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Biomedical subjects

F M Sacks

Publications and source records attributed to F M Sacks.

At least 73 records · Page 4Linked to original sources

A prospective study of plasma fish oil levels and incidence of myocardial infarction in U.S. male physicians.

OBJECTIVES: This study evaluated whether increased intake of fish oils (eicosapentaenoic and docosahexaenoic acids) might reduce the risk of coronary heart disease. BACKGROUND: Observational and clinical studies have suggested that increased intake of fish oils, as reflected in plasma levels of fish oils, may reduce the risk of myocardial infarction. METHODS: A nested case-control study was conducted among the 14,916 participants in the Physicians' Health Study with a sample of plasma before randomization. Each participant with myocardial infarction occurring during the first 5 years of follow-up was matched by smoking status and age with a randomly chosen control participant who had not developed coronary heart disease. RESULTS: Mean levels of fish oils (with 95% confidence interval [CI] for paired differences and p values) in case and control participants, expressed as percent of total fatty acids, were, for eicosapentaenoic acid, 0.26 versus 0.25 (95% CI -0.03 to 0.05, p = 0.70) in cholesterol esters and 0.56 versus 0.54 (95% CI -0.04 to 0.09, p = 0.44) in phospholipids, and for docosahexaenoic acid, 0.23 versus 0.24 (95% CI -0.07 to 0.04, p = 0.64) in cholesterol esters and 2.22 versus 2.14 (95% CI -0.10 to 0.27, p = 0.36) in phospholipids. Results adjusted for major cardiovascular risk factors showed a very similar lack of association between fish oil levels and the incidence of myocardial infarction. CONCLUSIONS: These results indicate no beneficial effect of increased fish oil consumption on the incidence of a first myocardial infarction. However, the effect of very high levels of fish oils could not be evaluated.

Adjuvants, Immunologic↗

Controlled trial of fish oil for regression of human coronary atherosclerosis. HARP Research Group.

OBJECTIVES: This randomized clinical trial tested whether fish oil supplements can improve human coronary atherosclerosis. BACKGROUND: Epidemiologic studies of populations whose intake of oily fish is high, as well as laboratory studies of the effects of the polyunsaturated fatty acids in fish oil, support the hypothesis that fish oil is antiatherogenic. METHODS: Patients with angiographically documented coronary heart disease and normal plasma lipid levels were randomized to receive either fish oil capsules (n = 31), containing 6 g of n-3 fatty acids, or olive oil capsules (n = 28) for an average duration of 28 months. Coronary atherosclerosis on angiography was quantified by computer-assisted image analysis. RESULTS: Mean (+/- SD) baseline characteristics were age 62 +/- 7 years, plasma total cholesterol concentration 187 +/- 31 mg/dl (4.83 +/- 0.80 mmol/liter) and triglyceride levels 132 +/- 70 mg/dl (1.51 +/- 0.80 mmol/liter). Fish oil lowered triglyceride levels by 30% (p = 0.007) but had no significant effects on other plasma lipoprotein levels. At the end of the trial, eicosapentaenoic acid in adipose tissue samples was 0.91% in the fish oil group compared with 0.20% in the control group (p < 0.0001). At baseline, the minimal lumen diameter of coronary artery lesions (n = 305) was 1.64 +/- 0.76 mm, and percent narrowing was 48 +/- 14%. Mean minimal diameter of atherosclerotic coronary arteries decreased by 0.104 and 0.138 mm in the fish oil and control groups, respectively (p = 0.6 between groups), and percent stenosis increased by 2.4% and 2.6%, respectively (p = 0.8). Confidence intervals exclude improvement by fish oil treatment of > 0.17 mm, or > 2.6%. CONCLUSIONS: Fish oil treatment for 2 years does not promote major favorable changes in the diameter of atherosclerotic coronary arteries.

Adipose Tissue↗

The effect of potassium supplementation in persons with a high-normal blood pressure. Results from phase I of the Trials of Hypertension Prevention (TOHP). Trials of Hypertension Prevention (TOHP) Collaborative Research Group.

