Biomedical subjects

Gary K Grunwald

Publications and source records attributed to Gary K Grunwald.

At least 19 recordsLinked to original sources

PubMed2006

The association between processes, structures and outcomes of secondary prevention care among VA ischemic heart disease patients.

BACKGROUND: Hyperlipidemia and hypertension are well-established risk factors for recurrent cardiovascular events among patients with ischemic heart disease (IHD). Despite national recommendations, concordance with guidelines for LDL cholesterol and blood pressure remains inadequate. The objectives of this study were to 1) determine concordance rates with LDL cholesterol and BP recommendations; and 2) identify patient factors, processes and structures of care associated with guideline concordance among VA IHD patients. METHODS: This was a cross sectional study of veterans with IHD from 8 VA hospitals. Outcomes were concordance with LDL guideline recommendations (LDL<100 mg/dl), and BP recommendations (<140/90 mm Hg). Cumulative logit and hierarchical logistic regression analyses were performed to identify patient factors, processes, and structures of care independently associated with guideline concordance. RESULTS: Of 14,114 veterans with IHD, 55.7% had hypertension, 71.5% had hyperlipidemia, and 41.6% had both conditions. Guideline concordance for LDL and BP were 38.9% and 53.4%, respectively. However, only 21.9% of the patients achieved both LDL <100 mg/dl and BP <140/90 mm Hg. In multivariable analyses, patient factors including older age and the presence of vascular disease were associated with worse guideline concordance. In contrast, diabetes was associated with better guideline concordance. Several process of care variables, including higher number of outpatient visits, higher number of prescribed medications, and a recent cardiac hospitalization were associated with better guideline concordance. Among structures of care, having on-site cardiology was associated with a trend towards better guideline concordance. CONCLUSION: Guideline concordance with secondary prevention measures among IHD patients remains suboptimal. It is hoped that the findings of this study can serve as an impetus for quality improvement efforts to improve upon secondary prevention measures and reduce the morbidity and mortality of patients with known IHD.

Adult↗

PubMed2006

The induction of human superoxide dismutase and catalase in vivo: a fundamentally new approach to antioxidant therapy.

A composition consisting of extracts of five widely studied medicinal plants (Protandim) was administered to healthy human subjects ranging in age from 20 to 78 years. Individual ingredients were selected on the basis of published findings of induction of superoxide dismutase (SOD) and/or catalase in rodents in vivo, combined with evidence of decreasing lipid peroxidation. Each ingredient was present at a dosage sufficiently low to avoid any accompanying unwanted pharmacological effects. Blood was analyzed before supplementation and after 30 and 120 days of supplementation (675 mg/day). Erythrocytes were assayed for SOD and catalase, and plasma was assayed for lipid peroxidation products as thiobarbituric acid-reacting substances (TBARS), as well as uric acid, C-reactive protein, and cholesterol (total, LDL, and HDL). Before supplementation, TBARS showed a strong age-dependent increase. After 30 days of supplementation, TBARS declined by an average of 40% (p = 0.0001) and the age-dependent increase was eliminated. By 120 days, erythrocyte SOD increased by 30% (p < 0.01) and catalase by 54% (p < 0.002). We conclude that modest induction of the catalytic antioxidants SOD and catalase may be a much more effective approach than supplementation with antioxidants (such as vitamins C and E) that can, at best, stoichiometrically scavenge a very small fraction of total oxidant production.

Adult↗

PubMed2006

Continuous time Markov models for binary longitudinal data.

Longitudinal data usually consist of a number of short time series. A group of subjects or groups of subjects are followed over time and observations are often taken at unequally spaced time points, and may be at different times for different subjects. When the errors and random effects are Gaussian, the likelihood of these unbalanced linear mixed models can be directly calculated, and nonlinear optimization used to obtain maximum likelihood estimates of the fixed regression coefficients and parameters in the variance components. For binary longitudinal data, a two state, non-homogeneous continuous time Markov process approach is used to model serial correlation within subjects. Formulating the model as a continuous time Markov process allows the observations to be equally or unequally spaced. Fixed and time varying covariates can be included in the model, and the continuous time model allows the estimation of the odds ratio for an exposure variable based on the steady state distribution. Exact likelihoods can be calculated. The initial probability distribution on the first observation on each subject is estimated using logistic regression that can involve covariates, and this estimation is embedded in the overall estimation. These models are applied to an intervention study designed to reduce children's sun exposure.

