PubMed Health⌕ Search

Biomedical subjects

G Schectman

Publications and source records attributed to G Schectman.

31 records · Page 2Linked to original sources
PubMed1992

Effectiveness of low-dose colestipol therapy in patients with moderate hypercholesterolemia.

Recommended doses of bile-acid binding resins have an established hypocholesterolemic effect, but data on responses to low doses, especially in women and subjects with moderate hypercholesterolemia, are sparse. A double-blind, placebo-controlled, randomized trial of 3 low doses of colestipol hydrochloride was conducted in women and men with moderate hypercholesterolemia. Men and women with plasma low-density lipoprotein (LDL) cholesterol concentrations greater than 4 mmol/liter (155 mg/dl) and triglyceride concentrations less than 2.82 mmol/liter (250 mg/dl) were recruited for the study. Eligible patients (54 women and 98 men) were placed on the American Heart Association step I diet 6 weeks before randomization. Participants were subsequently assigned to 1 of 4 drug treatment groups (placebo, and 5, 10 and 15 g/day of colestipol in 2 divided doses) for an additional 12 weeks. Of the 152 patients randomized, 141 completed all aspects of the study. For the treatment groups--placebo, and 5, 10 and 15 g of colestipol--LDL cholesterol reductions (mmol/liter) were observed respectively (n = 141): 0.10 +/- 0.49 (2.7%), 0.65 +/- 0.41 (16.3%), 0.98 +/- 0.36 (22.8%) and 1.17 +/- 0.47 (27.2%) (p less than 0.001). Similar changes were observed in total cholesterol and apolipoprotein B concentrations. The apolipoprotein B/LDL cholesterol ratio increased significantly with increasing colestipol dosage. Modest but insignificant changes in plasma triglyceride levels occurred, and high-density lipoprotein cholesterol levels remained unchanged. A dose of 5 g/day of colestipol achieved 51% of the LDL cholesterol reduction noted with 15 g/day. Low-dose colestipol therapy is effective in the treatment of patients with moderate hypercholesterolemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

The effect of interferon on the metabolism of LDLs.

Interferons have been shown to lower low density lipoprotein (LDL) cholesterol concentrations by 20-50%. To evaluate the effect of interferons on LDL metabolic behavior in individuals with normal and mildly elevated LDL cholesterol levels, autologous LDL labeled with 125I was administered to subjects at baseline and during interferon treatment. Interferon beta serine (IFN-beta serine) was administered intravenously at 4.5 x 10(6) units daily for at least 3 weeks before the start of kinetic study and continued for an additional 2 weeks. Results were analyzed by using a multicompartmental model that allows for two intravascular LDL compartments. In normal subjects, IFN-beta serine reduced LDL cholesterol and apolipoprotein (apo) B levels by 25% and 27%, respectively (p less than 0.05); LDL apo B synthesis was decreased by 59% (p less than 0.05). In hypercholesterolemic subjects, IFN-beta serine reduced LDL cholesterol levels by 38% (p less than 0.05); however, apo B concentrations and production rates were not significantly decreased. Clearance of LDL from the first intravascular apo B pool was markedly reduced in these subjects, resulting in a shift in the distribution of LDL apo B from the second to the first intravascular LDL apo B pool. We conclude that interferon's actions on LDL metabolism differ in normocholesterolemic and hypercholesterolemic subjects. In normal subjects, interferon decreased LDL cholesterol and apo B levels through a reduction in the LDL apo B production rate. However, in hypercholesterolemic subjects, interferon reduced LDL cholesterol by altering the distribution of apo B mass between LDL subspecies.

Adult↗
PubMed1992

Distribution of lipid phenotypes in community-living men with coronary heart disease. High prevalence of isolated low levels of high-density lipoprotein cholesterol.

