ABSTRACT: Chronic inflammation and oxidative stress are common risk factors for atherosclerosis. Zinc is an essential micronutrient that can function as an antiinflammatory and antioxidative agent, and as such, it may have atheroprotective properties.
We hypothesized that zinc down-regulates the production of atherosclerosis-related cytokines/molecules in humans.
To examine these effects, we conducted a randomized, double-blinded, placebo trial of zinc supplementation in elderly subjects. We recruited 40 healthy elderly subjects (aged 56-83 y) and randomly assigned them to 2 groups. One group was given an oral dose of 45 mg zinc/d as a gluconate for 6 mo. The other group was given a placebo. Cell culture models were conducted to study the mechanism of zinc as an atheroprotective agent.
After 6 mo of supplementation, the intake of zinc, compared with intake of placebo, increased the concentrations of plasma zinc and decreased the concentrations of plasma high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, macrophage chemoattractant protein 1 (MCP-1), vascular cell adhesion molecule 1 (VCAM-1), secretory phospholipase A2, and malondialdehyde and hydroxyalkenals (MDA+HAE) in elderly subjects. Regression analysis showed that changes in concentrations of plasma zinc were inversely associated with changes in concentrations of plasma hsCRP, MCP-1, VCAM-1, and MDA+HAE after 6 mo of supplementation. In cell culture studies, we showed that zinc decreased the generation of tumor necrosis factor-alpha, IL-1beta, VCAM-1, and MDA+HAE and the activation of nuclear transcription factor kappaB and increased antiinflammatory proteins A20 and peroxisome proliferator-activated receptor-alpha in human monocytic leukemia THP-1 cells and human aortic endothelial cells compared with zinc-deficient cells.
These findings suggest that zinc may have a protective effect in atherosclerosis because of its antiinflammatory and antioxidant functions.
American Journal of Clinical Nutrition 06/2010; 91(6):1634-41. · 6.67 Impact Factor
ABSTRACT: Zinc deficiency, cell-mediated immune dysfunction, susceptibility to infections, and increased oxidative stress have been observed in elderly subjects (ie, those >55 y old). Zinc is an effective antiinflammatory and antioxidant agent.
The primary objective was to determine the effect of zinc on the incidence of total infections in healthy elderly subjects. The secondary objective was to determine the effect of zinc on cytokines and oxidative stress markers.
A randomized, double-blind, placebo-controlled trial of zinc supplementation was conducted in elderly subjects. Fifty healthy subjects of both sexes aged 55-87 y and inclusive of all ethnic groups were recruited for this study from a senior center. The zinc-supplemented group received zinc gluconate (45 mg elemental Zn/d) orally for 12 mo. Incidence of infections during the supplementation period was documented. The generation of inflammatory cytokines, T helper 1 and T helper 2 cytokines, and oxidative stress markers and the plasma concentrations of zinc were measured at baseline and after supplementation.
Compared with a group of younger adults, at baseline the older subjects had significantly lower plasma zinc, higher ex vivo generation of inflammatory cytokines and interleukin 10, and higher plasma oxidative stress markers and endothelial cell adhesion molecules. The incidence of infections and ex vivo generation of tumor necrosis factor alpha and plasma oxidative stress markers were significantly lower in the zinc-supplemented than in the placebo group. Plasma zinc and phytohemagglutin-induced interleukin 2 mRNA in isolated mononuclear cells were significantly higher in the zinc-supplemented than in the placebo group.
After zinc supplementation, the incidence of infections was significantly lower, plasma zinc was significantly higher, and generation of tumor necrosis factor alpha and oxidative stress markers was significantly lower in the zinc-supplemented than in the placebo group.
American Journal of Clinical Nutrition 03/2007; 85(3):837-44. · 6.67 Impact Factor
ABSTRACT: Physicians are aware of the National Cholesterol Education Program guidelines; however, most patients fail to attain cholesterol goals.
To determine whether a combined program of patient education and provider awareness could improve the National Cholesterol Education Program goal attainment among patients at high risk for cardiovascular events.
One hundred seven high-risk patients with cardiovascular disease were educated in a single 15-minute session regarding their cholesterol levels, risk factors, and medication adherence. Those with scores of 2 or lower on the Morisky questionnaire were classified as low-adherence patients, and those with scores of 3 or higher were classified as high-adherence patients. Seven physicians were provided this information and were requested to evaluate the dyslipidemia management of these patients. Lipid levels were reevaluated 8 to 12 weeks after the intervention.
At the start of the study, 38 (35.5%) of the 107 patients were at target low-density lipoprotein cholesterol (LDL-C) levels, and 64 of the 107 patients (59.8%) were at target levels after the intervention. High-adherence patients decreased their LDL-C levels from a mean of 118.6 mg/dL (3.07 mmol/L) to 98.6 mg/dL (2.55 mmol/L); low-adherence patients increased their LDL-C levels after the intervention from 134.5 mg/dL (3.48 mmol/L) to 142.1 mg/dL (3.68 mmol/L). A comparison between the LDL-C goal achievers vs nonachievers revealed a significant difference in adherence (P = .001). Among the goal achievers, significant decreases in preintervention vs postintervention total cholesterol levels (P = .001) and LDL-C levels (P = .001) were also noted.
This study demonstrates that an intervention simultaneously targeting patients and providers is successful in improving goal attainment among high-risk patients.
The American journal of managed care 11/2006; 12(10):589-94. · 2.46 Impact Factor
ABSTRACT: This study notes the differences between trust and distrust perceptions by the elderly as compared with younger populations. Given the importance of trust and distrust in compliance, changing behaviors, and forming partnerships for both health and disease management, it is necessary to be able to measure patient-doctor trust and distrust (PDTD). Following recent conceptualizations on trust and distrust as coexistent states, this study hypothesizes predictors of PDTD. We are proposing that these predictors form the basis for designing, developing and validating a PDTD scale (PDTDS). It is important to capture the trust-distrust perceptions of older patients as they confront the complexities and vulnerabilities of the modem healthcare delivery system. This is necessary if we are to design interventions to change behaviors of both the healthcare provider and the older patient.
Clinical Interventions in Aging 02/2006; 1(2):175-88. · 2.08 Impact Factor
ABSTRACT: We compared teaching performance of medical school faculty using anonymous evaluations and open evaluations (in which the evaluator was not anonymous) and examined barriers to open evaluation.
Residents and medical students evaluated faculty using an open evaluation instrument in which their identity was indicated in the evaluation. Following this, they completed anonymous evaluation on the same faculty members. Aggregate outcomes using the two evaluation systems were compared. Outcomes by group of evaluators (residents and students) were analyzed. Trainees were also asked to rate the barriers to the open evaluation process.
A statistically significant difference between the open and anonymous evaluations was noted across all items, with faculty receiving lower scores on the anonymous evaluations. The mean score for all the items on the open evaluations was 4.45 +/- 0.65, compared to mean score of 4.07 +/- 0.80 on the anonymous evaluations. There was also a statistically significant difference between open and anonymous evaluations in five clinical teaching domains that were evaluated individually. Residents perceived that the three most common barriers to optimal evaluation were an apprehension of possible encounters with the same attending physician in the future, destruction of working relationships with the attending, and a feeling of frustration with the evaluation system.
The evaluation of faculty teaching performance is complex. Most academic medical centers use the open evaluation format. This study supports the case for the use of the anonymous evaluation method as a more accurate reflection of teaching performance.
Family medicine 02/2005; 37(1):43-7. · 1.33 Impact Factor