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Scholarly Works (38 results)

  • Thesis
  • Peer Reviewed
UC San Diego Electronic Theses and Dissertations (2017)

Background: Sedentary behavior has been associated with increased risk of diabetes and cardiovascular disease (CVD), but most studies rely on self-reported sedentary behavior measures, which are inaccurate. Furthermore, there is little evidence on these associations in adults over 80 years. The way sedentary time is accumulated (i.e., sedentary accumulation patterns) has shown acute effects on glucose and lipid metabolism in laboratory studies, but little evidence exists on how accumulation patterns relate to diabetes risk factors among adults and there are no previous studies on how accumulation patterns are related to diabetes risk in older adults.

Methods: This dissertation is composed of four separate studies. Data for Chapters 2 through 4 were from the Objective Physical Activity and Cardiovascular Health Study (OPACH), a cohort of older women (n=6489; average age = 79±7) that wore ActiGraph GT3X+ accelerometers around their hip for up to 7 days between 2012-2014 and were followed for incident CVD and diabetes through September 30, 2016. Data for Chapter 5 were from the 2011-2012 wave of the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab), a national, population-based cohort (n=739; average age 58±10 years) established to study the distribution and determinants of diabetes.

Results: Chapter 2 results suggest that women in the highest (≥ ~11 hr/day) quartile of sedentary time had higher risk for CVD events (hazard ratio (HR)=1.44; 95% confidence intervals (CI)=1.05-1.98) and coronary heart disease (CHD) events (HR=2.19; 95% CI=1.09-4.40) than women in the lowest quartile of sedentary time (≤ ~9 hr/day) with a linear dose-response relation (P-linear<.05; P-nonlinear>.05 | all). Results from Chapters 3 and 4 reveal that women in the highest quartile of sedentary time had higher odds of prevalent diabetes (odds ratio (OR) = 1.96; CI, 1.59-2.42) than women in the lowest quartile, after adjustment for covariates. Those that accumulated sedentary time with the most prolonged accumulation patterns (i.e., many long bouts of sedentary time with few short bouts and few interruptions) had higher odds of prevalent diabetes than women with the most interrupted patterns, though the ORs were weaker than for total sedentary time. Due to non-proportional hazards by family history of diabetes (FH+/-), models of diabetes incidence were stratified by FH. FH+ women in the highest quartile of sedentary time had higher risk for diabetes (HR=2.38; 95% CI=1.05-1.98) than women in the lowest quartile. Women with the most prolonged sedentary accumulation patterns had higher risk for new-onset diabetes (HR=2.32; 95% CI=1.15-4.71) than women with the most interrupted patterns. No significant associations were observed for FH- women. Results from Chapter 5 indicate that accumulation patterns of frequently interrupted sitting (compared to patterns with relatively more prolonged sitting) were significantly beneficially associated with BMI, waist circumference, HDL cholesterol, triglycerides, 2-hour post-load plasma glucose levels (PLG), and fasting plasma glucose levels. Significant interactions (p<0.05) showed that associations of sitting time with HDL, triglycerides and PLG became more deleterious with longer usual bout durations indicating a joint relationship between sedentary behavior and sedentary accumulation patterns.

Conclusion: High levels of sedentary time were associated with increased risk for CVD and diabetes in older women. Furthermore, prolonged sedentary accumulation patterns were associated with increased diabetes risk in older FH+ women and were deleteriously associated with several cardio-metabolic biomarkers in Australian adults. Accumulation patterns interacting with total sitting time in relations with key diabetes-related biomarkers (PLG, HDL, and triglycerides) provides further evidence that the way in which sedentary time is accumulated may be a relevant factor in diabetes etiology, in addition to the total amount of time sedentary.

    Cover page: Sedentary behavior and risk for cardiovascular disease and diabetes
    • Article
    • Peer Reviewed
    UC Berkeley Previously Published Works (2017)

    Objectives

    Preventive health services are important for child development, and parents play a key role in facilitating access to services. This study examined how parents' reasons for not having a usual source of care were associated with their children's receipt of preventive services.

