Nutrient intake,body fat,and lipid profiles of competitive male and female bodybuilders.

The purpose of this research was to measure nutrient intake, body fat, [estimated from seven skinfolds: chest, axilla, triceps, subscapular, abdominal, suprailiac, and thigh (Jackson and Pollock, 1985)], total cholesterol (TC), HDL-cholesterol (HDL-C), HDL2-C, and HDL3-C of 19 male and 8 female bodybuilders competing in the National Physique Committee's USA Bodybuilding Championships (Raleigh, NC, April 1988). Casual blood samples and anthropometric data were collected 18 hours prior to competition, whereas 7-day diet records were completed 1 week prior to competition. Only 11 males and 2 females provided blood samples. Competitors were not tested for steroid use. These data are unique because the measurements were collected on site at the competition. Data are presented as means and standard deviations. Estimated body fat for males (6.0 +/? 1.8%) and females (9.8 +/? 1.5%) was quite low. Blood lipids (mg%) for males (TC = 187 +/? 11, HDL-C = 37 +/? 6, HDL2-C = 13 +/? 4, and HDL3-C = 24 +/? 4) were not indicative of increased coronary heart disease (CHD) risk. Data for the 2 females (TC = 190, 205; HDL-C = 56, 56; HDL2-C = 22, 8; and HDL3-C = 34, 48) could only be evaluated on an individual basis. Body fat was significantly correlated with HDL-C (r = 0.63; p = 0.04) and HDL3-C (r = 0.65; p = 0.03), but not TC nor HDL2-C. Of the dietary variables, only saturated fat was significantly correlated with HDL2-C (r = 0.60; p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Determinants of total high density lipoprotein cholesterol and high density lipoprotein subfraction levels among Hispanic and non-Hispanic white persons with normal glucose tolerance: the San Luis Valley Diabetes Study.

Determinants of total high-density lipoprotein cholesterol (HDL-C) and HDL subfractions were assessed in Hispanic and non-Hispanic white persons (n = 932), aged 20-74 years, in the San Luis Valley, Colorado. Using multiple regression, BMI was negatively associated with HDL-C, HDL2-C, and HDL3-C in men and HDL-C and HDL3-C in women. Among females, current smokers had lower HDL-C and subfractions. Women on beta-blockers had lower HDL3-C levels. For both sexes, a positive association was observed between age and HDL-C and subfractions and physical activity with HDL-C and HDL3-C. Drinking alcohol (> or = 50 g/week) was associated with higher HDL-C and HDL3-C in both sexes and HDL2-C in women. The positive association of age and negative associations of the subscapular/triceps ratio and fasting insulin had consistent relationships with HDL-C, HDL2-C, and HDL3-C in men and women. Ethnicity was not significantly associated with HDL-C or subfractions after controlling for body fat distribution or fasting insulin.     

正常人群红细胞胆固醇与血浆脂蛋白组分胆固醇水平关系的研究

本文报告了1～90岁2333名正常人群红细胞胆固醇(REC—C)、高密度脂蛋白胆固醇(HDL—C)及亚组(HDL_2—C、HDL_3—C)、低密度脂蛋白胆固醇(LDL—C)、极低密度脂蛋白胆固醇(VLDL—C)水平及相关关系。结果显示RBC—C水平随年龄增长而升高,并呈正相关(r=0.154,P<0.05)。男、女RBC—C与HDL—C呈正相关,RBC—C与HDL_2—C、HDL_3-C、LDL—C、VLDL—C呈负相关。男性RBC-C与LDL—C相关密切(偏相关系数R=0.157,P<0.05),女性RBC—C与VLDL—C相关密切(偏相关系数R=0.153,P<0.05)。RBC—C与HDL-C、HDL_2—C、HDL_3-C、LDL-C、VLDL-C相关方向、相关强度因年龄增加,性别不同而变化。结合有关资料讨论了RBC—C水平变化及RBC—C与血浆脂蛋白组分胆固醇相关关系在动脉硬化形成及预防中的意义。     

