Biomedical subjects

R S Gibson

Publications and source records attributed to R S Gibson.

At least 55 records · Page 3Linked to original sources

PubMed1997

The electrocardiogram predicts one-year outcome of patients with unstable angina and non-Q wave myocardial infarction: results of the TIMI III Registry ECG Ancillary Study. Thrombolysis in Myocardial Ischemia.

OBJECTIVES: We sought to determine the prognostic value of the admission electrocardiogram (ECG) in patients with unstable angina and non-Q wave myocardial infarction (MI). BACKGROUND: Although the ECG is the most widely used test for evaluating patients with unstable angina and non-Q wave MI, little prospective information is available on its value in predicting outcome in the current era of aggressive medical and interventional therapy. METHODS: ECGs with the qualifying episode of pain were analyzed in patients enrolled in the Thrombolysis in Myocardial Ischemia (TIMI) III Registry, a prospective study of patients admitted to the hospital with unstable angina or non-Q wave MI. RESULTS: New ST segment deviation > or = 1 mm was present in 14.3% of 1,416 enrolled patients, isolated T wave inversion in 21.9% and left bundle branch block (LBBB) in 9.0%. By 1-year follow-up, death or MI occurred in 11% of patients with > or = 1 mm ST segment deviation compared with 6.8% of patients with new, isolated T wave inversion and 8.2% of those with no ECG changes (p < 0.001 when comparing ST with no ST segment deviation). Two other high risk groups were identified: those with only 0.5-mm ST segment deviation and those with LBBB, whose rates of death or MI by 1 year were 16.3% and 22.9%, respectively. On multivariate analysis, ST segment deviation of either > or = 1 mm or > or = 0.5 mm remained independent predictors of death or MI by 1 year. CONCLUSIONS: The admission ECG is very useful in risk stratifying patients with non-Q wave MI. The new criteria of not only > or = 1-mm ST segment deviation but also > or = 0.5-mm ST segment deviation or LBBB identify high risk patients, whereas T wave inversion does not add to the clinical history in predicting outcome.

Aged↗

PubMed1997

Dietary strategies to improve the iron and zinc nutriture of young women following a vegetarian diet.

Dietary strategies to enhance the content and bioavailability of iron and zinc in vegetarian diets were compiled. Strategies included increasing promoters and decreasing antagonists of iron and zinc absorption, adopting food preparation and processing methods which hydrolyze the phytate content of cereals and legumes, and using iron cookware. These strategies were used to devise two vegetarian menus based on food consumption patterns derived from three day weighed food records of 78 Canadian lacto-ovo-vegetarian adolescents. The iron and zinc, as well as calcium, phosphorus, thiamin, riboflavin, niacin, vitamin A, protein and energy content of the devised menus were all higher than the actual intakes and the corresponding Canadian recommended nutrient intakes. Results show the overall nutrient adequacy of the recommended vegetarian menus and indicate that young lacto-vegetarian women can potentially meet their estimated dietary requirements for absorbed iron and zinc through modest modifications to the diet. Laboratory studies designed to measure the total amount of iron and zinc absorbed from these diets by young vegetarian women are needed to verify the efficacy of the devised menus.

Absorption↗

PubMed1997

Association between dietary fiber intake and the folate status of a group of female adolescents.

The main objective of this study was to assess the association between dietary fiber intake and the folate status of Canadian female adolescents. We also assessed dietary folate intakes and evaluated the prevalence of biochemical folate deficiency in these subjects. Female adolescents aged 14-19 y (n = 224) were recruited and fasting blood samples were collected. Dietary intakes (3-d food record) were recorded and participants were classified as lactoovovegetarians, semivegetarians, or omnivores on the basis of food-consumption patterns assessed with food-frequency questionnaires. Fourteen percent, 17%, and 26% of lactoovovegetarians, semivegetarians, and omnivores, respectively, had dietary folate intakes below their predicted requirements; 1%, 4%, and 23%, respectively, had serum folate concentrations indicative of deficiency. Despite low dietary folate intakes and serum folate concentrations, few subjects had homocysteine concentrations indicative of deficiency, suggesting that the degree of folate depletion had not yet produced functional consequences. Most important, results suggest that the consumption of nonstarch polysaccharide is significantly associated with serum folate concentrations (P < 0.001). For each 1-g increase in nonstarch polysaccharide intake, a 1.8% increase in serum folate concentration is expected. In summary, we propose that an increase in nonstarch polysaccharide intake may promote the intestinal biosynthesis of folate, providing a complementary strategy to enhance the folate nutriture of humans.

