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Biomedical subjects

M H Davidson

Publications and source records attributed to M H Davidson.

At least 55 records · Page 3Linked to original sources
PubMed1998

A low-viscosity soluble-fiber fruit juice supplement fails to lower cholesterol in hypercholesterolemic men and women.

This study was designed to determine whether a soluble dietary fiber supplement containing gum arabic and pectin in apple juice would lower serum lipids in 110 hypercholesterolemic men and women. Subjects were stabilized on an American Heart Association Phase I Diet for 8 wk. Those with elevated low density lipoprotein cholesterol levels, despite dietary modification, continued to follow the diet and were randomly assigned to receive 720 mL/d of apple juice containing 0 (control), 5, 9 or 15 g of gum arabic and pectin (4:1 ratio) for 12 wk, followed by a 6-wk apple juice-only washout phase. Serum lipid profiles, body weight and 3-day diet records were collected at 3-wk intervals. No significant differences among groups were observed in serum lipid responses during treatment or washout. During the treatment phase, mean serum total cholesterol and triglyceride concentrations increased by 3.5 and 28.5%, respectively (all groups combined, P < 0.0001). The high density lipoprotein cholesterol level did not change significantly from baseline in any group. During washout, mean total cholesterol concentration rose by an additional 2.4% (P < 0.05) compared with the value at the end of the treatment period, suggesting that the apple juice used to deliver the fiber supplement may have contributed to the adverse changes observed in the serum lipid profile. These findings do not support the hypothesized hypocholesterolemic effect of the gum arabic/pectin (4:1) mixture studied, but do underline the importance of selecting appropriate vehicles for delivery of dietary fiber mixtures.

Adult↗
PubMed1998

The cost of reaching National Cholesterol Education Program (NCEP) goals in hypercholesterolaemic patients. A comparison of atorvastatin, simvastatin, lovastatin and fluvastatin.

OBJECTIVE: Recognising the importance of treating hyperlipidaemia, the National Cholesterol Education Program (NCEP) has established widely accepted treatment goals for low density lipoprotein cholesterol (LDL-C). Medications used most commonly to achieve these LDL-C goals are HMG-CoA reductase inhibitors. The relative resource utilisation and cost associated with the use of reductase inhibitors of different LDL-C lowering efficacy are unknown, but are major health and economic concerns. The objective of this study was to determine the mean total cost of care to reach NCEP goals with various reductase inhibitors. DESIGN: In a randomised, 54-week, 30-centre controlled trial we compared resources used and costs associated with treating patients to achieve NCEP goals using 4 reductase inhibitors: atorvastatin, simvastatin, lovastatin and fluvastatin. PATIENTS AND PARTICIPANTS: The trial studied 662 patients; 318 had known atherosclerotic disease. INTERVENTIONS: Reductase inhibitor therapy was initiated at recommended starting doses and increased according to NCEP guidelines and package insert information. For patients who did not reach the goal at the highest recommended dose of each reductase inhibitor, the resin colestipol was added. MAIN OUTCOME MEASURES AND RESULTS: Patients treated with atorvastatin, compared-with other reductase inhibitors, were more likely to reach NCEP goals during treatment (p < 0.05), required fewer office visits (p < 0.001) and less adjuvant colestipol therapy (p = 0.001). Consequently, the mean total cost of care (1996 values) to reach NCEP goals was lower with atorvastatin [$US1064; 95% confidence interval (CI): $US953 to $US1176] compared with simvastatin ($US1471, 95% CI: $US1304 to $US1648), lovastatin ($US1972; 95% CI: $US1758 to $US2186) and fluvastatin ($US1542; 95% CI: $US1384 to $US1710). Results were similar for patients with or without known atherosclerotic disease. CONCLUSIONS: In patients requiring drug therapy for hypercholesterolaemia, NCEP LDL-C goals are achieved significantly more often using fewer resources with atorvastatin compared with simvastatin, lovastatin or fluvastatin.

Aged↗
PubMed1997

Effectiveness of atorvastatin for reducing low-density lipoprotein cholesterol to National Cholesterol Education Program treatment goals.

