Climate change, human health, and biomedical research: analysis of the National Institutes of Health research portfolio.

BACKGROUND: According to a wide variety of analyses and projections, the potential effects of global climate change on human health are large and diverse. The U.S. National Institutes of Health (NIH), through its basic, clinical, and population research portfolio of grants, has been increasing efforts to understand how the complex interrelationships among humans, ecosystems, climate, climate variability, and climate change affect domestic and global health. OBJECTIVES: In this commentary we present a systematic review and categorization of the fiscal year (FY) 2008 NIH climate and health research portfolio. METHODS: A list of candidate climate and health projects funded from FY 2008 budget appropriations were identified and characterized based on their relevance to climate change and health and based on climate pathway, health impact, study type, and objective. RESULTS: This analysis identified seven FY 2008 projects focused on climate change, 85 climate-related projects, and 706 projects that focused on disease areas associated with climate change but did not study those associations. Of the nearly 53,000 awards that NIH made in 2008, approximately 0.17% focused on or were related to climate. CONCLUSIONS: Given the nature and scale of the potential effects of climate change on human health and the degree of uncertainty that we have about these effects, we think that it is helpful for the NIH to engage in open discussions with science and policy communities about government-wide needs and opportunities in climate and health, and about how NIH's strengths in human health research can contribute to understanding the health implications of global climate change. This internal review has been used to inform more recent initiatives by the NIH in climate and health.

Research opportunities for cancer associated with indoor air pollution from solid-fuel combustion.

BACKGROUND: Indoor air pollution (IAP) derived largely from the use of solid fuels for cooking and heating affects about 3 billion people worldwide, resulting in substantial adverse health outcomes, including cancer. Women and children from developing countries are the most exposed populations. A workshop was held in Arlington, Virginia, 9-11 May 2011, to better understand women's and children's potential health effects from IAP in developing countries. Workshop participants included international scientists, manufacturers, policy and regulatory officials, community leaders, and advocates who held extensive discussions to help identify future research needs. OBJECTIVES: Our objective was to identify research opportunities regarding IAP and cancer, including research questions that could be incorporated into studies of interventions to reduce IAP exposure. In this commentary, we describe the state of the science in understanding IAP and its associations with cancer and suggest research opportunities for improving our understanding of the issues. DISCUSSION: Opportunities for research on IAP and cancer include studies of the effect of IAP on cancers other than lung cancer; studies of genetic factors that modify susceptibility; studies to determine whether the effects of IAP are mediated via germline, somatic, and/or epigenetic changes; and studies of the effects of IAP exposure via dermal and/or oral routes. CONCLUSIONS: IAP from indoor coal use increases the risk of lung cancer. Installing chimneys can reduce risk, and some genotypes, including GSTM1-null, can increase risk. Additional research is needed regarding the effects of IAP on other cancers and the effects of different types of solid fuels, oral and dermal routes of IAP exposure, genetic and epigenetic mechanisms, and genetic susceptibility.

Evidence-based clinical recommendations regarding screening for oral squamous cell carcinomas.

BACKGROUND: This article presents evidence-based clinical recommendations developed by a panel convened by the American Dental Association Council on Scientific Affairs. This report addresses the potential benefits and potential risks of screening for oral squamous cell carcinomas and the use of adjunctive screening aids to visualize and detect potentially malignant and malignant oral lesions. TYPES OF STUDIES REVIEWED: The panel members conducted a systematic search of MEDLINE, identifying 332 systematic reviews and 1,499 recent clinical studies. They selected 5 systematic reviews and 4 clinical studies to use as a basis for developing recommendations. RESULTS: The panel concluded that screening by means of visual and tactile examination to detect potentially malignant and malignant lesions may result in detection of oral cancers at early stages of development, but that there is insufficient evidence to determine if screening alters disease-specific mortality in asymptomatic people seeking dental care. CLINICAL IMPLICATIONS: The panel suggested that clinicians remain alert for signs of potentially malignant lesions or early-stage cancers while performing routine visual and tactile examinations in all patients, but particularly in those who use tobacco or who consume alcohol heavily. Additional research regarding oral cancer screening and the use of adjuncts is needed.

Frontiers in cancer epidemiology: a challenge to the research community from the Epidemiology and Genomics Research Program at the National Cancer Institute.

