Low Cholesterol Group Research Articles

The possible association of decreased total cholesterol and severity of disease in elderly hospitalized patients

The object of our study was to determine if any association exists between low serum cholesterol (<4.14 mmol/l) and adverse outcomes in elderly patients >60 years. Patients with low serum cholesterol were compared to a patient population with high serum cholesterol (>6.22 mmol/l) and normal cholesterol (≥4.14 to ≤6.22 mmol/l). Only hospitalized patients >60 years, who were not on cholesterol lowering drugs, and did not have cardiovascular or liver disease were included in this study. The study group was 157 patients (79 with low, 78 with high, and 23 with normal cholesterol concentrations). Using the Kruskal–Wallis tests, the low cholesterol group was found to have statistically (p<0.05) longer length of stay (average difference of >11.1 days), higher hospital re-admission rate over a 1-year period (average difference of >0.4 re-admissions), greater use of acute care services (average difference of >0.6 days), and more emergency room (ER) visits over 1 year (average difference of >0.5 admissions).

MRI of rabbit atherosclerosis in response to dietary cholesterol lowering.

Direct imaging of the atherosclerotic plaque, rather than the angiographic lumen, may provide greater insight into the response of atherosclerosis to cholesterol-lowering therapy. Aortic plaque was studied in vivo by MRI in rabbits undergoing dietary cholesterol intervention. Thirty-one rabbits underwent aortic balloon injury and high-cholesterol diet for 4 months and then were assigned to low-cholesterol versus continued high-cholesterol diet for up to an additional 16 months. High-resolution (310 micrometer) fast spin-echo MRI of the abdominal aorta was performed at 4, 12, and 20 months and compared with histology. MRI demonstrated a significant reduction in % area stenosis in rabbits placed on low-cholesterol diet (44.6+/-2. 1% at 20 months versus 55.8+/-1.5% at 4 months, P=0.0002). In contrast, % area stenosis increased in rabbits maintained on high-cholesterol diet (69.8+/-3.8% at 20 months versus 55.8+/-1.5% at 4 months, P=0.001). Similarly, plaque thickness decreased significantly in the low-cholesterol group (0.60+/-0.05 mm at 20 months versus 0.85+/-0.06 mm at 4 months, P=0.006), with a trend toward increase in the high-cholesterol group (1.02+/-0.08 mm at 20 months versus 0.85+/-0.06 mm at 4 months, P=0.1). Thus, in rabbits undergoing dietary cholesterol lowering, MRI detected regression of aortic atherosclerotic plaque in vivo. Plaque progression was seen with maintenance of high-cholesterol diet. MRI is a promising noninvasive technology for directly imaging atherosclerosis and its response to therapeutic interventions.

Immune System Differences in Men with Hypo- or Hypercholesterolemia

Substantial epidemiologic evidence indicates that relative hypocholesterolemia in apparently healthy individuals is associated with increased subsequent mortality from cancer and other nonatherosclerotic causes of death. To test a hypothesis potentially underlying these unexplained associations, we evaluated whether individuals with hypo- and hypercholesterolemia differ in various enumerative and functional indices of the immune system. Nineteen healthy adult men with a mean age of 46 years and a mean total cholesterol concentration of 151 mg/dl constituted a low cholesterol group and were compared with 39 men of a similar age whose total cholesterol averaged 261 mg/dl. Relative to the high cholesterol group, hypocholesterolemic men had significantly fewer circulating lymphocytes, fewer total T cells, and fewer CD8+cells (P's < 0.05). Trends toward fewer CD4+cells and less IL-2 release in response to PHA were also noted in the low, compared to the high, cholesterol group. The low and high cholesterol groups did not differ in number of B lymphocytes, level of PHA-induced proliferation, number of natural killer (NK) cells, or degree of NK cytotoxicity. These data provide preliminary evidence of immune system differences in healthy individuals with hypo- and hypercholesterolemia.