Biometry↗

PubMed2006

Outcomes after acute coronary syndrome admission to primary versus tertiary Veterans Affairs medical centers: the Veterans Affairs Access to Cardiology study.

BACKGROUND: There is a concern that patients with acute coronary syndrome (ACS) admitted to primary care hospitals (without on-site cardiac procedures) may be at risk for worse outcomes compared with patients admitted to tertiary care hospitals. In addition to mortality, one way to assess patient outcomes is via health status and rehospitalization rates. We compared the health status and rehospitalization of patients with ACS admitted to primary versus tertiary care Veterans Affairs hospitals. METHODS: This was a cohort study of 2132 patients with ACS admitted to 21 Veterans Affairs hospitals (12 primary care and 9 tertiary care) from 1998 to 1999. Primary outcomes were 7-month health status as measured by the Seattle Angina Questionnaire and rehospitalization. Hierarchical multivariable regression was used to evaluate the association between admission to a primary (vs tertiary) care hospital and these outcomes. Discharge medications and 7-month cardiac procedure rates were also compared. RESULTS: There were no significant differences in discharge medication rates between primary and tertiary hospital patients. Forty-two percent of the patients admitted to a primary care hospital was transferred to a tertiary care hospital during index admission. Primary hospital patients had significantly lower 7-month rates of cardiac catheterization (36% vs 51%, P < .001) and percutaneous coronary intervention (11% vs 20%, P < .001), but there were no differences in coronary artery bypass graft surgery rates. After risk adjustment, there were no significant differences in 7-month angina frequency (odds ratio [OR] 0.98, 95% CI 0.78-1.22), physical limitation (OR 0.97, 95% CI 0.77-1.23), quality of life (OR 1.12, 95% CI 0.89-1.40), or rehospitalization (OR 1.07, 95% CI 0.54-2.14) between the 2 groups. CONCLUSIONS: These results suggest that an integrated health care system can achieve similar intermediate-term health status and rehospitalization outcomes for patients with ACS irrespective of the site of admission despite the lower rates of cardiac procedures for the primary care hospital patients.

Acute Disease↗

PubMed2006

Exploring the volume-outcome relationship for off-pump coronary artery bypass graft procedures.

BACKGROUND: The relationship between the surgical case volume and risk-adjusted clinical outcomes has been examined for different surgical specialties. The purpose of this study was to explore the relationship between the off-pump coronary artery bypass graft procedure volumes (OPCABG) with risk-adjusted outcomes within the Department of Veterans Affairs (VA) 44 cardiac surgery programs. METHODS: Based on VA Continuous Improvement in Cardiac Surgery Program data, the results of 5,076 OPCABG surgical procedures performed between October 1998 and September 2003 were analyzed. Hierarchical logistic regression models evaluated the relationship between OPCABG procedure volume with risk-adjusted 30-day operative mortality, perioperative morbidity, and 180-day mortality. Both a hospital's average OPCABG volume per 6-month period and the hospital's most recent 6-month OPCABG volume were examined. RESULTS: Hospital OPCABG average volume in a 6-month period ranged from 0.2 to 47.4 procedures; whereas the most recent 6-month OPCABG hospital volume ranged from 0 to 76 OPCABG per site. No relationship between the volume measures and the outcome variables was found. CONCLUSIONS: We did not find an association between OPCABG volume with short-term mortality, perioperative morbidity, or intermediate-term (180-day) mortality.

Aged↗

PubMed2006

Time-varying risk factors for long-term mortality after coronary artery bypass graft surgery.