Adolescent↗

PubMed1997

Technological approaches to combatting iron deficiency.

Iron deficiency is widespread among young children and women of reproductive age, especially in less industrialized countries. It is partly induced by plant-based diets containing low levels of poorly bioavailable iron. The most effective technological approaches to combat iron deficiency in less industrialized countries include supplementation targeted to high risk groups combined with a national program of food fortification and dietary strategies designed to maximize the bioavailability of both the fortificant and the intrinsic food iron. Prerequisites for effective supplementation include an efficient and consistent supply, delivery, and consumption of a highly bioavailable iron supplement. Fortification relies less heavily on compliance and an organized health service but must be regulated by government to eliminate competition with unfortified products. To be effective, a combination of an iron fortificant and food vehicle must be selected which is safe, acceptable to and consumed by the target population, does not adversely effect the organoleptic qualities and shelf-life of the food vehicle, and provides iron in a stable, highly bioavailable form. Bioavailability of both the fortificant and the intrinsic food iron can be improved by adding enhancing factors, removing inhibitors such as phytate by enzymatic and non-enzymatic hydrolysis, and using 'protected' fortification compounds.

Adult↗

PubMed1996

Influence of race, sex, and age on management of unstable angina and non-Q-wave myocardial infarction: The TIMI III registry.

OBJECTIVE: To investigate the natural history and response to treatment of patients with unstable angina or non-Q-wave myocardial infarction (MI). DESIGN: Inception cohort. SETTING: Patients in general community, primary care, or referral hospitals. PATIENTS: All patients with an episode of unstable exertional chest pain or chest pain at rest presumed to be ischemic in origin lasting 5 minutes or more but without persisting ST-segment elevation greater than 30 minutes or the development of Q-waves were identified and enumerated in 18 participating hospitals. A subset of enumerated patients was selected to be followed prospectively using specific sampling strategies that would provide adequate numbers of black, women, and elderly (aged > or = 75 years) patients for comparison with their respective counterparts. MAIN OUTCOME MEASURES: The primary analysis compared the incidence of death or MI at 42 days after entry into the prospective study according to race, sex, and age. Other outcomes considered were recurrent ischemia and the combined outcomes of death, MI, or recurrent ischemia by 42 days after entry. RESULTS: A total of 8676 admissions with unstable angina or non-Q-wave MI were enumerated and, of these, 3318 patients were selected for the prospective study. The direct adjusted mean age of 3318 patients was 63.8 years. There were 943 blacks and 2375 nonblacks. Compared with nonblacks, blacks were less likely to be treated with intensive anti-ischemic therapy for their qualifying anginal episode and less likely to undergo invasive procedures (risk ratio [RR], 0.65%; 95% confidence interval [CI], 0.58 to 0.72; P<.001). However, of those who underwent angiography (45% of blacks and 61% of nonblacks), blacks had less extensive and severe coronary stenoses than nonblacks. The incidence of death and MI was similar for blacks and nonblacks, but blacks had a lower incidence of recurrent ischemia. There were 1678 men and 1640 women. Women were less likely than men to receive intensive anti-ischemic therapy and less likely to undergo coronary angiography (RR, 0.71; 95% CI, 0.65 to 0.78; P<.001). Women had less severe and extensive coronary disease and were less likely to undergo revascularization, yet had a similar risk of experiencing an adverse cardiac event by 6 weeks. There were 2490 patients aged 75 years or less and 828 patients aged more than 75 years. Elderly patients received less aggressive anti-ischemic therapy and were less likely to undergo coronary angiography than their younger counterparts. Elderly patients had more severe and extensive coronary disease but fewer revascularization procedures than younger patients and experienced a much higher incidence of adverse cardiac events both in hospital and by 6 weeks. CONCLUSIONS: Among patients presenting with acute ischemic chest pain without persistent ST-segment elevation, blacks appeared to have less severe coronary disease, received revascularization less frequently, and had less recurrent ischemia compared with nonblacks. Women were also found to have less severe coronary disease and were treated less intensely than men, but experienced similar outcomes. Elderly patients had more severe coronary disease than younger patients on coronary angiography, but were more likely to be treated medically, and they experienced far more adverse outcomes. These data suggest that more aggressive strategies should be directed to those patients with the greatest likelihood of adverse outcomes.

