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PubMed2000

Quality of life in spina bifida: importance of parental hope.

BACKGROUND AND AIMS: Prognosis in spina bifida (SB) is often based only on neurological deficits present at birth. We hypothesised that both parental hope and the neurophysical examination predict quality of life in children and adolescents with SB. METHODS: A previously validated disease and age specific health related quality of life (HRQL) instrument was posted to families of children (aged 5-12 years) and adolescents (aged 13-20 years) with SB. We measured parental hope, determined the child's current physical function, and obtained retrospective data on the neonatal neurophysical examination (NPE). Regression analysis modelled HRQL firstly as a dependent variable on parental hope and NPE ("birth status"); and secondly on parental hope and current physical function ("current function"). RESULTS: Response rates were 71% (137 of 194) for families of children, and 54% (74 of 138) for families of adolescents. NPE data were available for 121 children and 60 adolescents. In children, the birth status model predicted 26% of the variability (R(2) hope 21%) compared with 23% of the variability (R(2) hope 23%)in the adolescents. The current function model explained 47% of the variability (R(2) hope 19%) in children compared with 31% of the variability (R(2) hope 24%) in the adolescents. CONCLUSIONS: In both age groups, parental hope was more strongly associated with the HRQL than neonatal or current physical deficits. A prospective study is required to determine whether a causal relation exists between parental hope and HRQL of children and adolescents with SB.

Adolescent↗

PubMed2006

Quality of life at older ages: evidence from the English longitudinal study of aging (wave 1).

OBJECTIVES: To investigate whether longstanding illnesses, social context, and current socioeconomic circumstances predict quality of life. DESIGN: Secondary analysis of wave 1 of the English longitudinal study of aging. Missing data were imputed and multiple regression analyses conducted. SETTING: England, 2002 PARTICIPANTS: Nationally representative sample of non-institutionalised adults living in England (n = 11 234, 54.5% women, age 65.1 (SD 10.2) years). MAIN OUTCOME MEASURE: Quality of life as measured by CASP-19, a 19 item Likert scaled index. RESULTS: The quality of life was reduced by depression (beta -0.265), poor perceived financial situation (beta -0.157), limitations in mobility (beta -0.124), difficulties with everyday activities (beta -0.112), and limiting longstanding illness (beta -0.112). The quality of life was improved by trusting relationships with family (beta 0.105) and friends (beta 0.078), frequent contacts with friends (beta 0.059), living in good neighbourhoods (beta 0.103), and having two cars (beta 0.066). The regression models explained 48% variation in CASP-19 scores. There were slight differences between age groups and between men and women. CONCLUSIONS: Efforts to improve quality of life in early old age need to address financial hardships, functionally limiting disease, lack of at least one trusting relationship, and inability to move out of a disfavoured neighbourhood. There is the potential for improved quality of life in early old age (the third age) if these factors are controlled.

Aged↗

PubMed2006

Health related quality of life in immigrants and native school aged adolescents in Spain.

OBJECTIVES: To compare health related quality of life (HRQL) between native and immigrant adolescents aged 12 to 18 years, and to analyse psychosocial factors associated with HRQL. DESIGN: A cross sectional study of adolescents (12-18 years old) who answered a self administered questionnaire. SETTING: All the secondary schools from Lloret de Mar (Girona, Spain). PARTICIPANTS: 1246 participants (88.9% of the eligible students). MAIN OUTCOME MEASURES: Main outcome was the Spanish version of the Vecu et Sante Percue de l'Adolescent (VSP-A), a HRQL measure addressed to adolescents. Mean scores of the VSP-A index of natives and immigrants were compared, as well as their sociodemographic and health related factors. Multiple regression examined the relation between HRQL and psychosocial factors, controlling for the effect of socioeconomic variables. RESULTS: Half of the sample were boys, in the middle socioeconomic status, and 18.2% were immigrants (n = 226). HRQL score was higher in native Spanish adolescents than immigrants (p<0.01). Multiple regression model explaining 48.1% of the VSP-A variance showed that migration in itself has no statistically significant impact on HRQL, and age, socioeconomic status, social support, discrimination, and psychological distress do play a part. CONCLUSIONS: Migrants have worse HRQL than natives but it seems to be mediated by their disadvantage in socioeconomic status, social support, and psychological distress.

Adolescent↗

PubMed1979

Ischaemic heart disease mortality risks for smokers and non-smokers.

