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Atherosclerosis and levels of serum cholesterol in postmortem investigations
Atherosclerosis in postmortem Zdzis!aw Marek, M.D. Kazimierz Jaegermann, Tadeusz Ciba, M.D. Cracow, Poland
ad levels of swum inrwf+gaGons
M.D.
E
levation of the levels of serum cholesterol in patients suffering from atherosclerosis is often cited in support of the metabolic theory of the development of atherosclerosis. The importance of the level of cholesterol in the clinical diagnosis of atherosclerosis is somewhat weakened by the fact that, up until now, the marked individual variations in the level of cholesterol in patients as well as in healthy individuals has not been adequately explained and defined. In pathogenetic and clinical considerations, the studies of Gofman and colleagues4 and Gertler and colleagues3 are of primary importance. They found a higher incidence of coronary disease in persons with elevated levels of cholesterol. This problem has also been investigated by way of autopsy. In 1936, Lande and Sperry’ in postmortem investigations did not find a correlation between the level of cholesterol in blood serum and the degree of atherosclerotic changes. Similar investigations have been carried out by Spain, Bradess and Greenblattio on the basis of determinations of beta-lipoproteins in blood serum. Some partly positive results were obtained. Our investigations were designed to show whether a relationship exists between the level of serum cholesterol and the inFrom the Institute of Forensic Received for publication April
768
cholesterol
Medicine, 11. 1961.
and Medical
tensity, localization, and type of atherosclerotic changes. The investigations were based on the autopsy material of the Institute of Forensic Medicine in Cracow. The results were compared with the studies of Tochowicz and colleague@ as well as those of Gabryelski and Ciba.2 These authors investigated the level of serum cholesterol in patients treated for myocardial infarction and hypertensive disease and in clinically healthy individuals from the same population as our subjects. Methods
and
results
A group of 106 persons who were over 20 years of age, and who had died suddenly from natural or violent causes were the object of our investigations. The autopsies were carried out in the Institute of Forensic Medicine of the Academy of Medicine in Cracow. The blood was drawn from the external jugular vein up to 20 hours after death. Only those cases were considered in which traces of hemolysis were not confirmed by spectroscopic examination. The experimental observations showed that the level of cholesterol does not depend on the vessel from which the sample of blood is drawn nor the degree of blood lost.’ Comparative tests were made in only 2 cases. The level of cholesterol in blood Clinic
I. Cracow
Academy
of Medicine,
Cracow,
Poland.
Volume Number
63 6
Atherosclerosis
taken immediately before, and that in blood taken a few hours after death were 12 and 7 mg. per cent, respectively. The level of total cholesterol was investigated by routine clinical methods. Particular attention was paid during autopsy to the precise localization and degree of atherosclerotic changes in the coronary arteries, the aorta, and the arteries at the base of the brain. Atherosclerosis found in postmortem investigations was classified into four groups according to a scheme the value of which was confirmed in previous studies.6 The atherosclerotic alterations were classified as “advanced,” “medium,” “mild,” and absent (cases “without atherosclerosis”). Independently of the afore-mentioned classification, the whole material was divided into the following groups: Group l-Cases designated further as the group of “coronary deaths,” e.g., cases of coronary atherosclerosis with or without myocardial infarction, with coronary thrombosis, with advanced coronary stenosis, or with rupture of the heart as a result of infarction or scars from previous infarction. Group 2-All other cases of confirmed atherosclerosis, without regard to the cause of death. Group 3-Cases without atherosclerosis. Because of the influence of different diseases on the level of serum cholesterol, additional macroscopic examinations of lesions in the liver, kidneys, and thyroid gland were made. The state of nutrition, quantity of alcohol consumed and tobacco smoked, as well as occupation and social conditions were also considered. In 43 cases, histologic preparations from the aortic arch and the proximal part of the left coronary artery were examined. Paraffin sections were stained with hematoxylin and eosin, and also with Gomori’s silver impregnation method for fibrous elements. Frozen sections were also examined for lipids (Sudan III, Nile blue) and for free cholesterol by Windaus’ digitonin method. In order to make preliminary calculations all the cases were divided into two groups, without regard to age or sex. These two groups were comprised of those cases without atherosclerosis, and those with atherosclerosis, regardless of the severity
