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Results for “Multivariate response regression”

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PubMed2005

Hemodynamic and autonomic changes induced by Ironman: prediction of competition time by blood pressure variability.

We hypothesized that the extreme endurance exercise of an Ironman competition would lead to long-standing hemodynamic and autonomic changes. We investigated also the possibility of predicting competition performance from baseline hemodynamic and autonomic parameters. We have investigated 27 male athletes before competition, 1 h after, and then for the following week after the competition. The Task Force monitor was used to measure beat-to-beat hemodynamic and autonomic parameters during supine rest and active standing. Heart rate (P < 0.001) was increased, and stroke index (P = 0.011), systolic blood pressure (P = 0.004), diastolic blood pressure (P < 0.001), total peripheral resistance index (P < 0.001), and baroreceptor reflex sensitivity (P < 0.001) were decreased after the competition. The 0.05- to 0.17-Hz band of heart rate and blood pressure variability was increased (P < 0.001 and P < 0.001, respectively), the 0.17- to 0.40-Hz band of heart rate interval variability was decreased after the competition (P < 0.001). All parameters returned to baseline values 3 days after the competition. After the competition, the autonomic response to orthostasis was significantly impaired. The 0.05- to 0.17-Hz band of diastolic blood pressure variability before competition and weekly net exercise training, but not the other hemodynamic and autonomic parameters, were related to competition time in multivariate regression analysis (multiple r = 0.70, P < 0.001). The marked hemodynamic and autonomic changes after an ultraendurance race, which are compatible with myocardial depression in the face of sympathetic activation and reduction of afterload, return to baseline after only 1-3 days. Because the 0.05- to 0.17-Hz band of diastolic blood pressure variability contributes to the prediction of competition time, the analysis of blood pressure variability in the frequency domain deserves further study for the prediction of endurance capacity.

Adaptation, Physiological↗

PubMed2006

The relation between gastroesophageal reflux and respiratory symptoms in a population-based study: the Nord-Trøndelag health survey.

BACKGROUND: In spite of numerous investigations, the relation between respiratory symptoms and reflux symptoms in the general population remains unclear, since population-based studies are few. STUDY OBJECTIVES: To investigate the relation between respiratory symptoms and reflux symptoms in the population. SUBJECT AND METHODS: In a cohort of 65,363 individuals representing 71.2% of the adult population in the Norwegian county of Nord-Trøndelag, 58,596 individuals (89.6%) responded to questions concerning reflux symptoms. The 3,153 persons (5.4%) with severe and recurrent reflux symptoms constituted the case group, and the 40,210 persons (68.6%) without reflux symptoms served as the control group. Odds ratios (ORs) with 95% confidence intervals (CIs) represented relative risks. Potential confounding was tested in multivariable logistic regression analysis. RESULTS: Persons with asthma had reflux to a 60% greater extent than those without asthma after including adjustment for asthma medication (OR, 1.6; 95% CI, 1.4 to 1.9). There was a statistically significant dose-response association between breathlessness and reflux symptoms (p for trend < 0.0001), and the OR of severe breathlessness was 12.0 (95% CI, 9.5 to 15.2). Persons with heavy and wheezy breathing, daily cough, daily productive cough, or chronic cough showed a twofold to threefold statistically significant increase in risk of reflux symptoms. Adjustment for asthma or use of asthma medication did not substantially influence the risk estimates for any of the studied respiratory disorders. CONCLUSIONS: Reflux symptoms commonly coexist with asthma and other respiratory symptoms on a population-based level, seemingly irrespective of asthma medication.

Adult↗

PubMedDate not supplied

Efficacy of racism-specific coping styles as predictors of cardiovascular functioning.