Atorvastatin is a highly efficacious hydroxymethylglutaryl-coenzyme A reductase inhibitor that has been shown to reduce low-density lipoprotein cholesterol by 40% to 60%. Monotherapy with atorvastatin (10 to 80 mg/day) is well-tolerated, convenient, and appears to be effective for achieving National Cholesterol Education Program treatment goals in most patients, regardless of risk status.

Anticholesteremic Agents↗
PubMed1997

A comparison of estrogen replacement, pravastatin, and combined treatment for the management of hypercholesterolemia in postmenopausal women.

OBJECTIVES: To evaluate and compare the lipid-altering effects of conjugated estrogens and pravastatin, alone and in combination, in postmenopausal women with hypercholesterolemia. METHODS: This was a double-blind, randomized, placebo-controlled clinical trial with 4 parallel groups. Participants (N = 76) were randomly assigned to receive conjugated estrogens, 0.625 mg/d; pravastatin sodium, 20 mg/d; conjugated estrogens plus pravastatin; or a placebo for 16 weeks. RESULTS: Primary end points were changes in serum lipid parameters. Among participants treated with conjugated estrogens, levels of non-high density lipoprotein cholesterol (non-HDL-C) (13.0%) and calculated low density lipoprotein cholesterol (LDL-C) (13.5%) decreased, while levels of HDL-C (22.5%) and triglycerides (4.2%) increased. Participants in the pravastatin group achieved reductions of 23.7% and 25.4% in non-HDL-C and calculated LDL-C levels, respectively. Levels of HDL-C increased slightly (3.7%) and triglycerides decreased by 12.1%. Among participants treated with a combination of conjugated estrogens plus pravastatin, the non-HDL-C (-25.2%) and calculated LDL-C (-28.7%) responses were similar to those of the pravastatin group, and the HDL-C response (21.2%) was similar to that observed in the conjugated estrogens group. Triglyceride levels remained similar to baseline (-0.9%) in the combined treatment group. CONCLUSIONS: Administration of conjugated estrogens resulted in potentially antiatherogenic changes in levels of non-HDL-C, HDL-C, and calculated LDL-C. The HDL-C response to combined treatment was similar to that observed in women taking conjugated estrogens alone, while the non-HDL-C and LDL-C responses to combined treatment were similar to those produced by pravastatin therapy alone. These findings support the position of the National Cholesterol Education Program that estrogen replacement, with a progestin where indicated, should be given consideration as a therapeutic option for the management of hypercholesterolemia in postmenopausal women.

Anticholesteremic Agents↗
PubMed1997

The efficacy and six-week tolerability of simvastatin 80 and 160 mg/day.

The hydroxymethylglutaryl coenzyme A reductase inhibitor simvastatin is the most effective of the currently approved hypolipidemic drugs and has been shown to reduce mortality and coronary morbidity in patients with coronary artery disease. For these patients the United States National Cholesterol Education Program advocates reducing low-density lipoprotein (LDL) cholesterol to <100 mg/dl. However, in some patients this cannot be achieved using monotherapy with simvastatin 40 mg/day, the current maximal recommended dose. To evaluate the effectiveness of extending the dosage range, 156 subjects with LDL cholesterol >160 mg/dl and triglycerides (TG) <350 mg/dl were randomized to simvastatin at doses of 40, 80, and 160 mg/day in a 26 week, double-blind, 3-period, complete block crossover study. Each active treatment period was 6 weeks in duration with intervening 2 week washout periods. Median reductions from baseline in LDL cholesterol were 41%, 47%, and 53% in the 40-, 80-, and 160-mg groups, respectively. The corresponding reductions in plasma TG were 21%, 23%, and 33%. High-density lipoprotein (HDL) cholesterol increased by 6% to 8% in each group. One patient (0.7%) taking 160 mg developed myopathy; 1 patient (0.7%) taking 80 mg, and 3 (2.1%) taking 160 mg had transaminase elevations > 3 times the upper limit of normal. No new or unexpected adverse effects were observed. We conclude that simvastatin at doses of 80 and 160 mg/day provides additional efficacy with a low short-term incidence of adverse effects; our results support the continued investigation of simvastatin at these doses.