Acute exposure to environmental tobacco smoke reduces HDL-C and HDL2-C

BACKGROUND: Chronic environmental tobacco smoke (ETS) exposure increases individuals risk of coronary artery disease by reducing high-density lipoprotein cholesterol (HDL-C). Currently, there is limited research on the acute effects of ETS on HDL-C. This study examined the acute influence of ETS on HDL-C and its subfractions. METHODS: Twelve male subjects (25.7 +/- 3.0 years) were examined to determine the influence of an acute 6-h exposure to ETS on lipid and lipoprotein levels. Baseline blood samples were drawn before ETS exposure from an antecubital vein at 6 am, 2 pm, and 10 pm. The following day, subjects were exposed to 6 h of ETS, approximately 4-10 pm. Blood was again collected at 8, 16 and 24 h following ETS exposure. Blood was assayed for total cholesterol (TC), HDL-C and its subfractions HDL(2)-C and HDL(3)-C. RESULTS: As a result of ETS exposure, HDL-C and HDL(2)-C levels were significantly reduced by 18% and 37%, respectively. This effect was sustained, with a decrease in HDL-C of 13% and HDL2-C of 28% still evident at 24-h post-exposure. TC was unchanged (pre- 187.3 +/- 41.6 and post- 187.0 +/- 46.3); however, there were significant decreases in the TC/HDL-C and HDL2-C/HDL3-C ratios by 16% and 29%, respectively, which were sustained for 24 h. CONCLUSIONS: The findings of this study demonstrate that a 6-h exposure has a negative impact on lipid and lipoprotein profiles and that these levels remained depressed for at least 24 h.     

Effects of a lacto-ovo vegetarian diet on serum concentrations of cholesterol, triglyceride, HDL-C, HDL2-C, HDL3-C, apoprotein-B, and Lp(a)

The effect of intervention with a lacto-ovo vegetarian diet on serum concentrations of cholesterol, triglyceride, total high-density lipoprotein cholesterol (HDL-C), HDL2-C, HDL3-C, low-density lipoprotein cholesterol, apoprotein-B, apoprotein-HDL, and Lp(a) was studied in 19 men and 17 women. Most weekday meals were obtained from a single source and dietary records were completed to assess the changes in nutrient intakes. Blood was collected in the 6th wk of each dietary period. Because of strong correlations between many of the changes in nutrient intakes, principal component (factor) analysis was used followed by stepwise multiple regression analysis to identify associations between changes in diet and changes in lipid, lipoprotein or apoprotein levels. Three principal components accounted for 92.0% of the variation in lipid levels: factor 1 represented an increase in saturated fat, total fat, monounsaturated fat, cholesterol, and energy intake: factor 2 represented an increase in fiber and polyunsaturated fat, and decrease in protein intake; factor 3 an increase in total carbohydrate, complex carbohydrate, and energy intake. Where a change in a variable was significantly associated with change in diet, one factor appeared primarily responsible for the change; total cholesterol (factor 2, p = 0.034); triglyceride (factor 3, p = 0.005); apo-HDL (factor 1, p = 0.014); HDL2-C (factor 2, p = 0.023), HDL3-C (factor 3, p = 0.015). A borderline significant association was seen for total HDL-C (factor 2, p = 0.055).     

Serum leptin levels and their association with several factors related to arteriosclerosis among medical students in Japan

The association between serum leptin levels and several factors related to arteriosclerosis were studied in subjects who were Japanese medical students taking no medications. The group was comprised of 75 males and 35 females. The age distribution in males was 21.4 to 29.8 years (median age, 24.0 years) and in females was 21.3 to 29.9 years (median age, 22.9 years). Statistical analyses were performed using the Wilcoxon rank sum test and Spearman correlation. Median levels of serum leptin were 3.3 ng/ml in males and 7.6 ng/ml in females. The largest correlation observed was widi percent body fat irrespective of sex [males; r=0.775, p<0.001, females; r=0.553, p<0.001]. However, body mass index (BMI) was similarly well correlated with serum leptin [r=0.631, p<0.001] in males but not in females [r=0.305, p=0.075]. A negative correlation was observed between high density lipoprotein cholesterol (HDL-C) and leptin in both sexes [males; r=-0.298, p<0.01, females; r=-0.363, p<0.05] .respectively. Percent body fat, BMI, diastolic blood pressure, apolipoprotein B, and HDL-C were the most significant factors in males. Percentage of body fat and HDL-C were the most important factors in females.     