OBJECTIVE: This study examined the relationship between racism-specific coping strategies and cardiovascular responses to an ethnically relevant speaking task. METHODS: Fifty-seven African-American females participated in a speaking task during which they discussed their experiences with inter-ethnic group racism. Blood pressure and heart rate responses were measured during a pre-speech, speech, and recovery period. Racism-specific coping strategies were assessed with both the Perceived Racism Scale (PRS) and the Ways of Coping Scale-Revised (WCS-R). RESULTS: Multivariate regression analyses indicated that racism-specific coping strategies assessed via the PRS and WCS-R predicted blood pressure and heart rate changes. Passive coping strategies were generally associated with greater changes in systolic blood pressure, diastolic blood pressure, and heart rate during the pre-speech and speech periods, and with incomplete diastolic blood pressure recovery and heart rate recovery. Unexpectedly, the use of more active roping strategies was also associated with greater changes in diastolic blood pressure, and with incomplete heart rate recovery. CONCLUSION: This study provides preliminary empirical evidence that racism-specific coping styles may contribute to blood pressure and heart rate variability in African-American females.

Adaptation, Psychological↗

PubMed2006

[Rapid and robust partial least squares regression and its application to NIR spectroscopy analysis].

Modern near infrared spectroscopy (NIRS), as an indirect analytical technique, is used to carriy out quantitative analysis of unknown samples by establishing a model with calibration samples. Taking into account the low sensitivity and poor disturbance rejection of NIRS, a new robust version of the SIMPLS algorithm was constructed from a robust covariance matrix for high-dimensional data and robust linear regression in the present paper. Because SIMPLS was based on the empirical cross-covariance matrix between the response variables and the regressors and on linear least squares regression, the results were affected by abnormal observations in the data set. In order to eliminate their negative impact on the accuracy and reliability of the model, a simple multivariate outlier-detection procedure and a robust estimator for the covariance matrix were embedded in the SIMPLS regression framework, based on the use of information obtained from projections onto the directions that maximize and minimize the kurtosis coefficient of the projected data. Finally, application of the proposed kurtosis-SIMPLS method to the NIR analysis was presented with a comparison to the SIMPLS. The results show that kurtosis-SIMPLS method not only finds out the very outliers from the data set with less computational cost, but also holds better prediction performance and steady capability for the normal samples.

English Abstract↗

PubMed1997

Psychological effects of chronic exposure to 50 Hz magnetic fields in humans living near extra-high-voltage transmission lines.

The validity of several published investigations of the possibility that residential exposures to 50 Hz or 60 Hz electromagnetic fields might cause adverse psychological effects, such as suicide and depression, may have been limited by inadequate controlling for confounders or inadequate measurement of exposures. We investigated the relationships between magnetic field exposure and psychological and mental health variables while controlling for potential confounders and careful characterising individual magnetic field exposures. Five-hundred-and-forty adults living near transmission lines completed neuropsychological tests in major domains of memory and attentional functioning, mental health rating scales and other questionnaires. Magnetic field measurements were taken in each room occupied for at least one hour per day to provide an estimate of total-time-integrated exposure. The data were subjected to joint multivariate multiple regression analysis to test for a linear relation between field exposure and dependent variables, while controlling for effects of possible confounders. Performance on most memory and attention measures was unrelated to exposure, but significant linear dose-response relationships were found between exposure and some psychological and mental health variables. In particular, higher time-integrated exposure was associated with poorer coding-test performance and more adverse psychiatric symptomatology. These associations were found to be independent of participants' beliefs about effects of electromagnetic fields.

Adolescent↗

PubMed1999

Inflammation enhances cardiovascular risk and mortality in hemodialysis patients.