and levels of serum cholesterol
769
of the lesions. It was found that the difference between the average levels of cholesterol in these two groups was 35 mg. per cent, which is statistically insignificant (t = 2.9). The atherosclerotic group was divided into subgroups : “advanced,” “ medium,” and “mild.” On the basis of this division it was shown that differences in average levels of cholesterol were statistically significant (t greater than 3) only between the subgroup of advanced atherosclerosis and the group without atherosclerosis (Table I). Another method of representing the results was by graphs, in which the different cases (taking into consideration the difference in sex) were plotted in relation to two axes (x = age; y = level of cholesterol). From Fig. 1 it appears that the cases with atherosclerosis are found mainly in the interval between 200 and 300 mg. per cent cholesterol. In the cases without atherosclerosis the levels of cholesterol were about 50 mg. per cent lower. There was no distinct influence of age on the level of cholesterol. In order to compare postmortem findings and clinical investigations on a mutual basis, we have selected two groups which appear to us to be homogeneous, namely, cases of coronary death and cases without atherosclerosis. The most interesting group from our point of view was the first, because of the correspondence to clinical coronary disease. The difference between the average level of cholesterol in the group without atherosclerosis and that in the group of coronary deaths (t = 3.3) is similar to the difference between cases without atherosclerosis and cases of advanced atherosclerosis. The mean level of cholesterol in 12 cases of fresh infarction was lower than in all cases of coronary death (Table II and Fig. 2). Differences in the results of biochemical tests in cases of recent infarction have already been found previously in postmortem studies. Similarly, clinical observations also indicated that levels of cholesterol in the blood of patients treated for cardiac infarctions were decidedly lower than in patients with healed infarctions controlled after several months in the outpatient department.” The material which related only to
770
Marek,
Jaegermann,
Am. Heart J. June, 1962
and Ciba
o mg.% c ADVANCED
500
’ ATUEROSCLEROSJS
WtMWr +
ATHEROSCLERWS
4w
0 +
AGE
18 20
30
40
, MEDIUM
so
60
z
w
’ AIHEROSCLEROSIS
” MlLD=ATHEROSCLEROSIS
8 B lc
400
0 famalas + md*r
Fig. 1. Relation atherosclerotic
of levels process.
of cholesterol
to age in material
classified
into
groups
according
to the intensity
of the
Table I
Without
Group
Number of cases
Cholesterol levels (w 70)
atherosclerosis
25
205
Test of significance (t)
3.2 Advanced Medium Mild
atherosclerosis atherosclerosis
atherosclerosis
Atherosclerosis
total
31
260
22
226
28
229
81
240
males was analyzed separately. A similar relationship was confirmed. Fig. 3 gives a summary of all values of the average levels of cholesterol in the different groups. For purposes of comparison, the group shown in Fig. 3 gives the average levels of cholesterol found in clinically healthy persons and in patients with infarcts. The level of serum cholesterol in our group of coronary deaths is very similar to the curve established by Tochowicz and co-workers.” On the other hand, the cor-
Mean age (Age groups)
Sigma
27.7 (20-35) 63.4 (55430) 59.1 (45-65) 44.6 (30-50) 55.5 (40-70)
48.8 76.9 49.4 46.7 62.6
responding values for clinically healthy persons, established by Gabryelski and Ciba,z lie distinctly below the average for our group of cases without atherosclerosis and are closer to the results obtained by American investigators. We considered also whether we couId explain the well-known individual fluctuations in the levels of cholesterol by alterations in other organs. But this analysis did not give positive results. We thought that alterations in the thyroid gland would be
Volume Number
63 6
Atherosclerosis
the easiest to evaluate, because the functional influence of this gland on the level of cholesterol is well known. However, on the basis of morphologic changes, deductions as to the functional state of the thyroid gland could not be made. Nevertheless, it is worth noting that in 66 per cent of the cases in the group of coronary deaths in our material the changes defined macroscopically included diffuse, nodular, and cystic goiters, calcifications, fibrotic
and levels of serum cholesterol
771
changes, and simple atrophy of the gland. In the other groups, such alterations were present in only about 20 per cent of all cases. Uotila and colleaguesi also found anatomic changes in the thyroid gland in a considerable percentage of individuals stricken with sudden cardiac death. Nikkila and Karlssong have not found functional alterations of the thyroid gland in clinical investigations of individuals with heart infarct.
ma% 0
500 , COROMRY
DEATHS
l +
400
0 +
I Jo0
c
+
L
+
++ *
AGE
400
CARDIAC
iNFARCTION .