BACKGROUND: Risk factor modification, including treatment of dyslipidemias, has been recommended for the prevention of future coronary events in patients with coronary heart disease (CHD). Since the prevalence of various dyslipidemias among outpatients with CHD has not been well documented, the purpose of this study was to determine the frequency of specific lipid phenotypes among ambulatory men with CHD. METHODS: Lipid profiles were obtained in 255 men (mean age, 65.5 +/- 9.1 years) with CHD in three Veterans Affairs medical centers. Desirable levels of lipids were defined according to National Cholesterol Education Program guidelines as follows: low-density lipoprotein cholesterol (LDL-C) levels less than 3.36 mmol/L (130 mg/dL); high-density lipoprotein cholesterol (HDL-C) levels equal to or greater than 0.90 mmol/L (35 mg/dL); and triglyceride levels less than 2.83 mmol/L. RESULTS: Seventy-six percent of the group had one or more abnormalities on lipid profile: 51% had high LDL-C levels with or without abnormalities of HDL-C and/or triglyceride levels; 22% had low HDL-C levels with desirable levels of LDL-C; and 3% had hypertriglyceridemia without any cholesterol abnormalities. Normal lipid profiles were significantly more prevalent in subjects over the age of 65 years than in younger patients (40% vs 14%). CONCLUSIONS: These data suggest that (1) a high proportion of men with CHD have dyslipidemia, including 50% with LDL-C level elevations. For these men, the potential benefits of therapeutic intervention have been documented in clinical trials, although the cost-efficiency of wide-scale treatment has not been determined; (2) isolated hypertriglyceridemia is rare in this population; and (3) low HDL-C levels in association with desirable LDL-C levels are present in more than one fifth of male patients with CHD. Clinical trials focusing on this large group are urgently needed to determine whether efforts to raise HDL-C levels result in reduced cardiac morbidity and/or mortality.

Aged↗
PubMed1991

Ascorbic acid requirements for smokers: analysis of a population survey.

The recommended dietary allowance (RDA) of ascorbic acid for smokers was recently increased from 60 to 100 mg. To determine whether this new RDA for smokers is sufficient to reduce the risk of low serum ascorbic acid (AA) concentrations (LoC) to the same concentration as nonsmokers, we analyzed the dietary intakes and serum concentrations of AA in 11,582 adult respondents in the National Health and Nutrition Examination Survey (1976-1980). Serum AA concentrations and the risk of LoC (serum ascorbic acid levels less than 23 mumol/L) for smokers consuming different amounts of AA were compared with those for nonsmokers whose AA intake exceeded the RDA (60 mg). Serum AA concentrations were reduced, and risk of LoC increased, in smokers maintaining AA intakes greater than 60, 100, and 150 mg. Only smokers consuming greater than 200 mg AA/d had serum ascorbate concentrations and risk of LoC equivalent to nonsmokers meeting the RDA.

Adult↗
PubMed1990

Dietary intake of Americans reporting adherence to a low cholesterol diet (NHANES II).

We studied the dietary intake of persons age 18 and over participating in the 1976-80 National Health and Nutrition Examination Survey (NHANES II). We compared the diets of those on a "low cholesterol" diet (dieters, n = 296) with the diets of individuals not following a special diet (non-dieters, n = 10,052). Dietary intakes were assessed by 24-hour recall and food frequency reports and were adjusted for differences in age, sex, race, education, smoking, and socioeconomic status by multivariate statistical techniques. Dieters consumed 16 percent (99% confidence interval(-) -24, -9 fewer calories than non-dieters, and had decreased intake of saturated fat by 25 percent (-34, -15) and cholesterol by 21 percent (-32, -10). However, their intake of vitamin A, thiamine, riboflavin, niacin, calcium, and iron were not significantly different from non-dieters and their ascorbic acid intake was 18 percent (1, 36) higher. The nutrient density (nutrient/1000 kcal) among dieters was increased over non-dieters by 35 percent (-3, 72) for vitamin A, 35 percent (1, 70) for thiamine, 30 percent (-4, 65) for riboflavin, 27 percent (9, 44) for niacin, 60 percent (40, 80) for vitamin C, 14 percent for calcium (-5, 32), and 15 percent for iron (6,25). Compared with non-dieters, dieters consumed 27 percent (9, 45) more poultry and 39 percent (12, 66) more fish, but consumed 30 percent (-44, -16) less eggs and 15 percent (-24, -6) less meat.

Adult↗
PubMed1989

Can the hypotriglyceridemic effect of fish oil concentrate be sustained?

