The association between body mass index and gastroesophageal reflux disease in the World Trade Center Health Program General Responder Cohort

BACKGROUND

There is increasing concern about the obesity epidemic in the United States. Obesity is a potential risk factor for a number of chronic diseases, including gastroesophageal reflux disease (GERD). This analysis examined whether body mass index (BMI) was associated with physician-diagnosed GERD in World Trade Center (WTC) general responders.

METHODS

19,819 WTC general responders were included in the study. Cox proportional hazards regression models were used to compare time to GERD diagnosis among three BMI groups (normal (<25 kg/m(2) ), overweight (≥25 and <30 kg/m(2) ), and obese (≥30 kg/m(2) )).

RESULTS

Among the responders, 43% were overweight and 42% were obese. The hazard ratio for normal versus overweight was 0.81 (95% Confidence Interval (CI), 0.75-0.88); normal versus obese 0.71 (95%CI, 0.66, 0.77); and overweight versus obese 0.88 (95%CI, 0.83-0.92).

CONCLUSION

GERD diagnoses rates were higher in overweight and obese WTC responders. Am. J. Ind. Med. 59:761-766, 2016. © 2016 Wiley Periodicals, Inc.

Poisson approximations for the distribution and moments of ordered m-spacings

This article investigates the accuracy of approximations for the distribution of ordered m-spacings for i.i.d. uniform observations in the interval (0, 1). Several Poisson approximations and a compound Poisson approximation are studied. The result of a simulation study is included to assess the accuracy of these approximations. A numerical procedure for evaluating the moments of the ordered m-spacings is developed and evaluated for the most accurate approximation.

Effect of Palliative Care-Led Meetings for Families of Patients With Chronic Critical Illness: A Randomized Clinical Trial

IMPORTANCE

Family caregivers of patients with chronic critical illness experience significant psychological distress.

OBJECTIVE

To determine whether family informational and emotional support meetings led by palliative care clinicians improve family anxiety and depression.

DESIGN, SETTING, AND PARTICIPANTS

A multicenter randomized clinical trial conducted from October 2010 through November 2014 in 4 medical intensive care units (ICUs). Adult patients (aged ≥21 years) requiring 7 days of mechanical ventilation were randomized and their family surrogate decision makers were enrolled in the study. Observers were blinded to group allocation for the measurement of the primary outcomes.

INTERVENTIONS

At least 2 structured family meetings led by palliative care specialists and provision of an informational brochure (intervention) compared with provision of an informational brochure and routine family meetings conducted by ICU teams (control). There were 130 patients with 184 family surrogate decision makers in the intervention group and 126 patients with 181 family surrogate decision makers in the control group.

MAIN OUTCOMES AND MEASURES

The primary outcome was Hospital Anxiety and Depression Scale symptom score (HADS; score range, 0 [best] to 42 [worst]; minimal clinically important difference, 1.5) obtained during 3-month follow-up interviews with the surrogate decision makers. Secondary outcomes included posttraumatic stress disorder experienced by the family and measured by the Impact of Events Scale-Revised (IES-R; total score range, 0 [best] to 88 [worst]), discussion of patient preferences, hospital length of stay, and 90-day survival.

RESULTS

Among 365 family surrogate decision makers (mean age, 51 years; 71% female), 312 completed the study. At 3 months, there was no significant difference in anxiety and depression symptoms between surrogate decision makers in the intervention group and the control group (adjusted mean HADS score, 12.2 vs 11.4, respectively; between-group difference, 0.8 [95% CI, -0.9 to 2.6]; P = .34). Posttraumatic stress disorder symptoms were higher in the intervention group (adjusted mean IES-R score, 25.9) compared with the control group (adjusted mean IES-R score, 21.3) (between-group difference, 4.60 [95% CI, 0.01 to 9.10]; P = .0495). There was no difference between groups regarding the discussion of patient preferences (intervention, 75%; control, 83%; odds ratio, 0.63 [95% CI, 0.34 to 1.16; P = .14]). The median number of hospital days for patients in the intervention vs the control group (19 days vs 23 days, respectively; between-group difference, -4 days [95% CI, -6 to 3 days]; P = .51) and 90-day survival (hazard ratio, 0.95 [95% CI, 0.65 to 1.38], P = .96) were not significantly different.

