Neighborhood of Residence is Associated with Daily Adherence to CPAP Therapy

Study Objectives:

Adherence to continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea is poor. Risk factors for nonadherence are not well understood but may reflect individual or neighborhood socioeconomic factors. We sought to determine the association of socioeconomic status and initial CPAP adherence.

Design:

Retrospective cohort study, 2005 to 2006.

Setting:

Philadelphia VA Medical Center.

Participants:

Of 330 consecutive veterans who met study criteria for initiation of CPAP therapy for newly diagnosed sleep apnea, 266 had complete data for study inclusion.

Interventions:

N/A.

Measurements:

Through a multivariable logistic regression model, using an outcome of objectively measured CPAP use ≥ 4 h daily during the first week of treatment, we tested whether patients from higher socioeconomic neighborhoods had higher CPAP adherence. We measured neighborhood socioeconomic status with an index derived from the 2000 U.S. Census at the block group-level composed of median household income, male and female employment, adult high school completion, married households, and minority composition.

Results:

CPAP adherence ≥ 4 h occurred on 48.9% of 1,805 patient-days observed for the 266 subjects. After adjustment for individual sociodemographic characteristics and medical comorbidity, the probability of daily CPAP use ≥ 4 h ranged from 34.1% (95% CI, 26.4–42.7) for subjects from a low socioeconomic neighborhood (5th percentile) to 62.3% (95% CI, 53.8–70.1) for subjects from a high (95th percentile) neighborhood.

Conclusions:

In a retrospective cohort of veterans, initial CPAP adherence was closely associated with higher neighborhood socioeconomic factors. Future investigation should target specific impediments to adherence in the home and neighborhood environment.

Citation:

Platt AB; Field SH; Asch DA; Chen Z; Gupta R; Roche DF; Gurubhagavatula I; Christie JD; Kuna ST. Neighborhood of residence is associated with daily adherence to CPAP therapy. SLEEP 2009;32(6):799-806.     

Endocrine abnormalities and impaired growth in human immunodeficiency virus-infected children

OBJECTIVES: Identify endocrine differences between human immunodeficiency virus- (HIV) infected versus uninfected children and evaluate associations of growth and body composition with endocrine measures. STUDY DESIGN: Nested case-control study in 21 HIV-infected and 46 age- and sex-matched uninfected children in the Women and Infant Transmission Study. Plasma specimens from children between 2.5 to 7.0 years of age, taken during 3-4 visits, were tested for insulin-like growth factor binding protein-3 (IGFBP-3), cortisol, dehydroepiandrosterone (DHEA), growth hormone and thyroid studies. Longitudinal mixed and generalized estimating equation models compared group means and examined effects of endocrine measures on growth and body composition, respectively. RESULTS: HIV-infected children had lower IGFBP-3 than uninfected children (1.96 +/- 0.09 mg/L versus 2.34 +/- 0.06 mg/L, P < 0.001). In infected but not in uninfected children, IGFBP-3 values and DHEA:cortisol ratios were associated with weight- and body mass index-for-age z scores ([WAZ] P = 0.019, <.001 respectively, and [BMZ] P = 0.029, 0.038). DHEA concentration was associated with height-for-age z score (P = 0.049). CONCLUSIONS: In these HIV-infected children compared with their uninfected counterparts, IGFBP-3 concentration was different between groups. Infected children had multiple endocrine associations with growth and body composition not found in their uninfected peers. We hypothesize that in HIV-infected children, growth hormone resistance and shunting of precursors from adrenal androgen to cortisol production contributes to altered body composition and stunting.     

Spatial and socio-behavioral patterns of HIV prevalence in the Democratic Republic of Congo

This study uses a 2007 population-based household survey to examine the individual and community-level factors that increase an individual’s risk for HIV infection in the Democratic Republic of Congo (DRC). Using the 2007 DRC Demographic Health Surveillance (DHS) Survey, we use spatial analytical methods to explore sub-regional patterns of HIV infection in the DRC. Geographic coordinates of survey communities are used to map prevalence of HIV infection and explore geographic variables related to HIV risk. Spatial cluster techniques are used to identify hotspots of infection. HIV prevalence is related to individual demographic characteristics and sexual behaviors and community-level factors. We found that the prevalence of HIV within 25 km of an individual’s community is an important positive indicator of HIV infection. Distance from a city is negatively associated with HIV infection overall and for women in particular. This study highlights the importance of improved surveillance systems in the DRC and other African countries along with the use of spatial analytical methods to enhance understanding of the determinants of HIV infection and geographic patterns of prevalence, thereby contributing to improved allocation of public health resources in the future.     

Necrotizing Enterocolitis in HIV-Exposed and Nonexposed Infants: Clinical Presentation and Histopathological Features

ABSTRACT Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in neonates and is associated with significant morbidity and mortality. An association between HIV-positive maternal status and increased risk of NEC in preterm infants has been described, and antiretroviral therapy has been proposed as an independent risk factor. Our aim was to compare the clinical presentation and histopathological features of necrotizing enterocolitis in HIV-exposed and unexposed infants. A retrospective study of archival material from the National Health Laboratory Services Histopathology Laboratory in Tygerberg Hospital/Stellenbosch University from 1992 to 2008 was conducted. All surgical specimens from infants who presented to pediatric surgery for a laparotomy and bowel resection for NEC and in whom the HIV status was known were included in the study. In the 37 cases that fulfilled these criteria, male gender was overrepresented in the study population (67%). Nonsteroidal anti-inflammatory drugs appeared to play a significant role in the development of surgical NEC in infants who were not exposed to HIV, but HIV-exposed infants had a significantly poorer survival rate. There was no significant difference in the histopathology between HIV-exposed and nonexposed infants, and Cytomegalovirus infection was not identified in any of the cases studied.     