The Epidemiology and Genomics Research Program (EGRP) at the National Cancer Institute (NCI) is developing scientific priorities for cancer epidemiology research in the next decade. We would like to engage the research community and other stakeholders in a planning effort that will include a workshop in December 2012 to help shape new foci for cancer epidemiology research. To facilitate the process of defining the future of cancer epidemiology, we invite the research community to join in an ongoing web-based conversation at http://blog-epi.grants.cancer.gov/ to develop priorities and the next generation of high-impact studies.

Cancer and environment: definitions and misconceptions.

BACKGROUND: Scientific evidence supports an association between environmental exposures and cancer. However, a reliable estimate for the proportion of cancers attributable to environmental factors is currently unavailable. This may be related to the varying definitions of the term "environment." The current review aims to determine how the reporting of the definition of the environment and of the estimates of environmentally attributable risks have changed over the past 50 years. METHODS: A systematic literature search was performed to retrieve all relevant publications relating to the environment and cancer from January 1960 to December 2010 using PubMed, EMBASE, Scopus, and Web of Science. Definitions of the environment and environmentally attributable risks for cancer were extracted from each relevant publication. RESULTS: The search resulted in 261 relevant publications. We found vast discrepancies in the definition of the environment, ranging from broad (including lifestyle factors, occupational exposures, pollutants, and other non-genetic factors) to narrow (including air, water, and soil pollutants). Reported environmentally attributable risk estimates ranged from 1% to 100%. CONCLUSIONS: Our findings emphasize the discrepancies in reporting environmental causation of cancer and the limits of inference in interpreting environmentally attributable risk estimates. Rather than achieving consensus on a single definition for the environment, we suggest the focus be on achieving transparency for any environmentally attributable risks.

Epigenetic Contributions to the Relationship between Cancer and Dietary Intake of Nutrients, Bioactive Food Components, and Environmental Toxicants.

Epigenetics is the study of heritable changes in gene expression that occur without a change in DNA sequence. Cancer is a multistep process derived from combinational crosstalk between genetic alterations and epigenetic influences through various environmental factors. The observation that epigenetic changes are reversible makes them an attractive target for cancer prevention. Until recently, there have been difficulties studying epigenetic mechanisms in interactions between dietary factors and environmental toxicants. The development of the field of cancer epigenetics during the past decade has been advanced rapidly by genome-wide technologies - which initially employed microarrays but increasingly are using high-throughput sequencing - which helped to improve the quality of the analysis, increase the capacity of sample throughput, and reduce the cost of assays. It is particularly true for applications of cancer epigenetics in epidemiologic studies that examine the relationship among diet, epigenetics, and cancer because of the issues of tissue heterogeneity, the often limiting amount of DNA samples, and the significant cost of the analyses. This review offers an overview of the state of the science in nutrition, environmental toxicants, epigenetics, and cancer to stimulate further exploration of this important and developing area of science. Additional epidemiologic research is needed to clarify the relationship between these complex epigenetic mechanisms and cancer.

Evidence-based clinical recommendations regarding screening for oral squamous cell carcinomas.

BACKGROUND: This article presents evidence-based clinical recommendations developed by a panel convened by the American Dental Association Council on Scientific Affairs. This report addresses the potential benefits and potential risks of screening for oral squamous cell carcinomas and the use of adjunctive screening aids to visualize and detect potentially malignant and malignant oral lesions. TYPES OF STUDIES REVIEWED: The panel members conducted a systematic search of MEDLINE, identifying 332 systematic reviews and 1,499 recent clinical studies. They selected five systematic reviews and four clinical studies to use as a basis for developing recommendations. RESULTS: The panel concluded that screening by means of visual and tactile examination to detect potentially malignant and malignant lesions may result in detection of oral cancers at early stages of development, but that there is insufficient evidence to determine if screening alters disease-specific mortality in asymptomatic people seeking dental care. CLINICAL IMPLICATIONS: The panel suggested that clinicians remain alert for signs of potentially malignant lesions or early-stage cancers while performing routine visual and tactile examinations in all patients, but particularly in those who use tobacco or who consume alcohol heavily. Additional research regarding oral cancer screening and the use of adjuncts is needed.

The effect of an international embargo on malnutrition and childhood mortality in rural Haiti.

