Secondary Type II Hyperlipoproteinemia in Patients With Anorexia Nervosa R. Mordosini, G. Klose, and H. Greten In 18 patients with anorexia nervosa, plasma cholesterol and triglyceride concentrations were repeatedly determined over a period of 14 mo. In 11 patients elevated cholesterol concentrations were found which were due to an increase of low-density lipoprotein cholesterol, whereas high-density lipoprotein and very low density lipoprotein cholesterol levels were in the normal range. The elevated cholesterol values did not correlate with clinical and laboratory parameters such as the degree of weight loss and thyroid
function tests. In follow-up studies it could be shown that in patients who regained their original weight, elevated plasma cholesterol concentrations fell to normal levels parallel to weight increase. In patients who showed no change in weight, however, cholesterol levels remained high. The cause for this secondary type II hyperlipoproteinemia in anorexia nervosa is not known. Hepatic triglyceride lipase and lipoprotein lipase activities in postheparin plasma were found to be low despite normal triglyceride concentrations.
D
URING THE PAST FEW YEARS, numerous studies on the metabolic changes in anorexia nervosa have been reported. Considerable weight loss, amenorrhea, hypotension, hypothermia, bradycardia, severe constipation, and low basal metabolic rate suggest an endocrine disorder in this complex striking changes in endocrine psychiatric disease. 3’-33*38In several studies, parameters were reported, especially low luteinizing hormone, follicle-stimulating hormone, and plasma growth hormone secretion. 1,4,10.12sl3.243 an addition, several authors found low or decreased serum triiodothyrodine (T3) and low serum thyroxine (T4) concentrations in patients with anorexia nervosa.‘0.27.28J0 Also reported were leukopenia in a large number of patients, electrocardiographic changes, disorders in intestine motility, and pathologic intestinal resorption.6*7q37 Klinefelter, in 1965, was the first to indicate increased cholesterol concentrations in the sera of patients with anorexia nervosa.” This finding was later confirmed by several authors. R*2g*38 Mainly nutritional factors7*’ or changes in cholesterol and bile acid turnover32 are discussed as causes of this metabolic disorder. The purpose of this study was to investigate the frequency, degree, and nature of lipid disorders in anorexia nervosa. Until now, no lipoprotein analyses in this disease had been performed. A number of recent reports reinforce the importance of accurate measurement of cu-lipoprotein cholesterol and B-lipoprotein cholesterol,26 as it has been realized that low levels of o-cholesterol and From the Klinisches Institut fir Herrinfarktforschung an der Medizinischen Universitiitsklinik Heidelberg, Heidelberg, Germany. Received for publication March 18, 1977. Supported by grants from the Schweizerischer Nationalfonds and the Deutsche Forschungsgemeinschaft (Sonderforschungsbereich 90. Cardiovasculiires System). Reprint requests should be addressed tq Dr. R. Mordasini, Klinisches lnstitut J&r Herzinfarktforschung an der Medizinisehen Universitiitsklinik Heidelberg. Bergheimer Str. 58, D-6900 Heidelberg. Germany. 0 I978 by Grune & Stratton, Inc. ISSN 0026-0495.0026-0495/78/2701-0009$0~.00/0
Met&Am,
Vol. 27, No. 1 (January), 1978
71
164.5
23.6
53.2
34.6
(kg)
Weight
LDL, low-density
162.8
(cm)
Height
22
(yr)
‘Abbreviotionr:
(n = 15)
(n=lB) Controls
Patients
subiws
Age
lipoprotein;
ml)
Serum
176zk34
348zt29
(ILJ)
Plasma Plasma
lOOzt24
194 l 19
Plasma
194 f
274 f
28
36
(mg/lOOml)
Phospholipids
LDL
115+14
lB5zt36
Chol
(m9/100
Chol, cholesterol; TG, triglycerides.