Serum Total Antioxidant Activity in Relative Hypo- and Hypercholesterolemia

Individuals with low serum cholesterol experience greater than expected age-adjusted mortality from non-atherosclerotic diseases, including cancer, respiratory and digestive illnesses, but the basis for these associations remains unclear. The current investigation considered the hypothesis that hypocholesterolemia is associated with reduced antioxidant reserve. Serum total antioxidant activity as well as concentrations of vitamin E, vitamin C, and thiols were compared in two groups of 24 subjects distinct in both mean low density lipoprotein (LDL) cholesterol (2.3 v. 4.9 mM) and mean total cholesterol (4.3 v. 7.0 mM). The low and high cholesterol groups were equivalent in gender mix, age, weight, and serum total protein. Results reveal that compared with the high group, the low cholesterol group had decreased total serum antioxidant activity (p < .05). Thiol concentrations were also lower in the low cholesterol group (p < .05). Group differences in serum total antioxidant activity and thiol concentration were larger among men than women. The two groups did not differ in vitamin C. Low cholesterol was associated with reduced absolute vitamin E levels, although the tocopherol: cholesterol ratio was the same in low and high cholesterol individuals. These data indicate that hypocholesterolemia may be associated with low serum antioxidant reserve, possibly increasing susceptibility to oxidative stress.

Plasma low density lipoprotein cholesterol concentration in cynomolgus monkeys; Differing effects of age and body weight in animals consuming low and high cholesterol diets

It has been reported in cross-sectional studies that plasma cholesterol concentration does not increase with age in nonhuman primates who consume a cholesterol-free diet over their lifetimes. However, dietary composition and body weight may confound any change in plasma cholesterol concentration during aging, as is the case in humans in industrialized societies. To determine if the relationship between age and plasma cholesterol concentration is affected by dietary cholesterol and body weight in nonhuman primates, we compared post-pubertal male cynomolgus monkeys consuming low cholesterol (0.04 mg cholesterol/kcal; n = 10) and high cholesterol (0.39 mg cholesterol/kcal: n = 21) diets. A univariate repeated measures analysis of covariance of low density lipoprotein (LDL) cholesterol concentration was performed from a longitudinal data set (monkeys aged 5 to 20 years), containing an average of 34 observations per animal. The interaction of age and body weight on LDL cholesterol concentration differed among the two dietary groups. In monkeys consuming the low cholesterol diet, an increase in age was associated with a small increase in mean LDL cholesterol concentration. This effect of age increased with increasing body weight. Monkeys on the high cholesterol diet had higher mean LDL concentration, but showed no significant effect of aging on concentration. Instead, at all ages, LDL concentration was strongly affected (positively) by body weight in this group. A qualitatively similar (but quantitatively smaller) effect of body weight was observed only at older ages in the low dietary cholesterol group. We conclude that the associations of LDL concentration with age and body weight in cynomolgus monkeys are strongly influenced by dietary cholesterol. The similarity of the interaction of age and body weight on LDL cholesterol concentration in older monkeys consuming 0.04 mg/kcal/day to those in older humans of industrial societies suggests that such animals may provide a useful experimental model of the effects of aging and weight on LDL metabolism.

Effects of stent design and serum cholesterol level on the restenosis rate in atherosclerotic rabbits

We investigated the effect of serum cholesterol level and stent design on the restenosis rate within the stent after balloon angioplasty and stent implantation using atherosclerotic rabbits. Two types of nicket/titanium stents with gaps (open stent) and without gaps (closed stent) between the wire coils were implanted into the aorta of the rabbits 10 weeks after atherosclerosis had been induced using a standard high cholesterol diet and balloon abrasion. Each rabbit had an open stent and a closed stent implanted into the infrarenal abdominal aorta. Between these two stents a control segment of the aorta was treated with angioplasty alone. The animals were divided into two groups according to the diet protocol as follows: in group I ( n = 9) a high cholesterol diet was stopped after stent implantation; in group II ( n = 10) a high cholesterol diet was maintained after stent implantation. Digital subtraction angiograms were obtained every 4 weeks for up to 24 weeks and the narrowest diameter of the arterial segments within each stent and in the segment between stents was measured. The diameter narrowing within the closed stent was greater in the high cholesterol group compared with the low cholesterol group: 12 weeks (2.57 ± 0.09 mm in group I vs 2.14 ± 0.15 mm in group II, mean ± S.E., p < 0.05); 16 weeks (2.55 ± 0.09 mm vs 2.14 ± 0.12 mm, p < 0.05); 20 weeks (2.59 ± 0.06 mm vs 1.98 ± 0.12 mm, p < 0.01); and 24 weeks (2.45 ± 0.11 mm vs 2.01 ± 0.11 mm, p < 0.05). No significant differences in the narrowest diameter of the arterial segments were observed between high and low cholesterol groups in the angioplasty alone areas or within the open stents. There was a significant difference in the narrowest diameter between stents with versus those without gaps (at 12, 16, and 20 weeks poststenting in group I and at 4, 8, 12, 16, 20, and 24 weeks in group II). Thus the stent with the least metal is correlated with less stenosis and intimal hyperplasia. From these data we conclude that both stent deign and serum cholesterol are important factors for restenosis after stent implantation.

