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Results for “Multivariate response regression”

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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↗

PubMed2002

Alcohol consumption is associated with improved health-related quality of life in head and neck cancer patients.

The study aim was to investigate the relationship between alcohol consumption and health-related quality of life (HRQL) in post-therapeutic head and neck cancer patients. A cross-sectional study design was used with a sample of 191 subjects. Data were collected through interview and chart review. Alcohol consumption was evaluated through the dichotomous response to the question "During the past month have you drunk alcohol on one or more occasions?" HRQL was evaluated through the EORTC QLQ-C30 and H&N35 instruments. Data were also collected concerning sociodemographic and clinical variables. Multivariate regression was used to evaluate the hypothesized association. Of 28 domains comprising the EORTC QLQ-C30 and H&N35 instruments, eight were significantly associated with alcohol consumption, while 19 of the 20 remaining domains showed a tendency towards an association. Alcohol drinking was associated with significantly better physical and role functioning, and better global HRQL, plus less fatigue, pain, problems swallowing, dry mouth and feelings of illness. This suggests that, while the study findings are limited by its design and the sample bias, despite alcohol's role as an aetiological factor, it may be reasonable to drink a little as one recovers from head and neck cancer.

Adult↗

PubMed2001

Compliance with home rehabilitation therapy by parents of children with disabilities in Jews and Bedouin in Israel.

Among key points in making progress and succeeding with a therapeutic programme for children with disabilities is parental compliance with the regime for their child. The purpose of this study was to evaluate factors influencing compliance with home therapy in the Jewish and Bedouin populations. Data were collected by structured questionnaires. A total of 193 families participated (84% response rate) with children who ranged in age from 6 months to 6 years (mean age at first visit to the centre was 9.5 years in Jews and 16.1 years in Bedouin). Compliance was significantly lower among the Bedouin. Multivariate regression analysis showed that the strongest contributory factor in lack of compliance was being Bedouin. The second factor was intensity of questioning destiny, indicating that parents with these feelings may be less likely to comply with therapeutic regimes. Other factors which were associated with compliance were parents' education and socioeconomic status: lower levels on these dimensions corresponded with lower parental compliance. These results were illuminated by a trial intervention programme for Bedouin families which involved telephone contact, translation facilities, and detailed explanations during visits to the centre. Intervention increased the compliance rate of the Bedouin appointments with specialists to 76% (91 of 120 appointments) thereby reaching similar levels to those of the Jewish group. These preliminary results indicate that the strong association between non-compliance and being Bedouin may be due to factors of communication, and that the Bedouin are receptive to therapeutic interventions when communicated in their own language.

Arabs↗

PubMed2005

The joint effect of smoking and AIB1 on breast cancer risk in BRCA1 mutation carriers.

Women with BRCA1 mutations are at an elevated risk for breast cancer. AIB1 (NCOA3/SRC3) genotype and smoking may alter this risk. We examined the differences in breast cancer risk by AIB1 polyglutamine repeat polymorphism and pre-diagnosis smoking habits for BRCA1 mutation carriers to determine if there was an interaction between smoking and AIB1 genotype. Multivariate Cox proportional hazards regression was used with 316 female BRCA1 mutation carriers to model breast cancer risk. Ever having smoked was associated with a decreased breast cancer risk [Hazard Ratio (HR) = 0.63, 95% CI, 0.47-0.87]. A dose-response relationship between number of pack-years smoked and breast cancer risk was also found for women who smoked <20 pack years of cigarettes (HR = 0.72, 95% CI, 0.52-1.00) and for women who smoked >/=20 pack years (HR = 0.41, 95% CI, 0.23-0.71; P for trend = 0.0007). Women with a 28 repeat allele for AIB1 had a significantly reduced risk of breast cancer (HR = 0.72, 95% CI, 0.51-1.00). Women who smoked >/=20 pack-years with a 28 repeat allele had an even greater reduced risk of breast cancer (HR = 0.19, 95% CI, 0.07-0.54) compared to women who were never smokers with no 28 allele. Since AIB1 appears to modulate the effect of endogenous hormones via the estrogen receptor, and smoking affects circulating hormone levels, these results support evidence that steroid hormones play an important role in breast carcinogenesis in BRCA1 mutation carriers, and suggest mechanisms for developing novel cancer prevention strategies for BRCA1 mutation carriers.