BACKGROUND: Atherosclerosis, a major problem in patients on chronic hemodialysis, has been characterized as an inflammatory disease. C-reactive protein (CRP), the prototypical acute phase protein in humans, is a predictor of cardiovascular mortality in the general population. We hypothesize that several of the classic, as well as nontraditional, cardiovascular risk factors may respond to acute phase reactions. An activated acute phase response may influence or predict cardiovascular risk. METHODS: In 280 stable hemodialysis patients, serum lipids, apolipoproteins (apo) A-I and B, lipoprotein(a) [Lp(a)], fibrinogen, and serum albumin (Salb) were determined in relation to CRP and serum amyloid A (SAA), two sensitive markers of an acute phase response. Mortality was monitored prospectively over a two year period. RESULTS: Serum CRP and SAA were found to be elevated (more than 8 and more than 10 mg/liter, respectively) in 46% and 47% of the patients in the absence of clinically apparent infection. Patients with elevated CRP or SAA had significantly higher serum levels of Lp(a), higher plasma fibrinogen, and lower serum levels of high-density lipoprotein cholesterol, apo A-I, and Salb than patients with normal CRP or SAA. The rise in Lp(a) concentration was restricted to patients exhibiting high molecular weight apo(a) isoforms. During follow-up, 72 patients (25.7%) had died, mostly due to cardiovascular events (58%). Overall mortality and cardiovascular mortality were significantly higher in patients with elevated CRP (31% vs. 16%, P < 0.0001, and 23% vs. 5%, P < 0.0001, respectively) or SAA (29% vs. 19%, P = 0.004, and 20 vs. 10%, P = 0.008, respectively) and were also higher in patients with Salb of lower than 40 g/liter (44% vs. 14%, P < 0.0001, and 34% vs. 6%, P < 0.0001, respectively). Univariate Cox regression analysis demonstrated that age, diabetes, pre-existing cardiovascular disease, body mass index, CRP, SAA, Salb, fibrinogen, apo A-I, and Lp(a) were significantly associated with the risk of all-cause and cardiovascular mortality. During multivariate regression analysis, SAA, fibrinogen, apo A-I, and Lp(a) lost their predictive values, but age and CRP remained powerful independent predictors of both overall death and cardiovascular death. CONCLUSION: These results suggest that a considerable number of hemodialysis patients exhibit an activated acute phase response, which is closely related to high levels of atherogenic vascular risk factors and cardiovascular death. The mechanisms of activated acute phase reaction in patients on chronic hemodialysis remain to be identified. A successful treatment of the inflammatory condition may improve long-term survival in these patients.

Acute-Phase Reaction↗

PubMed1990

[Clinical studies on endocrine therapy of prostatic carcinoma (1): Multivariate analyses of prognostic factors in patients with prostatic carcinoma given endocrine therapy].

The general trend on the treatment for prostatic carcinoma has been changing from endocrine therapy alone to an alternative type according to stage. We evaluated clinically the favorable and unfavorable outcome of endocrine therapy in Japan, so that others will be appropriately evaluated. In a cooperative study made by members of five universities, 572 patients with clinically or histologically reconfirmed prostatic carcinoma were entered in this retrospective study. We studied the true influence of prognostic factors on the prognosis of 497 patients with prostatic carcinoma who had received endocrine therapy, employing multivariate analyses, such as quantification method II, multiple regression analysis and Cox's proportional hazard model. Twelve factors were considered in the study; "age", "stage", "histological findings (structural atypism = SAT, nuclear anaplasia = NAN, Gleason's primary and secondary pattern)", "pretreatment level of total acid (ACP) and of alkaline phosphatase (ALP)", "castration performed or not performed", "doses of estrogen", "type of response of local prostatic tumor and of ACP to endocrine therapy". Analysis of the "importance" of a prognostic factor by a partial correlation determined by quantification method II, revealed "stage" to have the greatest "importance" on prognosis throughout the entire period. "Response of local prostatic tumor", "response of ACP" and "Gleason's primary pattern" tended to be important factors for prognosis, in particular, in the first half period, and "age" and "Gleason's secondary pattern" were important in the latter half. Multiple regression analysis revealed the "stage", once again to be the most influential factor on the prognosis for the entire observation period. Also "response of local prostatic tumor", "SAT" and "Gleason's primary pattern" affected the patients' prognosis in the first half of the observation period. In the latter half, "age" became more of an influential factor than "histological findings". Analysis with Cox's proportional hazard model revealed that "response of ACP", "stage", "age", "Gleason's primary and secondary pattern", and "response of local prostatic tumor" were definitely the more influential prognostic factors, of which chi-square values (or t values) were statistically significant. Comparison of the significant factors in each multivariate analysis revealed that common influential prognostic factors, such as "age", "stage", "histological findings (mainly Gleason's primary and secondary pattern)", "response of local prostatic tumor" and "response of ACP" were coincident to the clinical impression. The clarification of these factors would be clinically beneficial when treating patients with endocrine therapy.