We conducted a randomized, double-blind, placebo-controlled trial of oral potassium chloride supplementation (60 mmol/d) in 353 men and women with an initial average diastolic blood pressure between 80 and 89 mm Hg. In the active (n = 178) compared to the placebo (n = 175) treatment group, the urinary potassium level was significantly (p < 0.001) increased by an average of 44.0 and 42.3 mmol/24 h following 3 and 6 months of therapy, respectively. Compared to placebo, active treatment was associated with a small (mean = 1.8 mm Hg) but significant (p = 0.04) reduction in diastolic blood pressure following 3 months of therapy. Following 6 months, however, this apparent treatment effect had virtually disappeared (mean reduction in diastolic blood pressure = 0.3 mm Hg). There was no significant effect of potassium supplementation on systolic blood pressure at either follow-up visit. There was a significant, independent, dose-response relationship between change in both 24-hour urinary potassium excretion and urinary sodium-potassium ratio and the corresponding change in diastolic blood pressure (-1.49 mm Hg for the highest versus the lowest quartile of change in urinary potassium excretion.

Administration, Oral↗

Lack of blood pressure effect with calcium and magnesium supplementation in adults with high-normal blood pressure. Results from Phase I of the Trials of Hypertension Prevention (TOHP). Trials of Hypertension Prevention (TOHP) Collaborative Research Group.

Phase I of the Trials of Hypertension Prevention (TOHP) was a randomized, multicenter investigation that included double-blind, placebo-controlled testing of calcium and magnesium supplementation among 698 healthy adults (10.5% blacks and 31% women) aged 30 to 54 years with high-normal diastolic blood pressure (DBP) (80 to 89 mm Hg). Very high compliance (94 to 96% by pill counts) with daily doses of 1 g of calcium (carbonate), 360 mg of magnesium (diglycine), or placebos was corroborated for the active supplements by significant net increases in all urine and serum compliance measures in white men and for urine compliance measures in white women. Overall, neither calcium nor magnesium produced significant changes in blood pressure at 3 and 6 months. Analyses stratified by baseline intakes of calcium, magnesium, sodium, or initial blood pressures also showed no effect of supplementation. These analyses suggested that calcium supplementation may have resulted in a DBP decrease in white women and that response modifiers in this subgroup might have included lower initial urinary calcium levels, urinary sodium levels, or lower body mass index. However, overall analyses indicated that calcium and magnesium supplements are unlikely to lower blood pressure in adults with high-normal DBP. The subgroup analyses, useful to formulate hypotheses, raise the possibility of a benefit to white women, which requires testing in future trials.

Administration, Oral↗

Rationale and design of the Dietary Approaches to Stop Hypertension trial (DASH). A multicenter controlled-feeding study of dietary patterns to lower blood pressure.

Epidemiologic studies have found that dietary patterns characterized by high intakes of certain minerals and fiber are associated with low blood pressure. Dietary Approaches to Stop Hypertension (DASH) is a multicenter, randomized, controlled-feeding trial designed to test the effects on blood pressure of two such dietary patterns consumed for 8 weeks. The two experimental diets will be compared with each other and with a control dietary pattern that is relatively low in potassium, magnesium, calcium, and fiber, and has a fat and protein profile mirroring current consumption. The first experimental diet, arguably termed "ideal," is high in fruits, vegetables, whole cereal products, low-fat dairy products, fish, chicken, and lean meats designed to be low in saturated fat and cholesterol; moderately high in protein; and high in minerals and fiber. The second experimental diet tests the effect of fruits and vegetables alone. Its potassium, magnesium, and dietary fiber content will be at the same high levels as the ideal dietary pattern, while its fat, protein, and calcium content will resemble that of the control dietary pattern. The study population will consist of 456 healthy men and women, aged 22 years or older, with systolic blood pressure less than 160 mm Hg and diastolic blood pressure 80 to 95 mm Hg. African-American and other minority groups will comprise 67% of the population. Participants will eat one of the three dietary patterns. The DASH trial has unique features. First, dietary patterns rather than single nutrients are being tested. Second, all food for the experimental diets is provided to the participants using a standardized multicenter protocol. Because the dietary patterns are constructed with commonly consumed food items, the results, if positive, may be conveniently implemented in dietary recommendations to the general public.