Effect of soy protein diet versus standard low fat, low cholesterol diet on lipid and lipoprotein levels in children with familial or polygenic hypercholesterolemia

The effect on serum lipid and lipoprotein levels of a standard low fat, low cholesterol diet was compared with that of a soy protein-substituted low fat, low cholesterol diet in 23 children with familial or polygenic hypercholesterolemia: 12 boys and 11 girls (mean age, 9.3 +/- 4.5 years) were included in this outpatient program. Group 1 received the soy protein diet for 8 weeks; group 2 received the low fat, low cholesterol diet. After an interruption of 8 weeks, each group was placed on the alternate regimen. Fasting blood samples were collected at the beginning of each dietary period. During the soy protein diet, the levels of total cholesterol decreased by 16% in group 1 and 18% in group 2, and low-density lipoprotein cholesterol (LDL-C) levels decreased about 22% in group 1 and 25% in group 2. During the standard low fat, low cholesterol diet, total cholesterol and LDL-C levels were reduced by 8% and 7% in group 1 and by 12% and 13%, respectively, in group 2. The effect on LDL-C was significantly greater (p < 0.05) in the soy protein group than in the low fat, low cholesterol group. We conclude that a diet substituting soy protein for animal protein has a more beneficial short-term effect on total cholesterol and LDL-C levels in children with hypercholesterolemia than a standard low fat diet.

Morbidity and mortality in rural community-dwelling elderly with low total serum cholesterol.

Low serum cholesterol has been associated with morbidity and mortality in the elderly. This study compared the health, functional status, and two-year mortality rates of community-dwelling rural elderly with serum cholesterol < 150 mg/dl to age- and sex-matched controls with serum cholesterol 200-240 mg/dl. Self-reported disease history, disability, health habits, and cognitive function data were collected at a health risk appraisal interview. A single blood sample was also collected and analyzed for total serum cholesterol at a central lab. Of the 3,874 participants, 109 (2.8%) had total cholesterol levels < 150 mg/dl. Seventy-five percent of the low cholesterol group were male compared to 44% in the main study population. The low cholesterol group had significantly greater smoking history, current cigarettes smoked, diabetes history, angina and COPD symptoms, and assistance needed for heavy and light work. Men in the low cholesterol group had significantly lower blood pressure. After two years, 14 (12.8%) of the low cholesterol group had died vs 16 (7.3%) in the control group. There was no relationship to specific causes of death and cholesterol level. A very low cholesterol level in older individuals should be evaluated carefully to determine whether it is due to genetic or life-style factors such as diet or, more likely, is a marker of disease.

Normal genetic variation at the low density lipoprotein receptor (LDLR) locus influences cholesterol levels in children

The population of Czechoslovakia is at high risk of premature atherosclerosis. Normal DNA polymorphism at the low density lipoprotein receptor (LDLR) locus detectable with the restriction enzyme PvuII was analyzed in Czech children with a high or a low concentration of total serum cholesterol. The PvuII restriction site was found significantly more often in the low cholesterol group than in the high cholesterol group. Thus, normal genetic variation at the LDLR locus contributes to the population variation in cholesterol in children in the population studied.

Dependence on dietary cholesterol for n-3 polyunsaturated fatty acid-induced changes in plasma cholesterol in the Syrian hamster.

Male Syrian hamsters consumed diets containing incremental increases in dietary n-3 fatty acids from fish oil with either low (0.015% w/w) or moderate (0.1% w/w) dietary cholesterol content. Animals consuming diets containing moderate cholesterol, but not animals consuming diets containing low cholesterol, had increased plasma very low (VLDL)- and low density lipoprotein (LDL)-cholesterol levels with increasing fish oil consumption. The plasma concentration of high density lipoprotein (HDL)-cholesterol decreased by 43 and 32% with the consumption of the highest fish oil diets in the low and moderate dietary cholesterol groups, respectively. Hepatic LDL-receptor binding activity did not change with the consumption of low cholesterol diets, but gradually decreased with fish oil consumption in animals consuming the moderate cholesterol diets. Hepatic LDL-receptor binding and plasma LDL-cholesterol levels of the different dietary fish oil groups were highly correlated (r = -0.91). Fish oil consumption also caused an increase in hepatic free cholesterol but a decreased cholesteryl ester content. Therefore, in the Syrian hamster, the consumption of n-3 fatty acids increases LDL-cholesterol levels which can be partially explained by decreased hepatic LDL-receptor binding and this response to dietary n-3 fatty acids is dependent on the dietary cholesterol content. However, the effects of dietary n-3 fatty acids on HDL-cholesterol are independent of dietary cholesterol content.