Estrogens↗

PubMed2001

Hypertensive caudate hemorrhage prognostic predictor, outcome, and role of external ventricular drainage.

BACKGROUND AND PURPOSE: The purpose of the present study was to analyze the outcome and outcome predictors of caudate hemorrhage and role of external ventricular drainage in acute hydrocephalus. METHODS: Clinical data from 36 consecutive patients with hypertensive caudate hemorrhage was used in the present study. Age, gender, volume of parenchymal hematoma, hematoma in the internal capsule, initial Glasgow Coma Scale (GCS), hydrocephalus, severity of intraventricular hemorrhage, and hemorrhagic dilatation of the fourth ventricle were analyzed for effect on outcome. Effect of external ventricle drainage for hydrocephalus was evaluated by comparing preoperative and postoperative GCS scores. RESULTS: By univariate analyses, poor outcome was associated with a poor initial GCS score (P=0.016), hydrocephalus (P<0.001), intraventricular hemorrhage severity (P<0.01), and hemorrhagic dilatation of the fourth ventricle (P=0.02). By multivariate analysis, stepwise logistic regression revealed that hydrocephalus was the only independent prognostic factor for poor outcome (P<0.001). Postoperative 48-hour GCS score was better than the preoperative score by use of paired-sample t test (P<0.001). CONCLUSIONS: Hydrocephalus is the most important predictor of poor outcome. External ventricular drainage response for hydrocephalus was good in the present study, whereas an early decision should be made regarding preoperative neurological condition.

Basal Ganglia Hemorrhage↗

PubMed2006

Perceived spouse responses to pain: the level of agreement in couple dyads and the role of catastrophizing, marital satisfaction, and depression.

The primary objective of this study was to examine whether individuals with chronic pain ("participants") and their spouses agree on perceptions of solicitous, distracting, and punishing spouse responses to pain. The second aim was to examine the role of participant catastrophizing (a negative mental set about pain), participant and spouse marital satisfaction, and participant and spouse depression in participant perceptions of spouse responses, spouse perceptions of their responses, and agreement between participants and spouses. Individuals with chronic musculoskeletal pain and their spouses (N=108 couples) completed questionnaire packets. Examination of overall group averages (participants vs. spouses) indicated little or no differences between participant and spouse ratings. Examination of individual agreement in participant and spouse ratings indicated substantial disagreement. The proposed moderators predicted both participant and spouse perceptions and jointly made minor contributions to dyad agreement. Although neither participant nor spouse perceptions of spouse responses are necessarily a reflection of actual behavior, the lack of agreement in this study suggests it may not be valid to use only patient perceptions in research related to spouse responses.

Chronic Disease↗

PubMed1992

Exercise hyperventilation chronic congestive heart failure, and its relation to functional capacity and hemodynamics.

The ventilatory response to exercise was evaluated in 26 normal sedentary men and 68 patients with chronic heart failure using the slope of the relation between minute ventilation (VE) and carbon dioxide production (VCO2). All subjects underwent maximal upright bicycle cardiopulmonary exercise testing; 33 patients also underwent right-sided cardiac catheterization. The slope of VE/VCO2 was calculated by linear regression analysis using data from all the exercise tests and the first 60% of exercise duration; a high correlation was seen between these results (r = 0.83; p less than 0.001). The slope of VE/VCO2 was significantly, though weakly, related to peak exercise work load, oxygen consumption and ventilatory threshold (r = -0.49, -0.56 and -0.49, respectively), several peak exercise hemodynamic parameters and peak exercise dead space/tidal volume ratio (r = 0.70). With use of multivariate analysis, the only independent determinants of the slope were peak exercise dead space/tidal volume ratio and cardiac index. Thus, in patients with heart failure, exercise hyperventilation can contribute to the impairment of functional capacity and can be considered a compensatory response to abnormal hemodynamics and lung blood distribution in order to keep blood gas concentrations normal.

Cardiac Catheterization↗

PubMed1998

Changes in activities of dopamine and serotonin systems in the frontal cortex underlie poor choice accuracy and impulsivity of rats in an attention task.