Adult↗

Sex hormones, lipoproteins, and vascular reactivity.

The HDL-raising effect of estrogen replacement is mediated by an increase in HDL-apolipoprotein A-I production and not by a decrease in the clearance rate. Large-scale clinical trials have shown that medroxyprogesterone acetate removes most of the HDL-raising effects of concomitant estrogen treatment. Testosterone decreases HDL levels in both men and women. Lipoprotein (a) levels are reduced by estrogen replacement, but are not affected by medroxyprogesterone. The acute systemic administration of estrogen to postmenopausal women improves the endothelium-dependent vasodilation of coronary arteries and forearm resistance vessels. Usual doses of oral estrogen replacement therapy improve the endothelium-dependent and endothelium-independent vasodilator responses in the forearm in women who have risk factors for atherosclerosis. These effects may be mediated by an antioxidant action of estrogen.

Animals↗

Combinations of potassium, calcium, and magnesium supplements in hypertension.

Dietary intakes of potassium, calcium, and magnesium have each been reported to lower blood pressure, but the extent of blood pressure reduction in epidemiological studies and clinical trials has tended to be small and inconsistent. We hypothesized that combinations of these mineral supplements would lower blood pressure and that the reductions would be greater than that usually reported in studies of each cation alone. One hundred twenty-five patients 82 men and 43 women) with untreated mild or borderline hypertension were randomly assigned to daily treatment with one of the following four regimens: 60 mmol potassium and 25 mmol (1000 mg) calcium, 60 mmol potassium and 15 mmol (360 mg) magnesium, calcium and magnesium, or placebo. Standardized clinic blood pressure measurements were obtained on 3 days at baseline and after 3 and 6 months of treatment. At baseline, systolic and diastolic blood pressures (mean +/- SD) were 139 +/- 12 and 90 +/- 4 mm Hg, respectively, and dietary intakes of potassium, calcium, and magnesium were 77 +/- 32, 19 +/- 13, and 12 +/- 52 mmol/d, respectively. The mean differences (with 95% confidence intervals) of the changes in systolic and diastolic blood pressures between the treatment and placebo groups were not significant: -0.7 (-4.3 to +2.9) and -0.4 (-2.9 to +2.1) for potassium and calcium, -1.3 (-4.4 to +1.8) and 0.4 (-2.5 to +3.3) for potassium and magnesium, and +2.1 (-1.8 to +6.0) and +2.2 (-1.0 to +5.4) for calcium and magnesium. In conclusion, this trial provides little evidence of an important role of combinations of cation supplements in the treatment of mild or borderline hypertension.

Adult↗

Effect on coronary atherosclerosis of decrease in plasma cholesterol concentrations in normocholesterolaemic patients. Harvard Atherosclerosis Reversibility Project (HARP) Group.

Lipid-lowering therapy ameliorates coronary atherosclerosis in patients with raised concentrations of low-density-lipoprotein (LDL) cholesterol. We have investigated whether a similar benefit can be obtained in normocholesterolaemic patients. We studied 79 normocholesterolaemic patients with coronary heart disease (70 male, 9 female), mean age 58 years, all non-smokers, with mean total cholesterol concentration 5.5 mmol/L. All patients received diet therapy and were randomly assigned placebo (39) or active treatment (40) with pravastatin, nicotinic acid, cholestyramine, and gemfibrozil stepwise as needed to reach the specified goal (total cholesterol < or = 4.1 mmol/L, ratio of LDL/high-density-lipoprotein [HDL] cholesterol < or = 2.0). Coronary angiograms at baseline and after 2.5 years of treatment were analysed by computer-assisted quantitative techniques. There was no significant difference in coronary atherosclerosis during follow-up between the active treatment and placebo groups; the mean minimum diameter narrowed significantly but to the same extent in both groups (change baseline to 2.5 years 0.14 [SD 0.42] and 0.15 [0.42] mm, respectively, both p < 0.001). Similarly, the change in percentage stenosis did not differ between the groups (2.1 [10.6] vs 2.4 [10.3]%). By multiple regression analysis, the adjusted difference between the groups was a 0.04 mm (95% CI -0.04 to 0.12 mm) increase in minimum diameter and a 0% (-1.7 to 1.7) change in percentage stenosis. The groups differed significantly in plasma lipids (% change in active minus % change in placebo group: -28% total cholesterol, -41% LDL-cholesterol, 13% HDL-cholesterol, -26% triglycerides, -31% apolipoprotein B, all p < 0.001). Thus, intensive pharmacological treatment of normocholesterolaemic patients has significant effects on plasma lipid concentrations but no angiographically measurable benefit on the coronary arteries.

