Skip to main content
eScholarship
Open Access Publications from the University of California

Scholarly Works (6 results)

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

Immigrants in the United States make up 13% of the total population and have been a critical component in the country’s population growth. Previous studies have shown that immigrants tend to perform better in overall mortality and other health conditions, a phenomenon commonly known as the healthy immigrant effect. However, the growing literature on immigrant health has been primarily cross-sectional. A longitudinal perspective is needed, particularly since age of immigration or duration of stay in the receiving country can influence risk factors for adverse health conditions. Mexico is the most common country of origin for immigrants, and Hispanic adults carry significant cardiovascular burden due to their high levels of cardiovascular risk factors.

This dissertation focuses on two particular risk factors: low density lipoprotein cholesterol (LDL-C) and blood pressure, which are both strongly associated with myocardial infarction (MI) and stroke. In the first two chapters, a variable for immigration history is used and incorporates both nativity and age of immigration. The first chapter examines the role of immigration history on longitudinal changes in elevated LDL-C. The second chapter evaluates how immigration history affects trajectories of systolic blood pressure over time. Analyses also examine the associations between immigration history, LDL-C, and systolic blood pressure with MI/stroke. Chapter 3 extends the work of Chapter 2 by assessing the differences by nativity status in systolic and diastolic blood pressure trajectories before and after MI/stroke.

Analyses used data from the Sacramento Area Latino Study on Aging, a cohort study of community-dwelling older adults of Mexican-origin. Mixed effects and Cox proportional hazards models were used to address the research questions. Results indicate that participants born outside the United States and immigrated in later adulthood (i.e. after age 20) had poorer cardiovascular risk factors over time: they were more likely to have elevated LDL-C and had a faster rate of increase in systolic blood pressure. While risk of incident MI/stroke did not differ between each group of immigration history, there were nativity-related differences in blood pressure trajectories before and after MI/stroke. These results provide evidence to reevaluate previous perspectives on immigrant health and the healthy immigrant effect.

    Cover page: Nativity, Immigration, and Cardiovascular Health in Older Mexican-origin Adults
    • Article
    • Peer Reviewed
    UC San Francisco Previously Published Works (2016)

    Objectives

    To determine whether diabetes mellitus increases depressive symptoms in older Latinos in a population-based cohort.

    Design

    Prospective cohort study.

    Participants

    Individuals from the Sacramento Latino Study on Aging aged 60 and older in 1998-99 and followed annually until 2008 (N = 1,586).

    Measurements

    Diabetes mellitus was defined according to self-report, fasting blood glucose of 126 mg/dL or greater, glycosylated hemoglobin of 6.5% or greater, or diabetic medication use. Depressive symptoms were defined as Center for Epidemiologic Studies Depression Scale (CES-D) score of 16 or greater or use of antidepressant medication. Multistate Markov modeling was used to assess the effects of time-dependent diabetes mellitus on transitions between three states over time: low CES-D score (normal), high CES-D score or treated (depressed), and death. Bivariate analyses identified covariates significantly associated with any transition, including sex and baseline measures of age, education, body mass index, hypertension, and stroke.

    Results

    In a fully adjusted model, participants with diabetes mellitus had a 35% higher rate of developing depressive symptoms or starting treatment with an antidepressant (hazard ratio (HR) = 1.35, 95% confidence interval (CI) = 1.13-1.62). Time-dependent diabetes mellitus was associated with a lower rate of regression from depressed to normal (HR = 0.72, 95% CI = 0.59-0.88) and a 2.3 greater rate pf progression from depressed to death (HR = 2.31, 95% CI = 1.57-3.40).

    Conclusion

    Diabetes mellitus increased the risk of developing depressive symptoms in older Mexican Americans. Older Latinos with diabetes mellitus should be screened for depressive symptoms and prioritized for close follow-up, potentially through greater reliance on team-based models of care.
      Cover page: Diabetes Mellitus as a Risk Factor for Development of Depressive Symptoms in a Population‐Based Cohort of Older Mexican Americans
      • Article
      • Peer Reviewed
      UC San Francisco Previously Published Works (2018)
      Even after migration, immigrants and their descendants may continue to have ties to family and friends who remain in places of origin. Recent research suggests that these cross-border social ties have implications for health, although this scholarship has been limited to self-reported outcomes. Using data from the Sacramento Area Latino Study on Aging (SALSA), we estimate associations between cross-border social ties and inflammatory biomarkers among Latino adults (n = 1786). We find that immigrants who maintained any cross-border connection to family and friends in Latin America had significantly lower levels of baseline interleukin-6 (IL-6) and C-reactive protein (CRP) compared to their US-born counterparts with no cross-border ties. These results held for values of CRP at five-year follow-up for men only. In contrast, US-born women with cross-border ties to family and friends in Latin America had both significantly higher levels of CRP and significantly lower levels of tumor necrosis factor-alpha (TNF-α) at five-year follow-up relative to their US-born counterparts with no cross-border ties. We find descriptively that men who have cross-border ties are also less likely to be socially isolated within local contexts. Considering place-of-origin social connections may contribute critical nuance to studies of immigrant health, including disparities in inflammatory markers that may serve as indicators of underlying chronic disease.
        Cover page: Cross-border ties, nativity, and inflammatory markers in a population-based prospective study of Latino adults
        • Article
        • Peer Reviewed
        UC San Francisco Previously Published Works (2016)