Chronic disease risk factors in vitamin/mineral supplement users and nonusers in a farm population

Dietary, anthropometric, and chronic disease risk factors (CDRF) in vitamin/mineral supplement users (U) and non-users (NU) were measured in a farm population consisting of 162 subjects (46% females and 54% males; 20-79 years of age, mean age: 52 years). Subjects were white, except for two black males. Supplements were used by 62 subjects (38%); 47% of females and 31% of males used supplements; 43% of subjects over 50 years of age and 32% of subjects age 50 or under used supplements. Both dietary intake and energy expenditure were measured using 4-day records. Indices of adiposity included body weight, BMI, and estimated body fat. Total cholesterol (TC), high-density-lipoprotein cholesterol (HDL-C), serum ferritin, hemoglobin, hematocrit, zinc, copper, and vitamin C were based on 12-hr fasting blood samples. Dietary intake (excluding supplements) for vitamin/mineral U was greater than NU for vitamin C (p = 0.006), thiamin (p = 0.01), riboflavin (p = 0.03), niacin (p = 0.02), folic acid (p = 0.001), vitamin B6 (p = 0.01), and magnesium (p = 0.019). Vitamin C levels were significantly higher and the sum of four skinfolds was significantly lower among U than NU. In this population, 24% of males and 18% of females had TC levels over 240 mg%; 8% of both males and females had blood pressures (BP) greater than 140/90 mm Hg, while 49% of males and 46% of females had BP between 120/80 and 140/90; and 71% of males were more than 25% fat, and 56% of females were more than 35% fat. Despite the high prevalence of CDRF, there were no significant differences between supplement U and NU.     

Total and regional fat and serum cardiovascular disease risk factors in lean and obese children and adolescents

OBJECTIVE: This study was conducted to evaluate the association of total and central adiposity with serum cardiovascular disease (CVD) risk factors in lean and obese Portuguese children and adolescents. RESEARCH METHODS AND PROCEDURES: A total of 87 girls (13.2 +/- 1.6 years old, 29.9 +/- 6.4% body fat [mean +/- SD]) and 72 boys (13.2 +/- 1.6 years old, 20.8 +/- 9.9% body fat) volunteered for the study. Whole-body composition and fat distribution, from DXA and anthropometry, and serum lipids, lipoproteins, and apolipoproteins were evaluated. RESULTS: The sum of three trunk skinfolds (STS) was highly correlated with total trunk fat mass measured by DXA (p < 0.001). Body mass index, DXA-measured percentage of body fat, trunk fat mass, STS, and the waist-to-height ratio were generally found to be associated with triacylglycerol, the ratio of total cholesterol (TC) to high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), and apolipoprotein B levels, (significant age-adjusted r between 0.16 and 0.27, p < 0.05). Body mass index, STS, and the waist circumference were also associated with HDL-C (p < 0.05), whereas no body composition variable significantly correlated with TC or apolipoproteins A-I. The STS was significantly correlated with HDL-C (p < 0.01), TC/HDL-C (p < 0.05), and apolipoproteins A-I (p < 0.05) independently of whole-body fatness. Obese subjects (n = 73) had higher TC, LDL-C, TC/HDL-C, and apolipoprotein B than did non-obese subjects (n = 86), and significant associations between central adiposity and some lipid variables (triacylglycerol and HDL-C) were found in obese children and adolescents that were not present in leaner individuals. DISCUSSION: DXA- and anthropometry-based whole-body and central fat measures are associated with serum CVD risk factors in Portuguese boys and girls. Obese children and adolescents have a poorer lipid profile than do their leaner counterparts. Trunk skinfolds, which are easy to obtain even in large samples, predict CVD risk factors to the same extent as DXA-based variables, in some cases, independently of total fatness.     

Relation between the longitudinal development of lipoprotein levels and biological parameters during adolescence and young adulthood in Amsterdam, The Netherlands.