100 t
Fig. 2. Relation
of levels of cholesterol to age in the group of cases of coronary death and in the subgroup of cases of cardiac infarction. In the bottom section of the figure, the small dots indicate infarcts and the larger ones indicate cardiac rupture.
Table II
“Coronary
GYOUP
Number of cases
Cholesterol levels (w. %I
death”
31
261
Test of significance (t)
Mean age (43 groups)
Sigma
60.3
74.4
(yy (20-35) 60.9 (50-80)
48.8
3.3 Without Recent
atherosclerosis cardiac
infarction
25
205
12
238
54.3
772
Marek,
Jaegermann,
Am. Hcort J. Just?, 1962
and Ciba.
A. pottinfarct outpolknts
,’
. ComNARY
_
/’
-. -.=,
,/
aEArns
*
,)LW.4NCELfATHEROSLEROStS .
/ A’
CARDfAC
INFARCTION
.. MtLD*ATHEROSCLEROStS infarct CiA treated in the clinic
‘1
. MEDMM’A ‘1
/ I
r/-let--
WEROSCLEROYS
\
/
/‘clinicaMy hvaithy tndivlduais
/
,/’ r”
AGE 20
30
40
so
Go
70
do
9Q
Fig. 3. Mean levels of serum cholesterol in different groups of cases, also shown in relation to age. Horizontal lines show the age range of the majority (70 to 80 per cent) of the cases; the mean age in each group is indicated by points. The dashed lines show the mean levels of cholesterol according to age groups in clinically healthy individuals, and in a group of patients with cardiac infarction who were followed as outpatients after clinical treatment.
Since the results of comparison of the levels of serum cholesterol with rnacroscopic atherosclerotic changes were not unequivocal, we compared the microscopic alterations in arteries with the levels of cholesterol. Histologic investigations were carried out in 11 cases of coronary death, in 8 cases without atherosclerosis, and in 24 other cases with atherosclerosis. Microscopically, the arteries examined showed a considerable variety of alterations. The group of casesof coronary death did not show any specific microscopic changes. Therefore, of the various microscopic features which were analyzed, only those showing the most consistent behavior were considered; these included the foci of atherosclerotic necrosis, the presence of cholesterol, character of fatty degeneration, aggregation of inflammatory cells, and foci of calcification. However, we did not find any relationship between the various features, their intensity, and the levels of cholesterol in the blood. A division of the cases into four groups
was made on the basis of the abovementioned microscopic features. We found only old persons (up to 75 years) in a group of 6 cases with marked preponderance of fibrotic changes and calcification. In a group with greater preponderance of atherosclerotic necrosis and abundant deposits of cholesterol the majority of cases were coronary deaths. We have not found, however, any particular difference between average levels of cholesterol in separate groups divided according to microscopic changes. Finally, we were not able to establish a relationship between the total level of serum cholesterol and the free cholesterol in the atherosclerotic infiltrations. However, it should be remembered that total cholesterol was determined in the blood serum, and free cholesterol in the walls of the arteries. Discussion We have attempted to compare the level of serum cholesterol of persons who died suddenly from various causes with the
Volume Number
63 6
Atherosclerosis
intensity and localization of atherosclerotic changes found by postmortem investigations in the more important arteries. The results of our investigations were similar to the results of clinical investigations. The autopsy material examined was from the same population in which the clinical investigations were made. We have confirmed a higher average content of cholesterol in the group of cases with intensive atherosclerosis and also, using another classification, in the group of coronary deaths. The average level of cholesterol found in patients suffering from cardiac infarcts was slightly lower than that in the whole group of patients who died coronary deaths. In all other groups the differences encountered were not statistically significant. We have not found a definite relationship between the level of cholesterol, age of the patient, and localization of the atherosclerotic changes. The level of serum cholesterol in all cases with atherosclerotic changes was higher in only 37 per cent (over 2 + I. sigma = 254 mg. per cent), i.e., two thirds of those who died with confirmed atherosclerosis had levels of serum cholesterol lower than the upper limit of normal values. The very significant individual fluctuations in serum cholesterol were impossible to explain on the basis of coexisting alterations of other organs. One fact merits attention, namely, the frequency of macroscopic