BACKGROUND: There is a substantial literature on short-term mortality risk factors for coronary artery bypass graft (CABG) surgery. However, very few studies have examined risk factors for long-term mortality. METHODS: We analyzed 56,543 veterans who underwent CABG surgery at one of 43 VA cardiac surgery centers between October 1, 1991, and March 30, 2001. Each patient was followed for a minimum of 3.5 months and a maximum of 9.5 years for mortality assessment. The time-varying effects of 22 mortality preoperative risk factors were evaluated using both standard Cox regression models and Cox B-spline regression models. RESULTS: Six variables showed significant varying effects over time on mortality after surgery. The effects of previous heart surgery or preoperative intra-aortic balloon pump carried about 5 times and 3 times the risk, respectively, of dying on the first day after surgery, but were not significant during long-term follow-up. Conversely, diabetes had little additional risk immediately after surgery, but the risk increased steadily and doubled at 9.5 years after surgery. Three other risk variables--age, chronic obstructive pulmonary disease, and urgent or emergent status--also had risk changing by 50% to 60% over the next decade. Most of the other 16 risk variables were significantly associated with mortality, but the risk did not vary substantially over time. CONCLUSIONS: Risk associated with some preoperative variables can change significantly during the decade after surgery, and risk assessments that assume constant risk during the postoperative period may substantially overestimate or underestimate risk at some times. These findings may help clinicians identify appropriate management strategies for patients during the years after CABG surgery, and support an emphasis on noncardiac comorbidities during later postoperative periods.

Aged↗

PubMed2006

Zinc absorption in Guatemalan schoolchildren fed normal or low-phytate maize.

BACKGROUND: Poor bioavailability of zinc from high-phytate diets is an important contributory factor to zinc deficiency in low-income populations. OBJECTIVE: The objective of this study was to determine the effect of low-phytate maize consumption on zinc absorption. DESIGN: The participants were apparently healthy children from the Central Highlands of Guatemala. Sixty children (20 per group) were randomly assigned to be fed only the low-phytate maize or 1 of 2 control maizes, the isohybrid wild-type maize or a local maize, for a 10-wk period. During the final week, the fractional absorption of zinc for all meals was measured during 1 d with the use of zinc stable isotopes and a dual isotope ratio technique based on urine enrichment data. RESULTS: Mean (+/-SD) phytate intakes for the low-phytate, wild-type, and local maize groups were 1536 +/- 563, 2056 +/- 517, and 2253 +/- 687 mg/d, respectively. Corresponding zinc intakes were 8.6 +/- 2.5, 8.1 +/- 2.0, and 9.7 +/- 2.6 mg/d, and the dietary phytate:zinc molar ratios were 18 +/- 5, 26 +/- 6, and 23 +/- 5. Corresponding fractional absorptions of zinc were 0.32 +/- 0.07, 0.28 +/- 0.07, and 0.29 +/- 0.06. The respective values for total absorbed zinc were 2.72 +/- 0.88, 2.30 +/- 0.96, and 2.78 +/- 1.04 mg/d. No significant differences in either the fractional absorption of zinc or total absorbed zinc were seen between the maize groups. CONCLUSION: Under the conditions of the present study, zinc absorption was not increased by the long-term use of low-phytate maize in children whose major dietary staple is maize.

Anthropometry↗

PubMed2006

Carbohydrate balance predicts weight and fat gain in adults.

BACKGROUND: The prevention and treatment of obesity is a public health challenge. OBJECTIVE: We investigated the effects of dietary composition, insulin sensitivity (S(I)), and energy balance on predicted changes in body composition. DESIGN: In a randomized crossover design study, 39 normal-weight (n = 23), overweight (n = 8), and obese (n = 8) men and women (aged 25-36 y) each followed a 15-d isocaloric high-fat (HF; 50% fat) and high-carbohydrate [HC; 55% carbohydrate (CHO)] diet with a 4-6-wk washout period during the first year. During each treatment, energy balance was measured while the subjects were inactive by using indirect calorimetry on day 15, and S(I) was measured by using a euglycemic clamp study (40 mU . m(-2) . min(-1)) on day 16. Weight and body composition were then measured annually for 4 y. The outcomes for fat mass, percentage body fat, and weight were measured by using a linear 2-stage mixed model. RESULTS: CHO balance (day 15) and S(I) (day 16) on the HC diet were highly and significantly correlated (r = 0.55, P < 0.001). On the HC diet, the subjects who had a higher positive CHO balance (day 15) gained less fat mass (P < 0.001), percentage body fat (P = 0.006), and weight (P = 0.024) over time. When adjusted for S(I), CHO balance remained a significant predictor of changes in fat mass (P = 0.021) and percentage body fat (P = 0.025). CONCLUSIONS: On a HC diet, the subjects who had a higher positive CHO balance on day 15 while they were inactive gained less fat mass during 4 y, a predictive effect independent of S(I). As suggested in rodents, the capacity to expand the glycogen pool might reduce energy intake and protect against fat and weight gain.

