Biomedical subjects

Susan Redline

Publications and source records attributed to Susan Redline.

At least 73 records · Page 4Linked to original sources

PubMed2003

Decreased quality of life associated with obesity in school-aged children.

OBJECTIVES: To examine the association between health-related quality of life and body mass index (BMI) in preadolescent school-aged children and to provide the possible risk factors among participant characteristics, BMI status, and health-related quality of life. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional analysis of 371 (50% female; 32% minority) children from a community-based sample of 8- to 11-year-olds participating in an ongoing cohort study, excluding those who had sleep apnea or who were born prematurely. Using BMI percentiles for age and sex, 17.5% of the children were considered overweight (BMI > or =95th percentile), 12.4% were at risk for overweight (BMI 85th-94th percentile), 8.1% were relatively underweight (BMI <20th percentile), and the remaining 62.0% were of normal weight (BMI 20th-84th percentile). MAIN OUTCOME MEASURES: Health-related quality-of-life scores as determined by the Child Health Questionnaire-Parent Form 50, dichotomized into the bottom quartile or decile. RESULTS: After adjustment for covariates (host factors and health status measurements), overweight children compared with normal weight children scored lower on the Psychosocial Health Summary (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.1-3.6) and on subscales measuring self-esteem (OR, 3.5; 95% CI, 1.9-6.3), physical functioning (OR, 2.8; 95% CI, 1.7-6.8), and effect on the parent's emotional well-being (OR, 2.0; 95% CI, 1.1-3.6). Compared with the normal weight group, children who are at risk for overweight scored significantly lower for physical functioning. CONCLUSION: Overweight children have an increased odds of low scores for several health-related quality-of-life domains, suggesting the importance in considering such dimensions in programs aimed at further understanding obesity in children.

Asthma↗

PubMed2003

Recruitment of healthy adults into a study of overnight sleep monitoring in the home: experience of the Sleep Heart Health Study.

The Sleep Heart Health Study (SHHS) is a prospective cohort study using participants from several ongoing cardiovascular and respiratory disease research projects to investigate the relationship between sleep-disordered breathing and cardiovascular disease. This study design required unusual and different recruiting techniques to meet the study's enrollment goal of between 6000 and 6600 participants. Individuals were recruited to undergo an overnight home polysomnogram, completion of several questionnaires, and collection of a small amount of physical examination data. This article describes the methods used to recruit these participants and how these procedures influenced the final participation rate and the representativeness of SHHS to its parent cohorts. Of 30,773 people eligible for recruitment into SHHS, attempts were made to enroll 11,145 (36%). Of those contacted, 6441 ultimately agreed to participate (58%). Recruitment rates (38 to 91%) varied among sites. SHHS participants were slightly younger (63.0 vs. 65.0 years, p < 0.001), had more years of education (14.1 vs. 13.7, p < 0.001), more likely to snore (34% vs. 23%, p < 0.001), had higher Epworth sleepiness scores (7.7 vs. 6.5, p < 0.001), slightly higher higher systolic and diastolic blood pressures (127.6/73.9 vs. 127.2/72.1, p < 0.001 for diastolic only), and a slightly higher body mass index (BMI) (28.5 vs. 27.5, p < 0.001). We conclude that it is feasible to recruit existing participants from one large-scale epidemiologic study into another with a high degree of success. However, the characteristics of the new cohort may vary in several respects from their original cohorts and therefore interpretation of study results will have to consider these differences.

Adult↗

PubMed2003

Development and validation of school-based asthma and allergy screening instruments for parents and students.