CONCLUSIONS AND RELEVANCE

Among families of patients with chronic critical illness, the use of palliative care-led informational and emotional support meetings compared with usual care did not reduce anxiety or depression symptoms and may have increased posttraumatic stress disorder symptoms. These findings do not support routine or mandatory palliative care-led discussion of goals of care for all families of patients with chronic critical illness.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01230099.

Number of Comorbidities as a Predictor of Nosocomial Infection Acquisition

Infection control programs are primarily oriented toward chronicling the incidence of nosocomial infections (NI). Intervention programs oriented toward preventing infection would be facilitated by identifying patients at greatest risk of NI acquisition. We studied the number of comorbidities as a risk predictor for NIs in patients admitted to the medical intensive care unit (ICU) for three or more days. In 148 patients, we found by regression analysis that the number of comorbidities varied directly with the development of nosocomial infections, as well as with the appearance of new complications and length of ICU stay. Diagnosis-related groups did not adequately account for the variance in comorbidities observed.

Cancer in World Trade Center responders: Findings from multiple cohorts and options for future study

BACKGROUND

Three longitudinal studies of cancer incidence in varied populations of World Trade Center responders have been conducted.

METHODS

We compared the design and results of the three studies.

RESULTS

Separate analyses of these cohorts revealed excess cancer incidence in responders for all cancers combined and for cancers of the thyroid and prostate. Methodological dissimilarities included recruitment strategies, source of cohort members, demographic characteristics, overlap between cohorts, assessment of WTC and other occupational exposures and confounders, methods and duration of follow-up, approaches for statistical analysis, and latency analyses.

CONCLUSIONS

The presence of three cohorts strengthens the effort of identifying and quantifying the cancer risk; the heterogeneity in design might increase sensitivity to the identification of cancers potentially associated with exposure. The presence and magnitude of an increased cancer risk remains to be fully elucidated. Continued long-term follow up with minimal longitudinal dropout is crucial to achieve this goal.

Mortality among World Trade Center rescue and recovery workers, 2002-2011

BACKGROUND

Rescue and recovery workers responding to the 2001 collapse of the World Trade Center (WTC) sustained exposures to toxic chemicals and have elevated rates of multiple morbidities.

METHODS

Using data from the World Trade Center Health Program and the National Death Index for 2002-2011, we examined standardized mortality ratios (SMR) and proportional cancer mortality ratios (PCMR) with indirect standardization for age, sex, race, and calendar year to the U.S. general population, as well as associations between WTC-related environmental exposures and all-cause mortality.

RESULTS

We identified 330 deaths among 28,918 responders (SMR 0.43, 95%CI 0.39-0.48). No cause-specific SMRs were meaningfully elevated. PCMRs were elevated for neoplasms of lymphatic and hematopoietic tissue (PCMR 1.76, 95%CI 1.06-2.75). Mortality hazard ratios showed no linear trend with exposure.

CONCLUSIONS

Consistent with a healthy worker effect, all-cause mortality among responders was not elevated. There was no clear association between intensity and duration of exposure and mortality. Surveillance is needed to monitor the proportionally higher cancer mortality attributed to lymphatic/hematopoietic neoplasms.

Blood basophil activation is a reliable biomarker of allergic bronchopulmonary aspergillosis in cystic fibrosis

The diagnosis of cystic fibrosis (CF) patients with allergic bronchopulmonary aspergillosis (ABPA) is clinically challenging, due to the absence of an objective biological test. Since blood basophils play a major role in allergic responses, we hypothesised that changes in their surface activation pattern discriminate between CF patients with and without ABPA.

We conducted a prospective longitudinal study (Stanford cohort) comparing basophil activation test CD203c levels by flow cytometry before and after activation withAspergillus fumigatusallergen extract or recombinantAspf1 in 20 CF patients with ABPA (CF-ABPA) and in two comparison groups: CF patients withA. fumigatuscolonisation (AC) but without ABPA (CF-AC; n=13) and CF patients without either AC or ABPA (CF; n=12). Patients were tested every 6 months and when ill with pulmonary exacerbation. We also conducted cross-sectional validation in a separate patient set (Dublin cohort).