Adipose Tissue↗

PubMed2006

Glucose kinetics differ between women and men, during and after exercise.

As exercise can improve the regulation of glucose and carbohydrate metabolism, it is important to establish biological factors, such as sex, that may influence these outcomes. Glucose kinetics, therefore, were compared between women and men at rest, during exercise, and postexercise. It was hypothesized that glucose flux would be significantly lower in women than men during both the exercise and postexercise periods. Subjects included normal weight, healthy, eumenorrehic women and men, matched for habitual activity level and maximal oxygen uptake per kilogram lean body mass. Testing occurred following 3 days of diet control, with no exercise the day before. Subjects were tested in the overnight-fasted condition with women studied in the midluteal phase of the menstrual cycle. Resting (120 min), exercise (85% lactate threshold, 90 min), and postexercise (180 min) measurements of glucose flux and substrate metabolism were made. During exercise, women had a significantly lower rate of glucose appearance (Ra) (P<0.001) and disappearance (Rd) (P<0.002) compared with men. Maximal values were achieved at 90 min of exercise for both glucose Ra (mean+/-SE: 22.8+/-1.12 micromol.kg body wt-1.min-1 women and 33.6+/-1.79 micromol.kg body wt-1.min-1 men) and glucose Rd (23.2+/-1.26 and 34.1+/-1.71 micromol.kg body wt-1.min-1, respectively). Exercise epinephrine concentration was significantly lower in women compared with men (P<0.02), as was the increment in glucagon from rest to exercise (P<0.04). During the postexercise period, glucose Ra and Rd were also significantly lower in women vs. men (P<0.001), with differences diminishing over time. In conclusion, circulating blood glucose flux was significantly lower during 90 min of moderate exercise, and immediately postexercise, in women compared with men. Sex differences in the glucagon increase to exercise, and/or the epinephrine levels during exercise, may play a role in determining these sex differences in exercise glucose turnover.

Adult↗

PubMed2005

Association of transforming growth factor-beta1 single nucleotide polymorphism C-509T with allergy and immunological activities.

BACKGROUND: A single nucleotide polymorphism (SNP) C-509T within the tumor growth factor beta1 (TGFbeta1) gene has been associated with atopic asthma and asthma severity. To further understand the mechanisms involved, the association of C-509T with allergy, T-lymphocyte proliferation and plasma TGFbeta1 concentration has been explored in a case-control study with allergic and non-allergic subjects. METHODS: The recruited subjects including allergic (n = 38) and nonallergic (n = 25) participants have been genotyped for C-509T using allele discrimination assay. Association of C-509T with allergy status was examined using logistic regression analysis in both dominant and recessive models. Association of C-509T with T-cell proliferation in control and antigen-stimulated peripheral blood mononuclear cells (PBMCs), plasma TGFbeta1 and total IgE level were tested by multiple regression analysis. RESULTS: Individuals with homozygous mutant TT genotype showed a higher risk of allergy (TT: odds ratio = 5.099, 95% confidence limit: 1.355-19.190, p = 0.016) after covariates were adjusted. A trend to increased plasma TGFbeta1 in subjects with T allele has been discovered. In the meantime, the T allele is associated with lower T cell proliferation in controls and maximum response to above antigens. A low T-cell proliferation is correlated with higher plasma TGFbeta1 concentration (p < 0.01). The in vitro studies confirmed the suppressing effect of TGFbeta1 on T-cell proliferation at physiological range. A significant inhibitory effect on IL-4 production was also observed. CONCLUSIONS: A C to T base change in TGFbeta1 SNP C-509T has been associated with a higher risk of allergy. The mechanisms are not clear. Elevated TGFbeta1 levels associated with the C-509T polymorphism might suppress immune activation as well as Th2 cytokine production.

