Effects of a Household Air Pollution Intervention with Liquefied Petroleum Gas on Cardiopulmonary Outcomes in Peru. A Randomized Controlled Trial.

Rationale: Approximately 40% of people worldwide are exposed to household air pollution (HAP) from the burning of biomass fuels. Previous efforts to document health benefits of HAP mitigation have been stymied by an inability to lower emissions to target levels. Objectives: We sought to determine if a household air pollution intervention with liquefied petroleum gas (LPG) improved cardiopulmonary health outcomes in adult women living in a resource-poor setting in Peru. Methods: We conducted a randomized controlled field trial in 180 women aged 25-64 years living in rural Puno, Peru. Intervention women received an LPG stove, continuous fuel delivery for 1 year, education, and behavioral messaging, whereas control women were asked to continue their usual cooking practices. We assessed for stove use adherence using temperature loggers installed in both LPG and biomass stoves of intervention households. Measurements and Main Results: We measured blood pressure, peak expiratory flow (PEF), and respiratory symptoms using the St. George's Respiratory Questionnaire at baseline and at 3-4 visits after randomization. Intervention women used their LPG stove exclusively for 98% of days. We did not find differences in average postrandomization systolic blood pressure (intervention - control 0.7 mm Hg; 95% confidence interval, -2.1 to 3.4), diastolic blood pressure (0.3 mm Hg; -1.5 to 2.0), prebronchodilator peak expiratory flow/height2 (0.14 L/s/m2; -0.02 to 0.29), postbronchodilator peak expiratory flow/height2 (0.11 L/s/m2; -0.05 to 0.27), or St. George's Respiratory Questionnaire total score (-1.4; -3.9 to 1.2) over 1 year in intention-to-treat analysis. There were no reported harms related to the intervention. Conclusions: We did not find evidence of a difference in blood pressure, lung function, or respiratory symptoms during the year-long intervention with LPG. Clinical trial registered with www.clinicaltrials.gov (NCT02994680).

High blood pressure and cognitive decline in mild cognitive impairment.

OBJECTIVES: To determine whether high blood pressure (BP) levels are associated with faster decline in specific cognitive domains. DESIGN: Prospective longitudinal cohort. SETTING: Uniform Data Set of the National Institutes of Health, National Institute on Aging Alzheimer's Disease Centers. PARTICIPANTS: One thousand three hundred eighty-five participants with a diagnosis of mild cognitive impairment (MCI) and measured BP values at baseline and two annual follow-up visits. MEASUREMENTS: Neuropsychological test scores and Clinical Dementia Rating Sum of Boxes (CDR Sum) score. RESULTS: Participants with MCI with two or three annual occasions of high BP values (systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg) had significantly faster decline on neuropsychological measures of visuomotor sequencing, set shifting, and naming than those who were normotensive on all three occasions. High systolic BP values were associated as well with faster decline on the CDR Sum score. CONCLUSION: Hypertension is associated with faster cognitive decline in persons at risk for dementia.

Disease-related and genetic correlates of psychotic symptoms in Parkinson's disease.

Our aim was to examine disease-related and genetic correlates of the development of psychotic symptoms in a large population of patients with Parkinson's disease. We studied 500 patients with Parkinson's disease from the NeuroGenetics Research Consortium using logistic regression models. Predictors were demographic, clinical (motor/nonmotor features), and genetic, measured as continuous or dichotomous variables. Continuous measures were divided into population-based tertiles. Results are given as odds ratios (95% confidence intervals) for dichotomous variables and by ascending tertile for continuous variables. Psychotic symptoms were associated with increasing age: 4.86 (1.62-14.30) and 6.25 (2.09-18.74) (test for trend: P = 0.01); and duration of disease: 3.81 (1.23-11.76) and 5.33 (1.68-16.89) (test for trend: P = 0.03). For nonmotor features, we demonstrated positive trends with depression: 1.31 (0.47-3.61) and 5.01 (2.04-12.33) (test for trend: P < 0.0001); cognitive dysfunction: 0.69 (0.26-1.84) and 2.51 (1.00-6.29) (test for trend: P = 0.03); and an excess for those with sleep disorders: 2.00 (1.03-3.89) (P = 0.04). Psychotic symptoms were not associated with tremor or postural instability scores, but there was an association with freezing of gait: 3.83 (1.67-8.75) (P < 0.002). Psychotic symptoms were not associated with the presence of any examined polymorphisms in the apolipoprotein, alpha-synuclein, or microtubule associated protein tau genes. This is the largest study to examine correlates of psychotic symptoms in Parkinson's disease. We discovered a novel association with freezing of gait. We demonstrated an association with depression and duration of disease, both of which were inconsistently related in previous studies, and confirmed the association with age, cognitive dysfunction, and sleep disorders.

