are observed in Japan where both Addisonian pernicious anemia and per- nicious tapeworm anemia are extremely rare, in spite of the prolific occur- rence of the broad tapeworm in some parts of the country (Amano, Kiyono and Ainano).

To sum up-we are inclined to consider the stomach as a factor largely .determining the development of pernicious tapeworm anemia in the same way as in Addisonian pernicious anemia.

References.

Amano: Personal communication. - Birkeland: Medicine 12: 1, 1932. - Kiyono and Amano: Acta Schol. Med. Univers. Imper. Kiot. 19: 3, 1937. - Lindstrom: Finska Liik. Sallsk. Handl. 71: 155, 1929. - Schauman and Saltzman: In Schitten- helm: Handbuch der Krankheiten des Blutes und der blutbildenden Organe, Ber- lin, Julius Springer, Vol. 2, 1926.