Alleles↗

PubMed2005

Twenty-four-hour metabolic responses to resistance exercise in women.

Seven nonobese adult females (40 +/- 8 years) were studied in a room calorimeter on a day that resistance exercise (REX) was performed (4 sets of 10 exercises) and on a nonexercise control day (CON). Twenty-four-hour energy expenditure (EE) on the REX day (mean +/- SD, 2,328 +/- 327 kcal.d(-1)) was greater than CON (2,001 +/- 369 kcal.d(-1), p < 0.001). The net increase in EE during and immediately after (30 minutes) exercise represented 76 +/- 12% of the total increase in 24-hour EE. Twenty four-hour RQ on the REX day (0.86 +/- 0.06) did not differ from CON (0.87 +/- 0.02). Twenty four-hour carbohydrate oxidation was elevated on the REX day, but 24-hour fat and protein oxidation were not different. Thus, in women, the increase in EE due to resistance exercise is largely seen during and immediately after the exercise. The increased energy demand is met by increased carbohydrate oxidation, with no increase in 24-hour fat oxidation.

Adult↗

PubMed2004

Cardiology management improves secondary prevention measures among patients with coronary artery disease.

OBJECTIVES: The goal of this study was to determine if cardiology subspecialty involvement improves the attainment of recommended low-density lipoprotein (LDL) cholesterol and blood pressure (BP) targets in coronary artery disease (CAD) patients. BACKGROUND: The impact of physician specialty on secondary prevention measures for CAD in ambulatory care is unknown. METHODS: This was a retrospective cohort study of 13,995 patients with CAD seen at eight ambulatory care Veteran Affairs facilities from 1998 to 2000. Patients with cardiology involvement were defined as those seen in cardiology clinic in addition to primary care. The main outcomes of interest were LDL cholesterol < or =100 mg/dl and BP < or =130/85 mm Hg. Multivariable hierarchical regression analyses were used to determine the independent association of cardiology involvement with improved LDL cholesterol and BP control. RESULTS: Overall, 3,771 (27.0%) patients had cardiology involvement. A higher proportion of patients with cardiology involvement achieved LDL cholesterol (55.6% vs. 45.6%; p < 0.01) and BP (45.3% vs. 35.9%; p < 0.01) goals. In multivariable hierarchical regression analysis, cardiology involvement was independently associated with better LDL cholesterol (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.40 to 1.82) and BP (OR, 1.52; 95% CI, 1.32 to 1.77) control. The benefit of cardiology involvement was consistent across a range of LDL and BP targets, in analysis of LDL and BP as continuous outcomes, and among subgroups of high-risk patients, including diabetic patients, the elderly, and those with prior revascularization. CONCLUSIONS: Cardiology involvement is associated with better LDL cholesterol and BP control among CAD patients. However, significant room for improvement in secondary prevention measures remains, irrespective of physician specialty.

Adrenergic beta-Antagonists↗

PubMed2004

Effects of short-term overfeeding on hunger, satiety, and energy intake in thin and reduced-obese individuals.