Adult↗
PubMed1997

Effects of docosahexaenoic acid on serum lipoproteins in patients with combined hyperlipidemia: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: The objective of this study was to evaluate the effects of daily dietary supplementation with 1.25 g or 2.5 g of docosahexaenoic (DHA), in the absence of eicosapentaenoic acid (EPA), on serum lipids and lipoproteins in persons with combined hyperlipidemia (CHL) [serum low-density lipoprotein cholesterol (LDL-C) 130 to 220 mg/dL and triglycerides 150 to 400 mg/dL]. METHODS: After a 6-week dietary stabilization period, subjects entered a 4-week single-blind placebo (vegetable oil) run-in phase. Those with adequate compliance during the the run-in were randomized into one of three parallel groups (placebo, 1.25, or 2.5 g/day DHA) for 6 weeks of treatment. Supplements were administered in a triglyceride form contained in gelatin capsules. Primary outcome measurements were plasma phospholipid DHA content, serum triglycerides, high-density lipoprotein cholesterol (HDL-C). LDL-C and non-HDL-C. RESULTS: The DHA content of plasma phospholipids increased dramatically (2 to 3 fold) in a dose-dependent manner. Significant (p < 0.05) changes were observed in serum triglycerides (17 to 21% reduction) and HDL-C (6% increase) which were of similar magnitude in both DHA groups. Non-HDL-C [+1.6 (NS) and +5.7% (p < 0.04)] and LDL-C [+9.3% (NS) and +13.6% (p < 0.001)] increased in the DHA treatment groups. All lipid effects reached an apparent steady state within the first 3 weeks of treatment. CONCLUSION: Dietary DHA, in the absence of EPA, can affect lipoprotein cholesterol and triglyceride levels in patients with combined hyperlipidemia. The desirable triglyceride and HDL-C changes were present at a dose which did not significantly increased non-HDL-C or LDL-C. These preliminary findings suggest that dietary supplementation with 1.25 g DHA/day, provided in a triglyceride form, may be an effective tool to aid in the management of hypertriglyceridemia.

Administration, Oral↗
PubMed1997

Olestra's effect on vitamins D and E in humans can be offset by increasing dietary levels of these vitamins.

One hundred two normal healthy males and females were given 0, 8, 20 or 32 g/d olestra to which had been added graded amounts of vitamins A, D and E for 8 wk in a parallel, double-blind study. The primary purpose of the study was to determine the amounts of vitamins D and E needed to offset the effect of olestra on the availability of these vitamins. Serum concentrations of retinol, carotenoids, 25-hydroxyvitamin D metabolites, alpha-tocopherol, phylloquinone, lipids, ferritin and total iron, iron-binding capacity and hematology parameters, plasma concentrations of des-gamma-carboxyprothrombin and prothrombin, and urinary gamma-carboxyglutamic acid (Gla) excretion were measured biweekly. Clinical chemistry and urinalysis parameters, vitamin B12 absorption, and serum 1,25-dihydroxyvitamin D concentration were measured at wk 0 and 8. Serum concentrations of alpha-tocopherol and 25-hydroxyergocalciferol were restored to control concentration by adding 2.1 mg d-alpha-tocopheryl acetate and 0.06 microg ergocalciferol per gram of olestra, respectively, to the diet. Olestra reduced serum concentrations of 25-hydroxyergocalciferol, carotenoids and phylloquinone in a dose-responsive manner but did not affect Gla excretion, plasma des-gamma-carboxyprothrombin and prothrombin concentrations, overall vitamin D status, vitamin B12 absorption or iron status. Laboratory evaluations showed no olestra-related effects. Subjects in all groups reported mild to moderately severe transient gastrointestinal symptoms. These symptoms did not affect study compliance or the integrity of the data.

25-Hydroxyvitamin D 2↗
PubMed1997

Age-dependence of the relationship between adiposity and serum low density lipoprotein cholesterol in men.