Although many studies have shown that smoking is associated with an increased risk of death from ischaemic heart disease (IHD), and that the increase appears to vary with age and amount smoked, there has been little formal specification or estimation of the relationship. In this paper two alternative models are tested, using data for different ages and levels of smoking from four major studies in three countries. One model explains 80% of the variation in mortality in terms of a positive linear function of the number of cigerettes smoked, the parameters of which decrease with age. We estimate that every cigerette smoked per day increases the risk of dying from IHD by as much as 35% at ages 35 to 44, reducing to 2% at ages 65 to 74. The risk attributable to smoking may account for more than 80% of IHD deaths of men aged 35 to 44, and 27% of those of men aged 45 to 64. Although the relative risk is highest for younger age groups, the absolute risk of death from IHD that is attributable to smoking increases with age. The evidence suggests that both are increasing with time.

Adult↗

PubMed2001

Why don't patients do their exercises? Understanding non-compliance with physiotherapy in patients with osteoarthritis of the knee.

STUDY OBJECTIVES: To understand reasons for compliance and non-compliance with a home based exercise regimen by patients with osteoarthritis of the knee. DESIGN: A qualitative study, nested within a randomised controlled trial, examining the effectiveness of physiotherapy in reducing pain and increasing mobility in knee osteoarthritis. In the intervention arm, participants undertook a series of simple exercises and repositioning of the kneecap using tape. In depth interviews were conducted with a subset of participants in the intervention arm using open ended questions, guided by a topic schedule, to encourage patients to describe their experiences and reflect on why they did or did not comply with the physiotherapy. Interviews were audiotaped, fully transcribed and analysed thematically according to the method of constant comparison. A model explaining factors influencing compliance was developed. SETTING: Patients were interviewed at home. The study was nested within a pragmatic randomised controlled trial. PARTICIPANTS: Twenty participants in the intervention arm of the randomised trial were interviewed three months after they had completed the physiotherapy programme. Eight were interviewed again one year later. MAIN RESULTS: Initial compliance was high because of loyalty to the physiotherapist. Reasoning underpinning continued compliance was more complex, involving willingness and ability to accommodate exercises within everyday life, the perceived severity of symptoms, attitudes towards arthritis and comorbidity and previous experiences of osteoarthritis. A necessary precondition for continued compliance was the perception that the physiotherapy was effective in ameliorating unpleasant symptoms. CONCLUSIONS: Non-compliance with physiotherapy, as with drug therapies, is common. From the patient's perspective, decisions about whether or not to comply are rational but often cannot be predicted by therapists or researchers. Ultimately, this study suggests that health professionals need to understand reasons for non-compliance if they are to provide supportive care and trialists should include qualitative research within trials whenever levels of compliance may have an impact on the effectiveness of the intervention.

Aged↗

PubMed2003

Psychopathology in people with epilepsy and intellectual disability; an investigation of potential explanatory variables.

OBJECTIVES: There are few studies on epilepsy and psychopathology in people with intellectual disability (mental retardation) despite epilepsy prevalence rates that are thirty times higher than in the general population. The aims of this study, therefore, were to identify reliable, epilepsy-specific predictors of psychiatric and behavioural disorder in these patients, and to investigate reliable predictors of carer stress. METHODS: A database of 685 patients was compiled, from which 250 were randomly selected. Structured interviews were completed on 186 of these 250 patients (74%) (108 men, 78 women; mean age (SD) 35.5 (10.1)) comprising descriptive, clinical and functional components, and validated measures of psychopathology for which comparative data were available. Logistic and linear regression methods were used to identify predictors. RESULTS: One-third of patients with epilepsy and intellectual disability met criteria for possible psychiatric disorder, particularly affective/neurotic disorder; twice the comparison rates for intellectual disability alone. Behavioural problem levels, however, were lower than population norms. Regression models explaining modest amounts of variance (R(2)< or =24%) suggested certain seizure phenomena (greater seizure severity, more seizures in past month, lesser tendency to loss of consciousness during seizures) as particular risk factors for psychiatric disorder. General disability factors such as level of intellectual, sensory or motor disability and side effects of medication, however, contributed more to explaining behavioural problems. Around half of the family carers reported significant stress, and one-third exhibited clinically significant anxiety symptoms. Younger carers were more stressed, and side effects from patients' medication also contributed to carer stress. CONCLUSIONS: Although epilepsy in itself may be a risk factor for psychopathology in a minority of people with intellectual disability, some epilepsy-specific factors may predict psychiatric disorder. Behavioural problems need to be considered separately from psychiatric disorder because general factors, more closely associated with disability, are stronger predictors of their occurrence.

