Deborah E. Polk

Psychosocial demands and ambulatory blood pressure: a field assessment approach.

Ambulatory blood pressure (ABP) has been shown to have independent prognostic value, over and beyond the effects of clinic blood pressure (CBP) measures. We have examined the role of psychosocial demands in understanding ABP, using an electronic diary to measure ongoing experience in the field at the time of each blood pressure reading (ecological momentary assessment). In our previous work, several psychosocial factors were shown to be associated, within-person, with acute fluctuations in ABP in a healthy adult sample. Here, we replicate these findings in a new sample, and we also examine associations of the same variables with mean ABP (between-person) over a 6-day period. Five measures assumed to be markers of psychosocial demands (negative affect, arousal, task demand, decisional control, and social conflict) were shown here to be independently associated with ABP fluctuations during daily life, after adjustment for posture, activity, and substance use. Two of these, measures of task demand and decisional control, were also associated with mean ambulatory systolic blood pressure (SBP), and these latter associations persisted after controlling for CBP. These results support the possibility that psychosocial factors may account for some of the unique predictive value associated with ABP, and they support the value of these field assessment methods.

Partner interactions are associated with reduced blood pressure in the natural environment: Ambulatory monitoring evidence from a healthy, multiethnic adult sample

Objective The objective of this study was to examine the effects of partner interactions on ambulatory blood pressure in a sample of 120 healthy adults who were monitored over a 6-day period. Methods After each blood pressure measurement, participants rated characteristics of ongoing social interactions, along with emotional activation, physical activity, talking, posture, and other covariates, with computer-assisted self-report assessments. Results Using multilevel modeling, we showed that blood pressure was significantly lower during social interactions with one’s partner relative to social interactions with any other person and relative to periods of not interacting. Interactions with partners also were characterized by significantly less talking and emotional activation and more intimacy and perceived emotional support; however, these differences did not mediate the partner effect on blood pressure. In addition, the relative benefits of interacting with a partner were not moderated by relationship quality, gender, or race. Conclusions The effects of social situations on ambulatory blood pressure may represent one pathway through which social relationships affect cardiovascular health.

Socioeconomic factors in adolescents' oral health: are they mediated by oral hygiene behaviors or preventive interventions?

OBJECTIVES To determine whether there is a socioeconomic status (SES) disparity in caries experience (i.e., DMFT) in an adolescent sample from Pennsylvania and to determine whether differences in oral hygiene behaviors and preventive interventions account for this disparity. METHODS A cross-sectional clinical assessment was conducted on a representative sample of 9th grade and 11th grade students across Pennsylvania. These students also completed a brief questionnaire regarding their oral hygiene behaviors. From this group of students, a random subsample of 530 parents completed a questionnaire assessing SES, fluoride exposure, and recency of receipt of dental services. DMFT was examined at two thresholds of severity: simple prevalence (DMFT > 0) and severe caries (DMFT > 3). RESULTS Using structural equation modeling, we found that lower SES was associated with higher prevalence of DMFT and higher prevalence of severe caries. Although lower SES was associated with lower rates of brushing, less use of sealants, and less recent receipt of dental services, these oral health behaviors and preventive interventions did not account for the disparities in DMFT defined by SES. CONCLUSIONS There is an SES gradient in caries experience in adolescents in Pennsylvania. Disparities in caries experience, however, cannot be accounted for by SES-associated differences in brushing, flossing, sealant use, fluoride exposure, or recency of use of dental services. To facilitate the design of preventive interventions, future research should determine the pathways through which SES-associated disparities occur.

Study protocol of the Center for Oral Health Research in Appalachia (COHRA) etiology study

BackgroundPeople in Appalachia experience some of the worst oral health in the United States. To develop effective intervention and prevention strategies in Appalachia, we must understand the complex relationships among the contributing factors and how they affect the etiology of oral diseases. To date, no such comprehensive analysis has been conducted. This report summarizes the characteristics of the sample and describes the protocol of a study determining contributions of individual, family, and community factors to oral diseases in Appalachian children and their relatives.Methods/DesignFamilies participated in a comprehensive assessment protocol involving interviews, questionnaires, a clinical oral health assessment, a microbiological assessment, and collection of DNA. The design of the study is cross-sectional.ConclusionDue to its multilevel design and large, family-based sample, this study has the potential to greatly advance our understanding of factors that contribute to oral health in Appalachian children.