One measurement of serum total cholesterol is enough to predict future levels in healthy postmenopausal women

purpose: The purpose of this study was to investigate how well a single or double measurement of serum total cholesterol represents the spontaneous, future level in a particular person. subjects and methods: The spontaneous fluctuations in serum total cholesterol levels in 169 healthy early postmenopausal women were followed during the course of 12 years. Serum total cholesterol was measured enzymatically. results: The initial measurement and the long-term level of serum total cholesterol were highly related (p <0.0001). The long-term level (calculated for each woman as the area under the curve of serum total cholesterol versus time) was not statistically significantly different from the initial level (mean difference: 0.036 ± 0.046 mmol/L [mean ± SEM], NS). The initial serum total cholesterol level was then used to classify each woman into a high or a low cholesterol group, according to the current recommendations. The predictive value of an initial total cholesterol value in the high level (greater than or equal to 6.2 mmol/L) group was 84%, when compared with the long-term level. The predictive value of an initial total cholesterol level below 6.2 mmol/L was 80%. No improvement in these parameters was found when the average of the initial two (or three, when the difference exceeded 0.9 mmol/L) measurements were used as the baseline value. The fluctuations in serum total cholesterol levels were mainly due to short-term variations. conclusion: For screening purposes, one measurement of serum total cholesterol in a woman gives a good estimate of the long-term level. The current data indicate that repeated measurements of serum total cholesterol do not improve the predictability of future cholesterol levels. The data also suggest that, at least in postmenopausal women with an elevated level of serum total cholesterol, one should proceed immediately to lipoprotein analysis for further risk assessment.

Frequency of low serum high-density lipoprotein cholesterol levels in hospitalized patients with “desirable” total cholesterol levels

Because the National Cholesterol Education Program guidelines suggest that levels of total serum cholesterol < 5.17 mmol/liter (200 mg/dl) are “desirable,” we performed a retrospective observational analysis to determine the prevalence of coronary artery disease (CAD) in patients with total cholesterol < 5.17 mmol/liter (200 mg/dl) and the prevalence of total cholesterol< 5.17 mmol/liter (200 mg/dl) in patients with CAD by angiography. Cholesterol levels < 5.17 mmol/liter (200 mg/dl) were found in 1,084 of 2,535 patients (42%) having cholesterol measured on hospital admission; 690 of these 1,084 (64%) had CAD. These patients were mostly men, had a family history of premature CAD, and 60% (414 of 690) had high-density lipoprotein (HDL) cholesterol < 0.90 mmol/liter (35 mg/dl). In a separate group of patients defined from the same admission population but having angiographically established CAD, 32% (424 of 1, 197) had a total cholesterol < 5.17 mmol/liter (200 mg/dl), 59% of whom (252 of 424) had HDL < 0.90 mmol/liter (35 mg/dl). An analysis of persons admitted electively for angiography (to exclude any effects of hospitalization per se on serum lipids) revealed a similar proportion of persons with total cholesterol < 5.17 mmol/liter (200 mg/dl) (35%), CAD (82%), and HDL < 0.90 mmol/liter (35 mg/dl). Our observations suggest that low serum cholesterol levels (< 5.17 mmol/liter [200 mg/dl]) are seen frequently in patients suspected of having or who have established CAD; moreover, a false sense of security may be established among physician and patient with the finding of a serum cholesterol level < 5.17 mmol/liter (200 mg/dl) — men with a family history of premature CAD and low levels of HDL characterize persons with CAD in this low cholesterol group.