Basophil CD203c surface expression reliably discriminated CF-ABPA from CF-AC and CF over time. Ex vivostimulation withA. fumigatusextract or recombinantAspf1 produced similar results within the Stanford (p<0.0001) and the Dublin cohorts. CF-ABPA patients were likelier to have elevated specific IgE toA. fumigatusand were less frequently co-infected withStaphylococcus aureus.

Basophil CD203c upregulation is a suitable diagnostic and stable monitoring biomarker of ABPA in CF.

Testing for Clostridium difficile in patients newly diagnosed with inflammatory bowel disease in a community setting

BACKGROUND

The incidence of Clostridium difficile infection (CDI) in inflammatory bowel disease (IBD) is increasing, and CDI has a negative impact on IBD outcomes with both increased morbidity and mortality. Data are lacking regarding the rate of appropriate testing for CDI at the time of diagnosis.

METHODS

We sought to determine the rate of CDI testing and CDI positivity at diagnosis of IBD using data collected through the Ocean State Crohn's and Colitis Area Registry (OSCCAR), a prospective cohort of patients with newly diagnosed IBD. CDI testing and CDI positivity were determined by reviewing the medical records of patients enrolled into the registry and diagnosed with IBD between January 2008 and July 2011.

RESULTS

Of 320 enrolled patients, 227 (70.9%) reported diarrhea, and CDI testing was performed for 113 (49.8%) of the 227 patients. CDI testing was not recorded as being performed for the remaining 114 patients who reported having diarrhea. An additional 24 patients were tested for CDI but did not report having diarrhea. Seven (5.1%) of the 137 patients tested for CDI were positive.

CONCLUSIONS

Testing for CDI is significantly lower than expected at diagnosis of IBD. Although the prevalence of CDI among tested patients is approximately 5%, a low testing rate suggests a significant quality issue in the diagnosis of IBD, with the potential for delayed diagnosis of CDI.

How well do medical oncologists manage chronic cancer pain? A national survey

BACKGROUND

Cancer pain is usually managed by oncologists, occasionally with input from specialists in hospice and palliative medicine (PLM) or pain medicine (PMD). We evaluated the knowledge of cancer pain management in these three specialty groups.

METHODS

Eight vignettes depicting challenging scenarios of patients with poorly controlled pain were developed; each had five or six treatment choices. Respondents indicated choices likely to be safe and efficacious as "true" and choices likely to be unsafe or inefficacious as "false." Two questionnaires were created, each with four vignettes. Three anonymous mailings targeted geographically representative U.S. samples of 570 oncologists, 266 PMD specialists, and 280 PLM specialists, each randomly assigned one version of the questionnaire. Vignette scores were normalized to a 0-100 numeric rating scale (NRS); a score of 50 indicates that the number of correct choices equals the number of incorrect choices (consistent with guessing).

RESULTS

Overall response rate was 49% (oncologists, 39%; PMD specialists, 48%; and PLM specialists, 70%). Average vignette score ranges were 53.2-66.5, 45.6-65.6, and 50.8-72.0 for oncologists, PMD specialists, and PLM specialists, respectively. Oncologists scored lower than PLM specialists on both questionnaires and lower than PMD specialists on one. On a 0-10 NRS, oncologists rated their ability to manage pain highly (median 7, with an interquartile range [IQR] of 5-8). Lower ratings were assigned to pain-related training in medical school (median 3, with an IQR of 2-5) and residency/fellowship (median 5, with an IQR of 4-7). Oncologists older than 46-47 years rated their training lower than younger oncologists.

CONCLUSION

These data suggest that oncologists and other medical specialists who manage cancer pain have knowledge deficiencies in cancer pain management. These gaps help clarify the need for pain management education.

Abstract 280: Cancer risk in World Trade Center rescue and recovery workers

Objective: The purpose of this investigation was to evaluate cancer incidence in responders during the first 7 years after 11 September 2001.