Age Factors↗

PubMed1996

Dietary intakes of adolescent females consuming vegetarian, semi-vegetarian, and omnivorous diets.

PURPOSE: To determine the energy and nutrient intakes of some omnivorous and vegetarian female adolescents to compare their risk for nutrient inadequacies. METHODS: A convenience sample of 78 lacto-ovo-vegetarians (LOV), 15 semi-vegetarians (SV), and 29 omnivorous (OM) females aged 14-19 years completed three-day weighed records from which mean intakes and major food sources of energy, nutrients, and dietary fiber (as nonstarch polysaccharides (NSP)) were calculated. RESULTS: Mean daily intakes for energy and most nutrients were comparable for the three groups although LOV had higher intakes (p < 0.01) of NSP, copper, and manganese. Lacto-ovo-vegetarians consumed (g/d) less dairy products, flesh foods, and sweets but more legumes, nuts, and vegetables. Major food sources were cereal products for energy, most nutrients, NSP, dairy products for calcium, and fruits and vegetables for vitamin C. More LOV and SV had energy intakes less than two-thirds of Canadian recommendations, and higher probability estimates of inadequacy for protein, calcium, iron, zinc, and riboflavin than OM. Fewer LOV (35%) than SV (53%) and OM (41%) had diets with less than 30% energy from fat. CONCLUSIONS: LOV and SV were more at risk for nutrient inadequacies than OM, although about 33% of OM were also at risk for inadequate intakes of iron and zinc.

Adolescent↗

PubMed1996

Calcium channel antagonists: friend or foe in postinfarction patients?

Calcium antagonists represent a diverse group of therapeutic agents with heterogenous pharmacologic, pharmacokinetic, and pharmacodynamic properties. It seems clear that the role of these agents in the management of patients with ischemic heart disease and hypertension is, in part, predicated on the subclass of calcium antagonists (dihydropyridine versus nondihydropyridine [heart rate-lowering]) that are used. The reports by Psaty and Furberg are important in that they remind clinicians of the fact that use of short-acting dihydropyridine agents may be associated with increased cardiac event rates in patients with ischemic heart disease and hypertension. It is our opinion, however, that there are no data that support the extrapolation of these untoward effects to the more contemporary, long-acting dihydropyridines (eg, amlodipine) or, especially, to the non-dihydropyridine (heart rate-lowering) calcium antagonists, such as diltiazem or verapamil. On the contrary, data pooled from homogeneous populations of post-MI patients from DRS, MDPIT, DAVIT-I, and DAVIT-II indicate that clinical outcomes are favorably influenced in patients recovering from non-Q wave MI, and in hypertensive post-MI patients with preserved left ventricular function. These findings support the belief that the deleterious effects observed in certain studies with short-acting dihydropyridine calcium antagonists represent a "selective" rather than a "class action" effect of these agents. Psaty and Furberg have assailed the absence of "evidence-based medicine" regarding, the utility of calcium antagonists as the most compelling argument to call for a moratorium on this broad class of therapy, pending the completion of several prospective, randomized, controlled clinical trials that are presently underway or planned. However, a large body of scientific evidence provides no sound basis for physicians to discontinue therapy in patients who are being treated with long acting calcium antagonists, particularly those that lower heart rate. Moreover, the available data support the use of heart rate lowering calcium antagonists in selected patients, such as those recovering from acute non-Q wave MI, who may experience long-term benefit from diltiazem or verapamil. Until the results of controlled trials are completed, these data suggest that a generic moratorium of all calcium antagonists is ill-advised.