Genome-wide association Scan of dental caries in the permanent dentition

BackgroundOver 90% of adults aged 20 years or older with permanent teeth have suffered from dental caries leading to pain, infection, or even tooth loss. Although caries prevalence has decreased over the past decade, there are still about 23% of dentate adults who have untreated carious lesions in the US. Dental caries is a complex disorder affected by both individual susceptibility and environmental factors. Approximately 35-55% of caries phenotypic variation in the permanent dentition is attributable to genes, though few specific caries genes have been identified. Therefore, we conducted the first genome-wide association study (GWAS) to identify genes affecting susceptibility to caries in adults.MethodsFive independent cohorts were included in this study, totaling more than 7000 participants. For each participant, dental caries was assessed and genetic markers (single nucleotide polymorphisms, SNPs) were genotyped or imputed across the entire genome. Due to the heterogeneity among the five cohorts regarding age, genotyping platform, quality of dental caries assessment, and study design, we first conducted genome-wide association (GWA) analyses on each of the five independent cohorts separately. We then performed three meta-analyses to combine results for: (i) the comparatively younger, Appalachian cohorts (N = 1483) with well-assessed caries phenotype, (ii) the comparatively older, non-Appalachian cohorts (N = 5960) with inferior caries phenotypes, and (iii) all five cohorts (N = 7443). Top ranking genetic loci within and across meta-analyses were scrutinized for biologically plausible roles on caries.ResultsDifferent sets of genes were nominated across the three meta-analyses, especially between the younger and older age cohorts. In general, we identified several suggestive loci (P-value ≤ 10E-05) within or near genes with plausible biological roles for dental caries, including RPS6KA2 and PTK2B, involved in p38-depenedent MAPK signaling, and RHOU and FZD1, involved in the Wnt signaling cascade. Both of these pathways have been implicated in dental caries. ADMTS3 and ISL1 are involved in tooth development, and TLR2 is involved in immune response to oral pathogens.ConclusionsAs the first GWAS for dental caries in adults, this study nominated several novel caries genes for future study, which may lead to better understanding of cariogenesis, and ultimately, to improved disease predictions, prevention, and/or treatment.

Peer-Mentored Research Development Meeting: A Model for Successful Peer Mentoring among Junior Level Researchers.

ObjectiveThis report describes a model for the development, process, and tracking methods of a Peer-mentored Research Development Meeting (PRDM), an interdisciplinary peer mentoring program. The program was initiated in 2004 by a group of post-doctoral scholars and junior faculty from the Schools of the Health Sciences at the University of Pittsburgh.MethodFrom February 2004 through February 2006, PRDM’s first five members tracked and documented their research activity (e.g., manuscripts, grants) every 4 months. The defining features of PRDM are adherence to a structured frequency and format for meetings, systematic tracking and evaluation of research development activities, and maintenance of ongoing relationships with senior mentors.ResultsDuring the 24-month data collection period, members were involved in 91 research development projects including grant applications, journal article manuscripts, book chapters, and conference abstracts. Members’ productivity increased during the 24-month period, as did the efficiency and focus of the completed projects.ConclusionMembers increased the efficiency and focus of their research development activities during the study period. Structured peer-mentoring groups have the potential to enhance research productivity among junior investigators in research intensive environments.

Genome-wide association study of periodontal health measured by probing depth in adults ages 18-49 years.

The etiology of chronic periodontitis clearly includes a heritable component. Our purpose was to perform a small exploratory genome-wide association study in adults ages 18–49 years to nominate genes associated with periodontal disease−related phenotypes for future consideration. Full-mouth periodontal pocket depth probing was performed on participants (N = 673), with affected status defined as two or more sextants with probing depths of 5.5 mm or greater. Two variations of this phenotype that differed in how missing teeth were treated were used in analysis. More than 1.2 million genetic markers across the genome were genotyped or imputed and tested for genetic association. We identified ten suggestive loci (p-value ≤ 1E-5), including genes/loci that have been previously implicated in chronic periodontitis: LAMA2, HAS2, CDH2, ESR1, and the genomic region on chromosome 14q21-22 between SOS2 and NIN. Moreover, we nominated novel loci not previously implicated in chronic periodontitis or related pathways, including the regions 3p22 near OSBPL10 (a lipid receptor implicated in hyperlipidemia), 4p15 near HSP90AB2P (a heat shock pseudogene), 11p15 near GVINP1 (a GTPase pseudogene), 14q31 near SEL1L (an intracellular transporter), and 18q12 in FHOD3 (an actin cytoskeleton regulator). Replication of these results in additional samples is needed. This is one of the first research efforts to identify genetic polymorphisms associated with chronic periodontitis-related phenotypes by the genome-wide association study approach. Though small, efforts such this are needed in order to nominate novel genes and generate new hypotheses for exploration and testing in future studies.