The purpose of the present study was to investigate whether differences in the function of monoaminergic systems could account for the variability in attention and impulsive behaviour between rats tested in the five-choice serial reaction time task in a model of attention deficit hyperactivity disorder. The ability of a rat to sustain its attention in this task can be assessed by measuring choice accuracy (percent correct responses) to visual stimuli, whereas the percentage of premature responses indicates the level of impulsivity. Following training with the five-choice serial reaction time task, rats were decapitated and brain pieces taken for neurochemical determination. Levels of dopamine, noradrenaline, 5-hydroxytryptamine, the dopamine metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid and the 5-hydroxytryptamine metabolite, 5-hydroxyindoleacetic acid were determined in the frontal cortex, nucleus accumbens, dorsal striatum and hippocampus. Multivariate regression analysis with a stepwise method revealed that the indeces of utilization of serotonin (5-hydroxyindoleacetic acid/5-hydroxytryptamine) in the left frontal cortex and dopamine (3,4-dihydroxyphenylacetic acid/dopamine) in the right frontal cortex together accounted for 49% of the variability in attentional performance between subjects. According to the regression analysis, a negative correlation existed between the left frontal cortex 5-hydroxyindoleacetic acid/5-hydroxytryptamine and choice accuracy, and a positive correlation was observed between 3,4-dihydroxyphenylacetic acid/dopamine ratio and choice accuracy on the opposite hemisphere. Additionally, right frontal cortex serotonin utilization was found to correlate positively with the proportion of premature hole responses and this relation accounted for about 24% of the variability in this index of impulsivity between animals. These data indicate that frontal cortex dopamine and serotonin play an important role in the modulation of attention and response control.

Animals↗

PubMed1995

Prognostic significance of DNA content in bladder cancer based on flow cytometric analysis of 249 transitional cell carcinomas.

The prognostic significance of DNA index (DI), S-phase fraction, and heterogeneity determined by flow cytometric DNA analysis was assessed in a prospective study of 249 newly diagnosed transitional cell carcinomas of the bladder. The median observation time was 4.8 years. A total of 456 subpopulations were detected. The S-phases could be estimated in 299 subpopulations. A DI > 1.25 or an S-phase above 9.7% were strongly correlated to invasiveness. One hundred and ten patients were treated with transurethral resection (TUR). Relapse-free survival could not be predicted by the DNA-derived parameters. Univariate analysis of survival showed prognostic significance of diploidy (0.98 < DI < or = 1.02, P = 0.02), hypotetraploidy (1.50 < DI < or = 1.96, P = 0.002), and S-phase size (P = 0.008). Multivariate analysis pointed to the T-classification (RR = 1.64) and hypotetraploidy (RR = 1.57) as prognostic parameters for survival of TUR-treated patients. One hundred and thirty-nine patients received radiotherapy (RT). A significantly better response was found for tumors with a subpopulation with a hypertetraploid DNA content (DI > 2.04, P = 0.05), and a significantly worse response for subpopulations with a maximum S-phase > 24.5% (P = 0.04). T-classification and histological grade had no predictive value. A logistic regression analysis indicated an estimated probability of response to RT of 77% for tumors with a DI > 2.04 and an S-phase < 24.5%, whereas tumors with a DI < 2.04 and an S-phase > 24.5% had only a 28% probability of response. The poor response to RT, predicted by an S-phase > 24.5%, translated into a poor survival, whereas the better treatment response found for patients with a DI > 2.04 did not result in a longer survival. Multivariate analysis pointed to S-phase (RR = 1.70), T-classification (RR = 1.60), and grade (RR = 0.65) as independent prognostic parameters for survival of RT-treated patients.

Adult↗

PubMed2002

Basal serum testosterone as an indicator of response to clomiphene treatment in human epididymis, seminal vesicles and prostate.