Adrenergic beta-Antagonists↗

PubMed1995

Early versus late congestive heart failure after initially uncomplicated anterior wall acute myocardial infarction.

We determined the incidence and clinical, noninvasive, and angiographic variables contributing to postdischarge early (< or = 3 months) and late (> 3 months) congestive heart failure (CHF) after anterior wall acute myocardial infarction. The patient cohort consisted of 94 consecutive patients < 65 years of age who underwent predischarge exercise thallium-201 planar scintigraphy, rest radionuclide angiography, and coronary arteriography. At a mean of 49 months of follow-up, 10 of the 68 medically managed patients developed early CHF, and 10 had late CHF. The 10 patients with early CHF had significantly higher peak creatine kinase values (2,494 vs 1,032 IU/L, p = 0.01), and at discharge, a lower left ventricular (LV) ejection fraction (28 +/- 11% vs 41 +/- 11%, p < 0.02), more persistent thallium-201 defects (3.4 +/- 1.2 vs 2.1 +/- 1.2, p < 0.02), and fewer stress-induced redistribution defects (1.4 +/- 1.1 vs 0.4 +/- 1.1, p < or = 0.05) than those with late CHF. The early group had less multivessel disease (40% vs 90%, p < or = 0.03). Fifty percent (5 of 10) of patients who developed late CHF did so after a recurrent infarction compared with 10% (1 of 10) in the early CHF group (p < 0.07) and 8% in the group without CHF (p < 0.003). The 26 patients who underwent bypass surgery within 3 months had an LV ejection fraction and extent of ischemia and extent of angiographic stenoses comparable to patients with late CHF. None required hospitalization for CHF or had sustained a recurrent infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Iron and zinc status of young women aged 14 to 19 years consuming vegetarian and omnivorous diets.

OBJECTIVE: To assess the iron and zinc status of young females, aged 14 to 19 years, consuming vegetarian and omnivorous diets. METHODS: Dietary intakes (via 3-day weighed food records), BMI, and laboratory indices of iron and zinc status were compared in a convenience sample of 79 lacto-ovo-vegetarians (LOV), 16 semi-vegetarians (SV), and 29 omnivorous (OM) females. RESULTS: Twenty-nine percent LOV, 44% SV, and 17% OM had low iron stores (i.e., plasma ferritin < 12 micrograms/L); only 3% had anemia. As well, 24% LOV, 33% SV, and 18% OM had serum zinc < 10.71 mumol/L and 14% LOV, 14% SV, and 17% OM had hair zinc < 1.68 mumol/g. Intakes of iron and ascorbic acid from the weighed food records were associated with serum iron (p < 0.04) and total iron binding capacity (negatively; p < 0.02), respectively, whereas Phy:Zn molar ratios were associated with serum zinc (negatively; p < 0.04). Z-scores for BMI were associated with serum zinc (p < 0.02) and diet type (p < 0.001); serum AP activity was associated with age (p < 0.0001) and oral contraceptive use (p < 0.04). CONCLUSIONS: Suboptimal iron and zinc status was attributed to low intakes of poorly available iron and zinc in all dietary groups.

Adolescent↗

PubMed1995

Postpartum folic acid supplementation of adolescents: impact on maternal folate and zinc status and milk composition.