Acetyltransferases↗

PubMed2001

A pathological study of tumour regression in oesophageal adenocarcinoma treated with preoperative chemoradiotherapy.

AIMS: To measure residual tumour in oesophageal adenocarcinoma treated with preoperative chemoradiotherapy, to correlate specific pathological variables with survival, and to describe morphological changes in tumour and non-neoplastic tissue resulting from preoperative treatment. METHODS: Resection specimens from 47 cases of oesophageal adenocarcinoma treated with preoperative 5-fluorouracil/cisplatin and radiotherapy were reviewed. Residual tumour was assessed in terms of tumour regression grade (TRG), pTNM stage, lymphovascular space invasion, and resection margin involvement. Survival analysis was performed using the Kaplan-Meier method and log rank test. Cox's proportional hazard model was used for multivariate analysis. RESULTS: A complete pathological response (TRG1) was present in eight cases. The absence of residual tumour was confirmed by negative immunohistochemical staining for MNF116. Tumour corresponding to TRG2 was present in five cases, to TRG3 in nine, to TRG4 in 22, and to TRG5 in three. By multivariate analysis, pN0 status (n = 35) had a positive effect on survival (p = 0.04) and TRG had no significant effect on survival (p = 0.06). Patients with pN0 tumours had a median survival of 48 months versus eight months for those with pN1 tumours (log rank test, p < 0.0001). We found that giant fibroblasts were discernible from single large residual tumour cells on haematoxylin and eosin alone. CONCLUSION: Response to preoperative chemoradiotherapy in oesophageal adenocarcinoma is variable. Although there are as yet no reliable predictors of response to treatment, patients who are identified at diagnosis as having negative loco-regional lymph nodes should benefit considerably from this treatment approach.

Adenocarcinoma↗

PubMed1988

A prospective study of cisplatin-based combination chemotherapy in advanced germ cell malignancy: role of maintenance and long-term follow-up.

Two hundred fifty-three patients with advanced germ cell malignancy received initial chemotherapy with cisplatin, vinblastine, and bleomycin followed by surgical resection of residual masses if possible. Patients achieving complete remission (CR) were prospectively randomized to receive 6 months maintenance therapy with vinblastine or no further treatment. CR was achieved in 183 patients (72%) and a further eight patients (4%) had complete resection of residual viable malignancy (no evidence of disease [NED]). Pretreatment factors having a significant adverse influence on response by univariate analysis included extragonadal origin of the tumor, poor performance status, advanced lung or lung and abdominal disease, and elevated serum levels of human chorionic gonadotropin (HCG) and alpha-fetoprotein (AFP) greater than 1,000 ng/mL. Multivariate regression analysis indicated the independent prognostic factors of significance were advanced lung or advanced lung and abdominal disease, total tumor diameter greater than 10 cm, and a serum level of HCG greater than 1,000 ng/mL. Of the toxicities encountered, myelosuppression was significant, being exacerbated by radiotherapy, and seven deaths occurred from septicemia. Bleomycin pulmonary toxicity occurred in 46% of patients and was severe in 4%, resulting in eight deaths. With a median follow-up of 64 months, relapses have occurred in 25 patients with no significant difference between those patients receiving or not receiving maintenance vinblastine. Eight of these relapses occurred beyond 1 year and four beyond 2 years of follow-up. Presently, 68% of the total patient population is alive and disease-free, with 84% of the CR and NED patients alive and 81% alive and disease-free. It is concluded that with prolonged follow-up, vinblastine maintenance therapy does not improve treatment outcome. Moreover, late relapses occur, cautioning against premature pronouncements of cure.

Adolescent↗

PubMed2000

Risk factors for severe neuropsychiatric toxicity in patients receiving interferon alfa-2b and low-dose cytarabine for chronic myelogenous leukemia: analysis of Cancer and Leukemia Group B 9013.

