Use of an anion exchange resin in treatment of two siblings with familial hypercholesterolemia

T h e J o u r n a l o[ P E D I A T R I C S

201

r

Use of an anion exchange resin in treatment of two siblings with familial bypercbolesterolem ia ChoIestyramine, an insoluble anion exchange resin which absorbs bile acids in the intestine, was given orally to two siblings with [amilial hypereholesterolemia. A 3 week course o[ 9 Gin. of the drug each day [ailed to alter the plasma cholesterol concentration. However, after a 3 week course o[ 15 Gin. daily of the drug, there was a lowering o/plasma cholesterol levels by 12 to 44 per cent o/control values. No toxic effects were noted,. This drug appears to warrant [urther trial in individuals with [amilial hypercholesterolemia.

j. M. Horan, M.D., N. R. DiLuzio, Ph.D., and J. N. Etteldorf, M.D. "x" MEMPHIS,

TENN.

T I-I E a E are many factors which influence serum cholesterol levels; among them are age, diet, exercise, and heredity. In addition, there are technical factors such as analytic method and reproducibility which enter into the-evaluation of a given cholesterol level. Although there is a borderline range for normal levels of 250 to 300 mg. per 100 ml., cholesterol values of 300 mg. per 100 ml. or above are presently accepted as being abnormally high. While not uncommon in

From the Department o[ Pediatrics (]. M. H. and J. N. E.) and the Department of Physiology (N. R. D.), College of Medicine, University o[ Tenfiessee, and Frank T. Tobey Memorial Children's Hospital, City o / M e m p h i s Hospitals. This study was supported in part by United States Public Health Service 454 C14 and United States Public Health Service HE05367. "~Address, 048 Adams Avenue, Memphis 3, Tenn.

the adult population, hypercholesterolemia is unusual in children in the absence of such diseases as nephrotic syndrome, hypothyroidism, diabetes mellitus, and liver pathology. If unexplained hypercholesterolemia is discovered in a child with a similar finding in two or more of his relatives, 1 a diagnosis of familial idiopathic hypercholesterolemia may be made. T h e serum is clear and, in contrast to familial idiopathic hyperlipemia, the triglycerides are usually normal. Familial hypercholesterolemia may exist with no associated symptoms or the patient may have xanthomas (typically tendinous) and/or atherosclerotic cardiovascular disease. The increased incidence of coronary occlusion at a young age among members of families with idiopathic hypercholesterolemia and the postulated association of coronary atherosclerosis and hypercholesterolemia in the general population lead the physician to consider methods for lowering blood cho-

2 0 2 Horan, DiLuzio, and Etteldor[

lesterol in affected individuals. T h e r e is at present no safe, effective, a n d p r a c t i c a l m e t h o d of accomplishing this end. T h e cholesterol pool of blood has been d e m o n s t r a t e d to have a r a p i d rate of exchange with the cholesterol pool of the liver.2, a T h e liver contributes endogenous cholesterol synthesized from acetate 3' 4 and exogenously derived cholesterol processed after intestinal absorption. As the dietary intake of cholesterol is decreased, endogenous cholesterol p r o d u c t i o n increases2' 6 T h e m a i n catabolic p r o d u c t s of cholesterol are bile acids (cholic a n d chenodeoxycholic) which, after c o n j u g a t i o n with t a u r i n e or glycine a n d release into the intestine, are in large p a r t reabsorbed a n d re-used for cholesterol synthesis/-a~ A substance which prevents the intestinal r e a b s o r p t i o n of bile salts to an extent which exceeds the body's ability to f o r m cholesterol, f r o m o t h e r sources m i g h t be expected to lower blood cholesterol. Cholestyramine is a n a n i o n exchange resin which is insoluble, and, therefore, unabsorbable a n d which binds bile acids in a quantitative manner. A d m i n i s t e r e d orally, it has been f o u n d nontoxic in animals 11 a n d has been used in h u m a n adults to lower blood c h o l e s t e r o l levels? T M I n two siblings, aged 11 a n d 13 years, with familial hypercholesterolemia we were unsuccessful in lowering the serum cholesterol w i t h 9 Gm. of cholestyramine daily for 3 weeks b u t with 15 Gm. of the d r u g daily we observed a decrease in cholesterol to less t h a n 300 mg. p e r 100 ml. CASE