The objectives of the present study were to assess the impact of lactation on the folate status of adolescents and determine the effect of ingestion of a low-dose postpartum (PP) folic acid supplement on maternal folate and zinc status and milk composition. Pregnant adolescents (aged 14-19 y; n = 71) were recruited; those who initiated breast-feeding on delivery were randomly assigned to a folic acid supplement lactating (SL; 300 micrograms/d, n = 14) group or to a placebo lactating (PL; n = 15) group. Subjects who initiated formula feeding were given a placebo (FF; n = 18). Dietary intakes (two 24-h recalls) were recorded and blood and milk samples were collected at 4, 8, and 12 wk PP. Of the adolescents, 71%, 48%, 67%, and 60% had folate, iron, vitamin B-12, and zinc intakes, respectively, below their predicted requirements. Despite this, most blood indexes were within normal ranges, probably reflecting the subjects' use of supplements during pregnancy. Red blood cell (r = -0.49, P < 0.05) and plasma (r = -0.42, P = 0.08) folate concentrations were negatively correlated with milk zinc concentrations. Mean red blood cell folate content declined between 4 and 12 wk PP among PL (31%) and FF (34%) subjects (P < 0.05) but not among SL subjects. Hence, 300 micrograms folic acid/d was sufficient to prevent a decline in blood folate values of these adolescents PP.

Adolescent↗

PubMed1995

An interactive 24-h recall technique for assessing the adequacy of trace mineral intakes of rural Malawian women; its advantages and limitations.

OBJECTIVES: To assess the relative validity of an interactive 24-h recall for estimating mineral intakes of rural Malawian women. DESIGN: Repeated interactive 24-h recalls were compared with weighed records collected for the same 2 days of food intake, and for 2 days 1-2 weeks prior and subsequent to the weighed record data collection period. SETTING: Three villages in traditional authority Jalasi, Mangochi District, Malawi. SUBJECTS: 60 rural pregnant women. RESULTS: Median daily intakes of most minerals (Ca, Fe, Zn, Mn) were comparable for the two methods, but slightly overestimated for recalled (R) intakes expressed per MJ (mg/MJ) compared to weighed (W) (R vs W = Ca, 48 vs 38; Fe, 2.1 vs 1.9; Zn, 0.9 vs 0.8; Mn, 0.40 vs 0.38; P < or = 0.05). By contrast, recalled median daily intakes of energy (kJ), protein (g) fat (g) and Cu (mg) were slightly underestimated (R vs W = 6588 vs 7824; 51 vs 57; 14 vs 15; 1.3 vs 1.6, respectively; P < or = 0.05). Discrepancies were attributed primarily to inaccurate estimates of main meal food portions [R vs W = nsima (the main meal cereal style) 475 vs 557; and legume relish 171 vs 118 P < or = 0.001]. For classifying intakes into tertiles, agreement between the two methods was poor for daily intakes (Cohen's kappa < 0.40), but fair when expressed per MJ, and as a percentage of energy from food groups (Cohen's kappa > or = 0.40). Variance ratios for recall data were higher than corresponding ratios for the weighed intakes (R vs W = for energy, 4.87 vs 0.87), indicating poorer recall measurement precision. CONCLUSION: Results emphasise the importance of selecting the dietary method according to the study objectives, and the nutrients required.

Adult↗

PubMed1994

A pilot trial of recombinant desulfatohirudin compared with heparin in conjunction with tissue-type plasminogen activator and aspirin for acute myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) 5 trial.