Image-guided cerebrospinal fluid shunting in children: catheter accuracy and shunt survival

Object Cerebrospinal fluid shunt placement has a high failure rate, especially in patients with small ventricles. Frameless stereotactic electromagnetic image guidance can assist ventricular catheter placement. The authors studied the effects of image guidance on catheter accuracy and shunt survival in children. Methods Pediatric patients who underwent placement or revision of a frontal ventricular CSF shunt were retrospectively evaluated. Catheters were placed using either anatomical landmarks or image guidance. Preoperative ventricular size and postoperative catheter accuracy were quantified. Outcomes of standard and image-guided groups were compared. Results Eighty-nine patients underwent 102 shunt surgeries (58 initial, 44 revision). Image guidance was used in the placement of 56 shunts and the standard technique in 46. Shunt failure rates were not significantly different between the standard (22%) and image-guided (25%) techniques (p = 0.21, log-rank test). Ventricular size was significantly smaller in patients in the image-guided group (p < 0.02, Student t-test) and in the surgery revision group (p < 0.01). Small ventricular size did not affect shunt failure rate, even when controlling for shunt insertion technique. Despite smaller average ventricular size, the accuracy of catheter placement was significantly improved with image guidance (p < 0.01). Shunt accuracy did not affect shunt survival. Conclusions The use of image guidance improved catheter tip accuracy compared with a standard technique, despite smaller ventricular size. Failure rates were not dependent on shunt insertion technique, but an observed selection bias toward using image guidance for more at-risk catheter placements showed failure rates similar to initial surgeries.     

Gular pouch diversity in the Chamaeleonidae

Numerous chameleon species possess an out-pocketing of the trachea known as the gular pouch. After surveying more than 250 specimens, representing nine genera and 44 species, we describe two different morphs of the gular pouch. Species of the genera Bradypodion and Chamaeleo, as well as Trioceros goetzei, all possess a single gular pouch (morph one) formed from ventral expansion of soft tissue where the larynx and trachea meet. Furcifer oustaleti and Furcifer verrucosus possess from one to four gular pouches (morph two) formed by the expansion of soft tissue between sequential hyaline cartilage rings of the trachea. In Trioceros melleri, examples of both morphs of the gular pouch were observed. Morphometric data are presented for 100 animals representing eight species previously known to possess a gular pouch and two additional species, Bradypodion thamnobates and Bradypodion transvaalense. In the species with the absolutely and relatively largest gular pouch, Chamaeleo calyptratus, a significant difference was found between sexes in its width and volume, but not its length. In C. calyptratus, we show that an inflated gular pouch is in contact with numerous hyoid muscles and the tongue. Coupled with the knowledge that C. calyptratus generates vibrations from the throat region, we posit that the tongue (M. accelerator linguae and M. hyoglossus) and supporting hyoid muscles (i.e., Mm. sternohyoideus profundus et superficialis and Mm. mandibulohyoideus) are involved in the production of vibrations to produce biotremors that are amplified by the inflated gular pouch and used in substrate-borne communication.     

Lipid screening in HIV-infected veterans

BACKGROUND: Lipid screening is recommended for patients taking protease inhibitors (PIs). METHODS: We examined data from the Veterans Administration Immunology Case Registry to assess lipid screening among HIV-infected veterans who received PIs for at least 6 consecutive months during 1999 and 2001. We estimated crude and adjusted associations between lipid screening and patient characteristics (age, gender, HIV exposure, and race/ethnicity), comorbidities (AIDS, cardiovascular disease, diabetes, hypertension, smoking, and hyperlipidemia), and facility characteristics (urban location, case management, guidelines, and quality improvement programs). RESULTS: Among 4065 patients on PIs, clinicians screened 2395 (59%) for lipids within 6 months of initiating treatment. Adjusting for patient characteristics, comorbidities, facility traits, and clustering, lipid screening was more common among patients who were cared for in urban areas (relative risk [RR] = 1.3, confidence limits: 1.0-1.5), diabetic (RR = 1.2, confidence limits: 1.1-1.3), or previously hyperlipidemic (RR = 1.4, confidence limits: 1.3-1.5) and less common among patients with a history of intravenous drug use (IVDU) (RR = 0.90, confidence limits: 0.79-1.0) or unknown HIV risk (RR = 0.85, confidence limits: 0.75-0.95). CONCLUSIONS: Six in 10 patients taking PIs receive lipid screening within 6 months of PI use. Systemic interventions to improve overall HIV quality of care should also address lipid screening, particularly among patients with unknown or IVDU HIV risk and those cared for in nonurban areas.     

The sound of silence: modulating anergy in T lymphocytes

Understanding the intercellular and intracellular mechanisms that maintain anergy and prevent the induction of full effector function is one avenue that may allow us to manipulate immune responses. Recent studies of T cell receptor (TCR)-proximal signaling events in different models of T cell unresponsiveness have suggested that biochemically distinct forms of anergy may exist in vivo. T cell responsiveness can be altered through the control of the intracellular pool of key second messengers, such as diacylglycerol (DAG) or the lipid modification of signaling molecules, such as the Linker for activated T cells (LAT). Studies on the molecule programmed death-1 (PD-1) and its ligands have revealed that tissue-resident signals are essential in the maintenance of T cell unresponsiveness. Thus, the emerging view is that T cell anergy is a dynamic state whose establishment and maintenance can be influenced by numerous different signaling pathways.