The present study was designed to determine the response of human epididymis, seminal vesicles and prostate function after a 5-day course of clomiphene citrate in men attending an infertility service. In 45 men, the secretions of the epididymis, seminal vesicles and prostate were assessed by measurements of seminal alpha-glucosidase, fructose and acid phosphatase, respectively. Subjects were classified as normal or abnormal: abnormal men were defined as those who either had history of a sexually transmitted disease (STD), leukocytospermia, hypoandrogenism, or a low response of Leydig cells to clomiphene stimulation; and normal subjects were those who did not have these conditions. Mean serum testosterone luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels were significantly increased after the short course with clomiphene citrate. After clomiphene citrate stimulation, the men in the normal group showed significantly increased marker levels of the seminal vesicles (P < 0.02) and prostate (P < 0.05), but not of the epididymis (P : NS). Men classified as abnormal showed no response according to the markers of the seminal vesicles and epididymis. Men with history of STD and abnormal basal values of acid phosphatase did not respond to the treatment. Men with history of STD but normal basal values of seminal acid phosphatase increased significantly in their levels of seminal acid phosphatase after clomiphene stimulation (P < 0.02). Multivariate analysis showed that the basal serum testosterone level was the only variable in predicting the probability of response to the clomiphene in terms of true-corrected seminal fructose, seminal acid phosphatase and seminal alpha-glucosidase levels. In fact, a high response of the seminal vesicles was observed in men with the highest basal serum testosterone levels (0.45 +/- 0.17; coefficient of regression +/- standard error; P < 0.018). However, a high response in terms of seminal acid phosphatase (P < 0.004) or alpha-glucosidase (P < 0.037) was observed in men with low basal serum testosterone levels. In conclusion, in the normal men, true-corrected fructose and acid phosphatase but not alpha-glucosidase in semen increased after duplicate androgen stimulation. An absence of response was observed in cases with history of STD/leukocytospermia or hypoandrogenism.

Acid Phosphatase↗

PubMed2004

Improved analysis of the vascular response to arterial ligation using a multivariate approach.

Ligation of the murine common carotid artery induces a reproducible remodeling response. The contribution of individual genes can be determined by comparison of the phenotypes of genetically modified mice. Although studies have shown the response to carotid artery ligation is influenced by many factors, individual analyses typically only consider a single factor, the presence of a gene of interest. Because of this limitation, measurements of the response to ligation show large variation, making the determination of significant difference between test groups difficult. In this study, we examine the hypothesis that the variation in the response to ligation is due to non-genetic factors in addition to genetic factors. Distance from the ligature, a variable common to all arterial ligation experiments, is an important source of variation and a significant predictor of the remodeling response. We find that the use of statistical regression is an improved analysis technique, as it allows the simultaneous consideration of multiple variables. We demonstrate this by showing improved sensitivity and novel findings in the analysis of the remodeling response in mice genetically mutant for the osteopontin gene. We conclude regression analysis provides a simple way to improve both comparative power and description of vascular remodeling.

Animals↗

PubMed1988

Quantitative grading of exercise stress test for patients with coronary artery disease using multivariate discriminant analysis.

A group of 111 male patients who had undergone maximal or symptom-limited maximal exercise stress testing for evaluation of coronary artery disease (CAD) were subjected to coronary angiography. Group I comprised 33 patients with normal or single-vessel disease (SVD), while 78 patients with double-vessel disease (DVD) or triple-vessel disease (TVD) formed Group II. On univariate analysis of the exercise test, the following variables were found to be of significance in discriminating between the two groups: age, exercise duration, double product (heart rate X systolic blood pressure) at peak exercise, duration of ST-segment depression, number of leads showing ST depression, ST depression of 1 mm or more, configuration of the depressed ST segment, and diastolic blood pressure response to exercise. Multivariate analysis however revealed that only the following five variables had significant discriminant power: number of leads showing ST depression, exercise duration, double product, diastolic pressure response, and ST-segment configuration. On the basis of their relative importance, a regression equation was developed to give a quantitative score to individual patients. A score of less than zero detected multivessel disease (MVD) with high specificity (94%) and sensitivity (70%), while a score of 15 or more almost excluded MVD (sensitivity 87%). The scoring system as reported here improved the exercise stress test interpretation when compared with the conventional reporting system.

Adult↗

PubMed2004

An analysis of clustered categorical data--application in dental health.