REPORTS

Brenda D. She was born Aug. 14, 1949, after a 9 month gestation complicated by "measles" and hypertension in the last trimester. She slept a great deal as an infant and was delayed in development, noticing objects at 6 months, sitting at 9 months, and walking and talking at 2 years. She had an attack of vomiting and diarrhea at one month of age which was attributed to evaporated milk fornmla. At 6 months of age, fever, diaper rash, diarrhea, and severe weight loss occurred and lasted for about a month; the cause was not determined. She did well thereafter and was considered normal mentally and

February 1969

physically until 3 or 4 years of age when she had an unexplained episode of staggering gait which lasted 3 days. In 1955, after a preschool examination, she was referred to Baptist Hospital in Memphis because of a heart murmur and intermittently painful wrist and finger joints, and painful swelling of ankles, usually lasting from a few hours to a day. Rheumatic fever was sus. pected, but not proved. Because her father was known to have hypereholesterolemia, Brenda's serum cholesterol level was determined and observed to be elevated. She was followed in the Baptist Hospital clinic from 1955 to 1962 and her serum ch0lesterol remained consistently elevated (range 364 to 560 mg. per cent). Stle experienced upper abdominal pain and recurrent episodes of staggering gait at 7 years of age. At 8 years of age she said her eyes were painful and she was "seeing green and yellow spots:" On one occasion at the age of 7 or 8 she had hematuria and dysuria of undiagnosed origin. At 9 years of age she had several dizzy spells. At 10 years of age, while at school, she became weak and confused and feli across her desk. She was hospitalized for this episode April, 1960, and no explanation could be found. During the past 3 years she has had dizzy spells occurring at 1 to 2 month intervals, occasionally accompanied by epistaxis. Usually she lies down "a long time" and though improved, continues to feel weak and "short-winded with sighing respirations." She has fainted several times. She had had occasion~l mild chest pain. Her past history includes severe measles, mumps, and in 1956 a head injury which dazed her. She has failed two years in school because of illness but school performance is described as good. Dwight D. This boy was born Oct. 29, 1951, after an uneventful pregnancy. He was a healthy child and developed normally. He had mumps and severe measles with pneumonia at 1 year, pneumonia at 4 years of age, and a head laceration at age 5 years but no period of unconsciousness. He has complained of severe occipital headaches since 5 years of age. These occur about once a month, persist until he takes aspirin and goes to sleep; he remains asleep for 12 to 14 hours and cannot be fully awakened, then feels fine when he awakens. The headaches are currently continuing with similar frequency, severity, and duration. Because of the headaches and family history, Dwight has also been followed at Baptist Hospital since 1960; serum

Volume 64 Number 2

Exchange resin in hypercholesterolemia

P L A N OF T R E A T M E N T

cholesterol levels have ranged from 340 to 485 nag- per cent. He has had no other chronic symptoms. He is described as being slow in understanding school work and has repeated one grade. Family history. The father is of Irish-American Indian and the mother of Dutch-American Indian extraction. The father and his brother died with heart attacks and hypercholesterolernia (Fig. 1). None of the children's living siblings has hypercholesterolemia. The paternal grandmother refused to allow examination of her blood; although she, herself, has hypertension and xanthelasma, she stated that there was no heart disease in her family but that there were "many cases" among the paternal grandfather's relatives. Physical examination. During their clinic visits at Baptist Hospital no physical abnormalities were discerned. On referral to the Pediatric Department of the University of Tennessee Medical School, the children were found to be short but well proportioned, healthy appearing, and cooperative. Brenda was 58 inches tall (10 percentile) and weighed 80I~ pounds (10 to 25 percentile). Blood pressure was 98/40. She had a soft systolic murmur heard at the pulmonary area but no other remarkable findings. Dwight was 52 inches tall (3 percentile) and weighed 69~ pounds (25 to 50 percentile). Blood pressure was 90/50. The only findings noted were a few patches of elevated hair follicles on the thighs and body and a palpable liver edge 1 cm. below the right costal margin. In neither child were xanthomas found.