    Methods

    We used pooled data from the 2011-2014 National Health Interview Survey (n = 34 843 participants). Parents' reasons for not having a usual source of care were framed within the Penchansky and Thomas model of access and measured through 3 dichotomous indicators: financial barriers (affordability), attitudes and beliefs about health care (acceptability), and all other nonfinancial barriers (accessibility, accommodation, and availability). We used multivariable logistic regression models to test associations between parental barriers and children's receipt of past-year well-child care visits and influenza vaccinations, controlling for other child, family, and contextual factors.

    Results

    In 2014, 14.3% (weighted percentage) of children had at least 1 parent without a usual source of care. Children of parents without a usual source of care because they "don't need a doctor and/or haven't had any problems" or they "don't like, trust, or believe in doctors" had 35% lower odds of receiving well-child care (adjusted odds ratio = 0.65; 95% CI, 0.56-0.74) and 23% lower odds of receiving influenza vaccination (adjusted odds ratio = 0.77; 95% CI, 0.69-0.86) than children of parents without those attitudes and beliefs about health care. Financial and other nonfinancial parental barriers were not associated with children's receipt of preventive services. Results were independent of several factors relevant to children's access to preventive health care, including whether the child had a usual source of care.

    Conclusions

    Parents' attitudes and beliefs about having a usual source of care were strongly associated with their children's receipt of recommended preventive health services. Rates of receipt of child preventive services may be improved by addressing parents' attitudes and beliefs about having a usual source of care. Future studies should assess causes of these associations.
      Cover page: Association Between Parental Barriers to Accessing a Usual Source of Care and Children’s Receipt of Preventive Services
      • Article
      • Peer Reviewed
      Research Grants Program Office (RGPO) Funded Publications (2016)

      Introduction

      Thirdhand smoke (THS) residue results from secondhand smoke, and is emerging as a distinct public health hazard, particularly for medically fragile pediatric patients living with smokers. THS is difficult to remove and readily reacts with other pollutants to form carcinogens and ultrafine particles. This study investigated THS found in homes of high-risk infants admitted to a neonatal intensive care unit and their association with characteristics (eg, number of household smokers) hypothesized to influence THS.

      Methods

      Baseline data from 141 hospitalized infants' homes were analyzed, along with follow-up data (n = 22) to explore household smoking characteristics and THS changes in response to indoor smoking ban policies.

      Results

      Households with an indoor ban, in which not more than 10 cigarettes/d were smoked, had the lowest levels of THS contamination compared to homes with no ban (P < .001) and compared to homes with an indoor ban in which greater numbers of cigarettes were smoked (P < .001). Importantly, homes with an indoor ban in which at least 11 cigarettes/d were smoked were not different from homes without a ban. The follow-up sample of 22 homes provided initial evidence indicating that, unless a ban was implemented, THS levels in homes continued to increase over time.