BACKGROUND: The increasing morbidity attributable to asthma among school-aged children suggests the potential utility of school-based asthma screening programs. OBJECTIVE: We report our efforts to develop and validate culturally sensitive and clinically useful screening questionnaires (parent and child versions) for asthma and allergies among urban US school children. METHODS: Instrument development was accomplished through literature review, expert medical and child developmental input, focus group feedback, and a rigorous trial of the instruments in a public school setting. Questionnaires were distributed to 2,800 children and their families in an urban public school system (grades kindergarten through 6). Validity was evaluated by blinded comparison of results against a standardized clinical evaluation in 107 children, with final designations determined by an expert panel. RESULTS: Questionnaires pertaining to 2,083 children were returned (participation rate of 74%). A moderate level of agreement was observed between parent and student questionnaire responses (r values = 0.36 to 0.50; P values < 0.001). The highest frequency of asthma-like symptoms was reported for African-American boys and the lowest for Caucasian girls. The items from the parent questionnaire that best predicted asthma were "breathing problems" (occurring rarely or more; odds ratio 12.8; 95% confidence interval, 4.5 to 36.1) and "problems coughing" (sometimes or more; odds ratio 9.7; 95% confidence interval, 3.6 to 26.5). Considering the presence of cough (sometimes or more) and/or breathing problem (rarely or more) yielded a sensitivity of 80%; a specificity of 75%, a positive predictive value of 50%, and a negative predictive value of 92%. Similar levels of prediction were observed for the items "trouble breathing" and "noisy breathing" as directly reported by the students. Allergic rhinitis was best predicted by report of a runny/stuffy no se (sometimes or more; sensitivity of 83%, specificity of 61%). Allergic conjunctivitis was best predicted by "itchy eyes." CONCLUSIONS: Administration of a school-based questionnaire is feasible, with a high response rate and excellent internal consistency. A high sensitivity and acceptable specificity was achieved by using one to two questions for asthma, allergic rhinitis, and allergic conjunctivitis. Among the children in grades 2 or above, comparable levels of prediction could be achieved with the student or parent version.

Adolescent↗

PubMed2003

Prevalence and risk factors for sleep-disordered breathing in 8- to 11-year-old children: association with race and prematurity.

OBJECTIVES: To evaluate the extent to which sleep-disordered breathing (SDB) varies with putative demographic and medical risk factors and to estimate the prevalence of undiagnosed SDB. STUDY DESIGN: Prospective, cross-sectional study in a population-based cohort of 850 children (41% black, 46% preterm), 8 to 11 years of age. Participants' caretakers completed questionnaires about health and sleep. Children underwent overnight in-home cardiorespiratory recordings of airflow, respiratory effort, oximetry, and electrocardiography. SDB was identified by respiratory disturbance indices commonly applied in clinical practice. Risk factors were estimated by logistic regression. Prevalence was derived from cohort-specific estimates with birth weights from US live births data. RESULTS: Using the most inclusive definition, SDB was detected in 40 (4.7%) participants, with prevalence varying widely across population subsets. Depending on the definition used, SDB was 4 to 6 times more likely in black children compared with white children and almost 3 to 5 times more likely in former preterm compared with term children. The estimated population prevalence of SDB was 2.2% (95% CI, 1.2%, 3.2%). CONCLUSIONS: SDB is a relatively common condition in 8- to 11-year-old children. Potentially vulnerable subgroups, black children, and former preterm infants, are at increased risk.

Cardiovascular System↗

PubMed2003

Predicting attrition in a pediatric asthma intervention study.

OBJECTIVES: To operationalize a comprehensive description of attrition, including pre-inclusion, dropout, and attrition due to intermittent missing data, and to test a predictive model of attrition using a data set from a randomized controlled intervention in pediatric asthma. METHODS: Participants included children, ages 4-12, diagnosed with asthma and their caregivers. Demographic variables and outcome measures of asthma morbidity were examined in 327 families to determine their association with attrition. RESULTS: Families who did not complete randomization and the intervention tended to have younger caregivers than did completers. Caregiver age emerged as the most consistent predictor of pre-inclusion and dropout attrition. There were no significant predictors of attrition due to intermittent missing data. CONCLUSION: Younger caregivers may be at particular risk for attrition in pediatric asthma intervention studies and warrant special attention by investigators.

Asthma↗

PubMed2003

Predictors of longitudinal change in sleep-disordered breathing in a nonclinic population.