D. 12 DIABETE~ BELLtTU5

D. I COLITIS

0,37 HEART ATTAGKS

22

0.43 XANTHELASMA

0.5 OIPH~HERIA 2

T h e children were hospitalized, allowed free activity on the ward, and given a regular hospital diet. A record was kept of the a m o u n t of food offered and an estimate of the amount rejected was m a d e ; by means of tables of food composition, the approximate daily fat intake was determined to be q:4 per cent of the total calories for both children during the control period and 42 per cent during the drug administration. After an eight day period of observation, the children were given cholestyramine 3 capsules (0.750 Gin. each) 4 times daily for 3 weeks or a total daily dose of 9 Gin. for each child. T h e children preferred the capsules and had refused the powdered form because of taste and odor, even when mixed with fruit juice or ice cream. T h e children were studied in the hospital for q: days following the treatment period, then in the Metabolic and Endocrine OutPatient Clinic. Because the initial trial of cholestyramine could not be demonstrated to affect the blood cholesterol, the children were given a second trial a t home at a higher dose consisting of 15 Gm. daily (5 capsules 4 times daily). This dose is similar to that recommended for adults, la This was continued for 3 weeks. Weekly clinic visits permitted clinical and laboratory evaluation. T h e children were hospitalized for several

39 GALL 5TONI5

D. 2 w k s UNOE~OCVELO~O H~A~T r,

203

48 "HEART

D E P~E~ATUR

13

46 GALL

43

I0

41

3

SERUM GHOLESTEROL IN BOX H C ~ HYPERGHOLESTEROLEMIA D-DIED T G - TRIGLYGs

Fig. 1. Davis kindred: Familial hypercholesterolemia.

37

32

28

26

2 04

Horan, DiLuzio, and Etteldor[

February 1964

700. TOTAL CHOLESTEROL DWIGHT b . d BRENDA = =

600 ..J 0

,.,

500

I'(/) I.IJ -0 z 0

400

...... t*,,

J

. . . . . . ~_

300 (9

m

200 15

9 GM DALLY

IOO

GHOLESTYRAMI'NE

GHOLESTYRAMINE

TOTAL DAYS

GM DAILY

,

I

,

|

I

,

,

I

I0

20

30

40

50

70

80

90

days at the termination of cholestyramine therapy for complete evaluation. LABORATORY METHODS AND R E s Fasting blood lipid determinations were performed weekly. Plasma lipids were extracted and purified by the Folch procedure as outlined by Sperry. 1~ Phospholipid phosphorus was determined by the method of King 16 and phospholipid was calculated as lipid P times 25. Total and free cholesterol were determined by the Sperry-Webb proc e d u r e s Triglycerides were determined o n the chloroform-methanol extract by the method of Van Handel and Zilversmit. is Duplicate values agreed within 5 per cent. Serum cholesterol (Fig. 2; Table I) showed little if any effect from the 9 Gm. daily dose over a 3 week period. The lowest cholesterol levels occurred during the period when 15 Gin. was taken daily. If per cent lowering is calculated with respect to the cholesterol control level just before the second course, the weekly reductions on the drug are for Dwight, 33 per cent (145 mg.), 12 per cent (52 mg.), and 22 per cent (98 mg.); for Brenda, 32 per cent (187 mg.), 44 per cent (221 mg.), and 27 per cent (134 mg.). The widest spread of control values for Dwight was 43 mg. and for Brenda 109 mg. We think that changes in excess of 20 per cent are significant. The depression of levels appeared less marked at the end of

1

,

100 I10

Fig, 2. Plasma cholesterol levels during control and treatment periods with cholestyramine.

the treatment period but persisted for a week after treatment was stopped. Subsequent values returned t o the usual higher levels (452 and 479 mg. per cent). The effects on the other blood lipids are detailed in Table I. The phospholipids roughly paralleled the cholesterol, while free fatty acids were not altered. There was a tendency for the triglycerides to increase during treatment, but this .was no more marked during the second course than the first. CLINICAL FINDINGS DURING TREATMENT No untoward sign or symptom could be attributed to administration of the drug. There were slight daily weight variations but no consistent change. Temperature, pulse, respiration, and blood pressure while treatment was received were similar to those without treatment. During both hospitalizations, each child had what was interpreted as an intercurrent upper respiratory infection with associated symptoms unrelated to the drug. Neither child complained of abdominal discomfort or nausea while receiving cholestyramine, Stools were observed occasionally and appeared normal and with one exception were reported by the children to be normal in consistency and frequency; Brenda reported two loose brown stools on the eleventh day of the first cholestyramine period. Visual observation does not of course exclude the

Volume 64 Number 2

Exchange resin in hypercholesterolernia

possibility of steatorrhea. T h e c h i l d r e n h a d slight abdominal distention at the completion of the second course of t h e r a p y with 15 Gm. of cholestyramine daily.