Anticholesteremic Agents↗

Effect of postmenopausal estrogen replacement on plasma Lp(a) lipoprotein concentrations.

BACKGROUND: Women who receive postmenopausal estrogen replacement experience a lower rate of coronary heart disease than women who do not receive these hormones. Evidence suggests that mechanisms in addition to decreases in plasma low-density lipoprotein levels and increases in high-density lipoprotein concentrations are responsible for the apparent beneficial effect of estrogens. Therefore, we studied the effect of estrogen on plasma Lp(a) lipoprotein, newly suggested to be a risk factor for coronary heart disease in postmenopausal women. METHODS: The 31 healthy, normolipidemic subjects received placebo and conjugated equine estrogens (0.625 and 1.25 mg/d) for 3-month periods in a randomized, double-blind, crossover trial. RESULTS: The mean Lp(a) lipoprotein concentration was 20.4 +/- 14.6 mg/dL during placebo treatment; it decreased by 14% (P < .01) with 0.625 mg of conjugated estrogens and by 16% (P < .005) with 1.25 mg. The Lp(a) lipoprotein concentration during placebo treatment was not significantly correlated with the responses to either dose of estrogen. There was no effect of estrogen on the plasma concentration of cholesterol ester transfer protein, suggesting that this protein is not involved in estrogen-induced changes in very-low-density lipoprotein or high-density lipoprotein concentrations and composition. CONCLUSIONS: Estrogen decreases the plasma Lp(a) lipoprotein concentration, which could explain some of the protective effect of estrogen replacement therapy on coronary heart disease.

Carrier Proteins↗

Prospective study of plasma fatty acids and risk of prostate cancer.

BACKGROUND: Although some evidence suggests that dietary fat intake is related to prostate cancer, epidemiologic studies have been inconsistent. PURPOSE: Our purpose was to assess the association between plasma lipid levels, particularly linoleic and alpha-linolenic acids, and the development of prostate cancer. METHODS: In 1982, at the start of the Physicians' Health Study, 14916 U.S. male physicians provided plasma samples, which were frozen at -82 degrees C. Data accumulated from a series of questionnaires were used to assess the intake of various foods. We used a nested case-control design to compare the fatty acid compositions in plasma from 120 men who later developed prostate cancer with 120 matched controls who did not. Individual fatty acids were measured in plasma as a percentage of total fatty acids, using capillary gas chromatography. Conditional logistic regression models were used to obtain odds ratio estimates while adjusting simultaneously for the effects of one or more potential confounders. RESULTS: The relative risks (RRs) of prostate cancer for men in successively higher quartiles of plasma alpha-linolenic acid level were 3.0 (95% confidence interval [CI] = 1.2-7.3), 3.4 (95% CI = 1.6-7.5), and 2.1 (95% CI = 0.9-4.9), compared with those with levels below the detection threshold (P trend = .03). For linoleic acid, RRs in successively higher quartiles were 0.7 (95% CI = 0.4-1.5), 0.8 (95% CI = 0.4-1.6), and 0.6 (95% CI = 0.3-1.3), with the lowest quartile as referent (P trend = .24). The effect estimates were not notably altered by adjustment for exercise, body mass, meat and dairy consumption, or other fatty acid levels in the plasma. The RR for eating red meat at least five times per week compared with less than once a week was 2.5 (95% CI = 0.9-6.7) and was little changed by adjustment for alpha-linolenic acid, although alpha-linolenic acid levels were correlated with intake of red meat and butter. The association of alpha-linolenic acid levels with prostate cancer was greater among men with low linoleic acid and reduced meat intake. CONCLUSIONS: These results suggest that low plasma levels of alpha-linolenic acid might be associated with reduced risk of prostate cancer, independently of high meat intake. High linoleic acid and low marine fatty oils were not associated with increased risk, as previously hypothesized. IMPLICATIONS: The effects of dietary alpha-linolenic acid, particularly from vegetable sources, warrant further study. The effects of dietary linoleic acid and marine fatty acids seen in animal bioassays might not apply to human prostate cancer.