Prisoner survival inside and outside of the institution: implications for health-care planning.

The life expectancy of persons cycling through the prison system is unknown. The authors sought to determine the 15.5-year survival of 23,510 persons imprisoned in the state of Georgia on June 30, 1991. After linking prison and mortality records, they calculated standardized mortality ratios (SMRs). The cohort experienced 2,650 deaths during follow-up, which were 799 more than expected (SMR = 1.43, 95% confidence interval (CI): 1.38, 1.49). Mortality during incarceration was low (SMR = 0.85, 95% CI: 0.77, 0.94), while postrelease mortality was high (SMR = 1.54, 95% CI: 1.48, 1.61). SMRs varied by race, with black men exhibiting lower relative mortality than white men. Black men were the only demographic subgroup to experience significantly lower mortality while incarcerated (SMR = 0.66, 95% CI: 0.58, 0.76), while white men experienced elevated mortality while incarcerated (SMR = 1.28, 95% CI: 1.10, 1.48). Four causes of death (homicide, transportation, accidental poisoning, and suicide) accounted for 74% of the decreased mortality during incarceration, while 6 causes (human immunodeficiency virus infection, cancer, cirrhosis, homicide, transportation, and accidental poisoning) accounted for 62% of the excess mortality following release. Adjustment for compassionate releases eliminated the protective effect of incarceration on mortality. These results suggest that the low mortality inside prisons can be explained by the rarity of deaths unlikely to occur in the context of incarceration and compassionate releases of moribund patients.

Postural instability/gait disturbance in Parkinson's disease has distinct subtypes: an exploratory analysis.

OBJECTIVE: To test the hypothesis that postural instability with falling (PIF) and freezing of gait (FOG) are distinct subtypes of the postural instability/gait disturbance (PIGD) form of Parkinson's disease (PD). METHODS: 499 PD subjects from the NeuroGenetics Research Consortium were studied using logistic regression to examine, in a cross sectional analysis, predictors of FOG and PIF. Potential predictors were from four spheres; demographic, clinical motor, clinical non-motor and genetic. RESULTS: FOG and PIF were both associated with greater gait subscores and lower tremor subscores on the Unified Parkinson's Disease Rating Scale (p ≤ 0.02). However, they differed with regard to demographic, non-motor and genetic predictors. FOG was associated with greater duration of disease, with ORs of 3.01 (95% CI 1.35 to 6.72) and 4.91 (95% CI 2.29 to 10.54) for third and fourth quartiles of duration, respectively, versus the lowest half of duration. The risk of having psychotic symptoms was also significantly increased (OR 3.02, 95% CI 1.41 to 6.49; p=0.004). FOG was inversely associated with the presence of the CYP2D6*4 allele (OR 0.41, 95% CI 0.21 to 0.80; p=0.009) suggesting a protective effect. PIF was associated with depression (OR 1.08, 95% CI 1.01 to 1.15; p<0.02) and was inversely associated with APOE ε4 (OR 0.21, 95% CI 0.05 to 0.87; p=0.03), again suggesting a protective effect. CONCLUSION: FOG and PIF have different demographic, non-motor and genetic predictors suggesting that they may be pathophysiologically distinct subtypes of PIGD. These findings have implications in the discovery of therapeutic targets for these disabling features as well as for predicting outcomes of PD.

Confounding and bias in the attributable fraction.

Inappropriate methods are frequently used to calculate the population attributable fraction (AF) for a given exposure of interest. This commonly occurs when authors use adjusted relative risks (RRs) reported in the literature (the "source" data), without access to the original data. In this analysis, we examine the relationship between the direction and magnitude of confounding in the source data and resulting bias in the attributable fraction when incorrect methods are used. We assess confounding by the confounding risk ratio, which is the ratio of the crude RR to the adjusted RR. We assess bias in the AF by the ratio of the incorrectly calculated AF to the correctly calculated AF. Using generated data, we examine the relationship between confounding and AF bias under various scenarios of population prevalence of exposure and strength of the exposure-disease association. For confounding risk ratios greater than 1.0 (ie, crude RR >adjusted RR), the AF is underestimated; for confounding risk ratios less than 1.0 (ie, crude RR

A cross-sectional analysis of type II diabetes in a community with exposure to perfluorooctanoic acid (PFOA).