LABORATORY TESTS FOR DRUG T O X I C I T Y There were two m a j o r possibilities for drug toxicity since cholestyramine is an insoluble substance, not absorbed f r o m the intestine. By decreasing r e a b s o r p t i o n of bile acids a deficit of fat soluble vitamins, of calcium, or of trace elements m i g h t result.

205

Blood carotenes, p r o t h r o m b i n times, and serum c a l c i u m a n d m a g n e s i u m were within the n o r m a l range d u r i n g both t r e a t m e n t periods. T h e blood p h o s p h a t e a n d alkaline p h o s p h a t a s e levels were n o r m a l at the end of t h e first t r e a t m e n t p e r i o d b u t were not d e t e r m i n e d at the end of the second period. X-rays of wrist a n d knee showed no change in bone density d u r i n g either course of treatment. T h e second p r o b l e m which m i g h t arise would be a h y p e r c h l o r e m i c metabolic acidosis because eholestyramine acts by chloride

Table I. Plasma lipid p a r t i t i o n d u r i n g control a n d cholestyramine t r e a t m e n t periods

Date

Free cholesterol Ester cholesterol (rag. %) (mg. %)

Triglyeerides (rag. %)

Phospholipids (mg. %)

Free fatty acids (mEq./L.)

61.1 60.9

330.0 330.0

0.975 0.528

Brenda Control period 7/6/62 7/13/62

116.2 107.3

310.9 285.3

NrstchoIestyramine treatment per~d (9 Gm. daiS) 7/20/62 7/31/62 8/3/62

98.1 83.4 94.1

312.9 327.2 333.0

61.2 74.2 120.4

345.0 313.0 333.0

0.309 0.916 0.260

-127.0 141.0

-363.0 360.0

71.8 92.9 59.0

-393.0 363.0

0.626 0.477 1.171

Control period 8/6/62 8/10/62 9/15/62

Second cholestyramine treatment period (15 Gm, daiS) 9/22/62 9/29/62 10/6/62

84.3 60.4 88.2

229.7 219.2 278.3

66.5 122.8 110.3

303.0 260.0 334.0

0.817 0.633 0.484

86.4

29t.8

53.0

233..3

0.655

124.3 123.8

340.8 328.0

64.3 38.7

397.5 312.5

1.099 0.570

Post-treatment period 10/13/62

Dwight Control period 7/6/62 7/13/62

Fi~t cholestyramine treatment period (9 Gm. daily) 368.2 7/20/62 111.1 7/27/62 8/3/62

124.3 105.0

271.7 364.0

89.5 84.2 171.3

378.0 383.0 393.0

0.336 0.644 0.172

107.0 122.0 122.0

376.0 340.0 318.0

80.1 104.3 82.0

348.0 412.0 343.0

0.460 0.102 0.984

Control period 8/6/62 8/10/62 9/15/62

Second eholestyramine treatment period (15 Gm. daiS) 9/22/62 9/29/62 10/6/62

85.5 84.0 87.5

209.1 304.0 254.1

136.2 72.5 117.2

278.0 370.0 305.5

0.826 0.745 0.909

94.9

291.8

53.0

238.3

0.867

Post-treatment period 10/13/62

206

Horan, DiLuzio, and Etteldor[

exchange. The serum sodium and potassium remained in the normal range and no essential change in carbon dioxide-combining power or p H was observed. Dwight's serum chlorides after the second course of treatment were 112 mEq. per liter but were normal after the first course. Brenda's plasma chloride levels remained normal throughout. A further study of acid-base balance is indicated in future trials. Other tests performed include electrocardiogram, total plasma protein, blood urea nitrogen, fasting glucose, complete blood count, and urinalysis. These were within normal limits throughout. A qualitative test revealed a trace of proteinuria at the end of the second treatment period which was not confirmed by the Addis count (proteins 41 and 49 mg. per 12 hours). DISCUSSION Goldsmith 19 and Bergen and Van Itallie 2~ have discussed some of the measures used in the treatment of hypercholesterolemia. The most widely used regime has been a diet restricting saturated fats and increasing unsaturated fats? ~, 22 Prior to cholestyramine therapy, our patients had a prolonged dietary trial of decreased saturated fat intake with no apparent effect on their cholesterol levels. Other agents used in therapy reported in the literature in children are corn oil, along with diet,2a, 24 triparanol,2~ sitosterol, 2G nicotinic acid, 2z thyroid extract, and thyroid analogs and estrogens; toxic reactions or lack of sustained effect have discouraged their use. Tennent and colleagues 14 in 1959 described a quaternary ammonium anion exchange resin, ( M K 135, cholestyramine, or "Cuem i d " ) , with basic groups attached to a styrene divinyl benzene copolymer skeleton by carbon-to-carbon bonds. It is a lyophilic solid with no hydrolyzable bonds. It binds bile acids in a quantitative manner and prevents their absorption from the intestine. With the use of cholestyramine in patients with incomplete biliary obstruction Van Itallie and associates 12 and Carey and Williams 18 were able to reduce serum bile acids and cholesterol and in some cases relieve the