OBJECTIVES: The purpose of this study was to assess the value of recombinant desulfatohirudin (hirudin) as adjunctive therapy to thrombolysis in acute myocardial infarction. BACKGROUND: Failure to achieve initial reperfusion and reocclusion of the infarct-related artery remain major limitations of thrombolytic therapy despite aggressive regimens of heparin and aspirin. Hirudin, a direct thrombin inhibitor, has been shown in experimental models to enhance thrombolysis and reduce reocclusion. METHODS: The Thrombolysis in Myocardial Infarction (TIMI) 5 trial was a randomized, dose-ranging, pilot trial of hirudin versus heparin, given with front-loaded tissue-type plasminogen activator and aspirin to 246 patients with acute myocardial infarction. Patients received either intravenous heparin or hirudin at one of four ascending doses for 5 days. Patients underwent coronary angiography at 90 min and at 18 to 36 h, unless rescue angioplasty was performed. RESULTS: The primary end point, TIMI grade 3 flow in the infarct-related artery at 90 min and 18 to 36 h without death or reinfarction before the 18- to 36-h catheterization was achieved in 97 (61.8%) of 157 evaluable hirudin-treated patients compared with 39 (49.4%) of 79 evaluable heparin-treated patients (p = 0.07). All four doses of hirudin led to similar findings in the angiographic and clinical end points. At 90 min, TIMI grade 3 flow was present in 105 (64.8%) of 162 hirudin-treated patients compared with 48 (57.1%) of 84 heparin-treated patients (p = NS). Infarct-related artery patency (TIMI grade 2 or 3 flow) was similar in the two groups (82.1% and 78.6%, respectively). At 18 to 36 h, 129 (97.8%) of 132 hirudin-treated patients had a patent infarct-related artery compared with 58 (89.2%) of 65 heparin-treated patients (p = 0.01). Reocclusion by 18 to 36 h occurred in 2 (1.6%) of 123 hirudin-treated patients versus 4 (6.7%) of 60 heparin-treated patients (p = 0.07). Death or reinfarction occurred during the hospital period in 11 (6.8%) of 162 hirudin-treated patients compared with 14 (16.7%) of 84 heparin-treated patients (p = 0.02). Major spontaneous hemorrhage occurred in 1.2% of hirudin-treated patients versus 4.7% of heparin-treated patients (p = 0.09), and major hemorrhage at an instrumented site occurred in 16.3% and 18.6%, respectively (p = NS). CONCLUSIONS: Hirudin is a promising agent compared with heparin as adjunctive therapy with thrombolysis for acute myocardial infarction, and its evaluation in larger trials is warranted.

Adjuvants, Pharmaceutic↗

PubMed1994

Zinc status of a group of pregnant adolescents at 36 weeks gestation living in southern Ontario.

OBJECTIVE: Pregnant adolescents have very high zinc (Zn) requirements to support the developing fetus and to maintain skeletal maturation after menarche. METHODS: Sixty-six adolescents aged 17.1 +/- 0.15 years (mean +/- SEM; range 14.5-19.0 years) were recruited from three regions of Southern Ontario at 35.9 +/- 0.15 weeks gestation. Data on sociodemographic status, health, infant birth weight and birth length, smoking, alcohol consumption, and prenatal supplement use were collected. Fasting venipuncture blood was analyzed for Zn (via AAS) and alkaline phosphatase in plasma; scalp hair was analyzed for Zn by instrumental neutron activation. RESULTS: Mean (95% CI) values were: plasma Zn 10.7 (10.0-11.5) mumol/L; plasma alkaline phosphatase 46.6 (43.7-49.5) U/L; hair Zn 2.64 (2.52-2.77) mumol/g. None of the plasma and hair Zn values were indicative of suboptimal Zn status. Mean plasma Zn concentrations of subjects (n = 19) consuming a supplement with Zn sulfate were higher than those of subjects consuming a supplement with Zn oxide (n = 18) (12.2 vs 9.7 mumol/L; p < 0.02) and unsupplemented subjects (n = 11) (9.4 mumol/L). Plasma Zn concentrations correlated negatively with reported birth lengths (mean +/- SEM = 51.6 +/- 0.31 cm) while accounting for chronological age (r = 0.42; p < 0.01), but not with reported birth weights (mean +/- SEM = 3.439 +/- 0.107 kg). CONCLUSIONS: Results emphasize that the form of Zn must be taken into account when considering the impact of prenatal supplements containing Zn on plasma Zn concentrations. Suboptimal Zn status was not prevalent in these pregnant adolescents.

Adolescent↗

PubMed1994

Content and bioavailability of trace elements in vegetarian diets.

This review compares the content and major food sources of copper, manganese, selenium, and zinc in vegetarian and omnivorous diets. Interactions affecting trace element bioavailability and their impact on the trace element status of vegetarians are discussed. Adult vegetarian diets often have a lower zinc and selenium content but a higher copper and manganese content compared with omnivorous diets. Cereals are the primary sources of copper, manganese, and selenium in most diets and the major source of zinc in many vegetarian diets; flesh floods are the primary source of zinc and secondary source of selenium in omnivorous diets. Despite the apparent lower bioavailability of zinc, copper, manganese, and selenium in vegetarian diets because of the high contents of phytic acid and/or dietary fiber and the low content of flesh foods in the diet, the trace element status of most adult vegetarians appears to be adequate. Children, however, appear to be more vulnerable to suboptimal zinc status, presumably because of their high zinc requirements for growth and their bodies' failure to adapt to a vegetarian diet by increased absorption of dietary zinc.