BACKGROUND: Increased diabetes mortality has been reported in workers exposed to perfluorooctanoic acid (PFOA). We analyzed the relationships among serum PFOA, type II diabetes, and fasting glucose in a population with high levels of serum PFOA resulting from drinking contaminated water. METHODS: The study population was adults participating in a health survey in 2005-2006 (N=54,468). Subjects reported prevalent diabetes, age at diagnosis, and provided blood in which serum PFOA and glucose levels were measured. We conducted a case-control analysis restricted to long-time residents (> or =20 years, N=13,922), to maximize the likelihood that serum PFOA levels in 2005 reflected previous exposure. Cases (N=1055) were restricted to those with medical record validation and at least 10-year residence prior to diagnosis. We also studied fasting glucose and serum PFOA in a subset (N=21,642). RESULTS: Median serum PFOA was 28 ng/ml, compared with 4 ng/ml in the general US population. Reported diabetes prevalence was 7.8%, similar to what was expected. Adjusted for confounders, all upper deciles of serum PFOA had a decreased risk of diabetes compared with the lowest (odds ratios-ORs by decile, 1.00, 0.71, 0.60, 0.72, 0.65, 0.65, 0.87, 0.58, 0.62, 0.72). There was no consistent pattern between fasting serum glucose and PFOA (glucose by decile, 94, 95, 95, 93, 94, 92, 92, 92, 92, 93, adjusted for confounders). CONCLUSIONS: Our findings do not demonstrate an association between PFOA and either type II diabetes or fasting glucose level. Our data are limited by their cross-sectional nature, and do not preclude the possibility of a causal relationship.

Occupational exposure to polychlorinated biphenyls and risk of breast cancer.

BACKGROUND: Despite the endocrine system activity exhibited by polychlorinated biphenyls (PCBs), recent studies have shown little association between PCB exposure and breast cancer mortality. OBJECTIVES: To further evaluate the relation between PCB exposure and breast cancer risk, we studied incidence, a more sensitive end point than mortality, in an occupational cohort. METHODS: We followed 5,752 women employed for at least 1 year in one of three capacitor manufacturing facilities, identifying cases from questionnaires, cancer registries, and death certificates through 1998. We collected lifestyle and reproductive information via questionnaire from participants or next of kin and used semiquantitative job-exposure matrices for inhalation and dermal exposures combined. We generated standardized incidence ratios (SIRs) and standardized rate ratios and used Cox proportional hazards regression models to evaluate potential confounders and effect modifiers. RESULTS: Overall, the breast cancer SIR was 0.81 (95% confidence interval, 0.72-0.92; n = 257), and regression modeling showed little effect of employment duration or cumulative exposure. However, for the 362 women of questionnaire-identified races other than white, we observed positive, statistically significant associations with employment duration and cumulative exposure; only smoking, birth cohort, and self- or proxy questionnaire completion had statistically significant explanatory power when added to models with exposure metrics. CONCLUSIONS: We found no overall elevation in breast cancer risk after occupational exposure to PCBs. However, the exposure-related risk elevations seen among nonwhite workers, although of limited interpretability given the small number of cases, warrant further investigation, because the usual reproductive risk factors accounted for little of the increased risk.

Development of a rapid screening instrument for mild cognitive impairment and undiagnosed dementia.

Mild cognitive impairment (MCI) often presages development of Alzheimer's disease (AD). We recently completed a cross-sectional study to test the hypothesis that a combination of a brief cognitive screening instrument (Mini-Cog) with a functional scale (Functional Activities Questionnaire; FAQ) would accurately identify individuals with MCI and undiagnosed dementia. The Mini-Cog consists of a clock drawing task and 3-item recall, and takes less than 5 minutes to administer. The FAQ is a 30-item questionnaire completed by an informant. In addition to the Mini-Cog and FAQ, a traditional cognitive test battery was administered, and two neurologists and a neuropsychologist determined a consensus diagnosis of Normal, MCI, or Dementia. A classification tree algorithm was used to pick optimal cutpoints, and, using these cutpoints, the combined Mini-Cog and FAQ (MC-FAQ) predicted the consensus diagnosis with an accuracy of 83% and a weighted kappa of 0.81. When the population was divided into Normal and Abnormal, the sensitivity, specificity and positive predictive value were 89%, 90%, and 95%, respectively. The MC-FAQ discriminates individuals with MCI from cognitively normal individuals and those with dementia, and its ease of administration makes it an attractive screening instrument to aid detection of cognitive impairment in the elderly.