February 196~ subjects' pruritus. Lottsfeldt and co.authors28 reported the case of an infant with partial intrahepatic biliary atresia who was given cholestyramine, 6.7 to 10 Gm. daily, with a decrease in pruritus and in serum bilirubin and bile acids. They also observed a decrease in serum cholesterol of 113 mg. per 100 ml. and of 84 mg. per 100 ml. during two treat. ment periods. I n 26 adults with various cholesterol levels studied by Bergen and associates 14 tholes. tyramine decreased serum cholesterol, more markedly in those with initially high levels. In 3 patients with familial hypercholes. terolemia there was an average reduction of 24 per cent. In 6 patients with only slight effect from 15 Gm. per day, there was a definite decrease with 30 Gm. per day. The largest decrement reported was in the first week of treatment but no "escape" from the effect occurred in a 6 week or longer period. After the drug was stopped, about half the subjects got a rebound in values of 5 to 30 per cent above the control; this did not last more than 2 weeks. Side effects occasionally mentioned were nausea, vomiting, constipation, and borborygmi. When 30 Gin. a day of cholestyramine was given to adults, steatorrhea could be produced. 29 Kelley, Lehman, and Robinson 3~ detected no effect on vitamin K absorption in dogs when a 200 mg. per kilogram dose was given but in much larger doses decreased absorption was observed. O u r patients tolerated cholestyramine in capsule form with no demonstrable subjective or objective toxicity in short-term trials. Unfortunately the children did not like the taste and smell of the powdered form. One envelope of the powder contains 3.33 Gm. anhydrous cholestyramine, equivalent to over 4 capsules (0.75 Gm. each). Use of the powder would require 4 or 5 envelopes daily in our patients. Bile acid excretion seems to be qualitatively similar in older children al and adults but we have no quantitative information about bile acid turnover in the 10 to 15 year age group. In experimental animals it has been shown by Bergstr5m and Danielsson 3'2 that removal of bile acid via a biliary fistula causes an in-

Volume 64 Number 2

crease in production of bile acids, although this may not be sustained after the first few days (Gabel and co-workers33). Beher, Baker, and Anth~ described a regulatory relationship between bile acid serum levels and cholesterol synthesis in animals. This experimental work and the rebound phenomenon reported by Tennent suggest that removal of bile acids by cholestyramine might be expected to increase liver synthesis of cholesterol in humans, at least temporarily. Our patients' family history fits the hereditary pattern suggested by other studies. Familial hypercholesterolemia is transmitted as a dominant trait. About half the offsprings with one affected parent will show hypercholesterolemia when large kindreds are studied. The presence of x a n t h o m a s and atherosclerosis seems to be related, in part, to the degree and duration of hypercholesterolemia. Orrild and Piper, 35 Wheeler, 36 and others consider the clinical picture dependent on these factors alone. Wilkinson, 37, as Adlersberg,1, 39 and others support the opposing view that the hypercholesterolemia is a single trait and that two abnormal genes are required t o permit the full clinical picture. Epstein and co-authors 4~ state that present evidence is inadequate to support either conclusion. The metabolic error in familial hyperchoIesterolemia is unknown. Deviations in cholesterol metabolism observed in some subjects do not appear to be present in others. 41, ~2 Even in normal people the factors involved in establishing a given cholesterol level are multiple and complex?, 43-4G There is some natural fluctuation in level characteristic of any individual, more marked in some than others. Normal values for children from 2 months to 20 years lie below 250 mg. per cent, with no differences between Negro and white, male and femaleW -49 In children under 20 years, familial hypercholesterolemia is usually present as a serum abnormality alone?5 As in our cases, the children come to attention because of symptomatic disease in a relative. There is a hyPerphospholipidemia but the triglycerides are usually normal.