Methods: Cancers among 20,984 consented participants in the WTC Health Program were identified through linkage to state tumor registries in New York, New Jersey, Connecticut, and Pennsylvania. The follow-up lasted until 2008. Standardized incidence ratios (SIRs) were calculated to compare cancers diagnosed in responders to predicted numbers for the general population. Multivariate regression models were used to estimate associations with degree of exposure.

Results: A total of 575 cancers were diagnosed in 552 individuals. Increases above registry-based expectations were noted for all cancer sites combined (SIR = 1.15; 95% CI: 1.06, 1.25), thyroid cancer (SIR = 2.39; 95% CI: 1.70, 3.27), prostate cancer (SIR = 1.21; 95% CI: 1.01, 1.44), combined hematopoietic and lymphoid cancers (SIR = 1.36; 95% CI: 1.07, 1.71), and soft tissue cancers (SIR = 2.26; 95% CI: 1.13, 4.05). When restricted to 302 cancers diagnosed ≥ 6 months after enrollment, the SIR for all cancers decreased to 1.06 (95% CI: 0.94, 1.18), but thyroid and prostate cancer diagnoses remained greater than expected. All cancers combined were increased in very highly exposed responders and among those exposed to significant amounts of dust, compared with responders who reported lower levels of exposure.

Conclusion: Estimates should be interpreted with caution given the short follow-up and long latency period for most cancers, the intensive medical surveillance of this cohort, and the small numbers of cancers at specific sites. However, our findings highlight the need for continued follow-up and surveillance of WTC responders. The follow-up of the cohort is currently being updated and efforts are being made to improve the assessment of exposure to carcinogens related to WTC experience.

Citation Format: Paolo Boffetta, Samara Solan, Sylvan Wallenstein, Roberto Lucchini, Philip Landrigan. Cancer risk in World Trade Center rescue and recovery workers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 280. doi:10.1158/1538-7445.AM2014-280

Cancer incidence in world trade center rescue and recovery workers, 2001-2008

BACKGROUND

World Trade Center (WTC) rescue and recovery workers were exposed to a complex mix of pollutants and carcinogens.

OBJECTIVE

The purpose of this investigation was to evaluate cancer incidence in responders during the first 7 years after 11 September 2001.

METHODS

Cancers among 20,984 consented participants in the WTC Health Program were identified through linkage to state tumor registries in New York, New Jersey, Connecticut, and Pennsylvania. Standardized incidence ratios (SIRs) were calculated to compare cancers diagnosed in responders to predicted numbers for the general population. Multivariate regression models were used to estimate associations with degree of exposure.

RESULTS

A total of 575 cancers were diagnosed in 552 individuals. Increases above registry-based expectations were noted for all cancer sites combined (SIR = 1.15; 95% CI: 1.06, 1.25), thyroid cancer (SIR = 2.39; 95% CI: 1.70, 3.27), prostate cancer (SIR = 1.21; 95% CI: 1.01, 1.44), combined hematopoietic and lymphoid cancers (SIR = 1.36; 95% CI: 1.07, 1.71), and soft tissue cancers (SIR = 2.26; 95% CI: 1.13, 4.05). When restricted to 302 cancers diagnosed ≥ 6 months after enrollment, the SIR for all cancers decreased to 1.06 (95% CI: 0.94, 1.18), but thyroid and prostate cancer diagnoses remained greater than expected. All cancers combined were increased in very highly exposed responders and among those exposed to significant amounts of dust, compared with responders who reported lower levels of exposure.

CONCLUSION

Estimates should be interpreted with caution given the short follow-up and long latency period for most cancers, the intensive medical surveillance of this cohort, and the small numbers of cancers at specific sites. However, our findings highlight the need for continued follow-up and surveillance of WTC responders.

Diabetes, glucose control, glucose lowering medications, and cancer risk: a 10-year population-based historical cohort

Background

Both diabetes and glucose-lowering medications have been associated with an increased risk of cancer incidence. This study will compare cancer incidence rates in individuals with and without diabetes; and will investigate, in individuals with diabetes, an association between glucose control and cancer incidence; and between the use of specific glucose-lowering medications, as well as no drug exposure, and cancer incidence.