Characteristics of persons and jobs with needlestick injuries in a national data set.

BACKGROUND: Physicians, nurses, and others are at risk of needlesticks, yet little national information is available regarding incidence across demographic and occupational categories. METHODS: Analysis was conducted on national data on occupational injuries for 1992-2003 from the Bureau of Labor Statistics (BLS). Because BLS data were limited to cases with 1 or more days of work loss, and reasons related to reporting of incidents, the data only reflected a subset of all needlesticks. Nevertheless, the data were internally consistent across categories so that relative magnitudes were reliable. Statistical tests for differences in proportions were conducted that compared needlesticks with all other occupational injuries and employment. RESULTS: Cases with 1 or more days of work loss numbered 903 per year, on average, from 1992 through 2003. Women comprised 73.3% (95% CI: 72.5%-74.2%) of persons injured. For those reporting race, white, non-Hispanic comprised 69.3% of the total (95% CI: 68.1%-70.4%); black, non-Hispanic, 14.8% (95% CI: 13.9%-15.6%); and Hispanic, 13.8% (95% CI: 12.9%-14.6%). The age bracket 35 to 44 years had the highest percentage of injuries at 34.0% (95% CI: 33.1%-34.9%). Ages over 54 years reported smaller percentages of needlestick injuries than either all other injuries or employment. Occupations with greatest frequencies included registered nurses, nursing aides and orderlies, janitors and cleaners, licensed practical nurses, and maids and housemen. Occupations with greatest risks included biologic technicians, janitors and cleaners, and maids and housemen. Almost 20% (95% CI: 18.88%-20.49%) of needlesticks occurred outside the services industry. Seven percent (95% CI: 6.56%-7.53%) of needlesticks resulted in 31 or more days of work loss in contrast to 20.46% (95% CI: 20.44%-20.48%) of all other injuries. CONCLUSION: In this nationally representative sample, the most frequent demographic and occupational categories were women; white, non-Hispanic; ages 35 to 44 years; and registered nurses.

Evidence of shared risk for Alzheimer's disease and Parkinson's disease using family history.

This case-control study examined the potential for a common etiology of Parkinson's disease (PD) and Alzheimer's disease (AD) using reported family history. Structured interviews were used to collect AD and PD family history from subjects (n = 1,531) with AD, PD, AD/PD, or controls. Intergroup analysis compared reported AD and PD family histories in the three case groups to the histories reported in the control group. Intragroup analysis stratified each diagnostic group based on positive family history of AD, then compared the subgroups for a family history of PD. Subjects with AD had a higher risk of having a family history of AD [odds ratio (OR) 2.3; 1.5-3.4] and subjects with PD had a higher risk of having a family history of PD (OR 2.2; 1.2-4.0) as compared to control subjects. Intergroup analyses revealed no significant crossed risk, increased risk of subjects with AD having a family history of PD vs controls and vice versa. Intragroup analysis found that subjects with PD and a family history of AD were more likely to have a family history of PD (OR 1.7; 1.1-2.6) when compared to subjects with PD and no family history of AD. A similar trend was found for subjects with AD (OR 1.7; 0.9-3.1). AD and PD cases each have an increased familial risk of their respective disease. Probands with AD or PD and a family history of either disease have a higher crossed risk of a family history of the other disease. These findings suggest the existence of common genetic and/or environmental factors that predispose to both AD and PD in the subset of cases with positive family history of both neurodegenerative diseases.

Tenth revision U.S. mortality rates for use with the NIOSH Life Table Analysis System.

OBJECTIVE: The objective of this study was to update rate files for the NIOSH Life Table Analysis System for Personal Computers (PC LTAS) reflecting the newly adopted tenth revision changes to the International Classification of Diseases. METHODS: PC LTAS allows researchers to conduct comparative mortality and morbidity analyses for the purpose of identifying disease-exposure associations using person-time-at-risk for age, race, sex, and calendar time-specific reference rates from 1940. Previously available through 1998, files for the United States and individual states were updated through 2004 using uncensored population data. Tenth revision causes were added if compatible with earlier NIOSH death categories, based on revisions 5 through 9. A few new cause categories were added. RESULTS: The resulting NIOSH categories are described for two new U.S. rate files: 1960 through 2004 and 1940 through 2004. CONCLUSION: The new U.S. rate files are available online or on request.