Exchange resin in hyperchoIesterolemia

20 7

A number of authors 22' 2z, 36, 40, ~0-5~ have reported cases in which individuals under 20 years exhibit symptomatic hypercholesterolemia by the presence of xanthomas (typically tendinous) or atherosclerotic cardiovascular and valvular disease (coronary occlusion, angina pectoris, congestive heart failure, and heart murmurs). Where cardiovascular disease is present, there are usually tuberocutaneous as well as tendinous xanthomas, a greater elevation of triglycerides or total lipids than in asymptomatic cases, and often also a history suggesting hypercholesterolemia in both parents. These severe symptomatic cases may represent an overlapping of clinical entities or the operation of more than one gene or metabolic defect. It seems impossible to predict, however, when an asymptomatic hypercholesterolemic child will develop clinical manifestations. The only symptoms exhibited by our patients may well not be directly related to their hypercholesterolemia. T h e girl had joint pains in the absence of clinically detectable xanthomas; joint pains and murmurs suggestive of rheumatic fever have been described in hypercholesterolemic children with tendinous xanthomas in the literature (Rausen, 27 Carlson 2a) and attributed to local xanthomatous infiltration. The boy's headaches and the girl's dizzy spells are more severe than children usually complain of; cerebrovascular arteriosclerosis is being considered as an explanation. Low's ~5 patient had dizzy spells with aortic stenosis. SUMMARY

Two siblings with familial hypercholesterolemla were treated for 3 weeks with 9 Gin. daily of an insoluble anion exchange resin, cholestyramine, with no effect on their plasma cholesterol levels. With 15 Gin. daily there was a decrease of 12 to 44 per cent in their cholesterol levels. No toxic reactions were observed in these short periods. Cholestyramine warrants further trial in children with familial hypercholesterolemia, with careful attention to the effect on other blood lipids and on acid-base balance and to other possible sources of toxicity. For

2 08

Horan, DiLuzio, and EtteIdor[

p r a c t i c a l l o n g - t e r m t h e r a p y , a m o r e conc e n t r a t e d dosage f o r m w o u l d be a d v a n t a geous.

We wish to express our appreciation to Mrs. Donald Humphries, therapeutic dietician, John Gaston Hospital, who collected and analyzed the dietary records. Cholestyramine ("Cuemid") was supplied through the courtesy of Merck, Sharp & Dohme.

February 1964

14.

15. 16. 17.

18. REFERENCES 1. Adlersberg, D., Schaefer, L. E., and Drachman, S. R.: Incidence of hereditary hypercholesterolemia, J. Lab. & Clin. Med. 39: 237, 1952. 2. Chobanian, A. V., and Hollander, W.: Body cholesterol metabolism in man. I. Equilibration of serum and tissue cholesterol, J. Clin. Invest. 41: I"732, 1962. 3. Hellman, L., Rosenfeld, R. S., Eidinoff, M. L., Fukushima, D. K., Gallagher, T. F., Iwang, C., and Adlersberg, D.: Isotopic studies of plasma cholesterol of endogenous and exogenous origins, J. Clin. Invest. 34: 48, 1955. 4. Migicovsky, B. B.: Control of cholesterol metabolism, Adv. Int. Med. 11: 137, 1962. 5. Tomkins, G. M., Sheppard, H., and Chaikoff, I. L.: Cholesterol synthesis by the liver. III. Its regulation by ingested cholesterol, J. Biol. Chem. 201: 137, 1 9 5 3 . 6. Gould, R. G., Taylor, C. B., Hagerman, J. S., Warner, I., and Campbell, D. J.: Cholesterol metabolism. I. Effect of dietary cholesterol on the synthesis of cholesterol in dog tissue in vitro, J. Biol. Chem. 201: 519, 1953. 7. Lindstedt, S.: Turnover of cholic acid in man, Acta Physiol. scandinav. 40: 1, 1957. 8. Bergstrom, S.: Metabolism of bite acids, Fed. Proc. 20: 121, 1961. 9. Bergstrom, S.: Metabolism of bile acids, Fed. Proe. 21: 28, 1962. 10. Lindstedt, S.: Equilibration of dietary cholesterol and bile acids in man, Clin. chim. acta 7: i, 1962. 11. Tennent, D. M., Siegel, H., Zanetti, M. E., Kuron, G. W., Ott, W. H., and Wolf, F. J.: Plasma cholesterol lowering action of bile acid binding polymers in experimental animals, J. Lipid Res. 1: 469, i960. 12. Van Itallie, T. B., Hashim, S. A., Crampton, R. S., and Tennent, D. M.: Treatment of pruritus and hypercholesterolemla of primary biliary cirrhosis with cholestyramine, New England J. Med. 265: 469, i961. 13. Carey, J. B., Jr., and Williams, G.: Relief of the pruritus of jaundice with a bile acid