Aged↗

Sex hormones and lipoprotein metabolism.

Previous findings of increased production of large VLDL particles by estrogen have been confirmed in a trial using estrogen-dominant oral contraceptives. Estrogen has been found to have LDL subclass-specific effects and to shift the distribution of apolipoprotein (apo)E from HDL to VLDL. Several recent studies document decreases in lipoprotein (a) [Lp(a)] levels, but the metabolic mechanism is yet unknown. The effects of progestational agents on lipoprotein metabolism remain unclear in view of conflicting reports.

Androgens↗

The effect of fish oil on blood pressure and high-density lipoprotein-cholesterol levels in phase I of the Trials of Hypertension Prevention. Trials of Hypertension Prevention Collaborative Research Group.

OBJECTIVE: To study the effects of moderate doses of fish oil on blood pressure and high-density lipoprotein (HDL)-cholesterol. METHODS: The participants were 350 normotensive men and women aged 30-54 years who were enrolled from seven academic medical centers in phase I of the Trials of Hypertension Prevention. They were randomly assigned to receive placebo or 6 g purified fish oil once a day, which supplied 3 g n-3 polyunsaturated fatty acids for 6 months. RESULTS: Baseline blood pressure was (mean +/- SD) 123 +/- 9/81 +/- 5 mmHg. The mean differences in the blood pressure changes between the fish oil and placebo groups were not statistically significant. There was no tendency for fish oil to reduce blood pressure more in subjects with baseline blood pressures in the upper versus the lower quartile (132/87 versus 114/75 mmHg), low habitual fish consumption (0.4 versus 2.9 times a week) or low baseline plasma levels of n-3 fatty acids. Fish oil increased HDL2-cholesterol significantly compared with the placebo group. Subgroup analysis showed this effect to be significant in the women but not in the men. Increases in serum phospholipid n-3 fatty acids were significantly correlated with increases in HDL2-cholesterol and decreases in systolic blood pressure. CONCLUSION: Moderate amounts of fish oil (6 g/day) are unlikely to lower blood pressure in normotensive persons, but may increase HDL2-cholesterol, particularly in women.

Adult↗

Effects of postmenopausal hormone replacement with oral and transdermal estrogen on high density lipoprotein metabolism.