BACKGROUND: Certain individuals appear to be resistant to weight gain in an obesigenic environment, yet the mechanisms for this adaptation are unclear. These individuals may sense positive energy balance more appropriately than those individuals prone to weight gain. RESEARCH METHODS AND PROCEDURES: Thirteen thin (7 women, 6 men) and 9 reduced-obese (5 women, 4 men) individuals were studied. Measures of intake were obtained using visual analog scales before and after each meal during eucaloric feeding and during three days of 50% overfeeding. Ad libitum energy intake was measured post-overfeeding. RESULTS: Overfeeding resulted in a significant reduction in pre-meal hunger in the thin (68+/-6 to 41+/-6 mm, p<0.0001) compared to the reduced-obese individuals (63+/-7 to 65+/-7 mm, p=0.67). There was a significantly greater increase (p=0.0016) in post-meal satiety scores during overfeeding in the thin (65+/-4 to 88+/-4 mm, p<0.0001) compared to the reduced-obese individuals (72+/-5 to 80+/-5 mm, p=0.04). Thin women had a 30% reduction in daily energy intake (1831+/-47 to 1273+/-79 kcal/day, p=0.005) after overfeeding while no difference was seen in the thin men or reduced-obese group. DISCUSSION: Thin individuals appear to sense positive energy balance more appropriately with changes in measures of intake than reduced-obese individuals. These findings are especially true in thin women.

Adaptation, Physiological↗

PubMed2004

Comparison of short-term mortality risk factors for valve replacement versus coronary artery bypass graft surgery.

BACKGROUND: Risk factors for 30-day operative (short-term) mortality following coronary artery bypass graft (CABG only) procedures are well established. However, little is known about how the risk factors for short-term mortality following valve replacement procedures (with or without a CABG procedure performed) compare with CABG only risk factors. METHODS: Department of Veterans Affairs (VA) records (65,585 records) were collected from October 1991 through March 2001 and analyzed. Risk factors for short-term mortality were compared across three subgroups of patients: CABG only surgery (n = 56,318), aortic valve replacement (AVR) with or without CABG (n = 7450), and mitral valve replacement (MVR) with or without CABG (n = 1817). Multivariable logistic regression analyses were used to compare the relative magnitude of risk for 19 candidate predictor variables across subgroups. RESULTS: Only three patient baseline characteristics differed significantly in magnitude of risk between the procedure groups. Partially or totally dependent functional status significantly increased the risk of short-term mortality for AVR patients (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.29-2.09) and MVR patients (OR 2.21, 95% CI 1.48-3.30), but not for CABG only patients (OR 1.04, 95% CI 0.93-1.16). Conversely, previous heart surgery and New York Heart Association functional class III or IV symptoms conferred greater magnitude of risk for CABG only patients compared with the valve subgroups. CONCLUSIONS: Overall, the risk factors for short-term mortality following valve replacement and CABG surgery appear to be relatively consistent. However, clinicians should be aware of the importance of preoperative functional status as a unique predictor of mortality following valve surgery.

Aged↗

PubMed2004

Zinc absorption from low-phytate hybrids of maize and their wild-type isohybrids.

BACKGROUND: Identification of allelic variants in a single gene that determine the phytate content of maize kernels and the subsequent breeding of low-phytate maize have facilitated studies designed to determine quantitatively the effects of maize phytate on the bioavailability of minerals in maize. OBJECTIVE: The objective was to determine the relation between the fractional absorption of zinc (FAZ) and the phytate content and phytate:zinc molar ratios of maize tortillas prepared from hybrids with different phytate contents. DESIGN: Six healthy adults were fed, as the only food for 2 d, maize tortillas prepared from 1 of 2 low-phytate mutants: lpa1-1 (lpa1-1-LP) or Nutridense Low Phytate (ND-LP), which have phytate reductions of approximately 60% and approximately 80%, respectively, compared with their respective wild-type isohybrids. Four additional subjects were fed tortillas prepared from the corresponding wild-type isohybrids (lpa1-1-WT and ND-WT) according to the same study design. Meals were extrinsically labeled with zinc stable isotopes, and FAZ was determined with a dual-isotope-tracer ratio technique. Overall FAZ values were examined in relation to dietary phytate and phytate:zinc molar ratios by using a mixed nonlinear regression model. RESULTS: The mean (+/-SD) FAZ values from tortillas prepared from ND-LP, lpa1-1-LP, lpa1-1-WT, and ND-WT were 0.38 +/- 0.07, 0.28 +/- 0.04, 0.15 +/- 0.07, and 0.13 +/- 0.05, respectively. A negative relation (P < 0.001) was found between FAZ and both dietary phytate and the phytate:zinc molar ratio. The effect of dietary zinc (8-14 mg Zn/d) under these experimental conditions was not significant. CONCLUSIONS: FAZ from maize tortillas is positively related to the extent of phytate reduction achieved with low-phytate hybrids.