The study objective was to determine the effect of an international embargo against Haiti, from October 1991 through October 1994, on early childhood protein-energy malnutrition and all-cause mortality in a geographic area where humanitarian aid was continuously available to the children in the study. The authors used longitudinal anthropometric records on 1593 children, 24 months old or younger, living in the rural Grand Anse Department of Haiti from 1989 through 1996. Kaplan-Meier graphs for all-cause mortality accounting for malnutrition status and stratified by calendar period were applied to the database and assessed using logrank tests. Adjusted relative risks were assessed by Cox regression. The results show that despite the continuous availability of preventive services (1989-1996), higher all-cause mortality was more strongly associated with a calendar period coinciding with the international embargo than with periods before and after the embargo. The incidence of childhood mortality and of severe malnutrition were also higher during the period of the embargo than in the periods before and after the embargo. The findings suggest that future international sanctions, even those with humanitarian/medical exceptions, could result in substantial infant death.

The military oral health care system as a model for eliminating disparities in oral health.

BACKGROUND: Healthy People (HP) 2010 is a national health promotion and disease prevention initiative of the U.S. Department of Health and Human Services. The HP 2010 report highlighted a range of racial/ethnic disparities in dental health. A substantial portion of these disparities appear to be explained by differences in access to care. Members of the U.S. military have universal access to care that also has a compulsory component. The authors conducted a study to investigate the extent to which disparities in progress toward achievement of HP 2010 objectives were lower among the military population and to compare the oral health of the military population with that of the civilian population. METHODS: The participants in this study were non-Hispanic white and non-Hispanic black males aged 18 to 44 years. They were drawn from the Tri-Service Comprehensive Oral Health Survey (10,869 including 899 recruits who participated in the TSCOHS Recruit Study) and the Third National Health and Nutrition Examination Survey (4,779). RESULTS: We found no disparities between black and white adults in untreated caries and recent dental visit rates in the military population. Disparities in missing teeth were much lower among military personnel than among civilians. CONCLUSIONS: A universal access-to-care system that incorporated an aspect of compulsory treatment displayed little to no racial disparity in relevant oral health outcomes. This demonstrates that it is possible for large, diverse populations to have much lower levels of disparities in oral health even when universal access to care is not provided until the patient is 18 or 19 years of age.

Continuity of care and early diagnosis of head and neck cancer.

This study investigated whether receiving continuous regular care with the same primary care provider had an independent association with stage at diagnosis for head and neck cancers (HNCA) in a Medicare population. The study database (N = 10,662) linked files from the Surveillance, Epidemiology, and End Results Program 1991-2000 for patients with cancers of the oral cavity, pharynx, and larynx with their files from the Center for Medicare and Medicaid Services Program. Continuity of care displayed a statistically significant independent association and dose-response pattern with stage at diagnosis when the provider was an internist but not a general or family physician. An independent statistically significant association between continuity of care with an internist and stage at diagnosis was found for oral cavity tumors (adjusted odds ratio [AOR] = 0.85; 95%CI = 0.73-0.99), but not pharyngeal tumors (AOR = 1.02; 95%CI = 0.74-1.41). Laryngeal tumors were borderline statistically significant at p-value = 0.07 (AOR = 0.84; 95%CI = 0.69-1.02). Regular continuous care from the same primary care provider displayed an independent association with early diagnosis of HNCA when the anatomic site was the oral cavity and the provider was an internist, but not when the provider was a general or family physician. Primary care physicians including general/family physicians may represent a relevant group for encouraging increased opportunistic HNCA screening efforts among their patients.

Dental visits among smoking and nonsmoking US adults in 2000.

OBJECTIVE: To examine dental visits among smoking and nonsmoking adults in a nationally representative sample. METHODS: Logistic regression analysis was performed, using a sample of 15,250 US adults from the Medical Expenditure Panel Survey Household Component 2000. RESULTS: Current smokers were less likely to report dental visits (32.9%) than were nonsmokers (45.0%) during 2000. Differences were statistically significant even after accounting for other predictors of dental care use. CONCLUSIONS: Efforts to optimize the oral health of smokers and reduce serious oral diseases may benefit from addressing this lower use of dental services among smokers.

Dental insurance and clinical dental outcomes in NHANES III.

OBJECTIVES: The National Health and Nutrition Examination Survey (NHANES III) 1988-1994 is one of the few nationally representative data sets with information on both private dental insurance and a clinical dental exam. The objective of this analysis was to examine the possible associations between private dental insurance and clinical exam outcomes, demographic variables, and dental visits. METHODS: Using NHANES III data, analysis was limited to persons aged 20 years or older who had a dental exam and reported on their private dental insurance status. Initial analyses were based on comparisons between those with and without private dental insurance. Propensity scoring method was used to examine the effects of dental insurance on clinical exam variables. RESULTS: The percentage of individuals with private dental insurance was significantly greater among non-Hispanic blacks, those with higher educational attainment, those living at/above the federal poverty level, and those with a dental visit in the past year compared to their respective counterparts. Those with untreated caries, those with a loss of attachment of greater than 4 mm, and those with 12-27 missing teeth were significantly less likely to have dental insurance (p < 0.05) than their respective counterparts. CONCLUSIONS: These results suggest that having private dental insurance is associated with better clinical oral health status.