Estrogen treatment raises plasma high density lipoprotein (HDL) levels, which may reduce cardiovascular risk. To identify the responsible mechanisms as well as the importance of the route of administration, we treated eight healthy postmenopausal women in a double-blind crossover study with three treatments for 6 weeks each: oral estradiol, 2 mg daily; transdermal estradiol, 0.1 mg twice weekly; and placebo. At the end of each treatment, apoA-I of HDL2 (d 1.063-1.125 g/ml) and HDL3 (d 1.125-1.210 g/ml) was endogenously labeled by a constant intravenous infusion of trideuterated leucine. HDL2 and HDL3 were separated by preparative ultracentrifugation. The pool sizes and enrichment curves of HDL apoA-I were used to calculate production rates and fractional catabolic rates (FCR). Oral estradiol increased the levels of HDL2 apoA-I by 37% (P < 0.005) and of HDL3 apoA-I by 11% (P < 0.05). These increased apoA-I levels resulted entirely from increased production, by 36% for HDL2 (P < 0.01), and by 19% for HDL3, (P < 0.05) as their FCRs were unchanged (0.20 pool/d with placebo and 0.21 with estradiol for HDL2, and 0.19 with placebo and 0.21 with estradiol for HDL3). The isotopic enrichment curves of HDL2 apoA-I and HDL3 apoA-I were identical, implying that apoA-I rapidly cycles between HDL particles, or that rapid interconversion of these subfractions occurs. The changes in HDL apoA-I metabolic rates were positively correlated with changes in VLDL-apoB metabolic rates measured previously. Transdermal estradiol, with systemic potency similar to that of oral estradiol, had no significant effect on HDL levels or metabolic rates. Thus, the "first pass" effect of oral estradiol on the liver and/or intestine appears to increase HDL apoA-I levels (particularly in HDL2) by increasing HDL apoA-I production, and not by reducing HDL apoA-I catabolism.

Administration, Cutaneous↗

Short report: the effect of fish oil on blood pressure and high-density lipoprotein-cholesterol levels in phase I of the Trials of Hypertension Prevention.

OBJECTIVE: To study the effects of moderate doses of fish oil on blood pressure and high-density lipoprotein (HDL)-cholesterol. METHODS: The participants were 350 normotensive men and women aged 30-54 years who were enrolled from seven academic medical centers in phase I of the Trials of Hypertension Prevention. They were randomly assigned to receive placebo or 6 g purified fish oil once a day, which supplied 3 g n-3 polyunsaturated fatty acids for 6 months. RESULTS: Baseline blood pressure was (mean +/- SD) 123 +/- 9/81 +/- 5 mmHg. The mean differences in the blood pressure changes between the fish oil and placebo groups were not statistically significant. There was no tendency for fish oil to reduce blood pressure more in subjects with baseline blood pressure in the upper versus the lower quartile (132/87 versus 114/75 mmHg), low habitual fish consumption (0.4 versus 2.9 times a week) or low baseline plasma levels of n-3 fatty acids. Fish oil increased HDL2-cholesterol significantly compared with the placebo group. Subgroup analysis showed this effect to be significant in the women but not in the men. Increases in serum phospholipid n-3 fatty acids were significantly correlated with increases in HDL2-cholesterol and decreases in systolic blood pressure. CONCLUSION: Moderate amounts of fish oil (6 g/day) are unlikely to lower blood pressure in normotensive persons, but may increase HDL2-cholesterol, particularly in women.

Adult↗

Fatty acid composition of the subcutaneous adipose tissue and risk of proliferative benign breast disease and breast cancer.

BACKGROUND: Studies in animals and geographic correlations across populations suggest that fatty acid intake may have a positive relationship with breast cancer risk, but analytic epidemiologic studies of fat intake have been less supportive. Adipose tissue analysis provides a more objective assessment of intakes of fatty acids that are not endogenously synthesized than do the questionnaire survey methods used in many epidemiologic studies. PURPOSE: This case-control study of postmenopausal women was designed to examine the relationship between fatty acid composition of subcutaneous adipose tissue and risk of breast cancer and proliferative benign breast disease. In addition, we examined specific hypotheses that breast cancer risk is negatively associated with long-chain N-3 fatty acid intake, positively associated with trans fatty acid intake, and positively associated with increased intake of polyunsaturated fat together with low intake of antioxidants. METHODS: Aspirates of subcutaneous fat from the buttocks were obtained from 380 women with newly diagnosed stage I or II breast cancer and 176 with proliferative benign breast disease. A total of 397 women who were evaluated for breast abnormalities at the same institutions but did not require breast biopsy or whose biopsy revealed nonproliferative benign breast disease served as the control group. We examined associations between saturated, monounsaturated, polyunsaturated, trans, or long-chain N-3 fatty acids and breast cancer, atypical hyperplasia, or proliferative benign breast disease without atypia. RESULTS: We observed no consistent patterns of association between breast cancer risk and any of the categories of fatty acids or the individual constituent fatty acids in the adipose tissue. Saturated fatty acids were inversely associated with risk of proliferative benign breast disease without atypia but not with atypical hyperplasia or breast cancer. This association was not observed, however, when total fat intake was taken into account. Women with high levels of polyunsaturated fatty acids in adipose tissue and low serum or dietary levels of antioxidants were not observed to be at higher risk of breast cancer. CONCLUSIONS: Using an objective measure of intake, we observed no major associations between polyunsaturated fatty acids, including long-chain N-3 fatty acids and trans fatty acids, and risk of breast cancer or proliferative benign breast disease. IMPLICATIONS: These data do not support the hypothesis that intake of specific fatty acids, particularly polyunsaturated and trans fatty acids, is an important risk factor for malignant or benign breast disease.