alterations of the thyroid gland in the group of cases of coronary death. Also, the histologic investigations have not given basis for binding conclusions. From our investigations it would appear that even the possibility of objective evaluation of atherosclerosis during autopsy does not diminish the effect of the scatter of, individual levels of cholesterol in the different groups of cases. Although the material which we studied was small, it was at least homogeneous. The entire group of coronary deaths comprised cases of sudden death which occurred in people who were in full health, or which was preceded by a short period of illness. From this it can be concluded that the level of serum cholesterol found by us closely approximates the true level of cholesterol before illness and death. In our opinion, this condition could not be ful-
and levels of serum cholesterol
773
filled by investigations of levels of cholesterol in blood obtained from persons who died after a prolonged hospitalization, during which they were subjected to various diets, pharmacologic treatment, and influence of prolonged agony on the biochemistry of the blood. In reference to the problem of etiopathogenesis of atherosclerosis as a whole, we can only conclude, on the basis of our study, that the level of cholesterol does not stand in direct relation to the intensity and localization of atheroscIerotic changes. Summary
In our work we have compared the postmortem findings in material from the Forensic Institute in Cracow (persons who died suddenly from various causes) with the levels of cholesterol and the intensity and localization of atherosclerotic lesions. The total content of cholesterol in the serum was determined in 106 cases. Microscopically, examinations were made in 43 cases.The free cholesterol in atherosclerotic alterations was also investigated by the digitonin method. It was confirmed that the average level of cholesterol in individuals suffering from atherosclerosis (240 mg. per cent) is higher than that in those without atherosclerotic symptoms (20.5 mg. per cent). These differences are statistically significant only in the group of cases of advanced atherosclerosis (260 mg. per cent) and in the group of cases of sudden death from coronary sclerosis (261 mg. per cent). No significant statistical difference was found in the other groups, which differed from each other only in the degree of atherosclerotic changes. The average level of serum cholesterol in people who died from cardiac infarction (238 mg. per cent) was lower than the level of cholesterol in the whole group of persons who suffered sudden coronary death. Microscopic examinations gave no basis for binding conclusions. Also, no relationship was found between the free cholesterol in arterial walls and the total cholesterol in blood serum. The results of these examinations do not differ practically from the results obtained in analogous examinations in health and disease with atherosclerosis, conducted by
774
Marek,
Jaegermann,
Am. Heart I. June, I.962
and Ciba
the same methods, in the same laboratory, and in the same populations. REFERENCES Adamczyk, B., Marczynska, A., Oszacki, J., and Gedliczka, 0.: Wplyw krwotoku na zachowanie sic cholesterolu oraz poziomu sodu i chloru we krwi, Pol. Tyg. Lek. 14(1):15, 1959. Gabryelski, W., and Ciba, T.: Poziom cholesterolu calkowitego i wolnego w surowicy ludzi zdrowych z uwzglednieniem plci i wieku, Pol. Tyg. Lek. 15(12):417, 1960. Gertler, M. M., Woodburg, M. A., Gottsch, L. G., White, P. D., and Rusk, H. A.: The candidate for coronary heart disease. Discriminating power, biochemical, hereditary, and anthropometric measurements, J.A.M.A. 170:149, 1959. Gofman, J. W., Hardin, B., Lyon, T., Dingren, F., Strisower, B., Colman, D., and Herring, V.: On evolution of the lipoproteins and cholesterol measurement as predictors of clinical complications of atherosclerosis, Circulation 14:691, 1956.
5. Jaegermann, K., and Marek, Z.: Badania nad nasileniem miaidiycy w materiale sekcyjnym w latach 1900-1958. (In press.) Kritschevsky, D.: Cholesterol, New York, 1958, John Wiley & Sons, Inc. Lande and Sperry: Cited from Kritschevskye and Liebig.* Liebig, H. : Cholesterinamie und Atherosklerose. Klin. Wchnschr. 20:538. 1941. Nikkila( A., and Karlsson, K.: ‘Thyroid function and clinical coronary heart disease, Acta med. scandinav. 166:195, 1960. 10. Spain, D. M., Bradess, A. V., and Greenblatt, I. J.: Postmortem studies on coronary atherosclerosis, serum beta-lipoproteins and somatotypes, Am. J. M. SC. 229:294, 195.5. 11. Tochowicz, L., Pasyk, S., and Denikiewicz, W.: Ocena wartogci badania cholesterolu i lipemii pokarmowej w miaidiycy, Pol. Tyg. Lek.