19. 20. 21. 22.

23.

24.

25. 26. 27.

28.

29.

30.

31. 32.

sequestering resin, J. A. M. A. 176: 432, 1961. Bergen, S. S., Jr., Van Itaitie, T. B., Tennent, D. M., and SebrelI, W. H.: Effect of an anion exchange resin on serum cholesterol in man, Proc. Soc. Exper. Biol. & Med. 102: 676, 1959. Sperry, W. M.: Glick, D., editor: b~ methods of biochemical analysis, New York, 1955, Interscience Publishers Inc., vol. 2, p. 83. King, E. J.: Colorimetric determination of phosphorus, Biochem. J. 26: 292, 1932. Sperry, W. M., and Webb, M.: A revision of the Schoenheimer-Sperry method for eholes. terol determination, J. Biol. Chem. 187: 97, 1950. Van Handel, F., and Zilversmit, D. B.: M~eromethod for the direct determination of serum triglycerides, J. Lab. & Clin. Med. 50: 152, 1957. Goldsmith, G. A.: Mechanisms by which certain pharmacologic agents lower serum cholesterol, Fed. Proc. 21: 81, 1962. Bergen, S. S., Jr., and Van Itallie, T. B.: Approaches to the treatment of hypereholesteremia, Ann. Int. Med. 58: 355, 1963. Albrink, M. S.: Triglycerides, lipoproteins and coronary artery disease, Arch. Int. Med. 109: 345, 1962. Green, J. G., Brown, H. B., Meredith, A, P., and Page, I. H.: Use of fat modified foods for serum cholesterol reduction, J. A. M. A. 183" 5, 1963. Carlson, L. A., and Sterner, G.: Essential hypercholesterolemia in two siblings. Effect of corn oil on serum lipids, Acta paediat. 49: 168, 1960. Hellman, L., Rosenfeld, R. S., InsulI, W., Jr., and Ahrens, E. H.: Regulation of plasma cholesterol levels by fecal sterol excretion, Circulation 16: 497, 1957. Van Creveld, S.: Essential familial hypercholesterolemia, Ann. Paediat. 199: 429, 1962. Levkoff, A. H., and Knode, K. T.: Treatment of familial hypereholesterolemla with a plant sterol, Pediatrics 19: 88, 1957. Rausen, A. R., and Adlersberg, D.: Idiopathic (hereditary) hyperlipemia and hypercholesteremia in children, Pediatrics 28: 276, 1961. Lottsfeldt, F. I., Krivlt, W., Aust, J. B., and Carey, J. B., Jr.: Cholestyramine therapy in intrahepatic biliary atresla: Report of a case, New England J. Med. 269: 168, 1963. Hashim, S. A., Bergen, S. S., Jr., and Van Itallie, T. B.: Experimental steatorrhea induced in man by bile acid sequestrant, Proc. Soc. Exper. Biol. & Med. 106: 173, 1961. Kelley, K. L., Lehman, E. G., Robinson, H. J.: Effect of cholestyramine, a bile acid binding polymer on vitamin K absorption in dogs, Fed. Proc. 22: 434, 1963. Encrantz, J. C., and SjSvall, J.: On the bile acids in duodenal contents of infants ~nd children, Clin. chim. acta 4: 793, 1959. BergstrSm, S., and Danielsson, H.: On the

Volume 64 Number 2

33.

34.

35.

36. 37.

38. 39.

40.

41. 42.

43.