STUDY OBJECTIVES: To analyse the relation between the longitudinal development of total serum cholesterol (TC), high density lipoprotein cholesterol (HDL), and the TC/ HDL ratio and the longitudinal development of the biological parameters body fatness (SSF), lean body mass (LBM), and cardiopulmonary fitness (VO2-max). The relations were analysed with generalised estimating equations (GEE). SETTING: The relations were investigated with data from the Amsterdam growth and health study, a longitudinal study in which six measurements were carried out within a period of 15 years. PARTICIPANTS: Altogether 98 females and 84 males aged 13 years at the start of the study. MAIN RESULTS: Adjusted for lifestyle and other biological parameters, the longitudinal development of TC was inversely related to the development of LBM (standardised regression coefficient beta = -0.27; p < or = 0.01) and positively to SSF (beta males = 0.32; p < or = 0.01 and beta females = 0.15; p < or = 0.01). HDL was inversely related to LBM (beta = -0.26; p < or = 0.01) and positively to VO2-max (beta = 0.08; p < or = 0.05). The TC/HDL ratio was positively related to SSF (beta males = 0.39; p < or = 0.01 and beta females = 0.13; p < or = 0.01) and inversely to VO2-max (beta = -0.09; p < or = 0.05). CONCLUSIONS: The longitudinal analyses showed that body fatness was related to a high risk profile with respect to hypercholesterolaemia, and cardiopulmonary fitness to a low risk profile. Furthermore, it was shown that using body mass index as an indicator of body fatness in relation to lipoprotein values, has some important drawbacks.     

脂蛋白胆固醇用于冠心病筛检试验的评价

至今尚无适于人群筛检冠心病的理想方法。38例心电图踏车运动试验阳性的病例组,与同期试验阴性的71例对照组进行筛检试验评价研究。选择TC/HDL-C、HDL-C/TC、LDL-C/HDL-C、HDL₂-C/HDL₃-C等比值为筛检指标,评价其不同界限值的真实性、预测值等。TC/HDL-C与HDL₂-C/HDL₃-C并联使用可以提高检出率达92%。多元逐步回归分析只有TC/HDL-C选入方程,计算其5个组段的阳性似然比,并以不同的验前概率拟代,结果验后概率以TC/HDL-C≥3.2最大,因此,国内"动脉粥样硬化指标"TC/HDL-C的界限值可定为≥3.2。     

Replacing 40% of dietary animal fat with vegetable oil is associated with lower HDL cholesterol and higher cholesterol ester transfer protein in cynomolgus monkeys fed sufficient linoleic acid

This study was designed to evaluate whether replacing approximately 40 g/100 g dietary animal fat with vegetable oil would improve plasma lipids and lipoproteins when diets contained prudent levels of total saturated acid (SFA), monounsaturated acid (MUFA) and PUFA. Using a cross-over design, male Cynomolgus monkeys (n = 10) were fed purified diets containing a mixture of fats. For the diet based on animal fat (AF-diet), approximately 85 g/100 g of the total fat was derived from pork fat, and approximately 40 g/100 g of this was replaced with olive oil for the vegetable oil-based diet (VO-diet). Thus, the fat content of the VO diet comprised 50% pork fat and 35% olive oil. The remaining 15% of the total fat (for both diets) was safflower oil. Both diets provided approximately 30% of total energy (%en) from fat, <10%en SFA and approximately 6-7%en from PUFA. Monkeys were rotated through two 7-wk feeding periods, during which time plasma lipids and lipoproteins were evaluated. Compared with the AF diet, plasma total cholesterol (TC) concentrations tended to be lower ( approximately 10%) after monkeys consumed the VO diet (3.18 +/- 0.83 vs. 3.52 +/- 0.93 mmol/L, P = 0.099), and this was due entirely to a significant 12% reduction in HDL cholesterol (1.53 +/- 0.41 vs. 1.73 +/- 0.47, mmol/L, P = 0.0009). Although plasma lipoprotein compositional analyses revealed no significant differences in either lipoprotein composition or the estimated particle diameters, the measurement of cholesterol ester transfer protein (CETP) using (3)H-cholesterol ester-labeled HDL revealed that the lower HDL cholesterol (HDL-C) when monkeys consumed the VO diet was associated with a 31% increase in transfer (P = 0.04). However, despite the changes in HDL-C, the TC/HDL-C ratio did not differ between monkeys after the two diet treatments. Regression analyses of data from these monkeys revealed a significant correlation between the dietary 16:0/18:2 ratio and plasma HDL-C. These data suggest that within the context of currently recommended prudent diets, it may be possible to manipulate HDL-C beneficially. Whether a similar effect would occur in humans warrants investigation.     