Methods/design

This is a population based historical cohort study of all individuals aged 21 years or older (about 2,300,000) who were insured by Clalit Health Services, the largest health maintenance organization in Israel during a ten-year study period. Four study groups will be established according to the status of diabetes and cancer at study entry, Jan 1, 2002: cancer free, diabetes free; cancer free, diabetes prevalent; cancer prevalent, diabetes free; and cancer prevalent, diabetes prevalent. Individuals without diabetes at study entry will be followed for diabetes incidence, and all four groups will be followed for specific cancer incidence, including second primary neoplasms. Glucose control will be assessed by HbA1c and by fasting plasma glucose levels. Time dependent regression models for cancer incidence will account for glucose-lowering medications as they are added and changed over the follow-up period. A large number of demographic and clinical variables will be considered, including: age, gender, BMI, smoking status, concomitant medications, glucose control (assessed by HbA1c and by fasting plasma glucose) and cancer screening tests.

Discussion

Strengths of this study include the large population; high quality comprehensive data; comparison to individuals without diabetes, and to those with diabetes but not treated with glucose-lowering medications; and the extensive range of variables available for analysis. The great increases in diabetes prevalence and in treatment options render this study particularly relevant and timely. The Israeli national healthcare system, characterized by high standard and uniform healthcare, offers an advantageous environment for its conduct.

Meeting standards of high-quality intensive care unit palliative care: clinical performance and predictors

OBJECTIVES

High-quality care for intensive care unit patients and families includes palliative care. To promote performance improvement, the Agency for Healthcare Research and Quality's National Quality Measures Clearinghouse identified nine evidence-based processes of intensive care unit palliative care (Care and Communication Bundle) that are measured through review of medical record documentation. We conducted this study to examine how frequently the Care and Communication Bundle processes were performed in diverse intensive care units and to understand patient factors that are associated with such performance.

DESIGN

Prospective, multisite, observational study of performance of key intensive care unit palliative care processes.

SETTINGS

A surgical intensive care unit and a medical intensive care unit in two different large academic health centers and a medical-surgical intensive care unit in a medium-sized community hospital.

PATIENTS

Consecutive adult patients with length of intensive care unit stay ≥5 days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between November 2007 and December 2009, we measured performance by specified day after intensive care unit admission on nine care process measures: Identify medical decision-maker, advance directive and resuscitation preference, distribute family information leaflet, assess and manage pain, offer social work and spiritual support, and conduct interdisciplinary family meeting. Multivariable regression analysis was used to determine predictors of performance of five care processes. We enrolled 518 (94.9%) patients and 336 (83.6%) family members. Performances on pain assessment and management measures were high. In contrast, interdisciplinary family meetings were documented for <20% of patients by intensive care unit day 5. Performance on other measures ranged from 8% to 43%, with substantial variation across and within sites. Chronic comorbidity burden and site were the most consistent predictors of care process performance.

CONCLUSIONS

Across three intensive care units in this study, performance of key palliative care processes (other than pain assessment and management) was inconsistent and infrequent. Available resources and strategies should be utilized for performance improvement in this area of high importance to patients, families, and providers.

Persistence of multiple illnesses in World Trade Center rescue and recovery workers: a cohort study

BACKGROUND

More than 50,000 people participated in the rescue and recovery work that followed the Sept 11, 2001 (9/11) attacks on the World Trade Center (WTC). Multiple health problems in these workers were reported in the early years after the disaster. We report incidence and prevalence rates of physical and mental health disorders during the 9 years since the attacks, examine their associations with occupational exposures, and quantify physical and mental health comorbidities.

METHODS

In this longitudinal study of a large cohort of WTC rescue and recovery workers, we gathered data from 27,449 participants in the WTC Screening, Monitoring, and Treatment Program. The study population included police officers, firefighters, construction workers, and municipal workers. We used the Kaplan-Meier procedure to estimate cumulative and annual incidence of physical disorders (asthma, sinusitis, and gastro-oesophageal reflux disease), mental health disorders (depression, post-traumatic stress disorder [PTSD], and panic disorder), and spirometric abnormalities. Incidence rates were assessed also by level of exposure (days worked at the WTC site and exposure to the dust cloud).

