No abstract

Background-Few longitudinal studies have examined ethnic and sex differences, predictors and tracking stabilities of heart rate variability (HRV) at rest and in response to stress in youths and young adults. Results-AAs showed significantly higher resting root mean square of successive differences (RMSSD) of normal R-R intervals and high-frequency (HF) power than EAs (Ps< 0.01). Females displayed larger decrease of RMSSD and HF during video game challenge than males (Ps< 0.05). These ethnic and sex differences were consistent across 1.5 years. No significant sex difference of resting HRV or ethnic difference of HRV response to stress was observed. In addition to age, ethnicity or sex, baseline resting HRV or HRV response to stress are predictors of the corresponding variables 1.5 years later (Ps< 0.01). Furthermore, weight gain indexed by either body mass index or waist circumference predicts declined resting HRV levels during follow up (Ps < 0.05). Tracking stabilities were high (>0.5) for resting HRV, but relatively low (<0.3) for HRV in response to stress. Methods-TwoConclusion-AAs show higher resting HRV than EAs, and females display greater HRV response to stress than males; and these ethnic and sex differences are consistent across 1.5 years. Resting HRV declines with weight gain.

No abstract

Background Salivary biomarkers are potentially important for determining the presence, risk, and progression of periodontal disease. However, clinical translation of biomarker technology from lab to chairside requires studies that identify biomarkers associated with the transitional phase between health and periodontal disease (i.e., gingivitis). Methods Eighty participants (40 with gingivitis, 40 healthy) provided saliva at baseline and 7 to 30 days later. An additional sample was collected from gingivitis participants 10 to 30 days after dental prophylaxis. Clinical parameters of gingival disease were recorded at baseline and the final visit. Salivary concentrations of interleukin (IL)-1β, IL-6, matrix metalloproteinase (MMP)-8, macrophage inflammatory protein (MIP)-1α, and prostaglandin E2 (PGE2) were measured. Results Clinical features of health and gingivitis were stable at both baseline visits. Participants with gingivitis demonstrated significantly higher bleeding on probing (BOP), plaque index (PI), and gingival index (GI) (P ≤ 0.002) and a significant drop in BOP, PI, and GI post-treatment (P ≤ 0.001). Concentrations of MIP-1α and PGE2 were significantly higher (2.8 times) in the gingivitis group than the healthy group (P ≤ 0.02). After dental prophylaxis, mean biomarker concentrations did not decrease significantly from baseline in the gingivitis group, although concentrations of IL-1β, IL-6, and MMP-8 approached healthy levels, whereas MIP-1α and PGE2 concentrations remained significantly higher than in the healthy group (P ≤ 0.04). Odds ratio analyses showed that PGE2 concentrations, alone and in combination with MIP-1α, readily discriminated gingivitis from health. Conclusions Salivary PGE2 and MIP-1α discriminate gingivitis from health, and patients with gingivitis who return to clinical health continue to produce inflammatory mediators for weeks after dental prophylaxis.

We tested whether the heritability of heart rate variability (HRV) under stress is different from rest and its dependency on ethnicity or gender. HRV indexed by root mean square of successive differences (RMSSD) and high-frequency (HF) power was measured at rest and during 3 stressors in 427 European and 308 African American twins. No ethnic or gender differences were found for any measures. There was a nonsignificant increase in heritability of RMSSD (from 0.48 to 0.58) and HF (from 0.50 to 0.58) under stress. Up to 81% and 60% of the heritabilities of RMSSD and HF under stress could be attributed to genes influencing rest levels. The heritabilities due to genes expressed under stress were 0.11 for RMSSD and 0.23 for HF. The findings suggest that, independent of ethnicity and gender, HRV regulation at rest and under stress is largely influenced by the same genes with a small but significant contribution of stress-specific genetic effects.

No abstract

Objective The purpose of this study was to examine the timing of diagnostic and therapeutic services in cochlear implant recipients from a rural Appalachian region with healthcare disparity. Study design Retrospective analysis Methods Cochlear implant recipients from a tertiary referral center born with severe congenital sensorineural hearing loss were examined. Rural status and Appalachian status of their county of origin were recorded. A log-rank test was used to examine differences in the distributions of time to definitive diagnosis of hearing loss, initial amplification fitting, and cochlear implantation in these children. Correlation analysis of the rural status of each county and the timing of services was assessed. Results 53 children born with congenital hearing loss were included in the study (36 from rural counties and 17 from urban/suburban counties). The distribution of weeks after birth to diagnosis (p=0.006), amplification (p=0.030), and cochlear implantation (p=0.002) was delayed in rural children compared with urban children. An analysis factoring in the effect of implementation of mandatory infant hearing screening in 2000 demonstrated a similar delay in rural children for weeks to diagnosis (p=0.028), amplification (0.087) and cochlear implantation (p<0.0001). Conclusions Children with severe hearing loss in very rural areas, such as Appalachia, may have significant delays in diagnostic and rehabilitative services. Further investigation is warranted to assess causative factors in delays of cochlear implantation and to develop interventions to promote timely diagnosis and care.

Objective To examine whether the genetic influences on blood pressure (BP) during night-time are different from those during daytime and the extent to which they depend on ethnicity or sex. Methods Ambulatory BP was measured in 240 European–American and 190 African–American twins (mean ± SD age, 17.2 ± 3.4). Individuals with night-time BP falls more than 10% of the daytime values were defined as dippers. A bivariate analysis of the daytime and the night-time BP levels, as well as a liability-threshold model of dippers vs. nondippers were used. Results Bivariate model fitting showed no ethnic or sex differences for any of the measures, with heritabilities of 0.70 and 0.68 for SBP and 0.70 and 0.64 for DBP at daytime and at night-time. The genetic influences on daytime and night-time were not significantly different for SBP or DBP. The bivariate analysis also indicated that about 56 and 33% of the heritabilities of night-time SBP and DBP could be attributed to genes that also influenced daytime levels. The specific heritabilities due to genetic effects only influencing night-time values were 0.30 for SBP and 0.43 for DBP. The heritabilities of systolic and diastolic dipping were 0.59 and 0.81, respectively. Conclusion Independent of ethnicity and sex, an overlap exists between genes that influence daytime and night-time BP, as well as a significant genetic component that is specific to the night-time BP. These findings suggest that different genes or sets of genes contribute to BP regulation at daytime and night-time.