Adult↗

PubMed2004

Mixed models for the analysis of replicated spatial point patterns.

The statistical methodology for the analysis of replicated spatial point patterns in complex designs such as those including replications is fairly undeveloped. A mixed model is developed in conjunction with maximum pseudolikelihood and generalized linear mixed modeling by extending Baddeley and Turner's (2000, Australian and New Zealand Journal of Statistics 42, 283-322) work on pseudolikelihood for single patterns. A simulation experiment is performed on parameter estimation. Fixed- and mixed-effect models are compared, and in some respects the mixed model is found to be superior. An example using the Strauss process for modeling neuron locations in post-mortem brain slices is shown.

Brain↗

PubMed2004

Serum lithium concentration can be used to assess dietary compliance in adults.

With dietary intervention studies, it is important to ensure that subjects adhere to the test diet. Current methods to monitor adherence have substantial limitations. Therefore, a dose-response test curve was constructed to determine whether small differences in serum Li could be detected in response to ingestion of variable Li doses indicative of full or partial dietary compliance. During 3 separate weeks, subjects consumed a test meal that included a single food containing Li citrate daily for 4 d. Doses of 250, 213, or 175 micromol Li were used each week to approximate compliance levels of 100, 85, and 70%. On d 4, blood samples were taken before and 1, 2, 3, 5, 7, 9, and 24 h after ingesting the test meal. Compared with the 100% dose, serum Li was significantly lower at all times after the 70% dose and at most times after the 85% dose. Data were analyzed to determine a cutoff value so that if a subject's serum Li was below that value, they would be declared noncompliant. The probability that a subject was declared to be noncompliant when in fact they were compliant was set to 0.05 (specificity was set to 0.95) and the probability of noncompliance (sensitivity) was estimated. Test performance was best in the 3- to 9-h range, for which 90-95% of subjects "noncompliant" at the 70% dose were identified. Li can be used as a biomarker to determine dietary compliance. Measuring serum Li 3-9 h after the last dose provides the highest sensitivity and specificity for noncompliance at doses <70%.

Adult↗

PubMed2004

Relationship between processes of care and coronary bypass operative mortality and morbidity.

BACKGROUND: Information is limited regarding the effects of processes of care on cardiac surgical outcomes. Correspondingly, many recommended cardiac surgical processes of care are derived from animal experiments or clinical judgment. This report from the VA Cooperative Study in Health Services, "Processes, Structures, and Outcomes of Cardiac Surgery," focuses on the relationships between 3 process groups (preoperative evaluation, intraoperative care, and supervision by senior physicians) and a composite outcome, perioperative mortality and morbidity. METHODS: Data on 734 risk, process, and structure variables were collected prospectively on 3,988 patients who underwent coronary artery bypass grafting at 14 VA medical centers between 1992 and 1996. Data reduction was accomplished by examining data completeness and variation across sites and surgeon, using previously published data and clinical judgment. We then applied multivariable logistic regression to the 39 remaining processes of care to determine which were related to the composite outcome after adjusting for 17 patient-related risk factors and controlling for intraoperative complications. RESULTS: Our first analysis showed several measures of operative duration, the use of inotropic agents, transesophageal echo, lowest systemic temperature, and hemoconcentration/ultrafiltration, to be powerful predictors of the composite outcome. Because the use of inotropic agents and operative duration may be related to an intermediate outcome (eg, intraoperative complications), we performed a second analysis omitting these processes. The use of intraoperative transesophageal echo and hemoconcentration/ultrafiltration remained significantly associated with an increased risk of an event (odds ratios 1.60 and 1.36, respectively). CONCLUSIONS: Our results viewed in the context of past studies suggest the possibility that inotropic use, TEE, and hemoconcentration/ultrafiltration may have adverse effects on operative outcome. Further evaluation of these processes of care using observational data, as well as randomized trials when feasible, would be of interest.

Coronary Artery Bypass↗