STUDY OBJECTIVE: To determine whether high doses of fish oil concentrate followed by low-dose maintenance therapy can sustain the initial plasma triglyceride reductions. DESIGN: Before-and-after trial with 3-month treatment periods. SETTING: Outpatient lipid clinic at a university medical center. PATIENTS: Sixteen patients with hypertriglyceridemia recruited from the General Internal Medicine Clinics. Five had concomitant hypercholesterolemia (type IIb). INTERVENTION: Fish oil supplementation at two doses. After basal measurements, 9.8 g/d omega-3 fatty acids were provided for study months 1 to 3, and 3.9 g/d were provided for study months 4 to 6. MEASUREMENTS AND MAIN RESULTS: Blood was drawn monthly and plasma was analyzed for levels of triglycerides, low-density-lipoprotein (LDL) cholesterol and apolipoprotein B, high-density-lipoprotein (HDL) cholesterol and apolipoprotein A1, and glucose and glycohemoglobin. During therapy with the higher dose, mean plasma triglyceride levels were reduced from 3.65 +/- 0.35 mmol/L at baseline to 1.85 +/- 0.20 mmol/L at 1 month, but increased by 30% to 2.40 +/- 0.30 mmol/L by the third month of therapy (P less than 0.05): this increase could not be explained by changes in body weight or compliance. Plasma triglyceride levels continued to increase with low-dose therapy and remained only 11% below baseline values by the sixth month of therapy (P = not significant). Although fish oil therapy increased HDL cholesterol levels (+18% at high dose; 99% CI, 5% to 31%), favorable changes were not seen in LDL cholesterol, apolipoprotein B, or apolipoprotein A1 levels. CONCLUSIONS: Fish oil concentrate at high doses followed by low-dose maintenance therapy cannot sustain the initial large plasma triglyceride reductions. Moreover, the efficacy of the higher dose becomes less pronounced after the first month of therapy. This reduced efficacy during prolonged therapy, and the lack of beneficial effect on apolipoprotein and LDL cholesterol levels, may limit the practical benefit of fish oil in the treatment of hypertriglyceridemia.

Adult↗
PubMed1989

The influence of smoking on vitamin C status in adults.

To further define the relation between smoking and vitamin C status, the dietary and serum vitamin C levels of 11,592 respondents in the second National Health and Nutrition Examination Survey (NHANES II) were analyzed. Smokers of 20 cigarettes daily had the lowest vitamin C dietary intake (79 mg, 95% CI:73, 84) and serum levels (0.82 mg/dl, 95% CI: 0.77, 0.86; 46.6 mumol/L, 95% CI: 43.7, 48.8), while smokers of 1-19 cigarettes daily had decreased vitamin C intake (97 mg; 95% CI: 90, 104 mg) and serum levels (0.97 mg/dl, 95% CI: 0.92, 1.03; 55.1 mumol/L, 95% CI: 52.2, 58.5) compared to respondents who had never smoked (109 mg, 95% CI: 105, 113 and 1.15 mg/dl, 95% CI: 1.11, 1.18; 65.3 mumol/L, 95% CI: 63.0, 67.0, respectively). This inverse association between both intake and serum levels of vitamin C and smoking was independent of age, sex, body weight, race, and alcoholic beverage consumption. Following further adjustment for dietary vitamin C intake, the negative correlation between cigarette smoking and serum vitamin C levels persisted. The risk of severe hypovitaminosis C (serum levels less than or equal to 0.2 mg/dl; 11.4 mumol/L) was increased in smokers, particularly when not accompanied by vitamin supplementation (odds ratio 3.0, 95% CI: 2.5, 3.6). These data suggest that even though smoking adversely affects preferences for vitamin C rich foods, the inverse association between smoking and serum vitamin C levels occurs independently of dietary intake.

Adolescent↗
PubMed1988

Effect of fish oil concentrate on lipoprotein composition in NIDDM.

Non-insulin-dependent diabetes mellitus (NIDDM) is associated with elevated very-low-density lipoprotein (VLDL) triglyceride concentrations and abnormalities of low-density lipoprotein (LDL) composition. Because fish oil supplementation may favorably affect lipid and lipoprotein concentrations in nondiabetic subjects, we determined the effect of fish oil concentrate on plasma lipids and lipoprotein composition in patients with NIDDM. Dietary-supplementation 1-mo periods of 4.0 and 7.5 g of omega-3 fatty acids in fish oil were compared with a placebo of 12 g safflower oil by use of a single-blind crossover design. Medications, including antidiabetic therapy, were continued through the study. Compared with safflower oil treatment, fish oil supplementation resulted in a significant reduction of total plasma triglycerides of 24% at the 4-g dose and a larger reduction of 39% at the 7.5-g dose. These decreases were due to similar reductions in VLDL triglycerides. LDL cholesterol levels were mildly elevated, but a larger 20% increase in LDL apolipoprotein B (apoB) concentration was observed. During supplementation with the fish oil concentrate, the LDL cholesterol-to-apoB ratio was significantly reduced when compared with pretreatment values, but not when compared with safflower oil treatment. High-density lipoprotein (HDL) cholesterol and plasma apoA1 levels were not significantly changed during fish oil treatment. At the 7.5-g dose, fasting glucose and glycohemoglobin levels increased by 20 and 12%, respectively, but were unchanged at the lower level of supplementation. Thus, in NIDDM patients, dietary supplementation with omega-3 fatty acids induces a reduction in total plasma and VLDL triglyceride levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Polyunsaturated and saturated fat, cholesterol, and fatty acid supplementation.