15(20):737, 1960. 12.
Uotila, Goitre
U., Raekallo, J., and arteriosclerosis,
and Ehrnrooth, Lancet 2:171,
W.: 1958.
ad levels of swum inrwf+gaGons
M.D.
E
levation of the levels of serum cholesterol in patients suffering from atherosclerosis is often cited in support of the metabolic theory of the development of atherosclerosis. The importance of the level of cholesterol in the clinical diagnosis of atherosclerosis is somewhat weakened by the fact that, up until now, the marked individual variations in the level of cholesterol in patients as well as in healthy individuals has not been adequately explained and defined. In pathogenetic and clinical considerations, the studies of Gofman and colleagues4 and Gertler and colleagues3 are of primary importance. They found a higher incidence of coronary disease in persons with elevated levels of cholesterol. This problem has also been investigated by way of autopsy. In 1936, Lande and Sperry’ in postmortem investigations did not find a correlation between the level of cholesterol in blood serum and the degree of atherosclerotic changes. Similar investigations have been carried out by Spain, Bradess and Greenblattio on the basis of determinations of beta-lipoproteins in blood serum. Some partly positive results were obtained. Our investigations were designed to show whether a relationship exists between the level of serum cholesterol and the inFrom the Institute of Forensic Received for publication April
768
cholesterol
Medicine, 11. 1961.
and Medical
tensity, localization, and type of atherosclerotic changes. The investigations were based on the autopsy material of the Institute of Forensic Medicine in Cracow. The results were compared with the studies of Tochowicz and colleague@ as well as those of Gabryelski and Ciba.2 These authors investigated the level of serum cholesterol in patients treated for myocardial infarction and hypertensive disease and in clinically healthy individuals from the same population as our subjects. Methods
and
results
A group of 106 persons who were over 20 years of age, and who had died suddenly from natural or violent causes were the object of our investigations. The autopsies were carried out in the Institute of Forensic Medicine of the Academy of Medicine in Cracow. The blood was drawn from the external jugular vein up to 20 hours after death. Only those cases were considered in which traces of hemolysis were not confirmed by spectroscopic examination. The experimental observations showed that the level of cholesterol does not depend on the vessel from which the sample of blood is drawn nor the degree of blood lost.’ Comparative tests were made in only 2 cases. The level of cholesterol in blood Clinic
I. Cracow
Academy
of Medicine,
Cracow,
Poland.
Volume Number
63 6
Atherosclerosis
taken immediately before, and that in blood taken a few hours after death were 12 and 7 mg. per cent, respectively. The level of total cholesterol was investigated by routine clinical methods. Particular attention was paid during autopsy to the precise localization and degree of atherosclerotic changes in the coronary arteries, the aorta, and the arteries at the base of the brain. Atherosclerosis found in postmortem investigations was classified into four groups according to a scheme the value of which was confirmed in previous studies.6 The atherosclerotic alterations were classified as “advanced,” “medium,” “mild,” and absent (cases “without atherosclerosis”). Independently of the afore-mentioned classification, the whole material was divided into the following groups: Group l-Cases designated further as the group of “coronary deaths,” e.g., cases of coronary atherosclerosis with or without myocardial infarction, with coronary thrombosis, with advanced coronary stenosis, or with rupture of the heart as a result of infarction or scars from previous infarction. Group 2-All other cases of confirmed atherosclerosis, without regard to the cause of death. Group 3-Cases without atherosclerosis. Because of the influence of different diseases on the level of serum cholesterol, additional macroscopic examinations of lesions in the liver, kidneys, and thyroid gland were made. The state of nutrition, quantity of alcohol consumed and tobacco smoked, as well as occupation and social conditions were also considered. In 43 cases, histologic preparations from the aortic arch and the proximal part of the left coronary artery were examined. Paraffin sections were stained with hematoxylin and eosin, and also with Gomori’s silver impregnation method for fibrous elements. Frozen sections were also examined for lipids (Sudan III, Nile blue) and for free cholesterol by Windaus’ digitonin method. In order to make preliminary calculations all the cases were divided into two groups, without regard to age or sex. These two groups were comprised of those cases without atherosclerosis, and those with atherosclerosis, regardless of the severity