44.

regulation of bile acid formation in the rat liver, Acta physiol, scandinav. 43: 1, 1958. Gabel, A., Cox, G., Zabor, M., Economou, S.: Bile-renal fistulae and cholesterol metabolism in dogs; New techniques and findings, SurE. Forum 11: 99, 1960. Beher, W. T., Baker, G. D., and Anthony, W. L.: Feedback control of cholesterol biosynthesis in the mouse, Proc. Soc. Exper. Biol. & Med. 109: 863, 1962. Piper, J., and Orrild, L.: Essential familial hypercholesterolemia and xanthomatosis (followup studies of 12 Danish families), Am. J. Med. 21" 34, 1956. Wheeler, E. O.: Genetic aspects of arteriosclerosis, Am. J. Med. 23: 653, I957. Wilkinson, C. F.: Essential familiM hyper~ cholesterolemia: cutaneous, metabolic and hereditary aspects, Bull. New York Acad. Med. 26: 670, 1950. Wilkinson, C. F., Hand, E. A., and Fliegelman, M. T.: Essential familial hypercholesterolemla, Ann. Int. Med. 29: 671, 1948. Schaefer, L. E., Drachman, S. R., Steinberg, A. G., and Adlersberg, D.: Genetic studies on hypercholesterolemia: frequency in a hospital population and in families of hypercholesteremie index patients, Am. Heart J. 46: 99, 1953. Epstein, F. H., Block, W. D., Hand, E. A., and Francis, T., Jr.: Familial hypereholesterolemia, xanthomatosis and coronary heart disease, Am. J. Med. 26- 39, 1959. Engelberg, H.: Mechanisms underlying hypereholesterolemia and hypertriglyeeridemia, Dis. Chest 42: 119, 1962. Lindstedt, S., and Ahrens, E. H., Jr.: Conversion of cholesterol to bile acids in man, Proc. Soc. Exper. Biol. & Med. 108: 286, 1961. Wolf, S., McCabe, W. R., Yamamoto, J., Adsett, C. A., and Sehottstaedt, W. W.: Changes in serum lipids in relation to emotional stress during rigid control of diet and exercise, Circulation 26: 379, 1962. Shapiro, W., Estes, E. H., Jr., and Hilder-

Exchange resin in hypercholesterolemia

45.

46.

47.

48.

49.

50.

51.

52.

53. 54.

55.

209

man, H. L.: Diurnal variability of serum cholesterol at normal and reduced levels, J. Lab. & Clin. Med. 54: 213, 1959. Thomas, C. B., Hollies , H. W. D., Eisenberg, F. F.: Observations on seasonal variations in total serum cholesterol level among healthy prisoners, Ann. Int. Med. 54: 413, 1961. Peterson, J. E., Keith, R. A., and Wilcox, A. A.: Hourly changes in serum cholesterol concentration. Effects of the anticipation of stress, Circulation 25: 798, 1962. Haines, C. G., and Greenberg, B. G.: A comparative study of serum cholesterol levels in school children and their possible relation to atherosclerosis, Am. J. Public Health 51: 374, 1961. Hodges, R. G., Sperry, W. M., and Anderson, D. H.: Serum cholesterol values for infants and children, Am. J. Dis. Child. 65: 858, 1943. Adlersberg, D., Schaefer, L. E., Steinberg, A. G., and Wang, C. I.: Age, sex, serum lipids and coronary atherosclerosls, J. A. M. A, 162: 619, 1956. Sansone, G., Baruffaldi, O., and Romano, C.: Essential familial hypercholesterolemia with tendino-eutaneous and cardiovascular xanthomatosls, Ann. Pediat. 195: 35, 1960. MeCleary, J. E., Brunsting, L. A., and Kennedy, R. L. J.: Primary xanthoma tuberosum in children with classification of xanthomas, Pediatrics 23: 67, 1959. Maher, J. A., Epstein, F. H., and Hand, E. A.: Xanthomatosis and coronary heart disease--Necropsy studies of 2 affected siblings, A. M. A. Arch. Int. Med. 102: 437, 1958. Rigdon, R. H., and Willeford, G.: Sudden death during childhood with xanthoma tuberosum, J. A. M. A. 142: 1268, 1950. Cook, C. D., Smith, H. L., Giesen, C, W., and Berdez, G. L.: Xanthoma tuberosum aortic stenosis, coronary sclerosis and angina pectoris, Am. J. Dis. Child. 73: 326, 1947. Low, R. C.: Xanthoma tuberosum multiplex with lesions in the heart and tendon sheaths, Brit. J. Dermal. 22: 109, 1910.