Biomedical subjects

Cheryl A Gibson

Publications and source records attributed to Cheryl A Gibson.

7 recordsLinked to original sources

PubMed2006

Author contacts for retrieval of data for a meta-analysis on exercise and diet restriction.

OBJECTIVES: The mode of contact and response levels of authors who had been asked to provide missing or incomplete data for a systematic review on diet and exercise interventions for weight loss was examined. METHODS: We contacted authors by electronic mail, letter, or both. Survival analyses were performed with the Kaplan-Meier method to determine differences in the proportion of responders over time among the different modes of contact and to determine whether response rates differed between authors from the United States and those from other countries. Logistic regression was used to determine whether the number of items requested and publication date influenced the likelihood of response. RESULTS: Two hundred forty-one (39.9 percent) studies had missing or incomplete data (e.g., sample size, age, caloric restriction, exercise amount, and so on). We were unable to locate ninety-five authors (39.4 percent). Of the remaining authors, forty-six authors (31.5 percent) responded to information requests. Time to respond differed by contact method (p < .05): e-mail (3 +/- 3 days), letter (27 +/- 30 days), and both (13 +/-12 days). Response rates from U.S. authors did not differ from those of other countries. CONCLUSIONS: Our study suggests poor success in the acquisition of essential information. Given considerable time and resources, weight loss studies require improved reporting standards to minimize the relatively unsuccessful attempt to contact authors for important and necessary information.

Clinical Trials as Topic↗

PubMed2005

Effect of low-density lipoprotein apheresis on lipoprotein-associated phospholipase A2.

Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is a proinflammatory participant in atherosclerosis and a potential biomarker for coronary heart disease. The effects of low-density lipoprotein (LDL) apheresis on Lp-PLA(2) levels were evaluated in 8 patients with cardiovascular disease. Each patient received 5 LDL apheresis treatments over a 3-month period. The mean direct LDL cholesterol level reduction was 60% (252 to 100 mg/dl). LDL apheresis acutely reduced Lp-PLA(2) by 21.4%. Over the course of treatment, Lp-PLA(2) levels were reduced by 29%. Chronic LDL apheresis significantly reduces Lp-PLA(2) independent of LDL cholesterol, which may be a potential mechanism by which LDL apheresis diminishes coronary heart disease risk.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

PubMed2005

Reporting quality of randomized trials in the diet and exercise literature for weight loss.

BACKGROUND: To adequately assess individual studies and synthesize quantitative research on weight loss studies, transparent reporting of data is required. The authors examined the reporting quality of randomized trials in the weight loss literature, focusing exclusively on subject characteristics as they relate to enrollment, allocation, and follow-up. METHODS: An extensive literature review, which included a computerized search of the MEDLINE database, manual searches of bibliographic references, and cross-referencing of 92 review articles was conducted. A checklist, based on CONSORT recommendations, was used to collect information on whether or not authors reported age, gender, co-morbid disease, medication use, race/ethnicity, and postmenopausal status. Also tracked was whether or not initial and final sample size was reported and stratified by gender. RESULTS: Of 604 possible articles, 231 articles met eligibility criteria. Important subject characteristics were not reported as the following breakdown indicates: age (11%), gender (4%), race/ethnicity (86%), co-morbid disease states (34%), and medication use (92%). Additionally, 21% of articles failed to report initial sample size by gender while 69% neglected to report final sample size by gender. CONCLUSION: Inadequate reporting can create difficulties with interpretation and can lead to biased results receiving false credibility. The quality of reporting for weight loss studies needs considerable improvement.

Demography↗

PubMed2005

Effect of lipid-lowering drug therapy on small-dense low-density lipoprotein.

OBJECTIVE: To review the effects of lipid-lowering therapy on small-dense low-density lipoprotein cholesterol (sdLDL-C). DATA SOURCES: Literature was obtained from MEDLINE (1989-September 2004) and references of selected articles. Key search terms included small-dense LDL-C and lipid-lowering drug therapy. DATA SYNTHESIS: Statins, fibrates, and niacin have demonstrated favorable effects on sdLDL-C, especially among patients with mixed dyslipidemia or hypertriglyceridemia. These effects include a reduction of sdLDL-C and/or a shift to the larger, less atherogenic LDL-C. CONCLUSIONS: Data suggest that statins, fibrates, and niacin are effective at reducing concentrations of sdLDL-C and possibly normalizing LDL-C subclasses.

Cholesterol, LDL↗

PubMed2005

Association between hematological parameters and high-density lipoprotein cholesterol.

PURPOSE OF REVIEW: The ability of high-density lipoprotein cholesterol to reverse atherosclerosis and reduce cardiovascular disease has been shown in several randomized controlled trials. One mechanism by which high-density lipoprotein cholesterol protects the vascular system includes hemorheology, the study of blood flow. RECENT FINDINGS: Blood viscosity, or the resistance of flow, can be altered by red blood cell aggregation, red blood cell deformability, and plasma viscosity. Elevated high-density lipoprotein cholesterol levels may improve all of these rheological mediators. An infusion of recombinant high-density lipoprotein cholesterol can immediately release nitric oxide, a potent vasodilator and responder to changes in rheology, into the arteries by activation of endothelial nitric oxide synthase. The stimulation of nitric oxide release by high-density lipoprotein cholesterol may also alter blood rheology. SUMMARY: In this article, we will review hemorheology, particularly blood viscosity along with other hemorheological factors, and examine their association with high-density lipoprotein cholesterol.

Atherosclerosis↗

PubMed2005

Controlled endurance exercise training and VO2max changes in older adults: a meta-analysis.

This meta-analysis of controlled clinical trials quantifies the effect of aerobic exercise on VO2max (aerobic fitness) among sedentary older adults and examines the associations of such magnitude with variables of intervention. Forty-one trials including 2102 older subjects (within-group mean age of 60 years and older) were identified by searches of databases, hand searching, and cross-referencing. Outcomes were homogeneous. The pooled standardized effect size by a fixed-effect model showed a higher moderate effect (mean +/- SEM) of 0.64+/-0.05; 95% confidence interval, 0.56-0.73; p<0.001, representing a net increase in VO2max (mean +/- SEM) of 3.78+/-0.28 mL.kg-1.min-1; 95% confidence interval, 3.24-4.33; or a 16.3% improvement, compared with control groups. Greater improvement in VO2max was associated with training length more than 20 weeks and training intensity of approximately 60% but less than 70% of VO2max. Endurance training improves aerobic fitness in older adults, thus providing protective benefits for cardiovascular aging and quality of later life.

Exercise↗

PubMed2004

Effect of low-density lipoprotein cholesterol apheresis on blood viscosity.

Few studies have been designed to study the hemodynamic effects of low-density lipoprotein apheresis, especially on whole blood viscosity. Six patients with cardiovascular disease and hypercholesterolemia underwent a single low-density lipoprotein apheresis, resulting in significant reductions in whole blood viscosity at all shear rates.

Blood Component Removal↗