OBJECTIVE: The primary aim of this study was to evaluate the effects of age on the relationships between commonly used measures of adiposity [abdominal circumference (AC) and body mass index (BMI)] and serum lipids in men. METHODS: AC, height, weight, and a fasting serum lipid profile were measured in 194 male volunteers, aged 18 to 81 years, who were free of diabetes mellitus and had participated in one of several studies on metabolic cardiovascular risk factors in the authors' laboratory. Least squares linear regression and two-way analysis of variance were used to assess relationships between measures of adiposity and fasting serum lipid values in two age groups: 18 to 49 (n = 53) and 50 to 81 years (n = 141). RESULTS: Increasing AC correlated with serum triglycerides [r = 0.32 (younger) and 0.43 (older)], and was inversely associated with high-density lipoprotein cholesterol (r = -0.26 and -0.26). Regression lines for these relationships did not differ between age groups. Low-density lipoprotein cholesterol (LDL-C) increased with greater AC among younger subjects (r = 0.44), but not among men over 50 years (r = -0.01). The relationships between BMI and serum lipids generally paralleled those for AC, but were weaker than for AC in the younger group. CONCLUSIONS: These findings suggest that an interaction exists between age and adiposity as determinants of LDL-C levels, and that AC is a simple, clinically useful tool for assessing risk for adiposity-related dyslipidemia in men.

Abdomen↗
PubMed1996

Efficacy of the National Cholesterol Education Program Step I diet. A randomized trial incorporating quick-service foods.

OBJECTIVE: To determine the effect of incorporating quick-service meals into a Step I diet on the achievement of the National Cholesterol Education Program (NCEP) guidelines and on the blood lipid response of hyperlipidemic subjects (as possibly, the achievement of, and adherence to, dietary goals may be assisted by the inclusion of familiar foods, instead of their exclusion). METHODS: This was a randomized, parallel design study in free-living subjects. Hypercholesterolemic men and women (low-density lipoprotein cholesterol [LDL-C] level, 3.36 to 5.69 mmol/L [130 to 220 mg/dL]) who were consuming a high-fat diet (> 33% of total calories from fat) were randomly assigned to either a traditional NCEP Step I diet (n = 44) or an NCEP Step I diet with the incorporation of frequent quick-service meals (NCEP-QS, n = 45). RESULTS: After 8 weeks of treatment, both groups similarly reduced their reported dietary intakes of energy (approximately 30%), total percent fat (approximately 8%), percent saturated fat (approximately 3%), and cholesterol (approximately 38% to 28%). Both groups also experienced a decrease in the levels of total serum cholesterol (NCEP Step I diet, 8%; NCEP-QS Step I diet, 3%) and LDL-C (NCEP Step I diet, 10%; NCEP-QS Step I diet, 4%). However, compared with the group receiving the NCEP-QS Step I diet, the subjects who were consuming the NCEP Step I diet showed a significantly greater reduction in their total serum cholesterol and LDL-C levels over time (P < .05). Weight loss was significantly correlated (P < .001) with the decrease in the total serum cholesterol and LDL-C levels for all subjects combined. CONCLUSIONS: Hyperlipidemic subjects who were consuming an NCEP Step I diet, with or without the incorporation of quick-service meals, experienced a significant decrease in their total serum cholesterol and LDL-C levels, body weight, and reported fat intake. The beneficial responses in lipid levels were modestly mitigated in the quick-service diet group.

Adult↗
PubMed1996

Efficacy and safety of a new HMG-CoA reductase inhibitor, atorvastatin, in patients with hypertriglyceridemia.