Quite often in medical studies multiple discrete indicators are used to measure some characters that are defined only conceptually and are difficult to measure directly. Studies of this type exhibit categorical responses of dependent nature. Analysis of such categorical data appears to be extremely difficult (intractable) particularly in the presence of risk (causal) factors. In the present article, our purpose is to develop a latent mixture regression model for analysing such multivariate categorical data. Such a mixture model accommodates correlated and overdispersed data through the incorporation of random effects. Unfortunately, a full likelihood analysis is often hampered by the need for numerical integration. Two different procedures have been considered here. Both involve intensive computations. Numerical investigation has been carried out on the basis of a survey data covering 220 individuals from medical colleges in and around Calcutta (India). The purpose of the study is to compare tooth cleaning efficiency of brushes manufactured by different companies.

Cluster Analysis↗

PubMed2005

Cardiopulmonary exercise testing in the clinical and prognostic assessment of diastolic heart failure.

OBJECTIVES: This study sought to define the relative prognostic value of cardiopulmonary exercise testing (CPET) variables in heart failure (HF) patients with preserved versus reduced systolic function. BACKGROUND: Cardiopulmonary exercise testing has an established role in the assessment of patients with systolic heart failure (SHF). Two variables, peak Vo2 and, more recently, the VE/VCO2 slope, have been shown to be extremely valuable in risk stratification. However, data are lacking in terms of the prognostic value of CPET in patients with diastolic heart failure (DHF). METHODS: A total of 409 HF patients underwent CPET. Patients were divided into three groups according to the following left ventricular ejection fraction (LVEF) cutoffs: > or =40%, > or =45%, and > or =50%. The CPET response and the ability of peak VO2 and the VE/VCO2 slope to predict total mortality and hospitalization were examined. RESULTS: At univariate Cox regression analysis, both the peak VO2 and the VE/VCO2 slope were significant predictors in SHF and DHF. Multivariate analysis documented a similar prognostic power of VE/VCO2 slope and peak VO2 in all SHF groups. Conversely, in DHF patients, VE/VCO2 slope outnumbered peak VO2, remaining the only predictor regardless of LVEF. In DHF, the area under the receiver operating characteristic curve for the VE/VCO2slope identified a cutoff of 32.6 (74% sensitivity, 52% specificity), 33.1 (76% sensitivity, 62% specificity), and 33.3 (97% sensitivity, 40% specificity) for an LVEF cutoff of > or =40%, > or =45%, and > or =50%, respectively. CONCLUSIONS: These results extend the clinical and prognostic applicability of CPET to DHF. An impairment in exercise ventilation rather than peak VO2 holds clinical and prognostic impact in this increasing subset of patients.

Diastole↗

PubMed2001

Breast-feeding practices among WIC participants in Hawaii.

OBJECTIVE: To describe breast-feeding practices and identify correlates of breast-feeding among participants in the Hawaii Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) program. DESIGN: A cross-sectional survey. SUBJECTS/SETTING: We conducted structured, in-person interviews with 535 women at WIC clinics throughout Hawaii (95% response rate). The interview collected information on maternal characteristics and infant-feeding practices. STATISTICAL ANALYSES: Breast-feeding prevalence was examined by infant age and predictors of infant-feeding method were examined via bivariate tests and multivariable logistic regression analysis. Reported breast-feeding promotion efforts in health care settings outside of WIC were also examined. RESULTS: Most women (82%) attempted to breast-feed, albeit for short durations for many women; of the women who breast-fed in combination with formula feeding, 46% introduced formula within the first week after delivery. Significant predictors of breast-feeding initiation included previous breast-feeding experience, having a close relative or friend who breast-fed, multiparity, Asian/Pacific Island ethnicity (other than Filipino), and being foreign-born. Significant predictors of mixed feeding (vs exclusive breast-feeding) included working or attending school, age less than 20 years, Hawaiian/part Hawaiian or Filipino ethnicity, being Hawaiian-born, and residing in Oahu county. CONCLUSIONS: Although most women in this population initiated breast-feeding, formula was usually introduced at an early age. This study identified several factors associated with breast-feeding initiation and exclusive breast-feeding, factors that may prove useful for the development of appropriate interventions to promote these behaviors.

Adult↗