Effect of Cholesterol Deprivation on Piglet Small Intestine and Serum Lipids

SummaryUsing the neonatal piglet, the effects of dietary cholesterol deprivation on growth, intestinal enzyme activity, intestinal and hepatic 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase (HMG‐CoA reductase), and serum lipid were studied. Six litters of piglets were randomly assigned to one of two feeding regimens: restricted (800 ml of formula//24 h) versus unrestricted (1,200 ml of formula/24 h). Within litters, piglets were separated by sex, then randomly assigned to a formula containing low cholesterol (&lt;2 mg/dl) or high cholesterol (145 mg/dl). Piglets were fed for 2 weeks. Male piglets in the restricted low cholesterol group gained significantly less weight per milliliter of formula than the restricted high cholesterol males. No effect was observed in the females. Microvillus membrane lactase activity was greater in males fed a high versus low cholesterol diet. Intestinal and hepatic HMG‐CoA reductase activities and serum lipid profiles showed a trend toward compensation for dietary cholesterol deprivation but did not differ statistically between the cholesterol‐fed versus ‐deprived groups. It is concluded that dietary cholesterol deprivation in the male neonatal pig causes alterations in growth, but no other statistically significant responses were detectable in this study

Effect of Cholesterol Deprivation on Piglet Small Intestine and Serum Lipids

Using the neonatal piglet, the effects of dietary cholesterol deprivation on growth, intestinal enzyme activity, intestinal and hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), and serum lipid were studied. Six litters of piglets were randomly assigned to one of two feeding regimens: restricted (800 ml of formula/24 h) versus unrestricted (1,200 ml of formula/24 h). Within litters, piglets were separated by sex, then randomly assigned to a formula containing low cholesterol (less than 2 mg/dl) or high cholesterol (145 mg/dl). Piglets were fed for 2 weeks. Male piglets in the restricted low cholesterol group gained significantly less weight per milliliter of formula than the restricted high cholesterol males. No effect was observed in the females. Microvillus membrane lactase activity was greater in males fed a high versus low cholesterol diet. Intestinal and hepatic HMG-CoA reductase activities and serum lipid profiles showed a trend toward compensation for dietary cholesterol deprivation but did not differ statistically between the cholesterol-fed versus -deprived groups. It is concluded that dietary cholesterol deprivation in the male neonatal pig causes alterations in growth, but no other statistically significant responses were detectable in this study.

Lipogenic potential in liver of the preweanling rat: influence of dietary cholesterol.

We examined the effect of a lower dietary cholesterol load on hepatic lipogenic capacity and plasma cholesterol concentrations during the normal suckling period in artificially reared preweanling rats. The artificially reared rats were fed a milk formula that contained low or normal concentrations of cholesterol during the period from the 5th to 17th day after birth. The activities of HMG-CoA synthase and HMG-CoA reductase in livers of 17-day-old rat pups reared on the low-cholesterol diet were enhanced three- to five-fold over those observed in the age-matched rats in the normal cholesterol and mother-reared control groups. The concentration of cholesterol in plasma of rats reared on the low-cholesterol milk was about 20% lower than that for mother-reared controls. In contrast, rats reared on milk with normal cholesterol content exhibited plasma cholesterol levels about 25 and 50% higher than the mother-reared and low cholesterol groups, respectively. The long-term metabolic consequences of rearing rats on milk formulations without adequate cholesterol remains to be determined.

Significance of hepatic triglyceride lipase activity in the regulation of serum high density lipoproteins in type II diabetes mellitus.

We investigated the regulation of serum high density lipoprotein (HDL) cholesterol metabolism in patients with type II diabetes mellitus by determining the activities of the two lipolytic enzymes that play major roles in the production and degradation of HDL. The activity of lipoprotein lipase (LPL), the enzyme responsible for HDL cholesterol production, and the activity of hepatic triglyceride lipase (HTGL), the enzyme that facilitates the catabolism of HDL, were measured in plasma obtained after iv injection of heparin. Thirty patients were selected to represent a wide range of serum HDL cholesterol concentrations (low, normal, and high HDL cholesterol groups). Mean lipoprotein lipase activity was similar in all three groups [122 +/- 10 (SEM) U/mL in the low HDL, 141 +/- 11 U/mL in the normal HDL, and 148 +/- 30 U/mL in the high HDL group]. Mean HTGL activity was markedly decreased in the high HDL group; the mean values were 346 +/- 28 U/mL in the low HDL, 320 +/- 25 U/mL in the normal HDL, and 191 +/- 23 U/mL in the high HDL groups, respectively. Body weight and insulin requirement correlated directly with HTGL activity and inversely with serum HDL cholesterol levels. These findings suggest that in type II diabetes mellitus low serum HDL cholesterol levels may be due to an increased rate of clearance by HTGL.

Is there a relationship between hypercholesterolaemia and noise-induced hearing loss?