STUDY OBJECTIVES: To quantify and identify the determinants of the 5-year change in the respiratory disturbance index (RDI). DESIGN: Longitudinal cohort study (Cleveland Family Study). Multivariate analyses were used to quantify baseline RDI and RDI change. SETTING: Community-based study. PARTICIPANTS: 486 cohort members (62% from families of probands with sleep-disordered breathing [SDB])--mean age 31.6 +/- 17.9 (SD) years, 60% female, 21% Black ethnicity--who underwent 2 assessments over 5.3 +/- 0.9 (SD) years. INTERVENTIONS: NA. MEASUREMENTS: The RDI was measured twice over approximately 5 years with in-home monitoring. Symptoms and medical histories were obtained from standardized questionnaires, and weight, height, and blood pressure were measured. RESULTS: The prevalence of SDB (defined by a RDI > or = 15), increased from 13.7% to 23.4% (P < 0.01) in men and from 8.3% to 11.4% (P = 0.13) in females. Baseline and follow-up mean RDIs were 6.0 +/- 10.0 and 8.6 +/- 14.3; both were higher in older individuals, in men, and in those with a higher body mass index. Median 5-year change in RDI varied nonlinearly with age (-0.1, 1.1, 2.3, and 0.9, for those < 18, 19-40, 41-54, and > or = 55 years, respectively) and obesity (2.8 vs -0.1, for the top versus lowest body mass index quartile). The effects of changing weight and aging varied in population subgroups. At any given age and weight, the RDI increased less in women. CONCLUSIONS: Longitudinal change in the RDI varies nonuniformly with age, sex, and weight. Older heavier men may experience the highest rate of increase in RDI over time and, thus, may benefit most from prospective monitoring.

Adult↗

PubMed2003

Diabetes and sleep disturbances: findings from the Sleep Heart Health Study.

OBJECTIVE: To test the hypothesis that diabetes is independently associated with sleep-disordered breathing (SDB), and in particular that diabetes is associated with sleep abnormalities of a central, rather than obstructive, nature. RESEARCH DESIGN AND METHODS: Using baseline data from the Sleep Heart Health Study (SHHS), we related diabetes to 1). the respiratory disturbance index (RDI; number of apneas plus hypopneas per h of sleep); 2). obstructive apnea index (OAI; >or=3 apneas/h of sleep associated with obstruction of the upper airway); 3). percent of sleep time < 90% O(2) saturation; 4). central apnea index (CAI; >or=3 apneas [without respiratory effort]/h sleep); 5). occurrence of a periodic breathing (Cheyne Stokes) pattern; and 6) sleep stages. Initial analyses excluding persons with prevalent cardiovascular disease (CVD) were repeated including these participants. RESULTS: Of the 5874 participants included in this report, 692 (11.8%) reported diabetes or were taking oral hypoglycemic medications or insulin and 1002 had prevalent CVD. Among the 4872 persons without CVD, 470 (9.6%) had diabetes. Diabetic participants had worse CVD risk factor profiles than their nondiabetic counterparts, including higher BMI, waist and neck circumferences, triglycerides, higher prevalence of hypertension, and lower HDL cholesterol (P < 0.001, all). Descriptive analyses indicated differences between diabetic and nondiabetic participants in RDI, sleep stages, sleep time <90% O(2) saturation, CAI, and periodic breathing (P < 0.05, all). However, multivariable regression analyses that adjusted for age, sex, BMI, race, and neck circumference eliminated these differences for all sleep measures except percent time in rapid eye movement (REM) sleep (19.0% among diabetic vs. 20.1% among nondiabetic subjects, P < 0.001) and prevalence of periodic breathing (odds ratio [OR] for diabetic subjects versus nondiabetic subjects 1.80, 95% CI 1.02-3.15). Additionally, adjusted analyses showed diabetes was associated with nonstatistically significant elevations in the odds of an increased central breathing index (OR 1.42, 95% CI 0.80-2.55). Addition to the analysis of the 1002 persons with prevalent CVD (including 222 people with diabetes) did not materially change these results. CONCLUSIONS: These data suggest that diabetes is associated with periodic breathing, a respiratory abnormality associated with abnormalities in the central control of ventilation. Some sleep disturbances may result from diabetes through the deleterious effects of diabetes on central control of respiration. The high prevalence of SDB in diabetes, although largely explained by obesity and other confounders, suggests the presence of a potentially treatable risk factor for CVD in the diabetic population.