OBJECTIVE: To assess the lipid-lowering effect of atorvastatin (a new 3-hydroxy-3-methylglutaryl coenzyme A [HMG-CoA] reductase inhibitor) on levels of serum triglycerides and other lipoprotein fractions in patients with primary hypertriglyceridemia, determine if atorvastatin causes a redistribution of triglycerides in various lipoprotein fractions, and assess its safety by reporting adverse events and clinical laboratory measurements. DESIGN: Randomized double-blind, placebo-controlled, parallel-group, multicenter trial. SETTING: Community- and university-based research centers. PATIENTS: A total of 56 patients (aged 26 to 74 years) with a mean baseline triglyceride level of 6.80 mmol/L (603.3 mg/dL) and a mean baseline low-density lipoprotein cholesterol (LDL-C) level of 3.07 mmol/L (118.7 mg/dL). INTERVENTIONS: Cholesterol-lowering diet (National Institutes of Health National Cholesterol Education Program Step I Diet) and either 5 mg, 20 mg, or 80 mg of atorvastatin, or placebo. MAIN OUTCOME MEASURES: Percent change from baseline in total triglycerides for three dose levels of atorvastatin compared with placebo. RESULTS: Mean reductions in total triglycerides between 5 mg, 20 mg, and 80 mg of atorvastatin and placebo after 4 weeks of treatment were -26.5%, -32.4%, -45.8%, and -8.9%, respectively. Mean reductions in LDL-C were -16.7%, -33.2%, -41.4%, and -1.4%, respectively, and very low-density lipoprotein cholesterol (VLDL-C) were -34.3%, -45.9%, -57.7%, and -5.5%, respectively. Similar mean changes in total apolipoprotein B (apo B) (-16.9%, -32.8%, -41.7%, and +1.0%), apo B in LDL (-14.8%, -29.8%, -42.0%, and -3.1%), and apo B in VLDL (-23.8%, -35.8%, -34.4%, and +11.7%) were observed. In addition, comparable mean changes in LDL triglycerides (-22.5%, -30.7%, -39.9%, and +3.9%) and VLDL triglycerides (-28.1%, -34.0%, -47.3%, and -10.8%) were seen. CONCLUSIONS: In atorvastatin treatment groups, total serum triglyceride levels decreased in a dose-dependent manner, reductions in the 20-mg and 80-mg groups were statistically significant (P < .05) compared with placebo. Atorvastatin did not cause a redistribution of triglycerides but consistently lowered triglycerides in all lipoprotein fractions. Atorvastatin was well tolerated.

Adult↗
PubMed1996

A psyllium-enriched cereal for the treatment of hypercholesterolemia in children: a controlled, double-blind, crossover study.

Psyllium, a water-soluble fiber, has been shown to lower total serum and low-density-lipoprotein (LDL)-cholesterol concentrations in adult hypercholesterolemic subjects and may be effective in the treatment of hypercholesterolemia in children. The effects of a psyllium-enriched cereal were compared with a matched control cereal in a double-blind, crossover fashion in 25 children, 6-18 y old, with hypercholesterolemia. After an 8-wk diet-stabilization period, the subjects were randomly assigned to receive the active or control cereals for 6 wk, followed by a 6-wk washout period and a 6-wk crossover treatment period. Whereas no changes were noted in total and LDL-cholesterol concentrations during consumption of the control cereal, significant changes were seen during the psyllium-cereal periods [0.31 mmol/L (12.1 mg/dL) and 0.28 mmol/L (10.9 mg/dL); P = 0.03 and 0.01, respectively]. The psyllium-enriched cereal was well tolerated throughout the trial. Consumption of the psyllium-enriched cereal resulted in a modest 7% reduction in LDL-cholesterol concentrations compared with the control cereal when used in this pediatric hypercholesterolemic sample. Psyllium offers a potential adjunct to a low-fat diet for the treatment of hypercholesterolemia in the pediatric population because of its ease of incorporation into various foods.

Adolescent↗
PubMed1995

The effects of colestipol tablets compared with colestipol granules on plasma cholesterol and other lipids in moderately hypercholesterolemic patients.