Adolescent↗

PubMed2000

Oxidative enzyme activities of the vastus lateralis muscle and the functional status in patients with COPD.

BACKGROUND: Enzymatic and histochemical abnormalities of the peripheral muscle may play a role in exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). A study was undertaken to measure the mitochondrial enzyme activity of the vastus lateralis muscle in patients with COPD and to evaluate the relationship between enzyme activities and functional status. METHODS: Fifty seven patients with COPD of mean (SD) age 66 (7) years with forced expiratory volume in one second (FEV(1)) 39 (15)% predicted and peak oxygen uptake (VO(2)) of 14 (4) ml/min/kg and 15 normal subjects of similar age were included in the study. Each subject performed a stepwise exercise test up to maximal capacity during which five-breath averages of VO(2) were measured. Muscle specimens were obtained by percutaneous needle biopsy of the vastus lateralis muscle and the activity of two mitochondrial enzymes (citrate synthase (CS) and 3-hydroxyacyl CoA dehydrogenase (HADH)) was measured. The functional status of the patients was classified according to peak VO(2). RESULTS: CS and HADH activities were markedly reduced in patients with COPD compared with normal subjects (22.3 (2.7) versus 29.5 (7.3) micromol/min/g muscle (p<0.0001) and 5. 1 (2.0) versus 6.7 (1.9) micromol/min/g muscle (p<0.005), respectively). The activity of CS decreased progressively with the deterioration in the functional status while that of HADH was not related to functional status. Using a stepwise regression analysis, percentage predicted functional residual capacity (FRC), the activity of CS, oxygen desaturation during exercise, age, and inspiratory capacity (% pred) were found to be significant determinants of peak VO(2). The regression model explained 59% of the variance in peak VO(2) (p<0.0001). CONCLUSIONS: The oxidative capacity of the vastus lateralis muscle is reduced in patients with moderate to severe COPD compared with normal subjects of similar age. In these individuals the activity of CS correlated significantly with peak exercise capacity and independently of lung function impairment.

3-Hydroxyacyl CoA Dehydrogenases↗

PubMed1985

In vitro concatemerization of bacteriophage T7 DNA: role of DNA synthesis and gene 6 exonuclease.

The replication of bacteriophage T7 DNA in vivo proceeds via the synthesis of complex concatemeric intermediates which are joined via the 160 base pair terminal redundancies at either end of the phage chromosome. To gain some insight into the mode of generation of these structures, we have examined the role of DNA synthesis in the formation of concatemeric bacteriophage T7 DNA in vitro. Incubation of mature T7 DNA with T7-infected cell extracts and a deoxynucleoside [32P]triphosphate resulted in the incorporation of significant radioactivity into the DNA. Highest levels of incorporation were at the termini of the DNA and decreased toward the middle of the molecule. Incorporation was dependent upon the presence of the activity of the gene 6 exonuclease and correlated with the generation of concatemeric DNA. A model explaining the role of exonucleolytic degradation and DNA synthesis in the generation of concatemeric DNA is presented.

Carbon Radioisotopes↗

PubMed2004

The spinal cord in multiple sclerosis: relationship of high-spatial-resolution quantitative MR imaging findings to histopathologic results.

PURPOSE: To correlate quantitative magnetic resonance (MR) imaging data (ie, relaxation times and magnetization transfer ratios [MTRs]) with histopathologic findings of demyelination and axonal disease in cervical spinal cord specimens from patients with multiple sclerosis (MS) and control subjects. MATERIALS AND METHODS: Formaldehyde-fixed cervical spinal cord specimens from 11 patients with MS-three men and eight women (mean age at death, 66 years +/- 11.3 [standard deviation])-and two female control subjects without neurologic disease (83 and 41 years of age at death) were examined at 4.7 T. Relaxation time measurements and MTR mapping were performed. Analyses included the whole cord area and region-of-interest measurements. Histopathologic analyses included semiquantitative myelin and quantitative axonal analysis. RESULTS: Compared with control specimens (P < .001, analysis of variance), specimens from patients with MS had smaller cord areas (mean area, 59.0 mm(2) +/- 12.5 vs 72.7 mm(2) +/- 10.0), significant prolongation of T1 (mean prolongation, 30%) and T2 (mean prolongation, 13%), and decreased MTRs (mean, 10.5%). Within MS specimens, 58% of the white matter area displayed signal intensity abnormalities on intermediate-weighted MR images. The number of axons in normal-appearing white matter in MS specimens was, on average, 46% lower than the number of axons in white matter in control specimens. All quantitative MR parameters correlated well with demyelination; the correlation with T2 relaxation time was the strongest (r = 0.77, Spearman and Kendall nonparametric correlations). By contrast, quantitative MR parameters correlated less well with axonal density; the correlation with T2 relaxation time was the strongest (r = -0.44, Spearman and Kendall nonparametric correlations). Multilevel analysis, corrected for age and MS phenotype, could not result in a model explaining axonal density on the basis of quantitative MR parameters when myelin density was included as a predictor. CONCLUSION: Changes in quantitative MR imaging parameters in the cervical spinal cord in MS are mainly determined by demyelination and do not reflect axonal disease well.