FINDINGS

9-year cumulative incidence of asthma was 27·6% (number at risk: 7027), sinusitis 42·3% (5870), and gastro-oesophageal reflux disease 39·3% (5650). In police officers, cumulative incidence of depression was 7·0% (number at risk: 3648), PTSD 9·3% (3761), and panic disorder 8·4% (3780). In other rescue and recovery workers, cumulative incidence of depression was 27·5% (number at risk: 4200), PTSD 31·9% (4342), and panic disorder 21·2% (4953). 9-year cumulative incidence for spirometric abnormalities was 41·8% (number at risk: 5769); three-quarters of these abnormalities were low forced vital capacity. Incidence of most disorders was highest in workers with greatest WTC exposure. Extensive comorbidity was reported within and between physical and mental health disorders.

INTERPRETATION

9 years after the 9/11 WTC attacks, rescue and recovery workers continue to have a substantial burden of physical and mental health problems. These findings emphasise the need for continued monitoring and treatment of the WTC rescue and recovery population.

FUNDING

Centers for Disease Control and Prevention and National Institute for Occupational Safety and Health.

The effects of hypertension and body mass index on diffusion tensor imaging in schizophrenia

Recently, the negative effects of hypertension and elevated body mass index on cognitive functioning in schizophrenia have been reported (Friedman et al., 2010). Data suggests that cognitive changes in hypertensive patients from the general population may be mediated, in part, by white matter damage. Therefore, we performed diffusion tensor imaging (DTI) in the same subjects studied by Friedman et al. (2010) to investigate the effects of hypertension and elevated body mass index on the fractional anisotropy (FA) of several major white matter tracts. Significant interactions between a diagnosis of schizophrenia and hypertension on FA in several white matter regions were detected. Hypertension was associated with lower FA in the schizophrenic group and higher FA in the same tracts in the non-schizophrenic subjects. These results suggest hypertension-induced compensatory mechanisms in the brains of non-schizophrenic patients with hypertension which may be impaired in persons with schizophrenia.

"Sarcoid like" granulomatous pulmonary disease in World Trade Center disaster responders

BACKGROUND

More than 20,000 responders have been examined through the World Trade Center (WTC) Medical Monitoring and Treatment Program since September 11, 2001. Studies on WTC firefighters have shown elevated rates of sarcoidosis. The main objective of this study was to report the incidence of "sarcoid like" granulomatous pulmonary disease in other WTC responders.

METHODS

Cases of sarcoid like granulomatous pulmonary disease were identified by: patient self-report, physician report and ICD-9 codes. Each case was evaluated by three pulmonologists using the ACCESS criteria and only "definite" cases are reported.

RESULTS

Thirty-eight patients were classified as "definite" cases. Six-year incidence was 192/100,000. The peak annual incidence of 54 per 100,000 person-years occurred between 9/11/2003 and 9/11/2004. Incidence in black responders was nearly double that of white responders. Low FVC was the most common spirometric abnormality.

CONCLUSIONS

Sarcoid like granulomatous pulmonary disease is present among the WTC responders. While the incidence is lower than that reported among firefighters, it is higher than expected.

The effects of hypertension and body mass index on cognition in schizophrenia

OBJECTIVE

In recent years there has been a greater appreciation of the elevated prevalence of cardiovascular risk factors in the schizophrenia population and the liability some treatments have for their development. These vascular risk factors are in turn important risk factors in the development of dementia and more subtle cognitive impairments. However, their impact on the cognitive functions of patients with schizophrenia remains underexplored. The authors investigated whether vascular risk factors influence the cognitive impairments of schizophrenia and whether their effects on cognition in schizophrenia are different from those observed in nonpsychiatric comparison subjects.

METHOD

The authors compared 100 patients with schizophrenia and 53 comparison subjects on cognitive test performance in 2×2 matrices composed of individual vascular risk factors and group (schizophrenia patients and comparison subjects).

RESULTS

Hypertension exerted a significant negative effect on immediate delayed and recognition memory in both groups. Patients with schizophrenia and hypertension were adversely affected in recognition memory, whereas comparison subjects were not. A body mass index above 25 was associated with negative effects on delayed memory in both groups, although the association fell short of statistical significance.