      Conclusions

      Preliminary longitudinal data suggest that THS may continue to accumulate in homes over time and household smoking bans may be protective. However, for homes with high occupant smoking levels, banning indoor smoking may not be fully adequate to protect children from THS. Unless smoking is reduced and bans are implemented, medically fragile children will be exposed to the dangers of THS.
        Cover page: Thirdhand Smoke in the Homes of Medically Fragile Children: Assessing the Impact of Indoor Smoking Levels and Smoking Bans
        • Article
        • Peer Reviewed
        UC San Francisco Previously Published Works (2017)
        Tobacco smoking and exposure to tobacco secondhand smoke (SHS) can cause lung cancer. We determined uptake of NNK (4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone), a tobacco specific potent pulmonary carcinogen, in hookah smokers and non-smokers exposed to hookah tobacco SHS. We analyzed data from a community-based convenience sample of 201 of adult (aged ≥18 years) exclusive hookah smokers (n = 99) and non-smokers (n = 102) residing in San Diego County, California. Participants spent an average of three consecutive hours indoors, in hookah lounges or private homes, where hookah tobacco was smoked exclusively. Total NNAL [the sum of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronides], the major metabolites of NNK, were quantified in spot urine samples provided the morning of and the morning after attending a hookah event. Among hookah smokers urinary NNAL increased significantly (p<0.001) following a hookah social event; the geometric mean doubled, from 1.97 to 4.16 pg/mg. Among non-smokers the increase was not significant (p = 0.059). Post hookah event urinary NNAL levels were highest in daily hookah smokers, and significantly higher than in non-daily smokers or non-smokers (GM: 14.96 pg/mg vs. 3.13 pg/mg and 0.67 pg/mg, respectively). For both hookah smokers and non-smokers, pre-to-post event change in urinary NNAL was not significantly different between hookah lounges and homes. We suggest posting health warning signs inside hookah lounges, and encouraging voluntary bans of smoking hookah tobacco in private homes.
          Creative Commons 'BY-NC-SA' version 4.0 license
          • Article
          • Peer Reviewed
          Research Grants Program Office (RGPO) Funded Publications (2016)
          BACKGROUND:Over a 6-month period, we examined tobacco smoke pollutants (also known as thirdhand smoke, THS) that remained in the homes of former smokers and the exposure to these pollutants. METHODS:90 smokers completed study measures at baseline (BL). Measures were repeated among verified quitters 1 week (W1), 1 month (M1), 3 months (M3) and 6 months (M6) following cessation. Measures were analysed for THS pollutants on household surfaces, fingers and in dust (ie, nicotine, tobacco-specific nitrosamines) and for urinary markers of exposure (ie, cotinine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL)). RESULTS:We observed significant short-term reduction of nicotine on surfaces (BL: 22.2 μg/m2, W1: 10.8 μg/m2) and on fingers of non-smoking residents (BL: 29.1 ng/wipe, W1: 9.1 ng/wipe) without further significant changes. Concentrations of nicotine and nicotine-derived nitrosamine ketone (NNK) in dust did not change and remained near BL levels after cessation. Dust nicotine and NNK loadings significantly increased immediately following cessation (nicotine BL: 5.0 μg/m2, W1: 9.3 μg/m2; NNK BL: 11.6 ng/m2, W1: 36.3 ng/m2) before returning to and remaining at near BL levels. Cotinine and NNAL showed significant initial declines (cotinine BL: 4.6 ng/mL, W1: 1.3 ng/mL; NNAL BL: 10.0 pg/mL, W1: 4.2 pg/mL) without further significant changes. CONCLUSIONS:Homes of smokers remained polluted with THS for up to 6 months after cessation. Residents continued to be exposed to THS toxicants that accumulated in settled house dust and on surfaces before smoking cessation. Further research is needed to better understand the consequences of continued THS exposure after cessation and the efforts necessary to remove THS.
            • Article
            • Peer Reviewed
            Research Grants Program Office (RGPO) Funded Publications (2016)
            BACKGROUND:Over a 6-month period, we examined tobacco smoke pollutants (also known as thirdhand smoke, THS) that remained in the homes of former smokers and the exposure to these pollutants. METHODS:90 smokers completed study measures at baseline (BL). Measures were repeated among verified quitters 1 week (W1), 1 month (M1), 3 months (M3) and 6 months (M6) following cessation. Measures were analysed for THS pollutants on household surfaces, fingers and in dust (ie, nicotine, tobacco-specific nitrosamines) and for urinary markers of exposure (ie, cotinine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL)). RESULTS:We observed significant short-term reduction of nicotine on surfaces (BL: 22.2 μg/m2, W1: 10.8 μg/m2) and on fingers of non-smoking residents (BL: 29.1 ng/wipe, W1: 9.1 ng/wipe) without further significant changes. Concentrations of nicotine and nicotine-derived nitrosamine ketone (NNK) in dust did not change and remained near BL levels after cessation. Dust nicotine and NNK loadings significantly increased immediately following cessation (nicotine BL: 5.0 μg/m2, W1: 9.3 μg/m2; NNK BL: 11.6 ng/m2, W1: 36.3 ng/m2) before returning to and remaining at near BL levels. Cotinine and NNAL showed significant initial declines (cotinine BL: 4.6 ng/mL, W1: 1.3 ng/mL; NNAL BL: 10.0 pg/mL, W1: 4.2 pg/mL) without further significant changes. CONCLUSIONS:Homes of smokers remained polluted with THS for up to 6 months after cessation. Residents continued to be exposed to THS toxicants that accumulated in settled house dust and on surfaces before smoking cessation. Further research is needed to better understand the consequences of continued THS exposure after cessation and the efforts necessary to remove THS.