PURPOSE: Recombinant interferon alfa-2b (rIFNalpha2b) is a standard therapy for chronic myelogenous leukemia (CML). Severe neuropsychiatric toxicity has been described in patients receiving rIFNalpha2b, although the frequency of and the risk factors for developing this toxicity are not well described. The purpose of this study was to identify predictors for the development of severe neuropsychiatric toxicity in CML patients receiving rIFNalpha2b-based therapy. PATIENTS AND METHODS: From a prospective cohort of 91 Philadelphia chromosome-positive, previously untreated, chronic-phase CML patients treated on Cancer and Leukemia Group B (CALGB) 9013, a phase II trial of rIFNalpha2b plus cytarabine, the following were recorded at baseline: age, sex, race, pretreatment history of neurologic or psychiatric diagnosis, spleen size, blood counts, and peripheral blast count. Best response to treatment, rIFNalpha2b cumulative dose, dose duration, and dose-intensity were recorded during follow-up. Severe neuropsychiatric toxicity was defined as grade 3 or 4 events, according to CALGB expanded common toxicity criteria. Univariate and multivariate logistic regression analyses were used to identify variables that were associated with the development of severe neuropsychiatric toxicity. RESULTS: Severe neuropsychiatric toxicity developed in 22 patients (24.0%; 95% confidence interval [CI], 15.2% to 32.8%). Toxicity resolved after withdrawal of treatment in all patients. Five of six patients developed recurrence of symptoms with rechallenge. Twelve (63%) of 19 patients with a pretreatment neurologic or psychiatric diagnosis developed severe neuropsychiatric toxicity, as compared with 10 (14%) of 72 patients without a pretreatment neurologic or psychiatric diagnosis (P =.001), resulting in a relative risk of 4. 55 (95% CI, 2.33 to 8.88) for developing severe neuropsychiatric toxicity. No other variables were independently associated with the development of neuropsychiatric toxicity. CONCLUSION: CML patients with a pretreatment history of a neurologic or psychiatric diagnosis are at significantly increased risk of developing severe neuropsychiatric toxicity during therapy with rIFNalpha2b plus cytarabine. Monitoring for neuropsychiatric symptoms and avoiding rechallenge are recommended measures for such patients receiving rIFNalpha2b-based therapy.

Adult↗

PubMedDate not supplied

Hearing screening in a neonatal intensive care unit.

OBJECTIVE: Investigate the prevalence of hearing impairment in newborns hospitalized at the Intensive and Intermediate Care Unit at the Women's Comprehensive Health Center Neonatology Service (UNICAMP) and associated risk factors. METHODS: 979 newborn babies were assessed between January 2000 and January 2003, through automated auditory brainstem response (AABR) (ALGO 2e color screener). The result was considered normal when the newborn showed response to a 35dBNA signal bilaterally. The prevalence of AABR impairment and the odds ratio were analyzed with a 95% confidence interval using bivariate analysis. To identify the independent risk factors for hearing alterations, multivariate analyses were used with logistic regression. RESULTS: The prevalence of AABR impairment was 10.2%, of which 5.3% was unilateral and 4.9% bilateral. From the multivariate analyses, the following observations were made: family history of congenital hearing loss (OR = 5.192; p = 0.016), craniofacial deformity (OR = 5.530; p < 0.001), genetic syndromes associated with hearing loss (OR = 4.212; p < 0.001), weight below 1,000 g (OR = 3.230; p < 0.001), asphyxia (OR = 3.532; p < 0.001), hyperbilirubinemia (OR = 4.099; p = 0.002) and use of mechanical ventilation (OR = 1.826; p < 0.031) were the indicators that best characterized the group at risk for hearing impairment. CONCLUSIONS: The prevalence of hearing impairment using AABR is high. Therefore, it is essential for all newborns who present isolated or associated risk factors to undergo hearing screening in situations in which it is not possible to have universal hearing screening.

Epidemiologic Methods↗

PubMed2006

Catastrophic household expenditure for health care in a low-income society: a study from Nouna District, Burkina Faso.

OBJECTIVE: To quantify the extent of catastrophic household health care expenditure and determine the factors responsible for it in Nouna District, Burkina Faso. METHODS: We used the Nouna Health District Household Survey to collect data on 800 households during 2000-01 for our analysis. The determinants of household catastrophic expenditure were identified by multivariate logistic regression method. FINDINGS: Even at very low levels of health care utilization and modest amount of health expenditure, 6-15% of total households in Nouna District incurred catastrophic health expenditure. The key determinants of catastrophic health expenditure were economic status, household health care utilization especially for modern medical care, illness episodes in an adult household member and presence of a member with chronic illness. CONCLUSION: We conclude that the poorest members of the community incurred catastrophic health expenses. Setting only one threshold/cut-off value to determine catastrophic health expenses may result in inaccurate estimation leading to misinterpretation of important factors. Our findings have important policy implications and can be used to ensure better access to health services and a higher degree of financial protection for low-income groups against the economic impact of illness.