Adipose Tissue↗

Natural history of coronary atherosclerosis using quantitative angiography in men, and implications for clinical trials of coronary regression. The Harvard Atherosclerosis Reversibility Project Study Group.

Previous studies of the natural history of coronary disease generally relied on estimates of percent stenosis derived from visual assessment of the coronary angiogram. In a study of 26 patients, serial quantitative angiography was performed 3 years apart to determine changes in both absolute measurements of the luminal diameter and relative percent stenosis. Initially, the mean minimal diameter of 74 coronary obstructions was 1.94 +/- 0.09 mm, the mean "normal" reference diameter was 3.06 +/- 0.11 mm, and the mean percent stenosis was 37%. At follow-up, there was a mild reduction of 0.12 +/- 0.04 mm (6%) in the minimal diameter (p < 0.005), and an increase in percent stenosis to 39% (p = 0.03). The average diameter of 85 arterial segments without a focal obstruction either initially or at follow-up showed mild but significant progression (-0.11 +/- 0.04 mm; p = 0.02). Using a minimal change of 0.27 mm in arterial diameter as a categoric variable, progression occurred in 26% of 74 arterial segments, no significant change in 65%, and regression in 9%. The only significant determinant of disease progression was the initial severity of disease. Obstructed arteries with a larger initial minimal diameter and presumably milder disease progressed more rapidly than did those with a smaller diameter (r = -0.42; p = 0.0002). There was no effect of age on the rate of progression (r = 0.02; p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗

Differential effects of estrogen on low-density lipoprotein subclasses in healthy postmenopausal women.

The use of estrogen by postmenopausal women decreases plasma low-density lipoprotein (LDL) cholesterol levels. To determine whether LDL subclass profiles influence this response, we studied 31 healthy postmenopausal women who were administered two doses (0.625 and 1.25 mg/d) of conjugated equine estrogen in a placebo-controlled double-blind crossover study. Lipid-stained gradient gels were used to categorize LDL subclass patterns. All women were classified as LDL subclass pattern A (predominant LDL peak > or = 260 A). Within the pattern A classification, there were 12 women during placebo treatment with LDL subclass I pattern (predominant LDL peak > 271 A) and 19 women with LDL subclass II pattern (predominant LDL peak < or = 271 and > or = 260 A). Postmenopausal women with LDL subclass I on placebo treatment had significantly lower LDL cholesterol levels compared with women having LDL subclass II (126 +/- 28 v 147 +/- 23 mg/dL, P < .03). Postmenopausal women with LDL subclass I also had significantly (P < .05) lower very-low-density lipoprotein (VLDL) cholesterol, VLDL triglyceride, and VLDL apo B levels and significantly higher (P < .05) high-density lipoprotein 2 (HDL2) cholesterol, HDL3 cholesterol, and HDL2 apo A-I levels. Estrogen replacement significantly (P < .05) decreased LDL cholesterol levels and increased VLDL and LDL triglyceride, HDL2 and HDL3 cholesterol and apo A-I, and HDL2 apo A-II levels to a similar extent in postmenopausal women with LDL I or II subclass patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