              • Article
              • Peer Reviewed
              Research Grants Program Office (RGPO) Funded Publications (2019)
              Exposure assessment in children, especially young children, presents difficulties not found with adults. Simple silicone wristbands are passive samplers that have potential applicability in exposure studies of children. We investigated the performance of silicone wristbands as personal nicotine samplers in two wristbands worn by a child (n = 31) for 7 days and for 2 days (worn day 5 to day 7). We compared levels of nicotine in wristbands with urinary cotinine, a metabolite of nicotine, measured in the child's urine obtained on day 7. Children were recruited who were exposed to contaminants in tobacco smoke and/or vapor from electronic nicotine delivery systems (ENDS; commonly known as electronic cigarettes or EC) as well as children who lived in nonsmoking homes. Caregivers were interviewed to obtain reported measures of the child's exposure. Analysis was by liquid chromatography with triple quadrupole mass spectrometry and isotope dilution (LC-MS/MS). The nicotine detected in the wristbands worn for 2 days was highly correlated with urinary cotinine concentration (df = 29, r2 = 0.741, p < 0.001), as was nicotine in wristbands worn for 7 days (df = 28, r2 = 0.804, p < 0.001). The 2- and 7-day wristband nicotine amounts were also significantly correlated (df = 28, r2 = 0.852, p < 0.001). Silicone wristbands may be a useful tool for epidemiological and intervention studies of tobacco product exposure in children.
                Cover page: Nicotine levels in silicone wristband samplers worn by children exposed to secondhand smoke and electronic cigarette vapor are highly correlated with child’s urinary cotinine
                • Article
                • Peer Reviewed
                Research Grants Program Office (RGPO) Funded Publications (2017)
                Children are at risk for adverse health outcomes from occupant-controllable indoor airborne contaminants in their homes. Data are needed to design residential interventions for reducing low-income children's pollutant exposure. Using customized air quality monitors, we continuously measured fine particle counts (0.5 to 2.5 microns) over a week in living areas of predominantly low-income households in San Diego, California, with at least one child (under age 14) and at least one cigarette smoker. We performed retrospective interviews on home characteristics, and particle source and ventilation activities occurring during the week of monitoring. We explored the relationship between weekly mean particle counts and interview responses using graphical visualization and multivariable linear regression (base sample n = 262; complete cases n = 193). We found associations of higher weekly mean particle counts with reports of indoor smoking of cigarettes or marijuana, as well as with frying food, using candles or incense, and house cleaning. Lower particle levels were associated with larger homes. We did not observe an association between lower mean particle counts and reports of opening windows, using kitchen exhaust fans, or other ventilation activities. Our findings about sources of fine airborne particles and their mitigation can inform future studies that investigate more effective feedback on residential indoor-air-quality and better strategies for reducing occupant exposures.
                  Cover page: Fine particles in homes of predominantly low-income families with children and smokers: Key physical and behavioral determinants to inform indoor-air-quality interventionsCreative Commons 'BY-ND' version 4.0 license
                  • Article
                  • Peer Reviewed
                  Research Grants Program Office (RGPO) Funded Publications (2016)
                  BACKGROUND:Over a 6-month period, we examined tobacco smoke pollutants (also known as thirdhand smoke, THS) that remained in the homes of former smokers and the exposure to these pollutants. METHODS:90 smokers completed study measures at baseline (BL). Measures were repeated among verified quitters 1 week (W1), 1 month (M1), 3 months (M3) and 6 months (M6) following cessation. Measures were analysed for THS pollutants on household surfaces, fingers and in dust (ie, nicotine, tobacco-specific nitrosamines) and for urinary markers of exposure (ie, cotinine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL)). RESULTS:We observed significant short-term reduction of nicotine on surfaces (BL: 22.2 μg/m2, W1: 10.8 μg/m2) and on fingers of non-smoking residents (BL: 29.1 ng/wipe, W1: 9.1 ng/wipe) without further significant changes. Concentrations of nicotine and nicotine-derived nitrosamine ketone (NNK) in dust did not change and remained near BL levels after cessation. Dust nicotine and NNK loadings significantly increased immediately following cessation (nicotine BL: 5.0 μg/m2, W1: 9.3 μg/m2; NNK BL: 11.6 ng/m2, W1: 36.3 ng/m2) before returning to and remaining at near BL levels. Cotinine and NNAL showed significant initial declines (cotinine BL: 4.6 ng/mL, W1: 1.3 ng/mL; NNAL BL: 10.0 pg/mL, W1: 4.2 pg/mL) without further significant changes. CONCLUSIONS:Homes of smokers remained polluted with THS for up to 6 months after cessation. Residents continued to be exposed to THS toxicants that accumulated in settled house dust and on surfaces before smoking cessation. Further research is needed to better understand the consequences of continued THS exposure after cessation and the efforts necessary to remove THS.
                    • Article
                    • Peer Reviewed
                    Research Grants Program Office (RGPO) Funded Publications (2022)