Adult↗

PubMed1988

Red cell velocity during functional hyperemia: implications for rheology and oxygen transport.

Muscle blood flow increases during work. Any associated change in blood velocity that occurs during functional hyperemia can have profound effects on wall shear rate and arteriolar hemoglobin saturations. We measured arteriolar red cell velocity and cross-sectional area during muscle contraction to determine the physiological significance of any of these changes in calculations of wall shear rate and the in situ spectrophotometric measurement of hemoglobin oxygen saturation. Calculated cremaster muscle blood flow increased 64-236% during twitch and tetanic stimulation, respectively, which was due entirely to an increase in cross-sectional area, with muscle work producing little change in either the red cell velocity or the calculated wall shear rate. Small changes ranging from a 3% increase to a 4% decrease in hemoglobin saturation were evident in second- and third-order arterioles, which apparently reflects offsetting effects of the increase in metabolic rate and the increase in arteriolar blood volume. A simple model explaining the microcirculatory adjustments made during muscle work requires dilation of both feed arteries and arterioles if red cell velocity is to remain constant during hyperemia.

Animals↗

PubMed1999

Stress and visceral perception.

Functional bowel disorders are characterized by the presence of a visceral hyperalgesia in most patients. This visceral hyperalgesia is related to an enhanced perception of sensations originating from the gut. Stressful events can dramatically influence the course of functional bowel disorders, and patients suffering from these syndromes appear to be more susceptible to the stressful events of daily life. However, until now, few studies have evaluated the relationship between stress and visceral perception. Some studies of healthy volunteers indicated contradictory results, but the studies used different methodologies. During stress conditions, either physical or mental, thresholds of perception of rectal distension were increased, suggesting a 'distraction effect', or were decreased, supporting a sensitizing effect of stress. In most studies, rectal compliance was not affected, but stress has been shown to alter the rectal tone, as measured by a barostat. One study comparing irritable bowel syndrome patients with controls demonstrated the importance of cognitive processes in the modulation of visceral perception by stress. Animal studies have also demonstrated the sensitizing effect of stress on the perception of rectal distension. Mediators involved may be numerous, but corticotropin-releasing factor has been demonstrated to play a major role at the central level. Mast cells and histamine release may play a role at the peripheral level. Stress can thus be included in an integrative model explaining the pathophysiology of functional bowel disorders. Advances in the understanding of the relationship between stress and visceral perception may constitute a basis for a therapeutic approach of functional bowel disorders targeted on the central nervous system.

Animals↗

PubMed2005

Plasma levels of enterolactone and percentage mammographic density among postmenopausal women.

AIMS: Certain phytoestrogens, such as lignans, may protect against developing breast cancer. Enterolactone is a lignan metabolite produced by the intestinal flora from dietary precursors such as whole grains, vegetables, and fruits. Enterolactone has been shown to have weak estrogenic and antiestrogenic properties. We decided to examine the association between plasma levels of enterolactone and mammographic density, a biomarker for breast cancer risk. METHODS: We included data from postmenopausal women ages 55 and older who participated in a cross-sectional mammogram study in Tromsø, Norway. Mammograms, plasma enterolactone measurements, as well as information on anthropometric and hormonal/reproduction factors were available on 616 women. We assessed mammographic density using a previously validated computer-assisted method. We estimated correlation coefficients and conducted multiple regression analyses. RESULTS: Mean mammographic density increased slightly across quartiles of enterolactone; the women in the highest quartile had, on average, 3.1% (absolute difference) higher percentage mammographic density compared with the lowest quartile (P(trend) < 0.01). After adjustment for age, body mass index, number of full-term pregnancies, age at first birth, and use of postmenopausal hormone therapy, the mean difference in density was reduced to 2.0% (P(trend) = 0.05). Results were similar when restricted to the 454 current hormone nonusers. The fully adjusted statistical model explained 28.3% of the total variability in mammographic percentage density, with body mass index contributing 18.2% and enterolactone only 0.9%. CONCLUSION: In our study, higher levels of enterolactone were associated with slightly higher percentage mammographic density. Our results suggest that if higher enterolactone levels reduce the risk of developing breast cancer in postmenopausal women, then this effect is not through lowering mammographic density.