Biological Availability↗

PubMed1994

Effects of treatment on outcome in mildly symptomatic patients with ischemia during daily life. The Atenolol Silent Ischemia Study (ASIST)

BACKGROUND: Detection of asymptomatic ischemia in patients with coronary artery disease has been associated with increased risk for adverse outcome, but treatment of patients with asymptomatic ischemia remains controversial. Accordingly, the purpose of this study was to determine if treatment reduces adverse outcome in patients with daily life ischemia. METHODS AND RESULTS: A multicenter, randomized, double-blind, placebo-controlled study of asymptomatic or minimally symptomatic outpatients with daily life silent ischemia due to coronary artery disease was conducted. The primary outcome measure was event-free survival at 1 year by Kaplan-Meier analysis. Events were death, resuscitated ventricular tachycardia/fibrillation, myocardial infarction, hospitalization for unstable angina, aggravation of angina, or revascularization. The secondary outcome was ischemia during ambulatory ECG monitoring at 4 weeks. Three hundred six outpatients with mild or no angina (Canadian Cardiovascular Society class I or II), abnormal exercise tests, and ischemia on ambulatory monitoring were randomized to receive either atenolol (100 mg/d) or placebo. After 4 weeks of treatment, the number (mean +/- SD, 3.6 +/- 4.2 versus 1.7 +/- 4.6 episodes, P < .001) and average duration (30 +/- 3.3 versus 16.4 +/- 6.7 minutes, P < .001) of ischemic episodes per 48 hours of ambulatory monitoring decreased in atenolol- compared with placebo-assigned patients (4.4 +/- 4.6 to 3.1 +/- 6.0 episodes and 36.6 +/- 4.1 to 30 +/- 5.5 minutes). Event-free survival improved in atenolol-treated patients (P < .0066), who had an increased time to onset of first adverse event (120 versus 79 days) and fewer total first events compared with placebo (relative risk, 0.44; 95% confidence intervals, 0.26 to 0.75; P = .001). There was a nonsignificant trend for fewer serious events (death, resuscitation from ventricular tachycardia/fibrillation, nonfatal myocardial infarction, or hospitalization for unstable angina) in atenolol-treated patients (relative risk, 0.55; 95% confidence intervals, 0.22 to 1.33; P = .175). The most powerful univariate and multivariate correlate of event-free survival was absence of ischemia on ambulatory monitoring at 4 weeks. Side effects were mild and generally similar comparing atenolol- and placebo-treated patients, although bradycardia was more frequent with atenolol. CONCLUSIONS: Atenolol treatment reduced daily life ischemia and was associated with reduced risk for adverse outcome in asymptomatic and mildly symptomatic patients compared with placebo.

Activities of Daily Living↗

PubMed1994

The relative validity of the repeated 24 h recall for estimating energy and selected nutrient intakes of rural Ghanaian children.