Dietary influences on cardiovascular disease risk in anabolic steroid-using and nonusing bodybuilders

Recent studies have described an association between high-risk lipoprotein profiles and anabolic steroid abuse by athletes. However, none have included a comprehensive evaluation of diet as a confounding variable. The risk of cardiovascular disease (CVD) and its associations with drug abuse, dietary patterns, and training regimens were evaluated in 18 steroid-using (SU) and 17 non-steroid-using (NSU; no history of drug use or greater than or equal to 1 year drug-free) male bodybuilders. CVD risk was also evaluated in 10 control males. Fasting serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL) and HDL subfractions 2 and 3, low-density (LDL) and very-low-density (VLDL) lipoprotein cholesterol, apoproteins (APO) A-1 and B, and triglycerides (TG) were analyzed at baseline (greater than or equal to 6 months drug-free) and the peak of steroid self-administration in SU. NSU were tested at similar times. Baseline CVD risk factor ratios (TC/HDL) were elevated (greater than 4.97) in 44% of SU and 24% of NSU. When baseline LDL and HDL values were compared to National Cholesterol Education Program CVD risk guidelines, these percentages stayed the same. At the peak of steroid administration significant changes were observed in LDL (22% increase), HDL (63% decrease), HDL-2 (86% decrease), HDL-3 (54% decrease), and TC/HDL (85% increase). No similar measures were observed among NSU or controls. Diets of all bodybuilders were similar, and included a daily intake of 5739 (+/- 2500) kcal, 324 (+/- 163) g protein, 637 (+/- 259) g carbohydrate, 214 (+/- 109) g fat, 5 (+/- 8) g alcohol, 1413 (+/- 1151) mg cholesterol, and a P/S ratio of 0.6 (+/- 0.3). Significant relationships between dietary fats and serum lipids were observed in the NSU. Polyunsaturated fatty acids were correlated with TG and VLDL (r = 0.69; p = 0.01), and TC/HDL (r = 0.06; p = 0.04). Total fats were correlated with TG (r = 0.57; p = 0.05), HDL-3 (r = -0.62; p = 0.04), and VLDL (r = 0.57; p = 0.05), and saturated fats with HDL-3 (r = -0.59; p = 0.055). Diet was moderately associated with lipoproteins in SU, but steroids had a much greater influence on CVD risk. Despite disease promoting diets NSU had relatively average CVD risk that may be attributed to protective effects of rigorous training.     

Coronary heart disease risk factors in male adolescents, with particular reference to smoking and blood lipids.

PURPOSE: To examine coronary heart disease (CHD) risk factors, particularly blood lipids and smoking, in adolescent boys in the Sydney Metropolitan area, and to investigate possible differences between boys from English-speaking (ESB) and non-English-speaking backgrounds (NESBs). METHODS: Male volunteers aged 15-18 years were recruited from the senior years of four secondary schools in different geographical areas of Sydney. Body mass index (BMI), waist-hip ratio (WHR), blood lipids, and percent body fat were measured. Behavioral variables were estimated by questionnaire. RESULTS: A total of 110 boys were recruited; 74% were from an ESB. Mean WHR (0.836 +/- 0.045), waist circumference (80.6 +/- 9.4 cm), and percent body fat (21.0 +/- 6.3) were similar across age groups. Atherogenicity of the lipid profile, as measured by the ratio of total cholesterol to high-density lipoprotein cholesterol (TC:HDL-C), was lower in boys aged 15 years than in any other age group (p < .05). TC:HDL-C was strongly associated with BMI (r = .57; p < .0001) and WHR (r = .35; p < .01). Smokers had higher BMI, were less active and had lower HDL-C (p < .001) and higher TC:HDL-C (p < .0001) than nonsmokers. Smoking, even of short duration, and quite moderate consumption of cigarettes (6/day) were associated with a deterioration of the lipid profile. Boys from NESBs had a higher degree of risk in all of the factors examined. CONCLUSIONS: Regular smoking of short duration has an appreciable impact on lipid and lipoprotein concentrations in this sample of Australian adolescent boys. Boys from an NESB appear to be at greater risk of developing CHD in later life.     

Ascorbic acid, HDL, and total plasma cholesterol in the elderly

The relationships between ascorbic acid (plasma and dietary) and plasma HDL cholesterol (HDL-C), total plasma cholesterol (T-C) and T-C:HDL-C ratio were examined in a population of 235 males and 445 females, age 60-98 years. Many known or suspected determinants of HDL-C and T-C, including age, sex, triceps skinfold thickness, fasting blood glucose, alcohol intake, and others, were considered as covariates due to their potential confounding or modifying effects on the relationships under study. The results show that plasma ascorbic acid is significantly (p less than 0.05) correlated with HDL-C (r = 0.09), T-C:HDL-C (r = 0.10), but not with T-C (r = 0.03). There is a strong age interaction with the largest effect of ascorbic acid in the youngest age group studied (60-69 years). The effects of dietary ascorbic acid are similar but slightly reduced in magnitude.     