Many investigators who have analysed the possible correlation between hearing loss and high serum cholesterol levels have found that hearing appears to be influenced by high blood lipids. Noise, as is well known, also influences hearing, particularly at high frequencies. It increases serum cholesterol levels during short-term experiments. The present investigation addresses the question of a possibly increased ototraumatic influence by the combination of high serum cholesterol levels and occupational noise exposure. Seventy-eight 50-year-old men with high serum cholesterol levels from a WHO study were compared with 75 50-year-old men who were randomly selected from the same WHO material. Group mean audiograms showed that hearing was similar in both groups, with a moderate high frequency hearing loss having a configuration suggestive of a noise-induced hearing loss. Analysis of the individual histories and the pure-tone audiograms showed that noise was the most predominant factor influencing hearing at any specific frequency or combination of frequencies. There was a statistically significant tendency for the high-cholesterol group that had suffered the most noise exposure, to have a high-frequency hearing loss. There was also a tendency for the low-cholesterol group to have a high-frequency loss if they had been excessively exposed to occupational noise. No further correlations were found. The present results indicate a slightly increased risk of acquiring a high-frequency sensorineural hearing loss for people who work in noisy environments and have high serum cholesterol levels.

Effect of dietary modification on the uptake of glucose, fatty acids, and alcohols in diabetic rats

Nutrient uptake (Jd) is enhanced in diabetes mellitus (DM) in the rat; these studies were undertaken to determine the effect of 2 wk dietary modification on the Jd of fatty acids, fatty alcohols, and glucose. In control (C) rats, fatty acid Jd was lowest with the low essential fatty acid diet, but the incremental change in free energy (∫ΔFw➙ℓ) was not affected by the other diets; in DM ∫ΔFw➙ℓ was lower with the low cholesterol or high carbohydrate diets, and higher with the high cholesterol diet. The effective resistance of the intestinal unstirred layer was assessed from the Jd of lauryl alcohol. In C intestinal unstirred layer was lowest in the high carbohydrate group and highest in the low cholesterol group; intestinal unstirred layer was less in DM than in C only in the rats fed the low cholesterol diet. In C, varying the protein content of the diet was associated with a rise in the value of the maximal transport rate and the Michaelis constant, but a decline in the passive permeability coefficient for glucose. Glucose Jd was increased in DM rats fed a high carbohydrate or a high cholesterol diet; the values of the Kms were similar in DM and C, but the maximal transport rates were higher in the DM than in the C and these values were influenced by dietary modifications. Thus short-term dietary modification influences intestinal unstirred layer, ∫ΔFw➙ℓ, and the kinetic constants for Jd of glucose in control and diabetic rats.

Nutrition survey of Finnish rural children. IV. Serum cholesterol values in relation to dietary variables

In connection with a survey of child nutrition in Finland a study was carried out on the serum cholesterol concentration in childhood and its relationship to dietary and other variables. The material consisted of 1496 children ages 5,9, and 13 years from 14 local districts in Finland. Total cholesterol was determined from nonfasted venous serum samples by a modification of the p-toluenesulfonic acid reaction. Food consumption was investigated by the 24-hr recall method and nutrient intakes determined from these results using food composition tables. For analysis, children in each age group were classified into low, medium, and high cholesterol groups. The serum cholesterol concentrations of the 5, 9, and 13 year olds were 6.03 ± 1.03, 6.16 ± 1.04, and 6.08 ± 1.01 mmole/liter (233 ± 40, 238 ± 40, and 235 ± 39mg/100 ml), respectively. Of the children 10% had serum cholesterol concentrations of 7.4 mmole/liter (286 mg/100 ml) or more. Serum cholesterol concentration was not correlated with sex, relative body weight, or systolic or diastolic blood pressure. High cholesterol concentrations appeared to be associated with traditional dietary habits and especially with a high proportion of saturated fats in the diet.

DIET IN CORONARY ATHEROSCLEROSIS

To the Editor:— In his article, Diet in Coronary Atherosclerosis, inThe Journal, June 25, page 884, Dr. Morrison reports that 100 patients who had survived the first four to six weeks after myocardial infarction were alternately assigned to a normal diet group and a low-fat, low-cholesterol diet group. Mortality for each group was reported at 3, 5, and 12 years after infarction. Survival figures for the low-fat, low-cholesterol group were superior at all three intervals, but the author states, Statistical evaluation of the 100 patients reported in this study is impractical because of the smallness of the sample. A skeptic may question whether unconscious bias might be present as a result of selection of cases, the chance distribution of irrelevant but prognostically important characteristics, or important differences other than diet in the subsequent management. It appears unlikely that significant bias is present. Assuming no bias, there is a relatively