and levels of serum cholesterol
769
of the lesions. It was found that the difference between the average levels of cholesterol in these two groups was 35 mg. per cent, which is statistically insignificant (t = 2.9). The atherosclerotic group was divided into subgroups : “advanced,” “ medium,” and “mild.” On the basis of this division it was shown that differences in average levels of cholesterol were statistically significant (t greater than 3) only between the subgroup of advanced atherosclerosis and the group without atherosclerosis (Table I). Another method of representing the results was by graphs, in which the different cases (taking into consideration the difference in sex) were plotted in relation to two axes (x = age; y = level of cholesterol). From Fig. 1 it appears that the cases with atherosclerosis are found mainly in the interval between 200 and 300 mg. per cent cholesterol. In the cases without atherosclerosis the levels of cholesterol were about 50 mg. per cent lower. There was no distinct influence of age on the level of cholesterol. In order to compare postmortem findings and clinical investigations on a mutual basis, we have selected two groups which appear to us to be homogeneous, namely, cases of coronary death and cases without atherosclerosis. The most interesting group from our point of view was the first, because of the correspondence to clinical coronary disease. The difference between the average level of cholesterol in the group without atherosclerosis and that in the group of coronary deaths (t = 3.3) is similar to the difference between cases without atherosclerosis and cases of advanced atherosclerosis. The mean level of cholesterol in 12 cases of fresh infarction was lower than in all cases of coronary death (Table II and Fig. 2). Differences in the results of biochemical tests in cases of recent infarction have already been found previously in postmortem studies. Similarly, clinical observations also indicated that levels of cholesterol in the blood of patients treated for cardiac infarctions were decidedly lower than in patients with healed infarctions controlled after several months in the outpatient department.” The material which related only to
770
Marek,
Jaegermann,
Am. Heart J. June, 1962
and Ciba
o mg.% c ADVANCED
500
’ ATUEROSCLEROSJS
WtMWr +
ATHEROSCLERWS
4w
0 +
AGE
18 20
30
40
, MEDIUM
so
60
z
w
’ AIHEROSCLEROSIS
” MlLD=ATHEROSCLEROSIS
8 B lc
400
0 famalas + md*r
Fig. 1. Relation atherosclerotic
of levels process.
of cholesterol
to age in material
classified
into
groups
according
to the intensity
of the
Table I
Without
Group
Number of cases
Cholesterol levels (w 70)
atherosclerosis
25
205
Test of significance (t)
3.2 Advanced Medium Mild
atherosclerosis atherosclerosis
atherosclerosis
Atherosclerosis
total
31
260
22
226
28
229
81
240
males was analyzed separately. A similar relationship was confirmed. Fig. 3 gives a summary of all values of the average levels of cholesterol in the different groups. For purposes of comparison, the group shown in Fig. 3 gives the average levels of cholesterol found in clinically healthy persons and in patients with infarcts. The level of serum cholesterol in our group of coronary deaths is very similar to the curve established by Tochowicz and co-workers.” On the other hand, the cor-
Mean age (Age groups)
Sigma
27.7 (20-35) 63.4 (55430) 59.1 (45-65) 44.6 (30-50) 55.5 (40-70)
48.8 76.9 49.4 46.7 62.6
responding values for clinically healthy persons, established by Gabryelski and Ciba,z lie distinctly below the average for our group of cases without atherosclerosis and are closer to the results obtained by American investigators. We considered also whether we couId explain the well-known individual fluctuations in the levels of cholesterol by alterations in other organs. But this analysis did not give positive results. We thought that alterations in the thyroid gland would be
Volume Number
63 6
Atherosclerosis
the easiest to evaluate, because the functional influence of this gland on the level of cholesterol is well known. However, on the basis of morphologic changes, deductions as to the functional state of the thyroid gland could not be made. Nevertheless, it is worth noting that in 66 per cent of the cases in the group of coronary deaths in our material the changes defined macroscopically included diffuse, nodular, and cystic goiters, calcifications, fibrotic
and levels of serum cholesterol
771
changes, and simple atrophy of the gland. In the other groups, such alterations were present in only about 20 per cent of all cases. Uotila and colleaguesi also found anatomic changes in the thyroid gland in a considerable percentage of individuals stricken with sudden cardiac death. Nikkila and Karlssong have not found functional alterations of the thyroid gland in clinical investigations of individuals with heart infarct.
ma% 0
500 , COROMRY
DEATHS
l +
400
0 +
I Jo0
c
+
L
+
++ *
AGE
400
CARDIAC
iNFARCTION .