Burkina Faso↗

PubMed2003

[Relationship between tumor necrosis factor genetic polymorphisms and acute lymphocytic leukemia].

BACKGROUND & OBJECTIVE: Acute lymphocytic leukemia(ALL), which is sensitive to tumor necrosis factor (TNF) is one of hematological malignances derived from lymphoid tissue. Genetic polymorphisms in the tumor necrosis factor (TNF) locus can affect transcription and expression of TNF genes. This study was designed to investigate the relationship between -308 bp polymorphism in tumor necrosis factor-alpha(TNFalpha) gene and +252 bp in lymphotoxin-alpha(LTalpha) gene and the pathogenesis, clinical course, and outcome of ALL. METHODS: The single base mutation polymorphism in TNFalpha gene and LTalpha gene were analyzed among 29 Chinese patients with ALL and 72 normal controls using polymerase chain reaction (PCR)-restrictive fragment length polymorphism (RFLP). The clinical data were collected and survival analysis was performed. RESULTS: The difference of distribution of genotypes, alleles of TNFalpha(-308), LTalpha(+252), and TNF/LT polymorphic extended haplotypes between the ALL patients and control group were not statistically significant (P >0.05). In patients, no statistically significant association was found between the presence of a given TNF/LT haplotype status and clinical characters such as sex, white blood cell (WBC) counts, central nervous system involvement, and the response to therapy(P >0.05). The estimated 1-year overall survival rates in the groups of patients carrying high-risk and low-risk haplotypes were not statistically significant (P >0.05) using Kaplan-Meier method. In multivariate Cox regression models the TNF/LT haplotype status was not found to be a risk factor for outcome (P >0.05). CONCLUSION: These data suggest that genetic polymorphisms in the TNFalpha(-308) and LTalpha(+252) are not crucial in the pathogenesis, clinical course, and outcome of ALL patients.

Adolescent↗

PubMed1994

Parathyroid hypertensive factor and non-insulin-dependent diabetes mellitus.

The recently discovered parathyroid hypertensive factor (PHF) has been shown to increase intracellular free calcium levels. High intracellular calcium can cause insulin resistance, as seen in non-insulin-dependent diabetes mellitus (NIDDM) patients. We therefore compared plasma PHF activity in NIDDM patients and nondiabetic control subjects using a rat bioassay. More NIDDM patients (65%) than non-diabetic controls (33.3%) had detectable PHF activity. When injected into rats, plasma of 185 NIDDM patients caused an average increase of 4.89 +/- 0.68 mm Hg in rat mean arterial pressure (MAP). This change was significantly greater than a slight drop of 0.42 +/- 0.96 mm Hg (mean +/- SE) for the 127 nondiabetic control subjects (Student's t test, p < 0.001). A higher percentage of the NIDDM patients than of the non-diabetic patients were hypertensive. However, a stratified analysis showed that diabetic patients consistently had significantly higher PHF levels than did nondiabetic patients, regardless of being hypertensive or not. PHF activity did not correlate with age, sex, body mass index, or the type of hypoglycemic agent taken. However, multivariate logistic regression analysis showed a positive correlation between cholesterol and PHF level among the diabetic patients (p = 0.03), but such a correlation did not exist among the non-diabetic controls. Our data indicate that elevated PHF may be responsible for insulin resistance in a fraction of NIDDM patients and suggest that PHF may be related to serum cholesterol levels in NIDDM.

Adult↗

PubMed2006

Sensorineural hearing loss in combined modality treatment of nasopharyngeal carcinoma.