OBJECTIVES: To investigate the relative validity of the 24 h recall for rural southern Ghanaian children. DESIGN: Cross-sectional study, in which food consumption was estimated for the same two days, using the recall and weighed record dietary techniques. SETTING: Two villages in the Greater Accra Region of Ghana. SUBJECTS: 72 rural children (39 females and 33 males; 56.2 +/- 9.4 months). RESULTS: Overall agreement in the number of foods reported was noted for 42% of records; 53% of recalls under-reported and 5% over-reported the number of foods consumed. Over 65% of snacks compared to less than 6% of main meal foods were missed on recalls. Average recalled portions were similar to weighed with the exception of cereal staples; for Slepor 250 g vs 295 g, P = 0.007 and for Gidantuba 272 g vs 260 g, P = 0.02. Average daily recalled intakes of energy and most nutrients were lower (P < or = 0.05) than weighted intakes in Slepor, but similar in Gidantuba. In both villages, the recalled and weighted nutrient intakes per MJ, and percentage energy from food groups, were similar. Intraclass correlations between recalled and weighed intakes ranged from 0.06 (energy) to 0.78 (vitamin A) per day, and per MJ from 0.36 to 0.76 for Fe in Gidantuba and Slepor, respectively. Less than 35% of recalled energy and nutrient intakes were within +/- 10% of weighed intakes. CONCLUSIONS: The recall could be substituted for the weighted record to estimate average intakes of energy and most nutrients, dietary quality and food consumption patterns, provided the average recalled serving of cereal staples was accurately estimated. For assessment of individual intakes or snack consumption, however, the recall technique was invalid. SPONSORSHIP: The International Development Research Centre and Natural Sciences and Engineering Research Council of Canada.

Child↗

PubMed1993

Trace element intakes and dietary phytate/Zn and Ca x phytate/Zn millimolar ratios of periurban Guatemalan women during the third trimester of pregnancy.

Repeated 24-h recalls (9-14/subject) were conducted on 52 periurban Guatemalan pregnant women aged 25 +/- 5 y (means +/- SD). Intakes of energy, protein, calcium, zinc, copper, manganese, nonstarch polysaccharide (NSP), phytate, and millimolar ratios of phytate to zinc and (calcium x phytate) to zinc were calculated from food-composition values on the basis of chemical analysis and the literature. Mean (+/- SD) daily intakes were as follows: energy 8694 +/- 1674 kJ, protein 63.0 +/- 13.3 g, calcium 727 +/- 163, zinc 11.3 +/- 2.7, copper 1.3 +/- 0.3, manganese 2.8 +/- 0.6, phytate 2254 +/- 773 mg/d, NSP 26.6 +/- 6.9 g, phytate/zinc 18.8 +/- 4.2, (calcium x phytate)/zinc 706 +/- 21 mmol/MJ. Ninety-four percent had zinc intakes below the recommendations (15 mg) of WHO and the US recommended dietary allowances, assuming 20% absorption. Tortillas were a major source of zinc (46%), copper (20%), manganese (23%), calcium (39%), phytate (68%), and NSP (50%); 19% zinc from flesh foods. Thirty-eight percent had phytate-zinc ratios > 20; 94% had millimolar ratios of (calcium x phytate) to zinc per MJ > or = 22. The high prevalence of millimolar ratios of phytate to zinc and (calcium x phytate) to zinc per MJ above 20 and 22, respectively, may compromise zinc nutriture.

Adult↗

PubMed1993

Growth and body composition of periurban Guatemalan children in relation to zinc status: a cross-sectional study.

In a study of periurban Guatemalan school-children (89 males, 73 females) aged 81.5 +/- 7.0 mo (mean +/- SD), height, weight, arm circumference, and triceps-skinfold-thickness (TSF) measurements were examined in relation to plasma and hair zinc concentrations, plasma and red blood cell alkaline phosphatase activities, recognition thresholds for salt (RTS), delayed-cutaneous hypersensitivity response to seven recall skin test antigens, and cognitive measures. Children were stunted [median height-for-age (HA) Z score -1.49] but not wasted [median weight-for-height (WH) Z score 0.20], with median midarm muscle area (MAMA) and midarm-fat area (MAFA) Z scores of -0.57 and -0.35, respectively. Of the children, 63.5% of males and 44.1% of females had hair zinc < 1.68 mumol/g (P < 0.05); 12.3% of males and 1.5% of females had plasma zinc < 10.71 mumol/L (P < 0.05). Children with hair zinc < 1.68 mumol/g had higher (P < 0.05) medians for WA Z and WH Z scores, RTS, and phytic acid intake than did those with hair zinc > or = 1.68 mumol/g. Zinc status explained some of the variance in growth (HA, WA, and WH Z scores), body composition (MAFA Z scores), and taste acuity. Suboptimal zinc status arose partly from diets low in readily available zinc.

Aging↗