100 t
Fig. 2. Relation
of levels of cholesterol to age in the group of cases of coronary death and in the subgroup of cases of cardiac infarction. In the bottom section of the figure, the small dots indicate infarcts and the larger ones indicate cardiac rupture.
Table II
“Coronary
GYOUP
Number of cases
Cholesterol levels (w. %I
death”
31
261
Test of significance (t)
Mean age (43 groups)
Sigma
60.3
74.4
(yy (20-35) 60.9 (50-80)
48.8
3.3 Without Recent
atherosclerosis cardiac
infarction
25
205
12
238
54.3
772
Marek,
Jaegermann,
Am. Hcort J. Just?, 1962
and Ciba.
A. pottinfarct outpolknts
,’
. ComNARY
_
/’
-. -.=,
,/
aEArns
*
,)LW.4NCELfATHEROSLEROStS .
/ A’
CARDfAC
INFARCTION
.. MtLD*ATHEROSCLEROStS infarct CiA treated in the clinic
‘1
. MEDMM’A ‘1
/ I
r/-let--
WEROSCLEROYS
\
/
/‘clinicaMy hvaithy tndivlduais
/
,/’ r”
AGE 20
30
40
so
Go
70
do
9Q
Fig. 3. Mean levels of serum cholesterol in different groups of cases, also shown in relation to age. Horizontal lines show the age range of the majority (70 to 80 per cent) of the cases; the mean age in each group is indicated by points. The dashed lines show the mean levels of cholesterol according to age groups in clinically healthy individuals, and in a group of patients with cardiac infarction who were followed as outpatients after clinical treatment.
Since the results of comparison of the levels of serum cholesterol with rnacroscopic atherosclerotic changes were not unequivocal, we compared the microscopic alterations in arteries with the levels of cholesterol. Histologic investigations were carried out in 11 cases of coronary death, in 8 cases without atherosclerosis, and in 24 other cases with atherosclerosis. Microscopically, the arteries examined showed a considerable variety of alterations. The group of casesof coronary death did not show any specific microscopic changes. Therefore, of the various microscopic features which were analyzed, only those showing the most consistent behavior were considered; these included the foci of atherosclerotic necrosis, the presence of cholesterol, character of fatty degeneration, aggregation of inflammatory cells, and foci of calcification. However, we did not find any relationship between the various features, their intensity, and the levels of cholesterol in the blood. A division of the cases into four groups
was made on the basis of the abovementioned microscopic features. We found only old persons (up to 75 years) in a group of 6 cases with marked preponderance of fibrotic changes and calcification. In a group with greater preponderance of atherosclerotic necrosis and abundant deposits of cholesterol the majority of cases were coronary deaths. We have not found, however, any particular difference between average levels of cholesterol in separate groups divided according to microscopic changes. Finally, we were not able to establish a relationship between the total level of serum cholesterol and the free cholesterol in the atherosclerotic infiltrations. However, it should be remembered that total cholesterol was determined in the blood serum, and free cholesterol in the walls of the arteries. Discussion We have attempted to compare the level of serum cholesterol of persons who died suddenly from various causes with the
Volume Number
63 6
Atherosclerosis
intensity and localization of atherosclerotic changes found by postmortem investigations in the more important arteries. The results of our investigations were similar to the results of clinical investigations. The autopsy material examined was from the same population in which the clinical investigations were made. We have confirmed a higher average content of cholesterol in the group of cases with intensive atherosclerosis and also, using another classification, in the group of coronary deaths. The average level of cholesterol found in patients suffering from cardiac infarcts was slightly lower than that in the whole group of patients who died coronary deaths. In all other groups the differences encountered were not statistically significant. We have not found a definite relationship between the level of cholesterol, age of the patient, and localization of the atherosclerotic changes. The level of serum cholesterol in all cases with atherosclerotic changes was higher in only 37 per cent (over 2 + I. sigma = 254 mg. per cent), i.e., two thirds of those who died with confirmed atherosclerosis had levels of serum cholesterol lower than the upper limit of normal values. The very significant individual fluctuations in serum cholesterol were impossible to explain on the basis of coexisting alterations of other organs. One fact merits attention, namely, the frequency of macroscopic alterations of the thyroid gland in the group