4-Butyrolactone↗

PubMed2006

Motives of Belgian adolescents for using sunscreen: the role of action plans.

The first objective of this study was to analyze the differences between adolescents who use sunscreen frequently and those who do not. The second objective was to explore the importance of specific action plans when planning sunscreen use. Data was gathered among 602 Belgian secondary school students. Frequent and infrequent users of sunscreen were compared on several determinants related with sunscreen use, and a regression analysis on sunscreen use was done. Frequent users of sunscreen measures had significantly higher scores on attitudes, social influence, self-efficacy, some awareness factors, intention, and action plans. The integrated model for exploring motivational and behavioral change (I-Change model) explained 57% of the total variance of using sunscreen every 2 hours. Frequent sunscreen use was most strongly predicted by action plans, followed by positive intentions to use sunscreen, wearing protective clothing, seeking shade, attitude toward sunscreen use, education, social influence, and exposure to the sun. Our results suggest that skin cancer prevention programs aimed at promoting sunscreen use need to emphasize the advantages of sunscreen to infrequent users and to increase feelings of self-efficacy. Moreover, support by friends and parents should be stimulated. Finally, developing specific action plans for the use of sunscreen should be promoted to more effectively translate general intentions into actual sunscreen use.

Adolescent↗

PubMed2004

Effects of acyclic retinoid on growth, cell cycle control, epidermal growth factor receptor signaling, and gene expression in human squamous cell carcinoma cells.

We described recently the growth inhibitory effects of the novel compound acyclic retinoid (ACR) in human hepatoma cell lines (M. Suzui et al., Cancer Res., 62: 3997-4006, 2002). In this study we examined the cellular and molecular effects of ACR on human squamous cell carcinoma (SCC) cells. ACR inhibited growth of the esophageal SCC cell line HCE7, and the head and neck SCC cell lines YCU-N861 and YCU-H891, with IC(50) values of approximately 10, 25, and 40 microM, respectively. Detailed studies were then done with HCE7 cells. Treatment of these cells with 10 microM ACR caused an increase of cells in G(0)-G(1) and induced apoptosis. This was associated with two phases of molecular events. During phase 1, which occurred within 6-12 h, there was an increase in the retinoic acid receptor beta (RARbeta) and p21(CIP1) proteins, and their corresponding mRNAs, and a decrease in the hyperphosphorylated form of the retinoblastoma protein. During phase 2, which occurred at approximately 24 h, there was a decrease in the cellular level of transforming growth factor alpha, and the phosphorylated (i.e., activated) forms of the epidermal growth factor receptor, Stat3, and extracellular signal-regulated kinase proteins, and a decrease in both cyclin D1 protein and mRNA. Reporter assays indicated that ACR inhibited the transcriptional activity of the cyclin D1, c-fos, and activator protein promoters. On the other hand, ACR markedly stimulated the activity of a retinoic acid response element-CAT reporter when the cells were cotransfected with a RARbeta expression vector. A hypothetical model explaining these two phases is presented. The diverse effects that we obtained with ACR suggest that this agent might be useful in the chemoprevention and/or therapy of human SCCs.

Antineoplastic Agents↗

PubMed2005

Factors influencing length of hospital stay in patients with bacterial pleural effusion.