Aged↗

PubMed2002

A whole-genome scan for obstructive sleep apnea and obesity.

Obstructive sleep apnea (OSA) is a common, chronic, complex disease associated with serious cardiovascular and neuropsychological sequelae and with substantial social and economic costs. Along with male gender, obesity is the most characteristic feature of OSA in adults. To identify susceptibility loci for OSA, we undertook a 9-cM genome scan in 66 white pedigrees (n=349 subjects) ascertained on the basis of either an affected individual with laboratory-confirmed OSA or a proband who was a neighborhood control individual. Multipoint variance-component linkage analysis was performed for the OSA-associated quantitative phenotypes apnea-hypopnea index (AHI) and body mass index (BMI). Candidate regions on chromosomes 1p (LOD score 1.39), 2p (LOD score 1.64), 12p (LOD score 1.43), and 19p (LOD score 1.40) gave the most evidence for linkage to AHI. BMI was also linked to multiple regions, most significantly to markers on chromosomes 2p (LOD score 3.08), 7p (LOD score 2.53), and 12p (LOD score 3.41). Extended modeling indicated that the evidence for linkage to AHI was effectively removed after adjustment for BMI, with the exception of the candidate regions on chromosomes 2p (adjusted LOD score 1.33) and 19p (adjusted LOD score 1.45). After adjustment for AHI, the primary linkages to BMI remained suggestive but were roughly halved. Our results suggest that there are both shared and unshared genetic factors underlying susceptibility to OSA and obesity and that the interrelationship of OSA and obesity in white individuals may be partially explained by a common causal pathway involving one or more genes regulating both AHI and BMI levels.

Adult↗

PubMed2002

Health-related quality of life and sleep-disordered breathing in children.

STUDY OBJECTIVES: To assess the extent to which sleep-disordered breathing (SDB) is associated with impairment of health-related quality of life (HRQOL) in children DESIGN: Observational study of pediatric participants in a longitudinal genetic-epidemiologic cohort study of SDB. SETTING: Community-based; studies conducted at participants' homes PARTICIPANTS: 298 children, aged 11.1 years +/- 3.5 SD; 54% females; 61% African-American or Other; 81% with a family member identified with laboratory-confirmed SDB. INTERVENTIONS: Not applicable MEASUREMENTS AND RESULTS: The HRQOL was assessed with the Child Health Questionnaire (CHQ-PF50), a 50-item parent-completed form that measures 14 multidimensional health concepts. Sleep-disordered breathing (SDB) was assessed with ovemight in-home monitoring that recorded nasal-oral airflow, pulse oximetry, chest-wall impedance, and heart rate. Using logistic regression analyses, each CHQ scale outcome was analyzed independently for the effect of SDB, adjusting for other potential confounding variables and for family-correlated data. Significant differences in overall physical health and complaints of bodily pain were observed in children with generally mild levels of SDB. Relationships persisted after adjustment for age, gender, ethnicity, obesity, and asthma. CONCLUSIONS: SDB in children is associated with measurably lower levels of specific dimensions of HRQOL in children. Decrements in HRQOL are measurable even for children with mild SDB, with increasing effects observed with more severe SDB.

Adolescent↗

PubMed2002

Utility of noninvasive pharyngometry in epidemiologic studies of childhood sleep-disordered breathing.