119*41
(mg/lOOml)
Triglycerides
265~34
(mg/lOOml)
Cholesterol
density lipoprotein;
Amylose
VLDL, very low
1.44+0.24
88zt20 lipoprotein;
1.15ztO.30
T3 @g/ml)
81 ztl8
(r$ml)
HDL, high-density
7.3ztO.6
82 zt8
(g/loo
6.6ztO.7
ml)
Total Protein
6
80 f
(mg/lOO
Blood Sugar
Fasting
Table 1. Clinical and labomtory Data of Patients With Anorexia Nervosa and Controls
19&7
24k8
TG
ml)
42&t
40+8
Chol
TG
ml)
16zt5
14+7
HDL (mg/lOO
VLDL
25zt6
3919
Chol
ml) TG
65+15
76~18
(mg/lOO
SECONDARY
TYPE
73
II HYPERLlPOPROTElNEMlA
elevated &cholesterol concentrations are associated with premature atherosclerosis. Thus, it was of special interest to investigate the distribution of the increased cholesterol concentration among the individual lipoprotein classes in patients with anorexia nervosa. These results were correlated with other endocrinologic and metabolic parameters. MATERIALS
AND METHODS
Patients The patients studied were 18 females with a mean age of 22 (16-36) yr. The average duration of the disease was 28 (1649) mo. The main clinical and laboratory parameters are summarized in Table 1. Mean weight loss was 14.8 (7.3-24.2) kg. Only patients who had had amenorrhea for at least 12 mo were considered in this study. The diagnosis of anorexia nervosa was in each case confirmed by psychiatric examination. Nine patients who showed only minimal changes in the manifestation of the disease during the observation period were regularly examined at intervals of 6-8 wk for a period of 14 mo. Five patients who were clinically defined as “cured” were examined again after 14-25 mo under hospitalization. One of these patients had born a healthy child in the meantime; the others had reached their normal weight, and in some menstruation had started again. A group of I5 healthy female subjects of comparable age served as controls. A summary of the main clinical and laboratory data of this control group is given in Table I.
Methods Cholesterol and triglycerides were determined as previously described;37 phospholipids were determined as described by Lowry et al.23 and Bloor.3 Lipoprotein electrophoresis on agaroseagar was performed as described by Greten et al.14 Plasma obtained from the patients or normal subjects who had fasted overnight was collected in O.Ol’AEDTA and stored at 4°C. Fractionations were begun within 48 hr of collections. Standard sequential preparative ultracentrifugation of the plasma was performed in a Spinco model L2 65B ultracentrifuge using a type Ti 50 rotor at densities of 1.006, 1.019, 1.063, and 1.21 g/ml. I6 Other blood tests were performed according to standard laboratory techniques. Lipoprotein lipase (LPL) and hepatic triglyceride lipase (H-TGL) were performed as described by Greten et al.‘s An immunochemical method was used for selective measurement of these two enzymes in postheparin plasma. All blood samples were drawn 10 min after intravenous injection of heparin, at 60 U/kg body weight in tubes containing a final EDTA concentration of 0.01%. Blood was immediately centrifuged at 4°C and plasma was removed. Enzyme determinations were performed within 48 hr. RESULTS
The results of the lipid determinations in whole serum and after isolation of the individual lipoprotein fractions by ultracentrifugation are summarized in Table 1. As compared to the control group, cholesterol and phospholipid levels in the patients under investigation were significantly increased (Fig. 1). Plasma triglyceride concentrations were also higher than those of the control group; this difference, however, was only small and not statistically significant. The most obvious difference was in cholesterol levels. The mean serum cholesterol concentration in patients with anorexia nervosa was 265 mg/lOO ml, a value that is not only markedly increased as compared to a mean of 194 mg/lOO ml in the control group, but is also above the upper normal limit of approximately 230 mg/lOO ml. Phospholipid concentrations were in the upper normal range. The increase in total cholesterol was due to an increase of the cholesterol transported in the low-density lipoproteins (LDL), the &lipoproteins. Cholesterol concentrations in the high-density lipoproteins as well as in the very low density
MORDASINI,
74
KLOSE,
AND GRETEN
CKXESTEROL
300
7
,200 ii P 100
0 P LDL
NS
~OLxw5
150
I 7
IO0 F
50
a P awO5
P