The purpose of this study was to investigate and compare the efficacy, safety, and patient acceptability of a new formulation of colestipol, colestipol tablets (T), with those of colestipol granules (G), in a randomized, double-blind, placebo-controlled, multicenter study. Three hundred and seventeen patients with primary hypercholesterolemia who were following a low-fat, low-cholesterol diet (NCEP Step I diet), and had low-density lipoprotein cholesterol (LDL-C) levels > or = 4.14 mmol/l (160 mg/dl) and < or = 6.46 mmol/l (250 mg/dl) were studied. Study medication was taken twice a day, with breakfast and supper, for 8 weeks. The six parallel treatment groups consisted of colestipol tablets 2 g b.i.d. and 8 g b.i.d., matching placebo tablets b.i.d., colestipol granules 2 g b.i.d. and 8 g b.i.d., and matching placebo granules b.i.d.. Study endpoints included absolute change and percentage change from baseline in selected lipid, lipoprotein, and apolipoprotein measurements; LDL-C lowering was the primary efficacy endpoint. Treatment with colestipol tablets and colestipol granules resulted in virtually identical, statistically significant (P < or = 0.05) reductions of LDL-C, total cholesterol (TC), TC/HDL-C, and apolipoprotein B (apo B). Compared with placebo, all active treatments (tablets 4 g/day, tablets 16 g/day, granules 4 g/day, granules 16 g/day) significantly reduced LDL-C (12%, 24%, 12%, 25%, respectively), TC (7%, 15%, 8%, 15%, respectively), TC/HDL-C (8%, 14%, 9%, 15%, respectively) and apo B (12%, 20%, 13%, 22%, respectively). All active treatments significantly increased lipoprotein particle AI (LpAI) (5%, 23%, 14%, 18%, respectively). VLDL-C and triglycerides increased significantly in the high-dose groups. The proportions of patients reporting adverse events, largely gastrointestinal-related, were not different among the active treatment groups. The treatments were well-tolerated, and no drug-related serious adverse events were reported. Patients experienced with granule medication prior to this study preferred tablets over granules. This study demonstrates that colestipol tablets are an effective treatment to reduce LDL-C in patients with primary hypercholesterolemia, are equivalent to colestipol granules, are well-tolerated, and are preferred over granules by patients.

Adult↗
PubMed1995

Enhanced low-density lipoprotein cholesterol reduction and cost-effectiveness by low-dose colestipol plus lovastatin combination therapy.

A total of 96 patients with moderate elevations of low-density lipoprotein (LDL) cholesterol were randomly assigned to 4 different double-blind treatment regimens: placebo; colestipol 5 g and lovastatin 20 mg/day (C5 + L20); colestipol 10 g and lovastatin 20 mg/day (C10 + L20); and lovastatin 40 mg/day (L40). During 12 weeks of therapy, C10 + L20 achieved the greatest reduction in total cholesterol (-32%) and LDL cholesterol (-48%) levels from baseline. This combination also exhibited significantly greater reductions in LDL cholesterol levels than the C5 + L20 and L40 groups (p < 0.01). The differences in total and LDL cholesterol reduction between the C5 + L20 and L40 groups were not significant. Similar changes and differences between treatments were seen in apolipoprotein B levels. Whereas mean total apolipoprotein A-I levels increased with all treatments (p < 0.05), lipoprotein particles A-I were significantly increased in the C10 + L20 group (p < 0.01) only. Results demonstrate that the combination of low-dose lovastatin (20 mg/day) with low-dose colestipol (5 or 10 g/day) produces LDL cholesterol reductions equal to or greater than higher doses of lovastatin (40 mg/day). In addition, low-dose combinations are > 25% more cost-effective than high-dose monotherapy.

Apolipoproteins↗
PubMed1995

Reduction of LDL cholesterol by 25% to 60% in patients with primary hypercholesterolemia by atorvastatin, a new HMG-CoA reductase inhibitor.

This 6-week, double-blind clinical trial evaluated lipid parameter responses to different dosages of atorvastatin in patients with primary hypercholesterolemia. Atorvastatin is a new 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor under development. After completing an 8-week placebo-baseline dietary phase, 81 patients were randomly assigned to receive either placebo or 2.5, 5, 10, 20, 40, or 80 mg atorvastatin once daily for 6 weeks. Plasma LDL cholesterol reductions from baseline were dose related, with 25% to 61% reduction from the minimum dose to the maximum dose of 80 mg atorvastatin once a day. Plasma total cholesterol and apo B reductions were also dose related. Previously, reductions in LDL cholesterol of the magnitude observed in this study have been seen only with combination drug therapy. In this study, atorvastatin was well tolerated by hyperlipidemic patients, had an acceptable safety profile, and provided greater reduction in cholesterol than other previously reported HMG-CoA reductase inhibitors.

Adolescent↗