Measurement of pharyngeal dimensions may contribute to the characterization of anatomic risk factors for sleep-disordered breathing (SDB) in children. Acoustic pharyngometry, a noninvasive method, has been used successfully in adults, but application in children has been limited. We sought to evaluate the feasibility and utility of this technique in children, including assessment of the variation of pharyngeal measurements with height, sex, ethnicity, prematurity, and indices of SDB. Subjects were drawn from a large, community-based cohort of children of age 8-11 years. Demographic, morphologic, and sleep-related information were collected via standard questionnaires, direct measurement, and home cardiorespiratory monitoring during sleep. Pharyngeal dimensions were assessed in 203 children using acoustic pharyngometry performed with an optimized mouthpiece. In this sample, the coefficient of variation of minimum pharyngeal cross-sectional area (CSA) and mean CSA were similar to those in adults (8.0 and 11.1%, respectively). The minimum CSA, but not mean CSA, was significantly reduced in preterm children, habitual snorers, and children with SDB relative to unaffected children. Thus, minimum CSA is a useful measure for evaluating SDB risk factors in preadolescent children.

Acoustics↗

PubMed2002

The relationship between chronically disrupted sleep and healthcare use.

STUDY OBJECTIVES: To determine whether chronic sleep deprivation, sleep disruption, sleepiness, insomnia, and OSA are associated with increased healthcare use in a community-based population. DESIGN: Cross-sectional study. SETTING/PARTICIPANTS: 6440 Sleep Heart Health Study (SHHS) participants recruited from ongoing cohort studies. INTERVENTIONS: N/A. MEASUREMENTS: Polysomnography results (Apnea Hypopnea Index (AHI), percent of sleep time with oxyhemoglobin saturation below 90% (CT90), arousal index) as well as data on sleep related symptoms, medication use, and chronic illness. The indirect measure of predicted healthcare utilization was the modified Chronic Disease Score (CDS) calculated from medication data. RESULTS: After adjustment for age, gender, BMI and study site, subjects in the highest quartiles of AHI, CT90 and Epworth score had CDS that were 6%-9% higher than the lowest quartiles. The adjusted mean CDS for subjects with sleep apnea was similar to that for subjects with hypertension, chronic bronchitis or asthma and 18% greater than the mean CDS for subjects without sleep apnea. Among subjects who did not have significant sleep-disordered breathing, complaints of insomnia, sleepiness, fatigue, and not getting enough sleep were associated with increased CDS. CONCLUSIONS: This study demonstrated an association between subjective complaints of daytime sleepiness, inadequate sleep time, insomnia as well as objective measures of severity of SDB, and an indirect measure of healthcare utilization in a community-based sample. Though the percent increases in healthcare utilization observed were modest, the prevalence of these factors in the general population is high, and may therefore be associated with a substantial cost burden to the healthcare system.

Adult↗

PubMed2002

Predictors of sleep-disordered breathing in community-dwelling adults: the Sleep Heart Health Study.

BACKGROUND: Sleep-disordered breathing (SDB) is common, but largely undiagnosed in the general population. Information on demographic patterns of SDB occurrence and its predictive factors in the general population is needed to target high-risk groups that may benefit from diagnosis. METHODS: The sample comprised 5615 community-dwelling men and women aged between 40 and 98 years who were enrolled in the Sleep Heart Health Study. Data were collected by questionnaire, clinical examinations, and in-home polysomnography. Sleep-disordered breathing status was based on the average number of apnea and hypopnea episodes per hour of sleep (apnea-hypopnea index [AHI]). We used multiple logistic regression modeling to estimate cross-sectional associations of selected participant characteristics with SDB defined by an AHI of 15 or greater. RESULTS: Male sex, age, body mass index, neck girth, snoring, and repeated breathing pause frequency were independent, significant correlates of an AHI of 15 or greater. People reporting habitual snoring, loud snoring, and frequent breathing pauses were 3 to 4 times more likely to have an AHI of 15 or greater vs an AHI less than 15, but there were weaker associations for other factors with an AHI of 15 or greater. The odds ratios (95% confidence interval) for an AHI of 15 or greater vs an AHI less than 15 were 1.6 and 1.5, respectively, for 1-SD increments in body mass index and neck girth. As age increased, the magnitude of associations for SDB and body habitus, snoring, and breathing pauses decreased. CONCLUSIONS: A significant proportion of occult SDB in the general population would be missed if screening or case finding were based solely on increased body habitus or male sex. Breathing pauses and obesity may be particularly insensitive for identifying SDB in older people. A better understanding of predictive factors for SDB, particularly in older adults, is needed.