The incremental value of ambulatory blood pressure persists after controlling for methodological confounds: associations with carotid atherosclerosis in a healthy sample.

Background Ambulatory blood pressure assessments have been shown to be associated with subclinical and clinical endpoints even after controlling for the effects of clinic blood pressure. Objective To examine the incremental validity of ambulatory over clinic blood pressures using equivalent time periods, equivalent numbers of observations, and comparable measurement instruments across both settings. Design and Methods In this cross-sectional study of 216 healthy, community volunteers (ages 50–70 years), we compared three types of assessment in terms of their association with carotid artery atherosclerosis: manual clinic blood pressure (two readings, 10 min interval), automated clinic blood pressure (four readings, 2.5 h interval), and automated ambulatory blood pressure (four readings, 2.5 h interval) using the same type of automated device for the latter two conditions. These measurements were obtained during the morning hours on three separate occasions. Carotid intima–medial thickness and plaque were assessed, by ultrasound, as markers of atherosclerosis. Results Greater ambulatory systolic and diastolic blood pressure were associated with increased intima–medial thickness and an increased prevalence of plaque (odds ratios > 3.0), even after statistical adjustment for clinic blood pressure assessments and demographic covariates. Conclusions We conclude that the independent utility of ambulatory over clinic blood pressure cannot be attributed to methodological issues that have traditionally confounded these comparisons. These findings highlight the potential importance of behavioral and lifestyle factors in contributing to the incremental value of ambulatory blood pressure.

Heritable patterns of tooth decay in the permanent dentition: principal components and factor analyses

BackgroundDental caries is the result of a complex interplay among environmental, behavioral, and genetic factors, with distinct patterns of decay likely due to specific etiologies. Therefore, global measures of decay, such as the DMFS index, may not be optimal for identifying risk factors that manifest as specific decay patterns, especially if the risk factors such as genetic susceptibility loci have small individual effects. We used two methods to extract patterns of decay from surface-level caries data in order to generate novel phenotypes with which to explore the genetic regulation of caries.MethodsThe 128 tooth surfaces of the permanent dentition were scored as carious or not by intra-oral examination for 1,068 participants aged 18 to 75 years from 664 biological families. Principal components analysis (PCA) and factor analysis (FA), two methods of identifying underlying patterns without a priori surface classifications, were applied to our data.ResultsThe three strongest caries patterns identified by PCA recaptured variation represented by DMFS index (correlation, r = 0.97), pit and fissure surface caries (r = 0.95), and smooth surface caries (r = 0.89). However, together, these three patterns explained only 37% of the variability in the data, indicating that a priori caries measures are insufficient for fully quantifying caries variation. In comparison, the first pattern identified by FA was strongly correlated with pit and fissure surface caries (r = 0.81), but other identified patterns, including a second pattern representing caries of the maxillary incisors, were not representative of any previously defined caries indices. Some patterns identified by PCA and FA were heritable (h2 = 30-65%, p = 0.043-0.006), whereas other patterns were not, indicating both genetic and non-genetic etiologies of individual decay patterns.ConclusionsThis study demonstrates the use of decay patterns as novel phenotypes to assist in understanding the multifactorial nature of dental caries.

Hostility explains some of the discrepancy between daytime ambulatory and clinic blood pressures.

The authors examined whether hostility explained the discrepancy commonly observed between clinic and daytime ambulatory blood pressures. Daytime ambulatory blood pressure (DABP) was assessed every 45 min over 6 days in healthy adults (N = 120). After controlling for demographic variables, time-varying covariates such as position and activity level, and clinic blood pressure (CBP), the Cook-Medley Hostility Scale was significantly associated with daytime ambulatory diastolic blood pressure. No support was obtained for mediation by psychological factors. Discrepancies between DABP and CBP may be due, in part, to differences in the degree to which these 2 types of measures are associated with individual differences in hostility. These results suggest that the addition of hostility to CBP may improve its predictive power.