High-density lipoprotein cholesterol: Correlation with biochemical, anthropometric, behavioral, and clinical parameters in 6,500 Israeli men

Correlations of high-density lipoprotein cholesterol (HDL-C), expressed in either absolute or relative terms, with a series of coronary risk factors and other variables were examined in the Israeli Ischemic Heart Disease Study sample. The Quetelet overweight index showed the highest correlations with HDL-C (r = -0.21) as well as with HDL-C as a percentage of total cholesterol (TC) (HDL/TC; r = -0.28). Additional negative inverse associations were statistically different from zero but small. High-density lipoprotein cholesterol and HDL/TC were significantly reduced in cigarette smokers, and HDL/TC was significantly reduced in men with myocardial infarction or angina pectoris and (albeit marginally) in diabetes mellitus as well. The presence of these diseases correlated poorly with HDL-C (absolute values). The associations of HDL-C and HDL/TC with the Quetelet index persisted after adjustment for cigarette smoking and vice versa. Reported dietary intake failed to explain HDL-C or HDL/TC variability among individuals. The "net" relationship of HDL-C to several variables was examined in a multiple regression analysis. The Quetelet index accounted for 0.21 of a multiple correlation coefficient of 0.28 (i.e., a very small proportion of explained variability). This magnitude is of an order similar to multiple correlations found in our study for total cholesterol, systolic blood pressure, and serum uric acid. It indicates that our knowledge of the determinants of HDL-C in adults is insufficient. The possible roles of several anthropometric and behavioral variables in determining HDL-C levels are considered, as is the possible genetic factor in dictating interindividual HDL-C variability.     

Associations of HDL, HDL(2), and HDL(3) cholesterol and apolipoproteins A-I and B with lifestyle factors in healthy women and men: the Stanford Five City Project

BACKGROUND: Measures of the two major high-density lipoprotein (HDL) subfractions, HDL(2) and HDL(3), and the major apolipoproteins of HDL and low-density lipoprotein (LDL), Apo A-I and Apo B, may be etiologically important factors in the development of coronary artery disease. The association of lifestyle factors with these lipoprotein-related variables remains unclear. METHODS: HDL-C, HDL(2)-C, HDL(3)-C, Apo A-I, and Apo B levels were determined in a population-based sample of 1,027 healthy women and men aged 25-64 years, from four California cities who participated in the 1989/1990 survey of the Stanford Five City Project. In this cross-sectional study we examined the independent associations of these lipoprotein-related variables with body mass index (BMI), cigarette smoking, daily energy expenditure, alcohol intake, dietary intake, and hormone use (oral contraceptives and estrogen replacement therapy). RESULTS: In general, BMI and alcohol intake were the strongest independent predictors of the lipoprotein-related variables. The negative association of BMI with HDL-C was attributable primarily to the association with the HDL(2)-C subfraction, while for alcohol intake the positive association with HDL-C was attributable primarily to the association with HDL(3)-C, particularly in men. Among men, but not women, energy expenditure was a significant independent predictor of each of the lipoprotein-related variables, with positive associations observed for HDL-C, HDL(2)-C, HDL(2)-C, and Apo A-I and a negative association observed for Apo B (P < 0.005). CONCLUSIONS: Data from this population-based sample suggest that specific lifestyle factors are more strongly associated with some lipoprotein-related variables than with others, with notable gender differences.     