Adult↗

PubMed2002

Identification of sleep-disordered breathing in children: variation with event definition.

STUDY OBJECTIVES: To determine the effect of varying approaches to the measurement of the respiratory disturbance index (RDI) on identification of sleep disordered breathing (SDB) in children. DESIGN: Cross-sectional study of SDB in a well-characterized birth cohort (stratified for term and preterm birth) participating in longitudinal studies of cognition and behavior. SETTING: Community-based; overnight studies conducted in participant's homes. PARTICIPANTS: 433 children, ages 8-11 years, un-referred for clinical assessment of SDB. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Participants underwent unattended overnight in-home recording of respiratory inductance plethysmography, pulse oximetry, body position, and heart rate. The relationships among RDIs derived from various definitions of apnea and hypopneas and thresholds for frequency of events were assessed. Median RDI varied by more than 20-fold for definitions using the more liberal criteria for event definition (all respiratory events; i.e., central or obstructive events and hypopneas with no requirement for associated desaturation) to the most conservative definition (using obstructive apneas only or obstructive apnea and hypopneas requiring a 5% associated desaturation). Prevalence estimates for SDB based on RDIs that included central apneas were 40% to 140% higher than those that excluded central apneas. CONCLUSIONS: Different approaches for quantifying RDI contribute to substantial variability in identification and classification of SDB in children and will lead to discrepant estimates of its presence and severity.

Child↗

PubMed2002

Genetics of the apnea hypopnea index in Caucasians and African Americans: I. Segregation analysis.

Differences in age of presentation and anatomic risk factors for obstructive sleep apnea (OSA) in Caucasians and African Americans suggest possible racial differences in the genetic underpinnings of the disorder. In this study, we assess transmission patterns in a Caucasian sample consisting of 177 families (N = 1,195) and in an African American sample consisting of 125 families (N = 720) for two variables: 1) apnea hypopnea index (AHI) log transformed and adjusted for age, and 2) AHI log transformed and adjusted for age and body mass index (BMI). We allowed for residual familial correlations and sex-specific means in all models. Analysis of the Caucasian sample showed transmission patterns consistent with that of a major gene that were stronger in the age-adjusted variable than in the age- and BMI-adjusted variable. However, in the African American families, adjusting for BMI in addition to age gave stronger evidence for segregation of a codominant gene with an allele frequency of 0.14, accounting for 35% of the total variance. These results provide support for an underlying genetic basis for OSA that in African Americans is independent of the contribution of BMI.

Black or African American↗

PubMed2002

Underdiagnosis of sleep apnea syndrome in U.S. communities.

We hypothesize that clinical recognition rates for obstructive sleep apnea-hypoapnea syndrome (OSAHS) are influenced by comorbidity and demographic factors. Data on medical disorders, symptoms of sleep disorders, and cardiovascular risk factors gathered from 15,699 individuals in the Sleep Heart Health Study were compared. Participants were classified into three groups: those with a self-reported physician diagnosis of OSAHS, those with self-reported physician-diagnosed and -treated OSAHS, and those reporting both frequent snoring and daytime sleepiness (two-symptom group). Among all participants, 4.1% reported two symptoms (range across sites: 1.55 to 7.23%), whereas 1.6% reported a physician diagnosis of OSAHS (range: 0.66 to 2.88%) and 0.6% reported physician diagnosis and treatment (range: 0.11 to 0.88%). Recognized OSAHS groups were similar to the two-symptom group in age, having a sleeping partner, measured blood pressure, total cholesterol, and race. In a logistic model that included age along with characteristics found to vary significantly among the three groups (gender, body mass index [BMI], high-density lipoprotein cholesterol levels, hypertension), only male gender and BMI were increased in those with physician-diagnosed and -treated OSAHS. We conclude that disparities (especially in women and in those with lower BMI) exist between current recognition rates for OSAHS and the estimated prevalence by symptom report across the United States.