CONCLUSIONS

Given that patients with schizophrenia have a higher prevalence of vascular risk factors than the general population and are undertreated for them, treatment of these risk factors may significantly improve cognitive outcome in schizophrenia.

Gene expression profiles of the one-carbon metabolism pathway

One-carbon metabolism plays a critical role in both DNA methylation and DNA synthesis. Accumulating evidence has shown that interruptions of this pathway are associated with many disease outcomes including cardiovascular diseases and cancers. Mechanistic studies have been performed on genetic polymorphisms involved in one-carbon metabolism. However, expression profiles of these inter-related genes are not well-known. In this study, we examined the gene expression profiles of 11 one-carbon metabolizing genes by quantifying the mRNA level of the lymphocyte among 54 healthy individuals and explored the correlations of these genes. We found these genes were expressed in lymphocytes at moderate levels and showed significant inter-person variations. We also applied principle component analysis to explore potential patterns of expression. The components identified by the program agreed with existing knowledge about one-carbon metabolism. This study helps us better understand the biological functions of one-carbon metabolism.

Epidemiologic research on man-made disasters: strategies and implications of cohort definition for World Trade Center worker and volunteer surveillance program

Studies of long-term health consequences of disasters face unique methodologic challenges. The authors focused on studies of the health of cleanup and recovery workers, who are often poorly enumerated at the outset and difficult to follow over time. Comparison of the experience at the World Trade Center disaster with 4 past incidents of chemical and radiation releases at Seveso, Italy; Bhopal, India; Chernobyl, Ukraine; and Three Mile Island, USA, provided useful contrasts. Each event had methodologic advantages and disadvantages that depended on the nature of the disaster and the availability of records on area residents, and the emergency-response and cleanup protocol. The World Trade Center Worker Monitoring Program has well-defined eligibility criteria but lacks information on the universe of eligible workers to characterize response proportions or the potential for distortion of reported health effects. Nonparticipation may result from lack of interest, lack of awareness of the program, availability of another source of medical care, medical conditions precluding participation, inability to take time off from work, moving out of the area, death, or shift from initially ineligible to eligible status. Some of these considerations suggest selective participation by the sickest individuals, whereas others favor participation by the healthiest. The greatest concern with the validity of inferences regarding elevated health risks relative to external populations is the potential for selective enrollment among those who are affected. If there were a large pool of nonparticipating workers and those who suffered ill health were most motivated to enroll, the rates of disease among participants would be substantially higher than among all those eligible for the program. Future disaster follow-up studies would benefit substantially by having access to accurate estimates of the number of workers and information on the individuals who contributed to the cleanup and recovery effort.

Risk factors for decreased bone density and effects of HIV on bone in the elderly

Most studies of bone density in HIV-infected individuals focus on young men. This study compares differences in bone density in elderly HIV positive men and women to HIV negative controls. Bone density was lower in the lumbar spine and hip in the HIV-infected group. Antiretrovirals may be associated with decreased bone mineralization.

INTRODUCTION

Individuals with human immunodeficiency virus (HIV) may be at increased risk for osteoporosis. Prolonged exposures to HIV and/or antiretroviral therapy are possible causes for this association. This study compares differences in bone mineral density (BMD) in elderly HIV positive men and women to HIV negative controls.

METHODS

A cross-sectional study was conducted among 57 HIV-infected and 47 HIV negative subjects over age 55. BMD at the lumbar spine and total hip and markers of bone turnover were compared.

RESULTS

BMD was borderline lower in the lumbar spine and significantly lower in the hip in the HIV-infected group. Controlling for age, sex, race and body mass index, differences between the groups were significant at both sites. There was no difference in markers of bone turnover between the groups. Tenofovir use was significantly associated with decreased BMD at the spine while protease inhibitor use was significantly associated with decreased BMD at the hip.

CONCLUSION

Elderly men and women with HIV have lower bone mass than HIV negative controls. Decreased body mass index was the most important risk factor associated with decreased BMD. Bone demineralization was observed among HIV-infected subjects receiving either tenofovir or a protease inhibitor.