Comorbidity and early diagnosis of head and neck cancer in a Medicare population.

BACKGROUND: This study assessed potential opportunities for an early diagnosis of head and neck cancers (HNCA), and the role played by comorbidity, among contacts by Medicare patients with the healthcare system before their diagnosis. Comorbidity was hypothesized to affect the relationship between use of healthcare services and stage of disease. METHODS: The study database (n =11,312) was constructed by linking files from the Surveillance, Epidemiology, and End Results Program 1991 through 1999 and those of the Center for Medicare and Medicaid Services Program. HNCA cases were comprised of the lip, oral cavity, pharynx, and larynx anatomic sites. RESULTS: Among persons with no alcohol and tobacco-related comorbidities (ATC), increasing numbers of physician visits were independently associated with a reduced risk of advanced stage at diagnosis for all anatomic sites, but especially the pharynx and larynx. Among persons with one or more ATC, physician visits displayed no association with stage at diagnosis with the exception of laryngeal tumors, where physician visits were strongly associated with reduced risk of late stage at diagnosis. Over 46% of cases with advanced stage tumors, most of whom also had ATC disease, had > or =11 physician visits in the year preceding their diagnosis of HNCA. CONCLUSIONS: Potential opportunities for an earlier diagnosis of HNCA were found among the numerous contacts with the healthcare system that patients had prior to their cancer diagnosis. Such opportunities were especially numerous and relevant for persons with ATC and form the basis for combining high-risk with opportunistic screening approaches.

Dental visits among older U.S. adults, 1999: the roles of dentition status and cost.

BACKGROUND: The proportion of older adults in the United States will continue to grow during the next few decades. Aging populations will bring unique challenges to dentistry. Understanding dental visit patterns will help the profession become prepared. METHODS: The authors used data from the 1999 National Health Interview Survey to describe dental visit patterns among adults aged 55 years or older. Outcome variables included presence of a dental visit in the previous year, reasons for the last dental visit and reasons for not having had a dental visit. Descriptor variables included age, sex, race/ethnicity, poverty status, region, private dental insurance status and dentition status. RESULTS: Approximately 71 percent of dentate and 20 percent of edentulous adults had had a dental visit in the previous year. Among dentate adults, age, sex, race/ ethnicity, poverty status, region and dental insurance were associated with visits. Among edentulous adults, age, poverty status and dental insurance were associated with visits. Among all older adults, the main reason for a visit was preventive/ diagnostic. Edentulous adults also were likely to visit for problems. The majority of adults who had not had a dental visit did not recognize a need for one; however, dentate adults were more likely to recognize a need than were edentulous adults. For those who recognized a need but did not visit a dentist, cost was a prevalent barrier. CONCLUSIONS: Among those who visited a dentist, most went for a diagnostic/preventive procedure. Among those who did not visit a dentist, most did not recognize a need to do so. Cost remains a serious barrier. CLINICAL IMPLICATIONS: Some older adults recognize a need to visit a dentist, whereas others (particularly the edentulous) do not. As more adults recognize their oral health care needs, cost may prevent some from seeking care.

Race/ethnicity and untreated dental caries: the impact of material and behavioral factors.

OBJECTIVE: To use nationally representative data, group variables into categories of material and behavioral factors, and assess their relative contribution to racial/ethnic variation in untreated caries. METHODS: Participants were from the Third National Health and Nutrition Examination Survey (NHANES III), aged 20-50 years. Material factors were income, education, employment status, dental insurance status, and urban residence. Behavioral factors were marital status, tobacco use, alcohol use, obesity, and social support. All models were additionally adjusted for age, gender, and quartile of missing teeth. The outcome was three or more carious teeth. RESULTS: Non-Hispanic blacks and Mexican-Americans displayed excess risk of untreated caries compared with non-Hispanic whites when adjusted for age, sex, and missing teeth (adjusted odds ratios 1.73 and 1.69, respectively). The addition of behavioral factors to this model resulted in virtually no changes in the adjusted odds ratios for race/ethnicity and untreated caries. When material factors were added to the basic model the excess risk for untreated caries among non-Hispanic blacks was reduced by approximately 21% and that of Mexican-Americans was no longer statistically significant compared with non-Hispanic whites (adjusted odds ratios 1.36 and 0.83, respectively). CONCLUSIONS: Much of the excess risk for untreated dental caries among non-Hispanic blacks and Mexican-Americans compared with non-Hispanic whites was eliminated when material factors were controlled, while no risk reductions were observed when behavioral factors were controlled. Addressing material factors may provide greater reductions in untreated caries disparities than behavioral interventions, and these risk reductions may vary with racial/ethnic group.