Almost all of risk factors for arteriosclerosis and coronary heart disease identified in population studies are overrepresented in diabetes. Of these risk factors, plasma lipids and lipoproteins are the target for altered dietary habits, particularly regarding fat. Such an alteration must be qualified with an understanding of the relationship between diabetes mellitus and lipoprotein metabolism and evidence of a favorable outcome of a fat-modified diet on this relationship. In seeking a revision of the current dietary fat recommendations of the American Diabetes Association, we have addressed five major questions. Is the serum lipid or lipoprotein concentration in diabetes different from that of the nondiabetic population? Are the familial or genetic forms of hyperlipidemia coinherited and/or overrepresented in diabetic subjects? What is the mechanism of the lipid/lipoprotein disorder in diabetes, and to what extent could it be related to the diabetic metabolic milieu? What is the effect of antidiabetic treatment on plasma lipids and lipoprotein metabolism? What evidence is there that a modified-fat diet could exert favorable benefits over and above what could be achieved by optimal antidiabetic therapy? This article outlines the revised dietary fat recommendations of the American Diabetes Association Nutrition Task Force and their rationale.

Arteriosclerosis↗
PubMed1988

A history of hypercholesterolemia influences cholesterol measurements.

Elevated plasma cholesterol levels identified during cholesterol screening are often lower when repeated because of the regression to the mean effect. We evaluated the effect of the presence or absence of a history of hypercholesterolemia on the regression to the mean phenomenon. Of 564 volunteers undergoing cholesterol screening, 53 subjects between the ages of 20 and 65 years found to have total plasma cholesterol levels above the 90th percentile for age and sex returned for a second determination. No dietary or behavioral changes occurred during the study. Individuals with a history of hypercholesterolemia showed no change in plasma cholesterol level between the first and second visits; however, a net 13.1% reduction in mean plasma cholesterol level was observed in the group without this history, with 59% of subjects dropping below the 90th percentile level. These findings demonstrate that the regression to the mean effect is confined to those individuals who do not report a history of hyperlipidemia. Subjects with this history are more likely to have their initial cholesterol elevation confirmed when the test is repeated.

Adult↗
PubMedDate not supplied

Heterogeneity of low density lipoprotein responses to fish-oil supplementation in hypertriglyceridemic subjects.

Previous studies have demonstrated a variable effect of fish oil on low density lipoprotein (LDL) cholesterol and apolipoprotein (apo) B levels, particularly in hypertriglyceridemic subjects. Since heterogeneity of LDL composition and metabolism in hypertriglyceridemic subjects is well described, the present study was undertaken to determine if the response of LDL to dietary fish-oil supplementation is dependent upon pretreatment differences in LDL composition. A single-blind, cross-over design was used with 18 hypertriglyceridemic subjects, who were given supplements of a safflower-oil placebo or a fish-oil concentrate (4.0 g omega-3 fatty acids; [F4 dose]) for 1 month. Sixteen subjects then received an additional month of fish-oil supplementation at a higher dose (7.5 g omega-3 fatty acids [F7.5 dose]). The initial LDL cholesterol/apo B ratio, an index of LDL composition, was correlated positively with changes in LDL apo B levels (F4.0 dose: r = 0.41, p = 0.06; F7.5 dose: r = 0.51, p = 0.03) and negatively with changes in LDL cholesterol concentrations (F4.0 dose: r = -0.51, p = 0.01; F7.5 dose: r = -0.50, p = 0.02). Twelve subjects with LDL cholesterol/apo B ratios above 1.4 had large increases in LDL apo B (51% at both doses, p less than 0.05) but much smaller changes in LDL cholesterol levels during fish-oil treatment. Six subjects with LDL cholesterol/apo B ratios below 1.4 showed a trend toward increased LDL cholesterol (12% increase from baseline at F4 dose, 10% increase from baseline at F7.5 dose, p greater than 0.05) but not in LDL apo B levels during fish-oil therapy. These data suggest that LDL responses to fish oil may be linked to underlying differences in LDL composition and, presumably, to differences in LDL metabolic behavior.

Adult↗