Diagnosis, Differential↗

PubMed2002

Short-term variability of respiration and sleep during unattended nonlaboratory polysomnography--the Sleep Heart Health Study. [corrected].

STUDY OBJECTIVES: To determine the short-term variability of indices of disturbed respiration and sleep during 2 nights of unattended nonlaboratory polysomnography conducted several months apart. DESIGN: Participants were randomly selected using a block design with stratification on preliminary estimates of 2 criteria: respiratory disturbance index [RDI3% (apnea or hypopnea events associated with > or = 3% O2 desaturation): < 15/hour total sleep time, > or = 15/hour total sleep time] and sleep efficiency (SEff: < 85% and > or = 85%). The RDI and sleep data from initial and repeated polysomnography were compared. SETTING: NA. PARTICIPANTS: A subset of 99 participants in the Sleep Heart Health Study who agreed to have a repeat polysomnogram within 4 months of their original study. INTERVENTIONS: NA. MEASUREMENTS AND RESULTS: Acceptable repeat polysomnograms were obtained in 91 subjects (mean study interval: 77 +/- 18 [sd] days; range: 31-112 days). There was no significant bias in RDI between study nights using several different RDI definitions including RDI3% and RDI4% (apnea or hypopnea events associated with > or = 4% O2 desaturation). Variability between studies estimated using intraclass correlations (ICC) ranged from 0.77 to 0.81. For subjects with a RDI3% < 15, variability increased as a function of increasing RDI, but for those with a RDI3% > or = 15, variability was constant. Body mass index, SEff, gender, or age did not directly predict RDI variability. Using RDI4% cutpoints of < or = 5, < or = 10 and < or = 15 events per hour of sleep demonstrated that 79.1%, 85.7%, and 87.9% of subjects, respectively, had the same classification of SDB status on both nights of study. There also was no significant bias in sleep staging, sleep efficiency, or arousal index between studies. However, variability was greater with ICC values ranging from 0.37 (% time in REM) to 0.76 (arousal index). CONCLUSION: In the Sleep Heart Health Study, accurate estimates of the severity of sleep-disordered breathing and the quality of sleep were obtained from a single night of unattended nonlaboratory polysomnography. These findings may be applicable to other large epidemiologic studies provided that similar recording techniques and quality-assurance procedures are followed.

Adult↗

PubMed2000

Evaluation of a model of attention with confirmatory factor analysis.

Structural equation modeling (specifically, analysis of moment structures; J. L. Arbuckle, 1996) was used to evaluate the goodness of fit of a model of components of attention (A. F. Mirsky, B. J. Anthony, C. C. Duncan, M. B. Aheam, & S. G. Kellam, 1991) to neuropsychological test data from 2 samples. One sample consisted of psychiatrically normal persons with and without sleep-disordered breathing, and the other sample consisted of the adults studied by A. F. Mirsky et al. (1991), who gave rise to this model. That sample included psychiatric patients as well as normals. An exploratory data reduction procedure, principal-components analysis, suggested that attention might be conceptualized as composed of 4 independent elements or components: focus-execute, sustain, shift, and encode. Neither the proposed orthogonal model nor a model permitting correlated factors adequately fit either data set, suggesting that these 4 attention constructs are as yet not clearly validated in the measures used to assess them.

Adult↗

PubMed2000

The genetics of sleep apnea.

Obstructive sleep apnea hypopnea syndrome (OSAHS) is a complex chronic condition that is undoubtedly influenced by multiple factors. Accumulating data suggest that there are strong genetic underpinnings for this condition. It has been estimated that approximately 40% of the variance in the apnea hypopnea index (AHI) may be explained by familial factors. It is likely that genetic factors associated with craniofacial structure, body fat distribution and neural control of the upper airway muscles interact to produce the OSAHS phenotype. Although the role of specific genes that influence the development of OSAHS have not yet been identified, current research in rodents suggests that several genetic systems may be important. In this chapter, we shall first define the OSAHS phenotype, and then review the evidence that suggests an underlying genetic basis of OSAHS, the risk factors for OSAHS that may be inherited, and potential candidate genes.

Journal Article↗