Dental insurance visits and expenditures among older adults.

OBJECTIVES: We examined the effect of age, income, and coverage on dental service utilization during 1996. METHODS: We used data from the 1996 Medical Expenditure Panel Survey. RESULTS: Edentulous and poorer older adults are less likely to have coverage and less likely to report a dental visit than dentate or wealthier older adults. CONCLUSIONS: These analyses help to describe the needs of older adults as they cope with diminishing resources as a consequence of retirement, including persons previously accustomed to accessing oral health services with dental insurance.

A comparison of health professions student attitudes regarding tobacco curricula and interventionist roles.

Health care providers who feel prepared are more apt to assume tobacco interventionist roles; therefore, educational preparation is critical. A nonprobability sample of health professions students at an urban academic health center were asked to respond to a twenty-two-item survey eliciting demographic, behavioral, and tobacco-related attitudinal information. Frequency distributions were assessed with Pearson chi-square statistics. The overall response rate was 76.7 percent, and final sample size was 319. Current use of spit tobacco (ST) was 2.5 percent and current smoking 5.6 percent. In comparing current smokers to nonsmokers and current ST users to nonusers, we found that no differences in proportion agreeing with any of the five questions about attitudes and opinions were statistically significant at p-value 0.05. At least 70 percent of students from each of six health professions programs agreed it was their professional responsibility to help smokers quit, and at least 65 percent agreed to the same responsibility for helping ST users quit. The proportion agreeing that their programs had course content describing their role in helping patients quit tobacco use varied widely by program from 100 percent agreement among dental hygiene and pharmacy students to 14.6 percent of physical therapy students (p-value <0.001). When asked whether their program adequately prepared them to help smokers quit, agreement ranged from 100 percent among dental hygiene students to only 5.5 percent among physical therapy students (p-value <0.001). Almost 90 percent of dental hygiene students agreed that they were adequately trained to help ST users quit, but no other program had a percentage of agreement above 34 percent (p-value <0.001). Consistent and comprehensive multidisciplinary tobacco-related curricula could offer desirable standardization.

Cigarette smoking, periodontal disease: and chronic obstructive pulmonary disease.

BACKGROUND: Cigarette smoking is a significant risk factor for both chronic obstructive pulmonary disease (COPD) and periodontal disease. The goal of this study was to better understand the role of smoking in a possible relationship between periodontal disease and COPD. METHODS: The study population consisted of 7,625 participants in the Third National Health and Nutrition Examination Survey (NHANES III) during 1988-1994 who were aged 30 years or older when examined and who received a spirometric examination. The data analysis employed logistic regression models and accounted for the complex sampling design used in NHANES III. RESULTS: After adjustment for potential confounders, there was no statistically significant association between periodontal disease and COPD among former or non-smokers. Current smokers with > or = 4 mm mean loss of attachment had an odds ratio of 3.71 (95% confidence interval: 1.74, 7.89). CONCLUSIONS: These results suggest that cigarette smoking may be a cofactor in the relationship between periodontal disease and chronic obstructive pulmonary disease. The key role played by smoking in the etiology of both periodontal disease and chronic obstructive pulmonary disease suggests that much of the observed increase in risk may actually reflect the exposure to smoking. Additional research into smoking-related effect modification is needed to clarify the role of periodontal disease in the etiology of smoking-related systemic diseases.

Opportunities for oral cancer screening among older African-American women.

BACKGROUND: Older persons with smoking histories are important targets for oral cancer screening. Although older persons in low-income communities often lack regular dental care, little is known about the characteristics of groups at greatest risk for poor screening. METHODS: Survey data from 576 African-American women aged 45-93 were used to identify predictors of smoking and recency and type of dental care. RESULTS: Fifty-nine percent of respondents were current or former smokers, and 62% reported dental care within the past 3 years. Among smokers, no recent dental care was associated with older age, worse health, not working, no regular medical provider, and no recent mammography. CONCLUSIONS: These results suggest that episodic visits to non dentist providers offer opportunities for oral screening in high-risk populations.