                    Objective

                    Tobacco residue, also known as third-hand smoke (THS), contains toxicants and lingers in dust and on surfaces and clothes. THS also remains on hands of individuals who smoke, with potential transfer to infants during visitation while infants are hospitalized in neonatal intensive care units (NICUs), raising concerns (e.g., hindered respiratory development) for vulnerable infants. Previously unexplored, this study tested handwashing (HW) and sanitization efficacy for finger-nicotine removal in a sample of adults who smoked and were visiting infants in an NICU.

                    Study design

                    A cross-sectional sample was recruited to complete an interview, carbon monoxide breath samples, and three nicotine wipes of separate fingers (thumb, index, and middle). Eligible participants (n = 14) reported current smoking (verified with breath samples) and were randomly assigned to 30 seconds of HW (n = 7) or alcohol-based sanitization (n = 7), with the order of finger wipes both counterbalanced and randomly assigned. After randomization, the first finger was wiped for nicotine. Participants then washed or sanitized their hands and finger two was wiped 5 minutes later. An interview assessing tobacco/nicotine use and exposure was then administered, followed by a second breath sample and the final finger wipe (40-60 minutes after washing/sanitizing).

                    Results

                    Generalized linear mixed models found that HW was more effective than sanitizer for nicotine removal but failed to completely remove nicotine.

                    Conclusions

                    Without proper protections (e.g., wearing gloves and gowns), NICU visitors who smoke may inadvertently expose infants to THS. Research on cleaning protocols are needed to protect vulnerable medical populations from THS and associated risks.

                    Key points

                    · NICU infants may be exposed to THS via visitors.. · THS is not eliminated by HW or sanitizing.. · THS removal protections for NICU infants are needed..
                      Cover page: Handwashing Results in Incomplete Nicotine Removal from Fingers of Individuals who Smoke: A Randomized Controlled Experiment
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