BACKGROUND: Factors influencing length of hospital stay have been poorly analyzed in parapneumonic pleural effusions (PPE). OBJECTIVES: The aim of this work is to identify the variables that determine increased hospital stay in patients with infectious pleural effusion (PE). PATIENTS AND METHODS: We analyzed 112 patients with PE: empyema, complicated parapneumonic and non-complicated parapneumonic. Epidemiologic, biochemical, therapeutic and radiological variables were analyzed. Correlations with hospital stay were studied using the Student's t test, analysis of variance, Mann-Whitney U-test and linear regression model. RESULTS: Among the 112 patients studied, there were 32 empyema, 50 complicated and 30 non-complicated parapneumonic cases. The median of length stay for all patients was 17 days. Longer hospitalization was required in patients with empyemic PE (p = 0.015), patients with underlying diseases (p = 0.003), those needing pleural drainage (p = 0.005) or decortication (p = 0.043) and those presenting unfavorable radiological outcome after treatment (p = 0.02). Biochemical parameters associated with longer hospital stay were elevated pleural fluid polymorphonuclear elastase (p = 0.001, r = 0.307) and lactate dehydrogenase (p = 0.001, r = 0.312). After linear regression analysis, only underlying disease, pleural drainage and pleural fluid polymorphonuclear elastase values remained in the model, explaining 23.1% of the variability of days of hospitalization. CONCLUSIONS: The patients with PPE and empyema who required longer hospitalization were those with purulent fluid, underlying disease, surgical drainage and/or decortication, with unfavorable radiological outcome and higher pleural fluid levels of lactate dehydrogenase and polymorphonuclear elastase.

Adult↗

PubMed2003

C-reactive protein is independently associated with fasting insulin in nondiabetic women.

OBJECTIVE: Insulin resistance is associated with chronic subclinical inflammation, and both conditions are linked with increased risk for type 2 diabetes mellitus and atherothrombotic cardiovascular disease. METHODS AND RESULTS: In a cross-sectional study conducted among participants in the Women's Health Study, an ongoing US primary prevention trial of cardiovascular disease and cancer, we evaluated the correlates of elevated fasting insulin, a marker of insulin resistance, among 349 healthy, nondiabetic women who remained free from clinically diagnosed type 2 diabetes mellitus during a 4-year period from biomarker assessment. Fasting insulin was strongly associated with body mass index (BMI) (r=0.53, P<0.001), C-reactive protein (CRP) (r=0.38, P<0.001), and interleukin-6 (r=0.33, P<0.001). Physical activity level, alcohol consumption, and use of hormone replacement therapy were also related to fasting insulin. However, in multivariable linear regression analysis, BMI and CRP were the only independent correlates of log-normalized fasting insulin. Overall, the final model explained 32% of the variance in log insulin level. In multivariable logistic regression, the fully adjusted odds ratio (OR) for elevated fasting insulin (>or=51.6 pmol/L) increased with tertile of BMI, CRP, and IL-6, such that the ORs in the highest versus lowest tertile of each parameter were 9.0 (95% confidence interval [CI], 4.4 to 18.7), 4.4 (95% CI, 1.9 to 10.1), and 2.0 (95% CI, 0.9 to 4.2), respectively. Furthermore, increasing levels of CRP were associated with a stepwise gradient in odds for elevated fasting insulin among both lean and overweight women. CONCLUSIONS: CRP is independently associated with fasting hyperinsulinemia in nondiabetic women. These data provide additional support for previously reported associations between subclinical inflammation and the risk of type 2 diabetes and cardiovascular disease.

Adipose Tissue↗

PubMed2005

Convergence time for the linkage learning genetic algorithm.

This paper identifies the sequential behavior of the linkage learning genetic algorithm, introduces the tightness time model for a single building block, and develops the connection between the sequential behavior and the tightness time model. By integrating the first-building-block model based on the sequential behavior, the tightness time model, and the connection between these two models, a convergence time model is constructed and empirically verified. The proposed convergence time model explains the exponentially growing time required by the linkage learning genetic algorithm when solving uniformly scaled problems.

Algorithms↗

PubMed1994

Review and analysis of variation between spirometric values reported in 29 studies of healthy African adults.

Within- and between-population variation in spirometric measurements has been addressed in a systematic review of spirometric measurements from 29 studies published between 1965 and 1990 involving 9,690 men and 2,638 women of sub-Saharan African ancestry; FVC and FEV1 were age- and height-standardized at BTPS. Between- population differences were related to geographic region and sample source (workforce versus community). The effects of altitude, variation in sample mean height, and year of study publication were also significant variables in multivariate models explaining between-population differences. Altitude was the most important variable with an effect of 263 ml/1,000 m (95% confidence interval [CI] 120-410) on FVC in men. In women, variation in sample mean height was also important, with taller populations having larger values for FVC (64 ml/cm). In men, secular trends were evident, with date of study associated with negative trends among men in the U.S.A. (-35.3 ml/year), and positive trends (14.7 ml/year) in other regions. These differences in trend could not be explained. Population selection factors, altitude, date of study, and other biological sources of variation need to be taken into account in evaluating between- and within-population comparisons of spirometric measurements.

Adult↗