BACKGROUND: Combined modality therapy has become the standard of care for nasopharyngeal carcinoma, yet the combined ototoxic effects of radiation and cisplatin are poorly understood. The incidence and severity of sensorineural hearing loss (SNHL) with combined modality therapy was evaluated and the dose-response relation between radiation and hearing loss was investigated. METHODS: Patients with newly diagnosed AJCC Stage II-IVB nasopharynx carcinoma treated from 1994-2003 were identified. The records of 44 ears in 22 patients who received a preirradiation pure tone audiogram and followup audiograms 12+ months postirradiation were included in the analysis. All patients were treated with conformal radiotherapy to 70 Gy and received platinum-based chemotherapy similar to the Intergroup 0099 trial. Composite cochlear dose distributions were calculated. Ototoxicity was measured using intrasubject audiogram comparisons and SNHL was defined as per the American Speech and Hearing Association guidelines, with standard range of speech between 2000-4000 Hz. SNHL was analyzed using Fisher exact test and linear and logistic regression models. RESULTS PATIENT CHARACTERISTICS: median age, 45; 27% Asian; 68% male; 64% WHO III. Median audiologic followup was 29 months (range, 12-76 mos). Mean cochlear dose (Dmean) ranged from 28.4-70.0 Gy (median, 48.5 Gy). SNHL was detected in 25 of the 44 ears (57%) studied. There was an increased risk of SNHL for ears receiving Dmean > 48 Gy compared with those receiving < or = 48 Gy at all frequencies within the range of speech (P = 0.04). Using univariate logistic regression analysis, Dmean to the cochlea, cycles of cisplatin, and time postradiotherapy were independently significant factors in determining the incidence of SNHL (P = 0.02, P = 0.03, and P = 0.04, respectively). In univariate and multivariate linear regression analysis, Dmean was statistically significant at all frequencies in affecting degree of SNHL, whereas the significance of cisplatin and time was variable. CONCLUSIONS: There was a significant increase in risk of SNHL among patients receiving > 48 Gy, suggesting a threshold in cochlear radiation dose-response in the setting of combined modality therapy. This dose should serve as a Dmean constraint maximum for intensity-modulated radiotherapy treatment of nasopharynx carcinoma.

Adolescent↗

PubMedDate not supplied

Predictors of erythropoietin responsiveness in chronic hemodialysis patients.

The impact of dialysis intensity on erythropoietin (EPO) requirements is unclear. Previous work suggests that increased dialysis is associated with increased erythropoietin responsiveness (ERSP), but average dialysis intensity has increased since those publications. We hypothesized that ERSP would be independent of delivered Kt/V(urea) at current intensities of hemodialysis. We prospectively studied 135 stable chronic hemodialysis patients who receive iron and subcutaneous EPO dosed according to current guidelines. We collected biochemical, hematologic, and single pool urea kinetics data. ERSP was expressed as units per kilogram per week of EPO administered. Simple and multiple linear regression were used to identify characteristics predictive of ERSP. The mean age of the patients was 62 +/- 17 years (range, 17-90 years); 68 of 135 (50.3%) were women, and 120 of 135 (88.9%) were Caucasian. Mean delivered Kt/V(urea) was 1.60 +/- 0.49, with 102 of 135 (75.6%) of patients with a delivered Kt/V(urea) > 1.3. Univariate linear regression showed seven significant independent predictors of erythropoietin requirements. Low serum albumin (p < 0.001), low serum calcium (p = 0.002), high serum phosphate (p = 0.004), and high serum iPTH (p = 0.007) were all associated with lower levels of ERSP. Lower ERSP was also correlated with lower hemoglobin and lower serum iron and transferrin saturation. Delivered dialysis (Kt/ V(urea)) was not a significant predictor of ERSP (p = 0.61). Multivariate regression confirmed low serum albumin (p < 0.01), high serum phosphate (p = 0.001), high immunoreactive parathyroid hormone (p = 0.025), and low transferrin saturation (p < 0.0005) as predictors of low ERSP, and also found high serum ferritin to be correlated with low ERSP (p = 0.016). We found no relationship between erythropoietin responsiveness and intensity of hemodialysis in this population of patients with a mean delivered Kt/V(urea) of 1.6. This may indicate a threshold effect beyond which more dialysis will not improve ERSP. However, markers of an underlying inflammatory state and of secondary hyperparathyroidism were associated with decreased response to erythropoietin.

Adolescent↗

PubMed1992

Standardized residuals as a means for detection of growth alteration in the pathologic human fetus.

This paper introduces and discusses the use of standardized residuals as a technique for comparing the growth of normal and pathologic human fetuses. Anthropometric measures, radiographic measures, and organ weights were regressed on known gestational age of second- and third-trimester fetuses. Standardized residuals were calculated for a group of potentially growth-impaired fetuses. Use of residuals aids in identification of patterns of growth alteration in specific pathologies. Most important, studying the response of developing organ systems to a variety of insults may elucidate mechanisms of growth regulation in the fetus. We emphasize the special quality of the multivariate measures of the core sample of fetuses from the Akron Children's Hospital collection.

Anthropometry↗