of cases of coronary death. Also, the histologic investigations have not given basis for binding conclusions. From our investigations it would appear that even the possibility of objective evaluation of atherosclerosis during autopsy does not diminish the effect of the scatter of, individual levels of cholesterol in the different groups of cases. Although the material which we studied was small, it was at least homogeneous. The entire group of coronary deaths comprised cases of sudden death which occurred in people who were in full health, or which was preceded by a short period of illness. From this it can be concluded that the level of serum cholesterol found by us closely approximates the true level of cholesterol before illness and death. In our opinion, this condition could not be ful-
and levels of serum cholesterol
773
filled by investigations of levels of cholesterol in blood obtained from persons who died after a prolonged hospitalization, during which they were subjected to various diets, pharmacologic treatment, and influence of prolonged agony on the biochemistry of the blood. In reference to the problem of etiopathogenesis of atherosclerosis as a whole, we can only conclude, on the basis of our study, that the level of cholesterol does not stand in direct relation to the intensity and localization of atheroscIerotic changes. Summary
In our work we have compared the postmortem findings in material from the Forensic Institute in Cracow (persons who died suddenly from various causes) with the levels of cholesterol and the intensity and localization of atherosclerotic lesions. The total content of cholesterol in the serum was determined in 106 cases. Microscopically, examinations were made in 43 cases.The free cholesterol in atherosclerotic alterations was also investigated by the digitonin method. It was confirmed that the average level of cholesterol in individuals suffering from atherosclerosis (240 mg. per cent) is higher than that in those without atherosclerotic symptoms (20.5 mg. per cent). These differences are statistically significant only in the group of cases of advanced atherosclerosis (260 mg. per cent) and in the group of cases of sudden death from coronary sclerosis (261 mg. per cent). No significant statistical difference was found in the other groups, which differed from each other only in the degree of atherosclerotic changes. The average level of serum cholesterol in people who died from cardiac infarction (238 mg. per cent) was lower than the level of cholesterol in the whole group of persons who suffered sudden coronary death. Microscopic examinations gave no basis for binding conclusions. Also, no relationship was found between the free cholesterol in arterial walls and the total cholesterol in blood serum. The results of these examinations do not differ practically from the results obtained in analogous examinations in health and disease with atherosclerosis, conducted by
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Am. Heart I. June, I.962
and Ciba
the same methods, in the same laboratory, and in the same populations. REFERENCES Adamczyk, B., Marczynska, A., Oszacki, J., and Gedliczka, 0.: Wplyw krwotoku na zachowanie sic cholesterolu oraz poziomu sodu i chloru we krwi, Pol. Tyg. Lek. 14(1):15, 1959. Gabryelski, W., and Ciba, T.: Poziom cholesterolu calkowitego i wolnego w surowicy ludzi zdrowych z uwzglednieniem plci i wieku, Pol. Tyg. Lek. 15(12):417, 1960. Gertler, M. M., Woodburg, M. A., Gottsch, L. G., White, P. D., and Rusk, H. A.: The candidate for coronary heart disease. Discriminating power, biochemical, hereditary, and anthropometric measurements, J.A.M.A. 170:149, 1959. Gofman, J. W., Hardin, B., Lyon, T., Dingren, F., Strisower, B., Colman, D., and Herring, V.: On evolution of the lipoproteins and cholesterol measurement as predictors of clinical complications of atherosclerosis, Circulation 14:691, 1956.
5. Jaegermann, K., and Marek, Z.: Badania nad nasileniem miaidiycy w materiale sekcyjnym w latach 1900-1958. (In press.) Kritschevsky, D.: Cholesterol, New York, 1958, John Wiley & Sons, Inc. Lande and Sperry: Cited from Kritschevskye and Liebig.* Liebig, H. : Cholesterinamie und Atherosklerose. Klin. Wchnschr. 20:538. 1941. Nikkila( A., and Karlsson, K.: ‘Thyroid function and clinical coronary heart disease, Acta med. scandinav. 166:195, 1960. 10. Spain, D. M., Bradess, A. V., and Greenblatt, I. J.: Postmortem studies on coronary atherosclerosis, serum beta-lipoproteins and somatotypes, Am. J. M. SC. 229:294, 195.5. 11. Tochowicz, L., Pasyk, S., and Denikiewicz, W.: Ocena wartogci badania cholesterolu i lipemii pokarmowej w miaidiycy, Pol. Tyg. Lek.
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