Effect of low and high fat diets on nutrient intakes and selected cardiovascular risk factors in sedentary men and women

OBJECTIVE: The desired level of dietary fat intake is controversial. The effect of decreasing fat intake to 19% and increasing it to 50% from a control diet of 30% on nutritional status and cardiovascular risk factors in healthy individuals was studied. METHODS: Eleven healthy subjects (5 men and 6 women) were randomized to consume diets with 19% and 50% calories from fat. Each diet lasted 3 weeks, with a one-week washout. The habitual and washout diets were determined to be 30% fat. At the beginning and the end of each diet, fasting blood was collected to determine plasma lipoproteins, and physiological factors were measured. RESULTS: Total caloric expenditure was similarly balanced to intake on the 30% and 50% fat diets, but intake was significantly lower on the 19% fat diet and led to a loss of 0.6 kg body weight. Consumptions of essential fatty acids, vitamin E and zinc were improved with increased fat intake, but folate intake was compromised on the 30% and 50% fat diets. Compared with the 50% fat diet, subjects consuming the 19% fat diet had significantly lower HDL cholesterol (HDL-C) (54 +/- 3 vs. 63 +/- 3 mg. dL(-1), p < 0.05) and apolipoprotein A1 (ApoA1) (118 +/- 4 vs. 127 +/- 3 mg/dL, p < 0.05). Changing the levels of fat intake did not affect % body fat, heart rate, blood pressure, blood triglycerides, total cholesterol (TC), LDL cholesterol, apolipoprotein B (ApoB), TC/HDL-C and ApoA1/ApoB ratios. CONCLUSION: A low fat diet (19%) may not provide sufficient calories, essential fatty acids, and some micronutrients (especially vitamin E and zinc) for healthy untrained individuals, and it also lowered ApoA1 and HDL-C. Increasing fat intake to 50% of calories improved nutritional status, and did not negatively affect certain cardiovascular risk factors.     

Population frequency distributions of HDL, HDL(2), and HDL(3) cholesterol and apolipoproteins A-I and B in healthy men and women and associations with age, gender, hormonal status, and sex hormone use: the Stanford Five City Project

BACKGROUND: The purpose of this study is to present population-based frequency distribution data for several lipoprotein-related variables and to examine their associations with gender, age, menopausal status, and sex hormone use. METHODS: High-density lipoprotein cholesterol (HDL-C), HDL(2)-C, HDL(3)-C, apolipoprotein (Apo) A-I, and Apo B were measured in a population-based sample of 1, 027 healthy adults from four California cities who participated in the 1989-1990 survey of the Stanford Five City Project. These data were examined cross-sectionally with sociodemographic and other related variables. RESULTS: Relative to men, all of the HDL-related parameters-HDL-C, HDL(2)-C, HDL(3)-C, Apo A-I-were significantly higher and Apo B levels were significantly lower among women (P < 0. 001). Menopausal status was not associated with HDL-related parameters, but Apo B levels were higher in post- versus premenopausal women (P < 0.001). Among women, HDL-C and Apo A-I levels were higher in oral contraceptive and estrogen replacement therapy users (P = 0.003). Most of the significant findings remained statistically significant after adjusting for age, body mass index, smoking, energy expenditure, and alcohol intake. CONCLUSIONS: These population-based data indicate that gender, menopausal status, and the use of sex hormones among women are associated with differential levels of one or more of HDL-C, HDL(2)-C, HDL(3)-C, Apo A-I, and Apo B, independent of age and a broad set of lifestyle factors.     

Walking, lipids, and lipoproteins: a meta-analysis of randomized controlled trials

BACKGROUND: The purpose of this study was to use the meta-analytic approach to examine the effects of walking on lipids and lipoproteins in adults. METHODS: Randomized controlled trials that examined the effects of walking on total cholesterol (TC), high- and low-density lipoprotein cholesterol (HDL-C and LDL-C), the ratio of TC/HDL, and triglycerides (TG) in adults ages 18 years and older were retrieved via computerized literature searches, cross-referencing, hand-searching, and expert review of our reference list. RESULTS: Twenty-five studies that included 1,176 subjects (692 walkers, 484 controls) and up to 33 outcomes were available for pooling. Using random-effects modeling, statistically significant, walking-induced decreases of 5% and 6% were observed for LDL-C and TC/HDL-C (LDL-C, mean +/- SE, -5.5 +/- 2.2 mg/dL, 95% CI, -9.9 to -1.2 mg/dL; TC/HDL-C, mean +/- SE, -0.3 +/- 0.1, 95% CI, -0.6 to -0.1). No statistically significant changes were observed for TC, HDL, or TG (P > 0.05), although changes were in the direction of benefit. No statistically significant changes occurred in body composition (P > 0.05). CONCLUSIONS: Walking reduces LDL-C and TC/HDL-C in adults independent of changes in body composition.