        Background

        Comorbidity (COM) is an important issue in aging. Cardiovascular disease (CVD) and osteoarthritis separately and together may modify the trajectories of functional decline. This analysis examines whether specific and unrelated COMs influence functional change differently and vary by gender.

        Methods

        A cohort study of 1,789 (aged 60 years and older) Mexican Americans was followed annually for up to 10 years. We created four groups of COM (CVD alone, lower body osteoarthritis alone [OA], neither, or both). We employed mixed effects Poisson models with Instrumental Activities of Daily Living (IADL) as the outcome. We tested whether the association between COM and decline in functional status differed by gender.

        Results

        IADL impairments in those with CVD, OA, or both were significantly higher at baseline and increased more rapidly over time compared to those with neither condition. Compared to women with no COM, the number of IADL impairments in women with CVD alone were 1.36 times greater, with OA were 1.35 times greater, and both conditions were 1.26 times greater. Compared to men with no COM, IADL impairments in men with CVD alone were 1.15 times greater, OA alone were 1.12 times greater, and both were 1.26 times greater.

        Conclusions

        Over time, the influence of COM on functional decline differs by specific combinations of COM and by gender. Aggregate COM scales obscure the biological and temporal heterogeneity in the effects of COM. Time-dependent-specific COMs better assess the development of impairment. Women experience a higher burden of functional impairment due to COM than men.
          Cover page: Gender Differences in the Combined Effects of Cardiovascular Disease and Osteoarthritis on Progression to Functional Impairment in Older Mexican Americans
          • Article
          • Peer Reviewed
          UC San Francisco Previously Published Works (2016)

          Purpose

          Low educational attainment has been associated with depression among Latinos. However, few studies have collected intergenerational data to assess mental health effects of educational mobility across generations.

          Methods

          Using data from the Niños Lifestyle and Diabetes Study, we assessed the influence of intergenerational education on depressive symptoms among 603 Mexican-origin individuals. Intergenerational educational mobility was classified: stable-low (low parent and/or low offspring education), upwardly mobile (low parent and/or high offspring education), stable-high (high parent and/or high offspring education), or downwardly mobile (high parent and/or low offspring education). High depressive symptoms were defined as scoring ≥10 on the Center for Epidemiological Studies Depression Scale-10 (CESD-10). We examined prevalence ratios (PRs) for depressive symptoms with levels of educational mobility. We used general estimating equations with log-binomial models to account for within-family clustering, adjusting for age, gender, and offspring and parent nativity.

          Results

          Compared with stable-low participants, the lowest prevalence of CESD-10 score ≥10 occurred in upwardly mobile (PR = 0.55; 95% confidence interval [CI] = 0.39-0.78) and stable-high (PR = 0.62; 95% CI = 0.44-0.87) participants. Downwardly mobile participants were also less likely to have a CESD-10 score ≥10 compared with stable-low participants (PR = 0.65; 95% CI = 0.38-1.11), although the estimate was not statistically significant.

          Conclusions

          Sustained stress from low intergenerational education may adversely affect depression. Latinos with stable-low or downwardly mobile intergenerational educational attainment may need closer monitoring for depressive symptoms.
            Cover page: Intergenerational education mobility and depressive symptoms in a population of Mexican origin
            • Article
            • Peer Reviewed
            UCLA Previously Published Works (2018)

            Background

            Cognitive impairment is a major health concern among older Mexican Americans, associated with significant morbidity and mortality, and may be influenced by environmental exposures.

            Objectives

            To investigate whether agricultural based ambient organophosphorus (OP) exposure influences 1) the rate of cognitive decline and mortality and 2) whether these associations are mediated through metabolic or inflammatory biomarkers.

            Methods

            In a subset of older Mexican Americans from the Sacramento Area Latino Study on Aging (n = 430), who completed modified mini-mental state exams (3MSE) up to 7 times (1998-2007), we examined the relationship between estimated ambient OP exposures and cognitive decline (linear repeated measures model) and time to dementia or being cognitively impaired but not demented (CIND) and time to mortality (cox proportional hazards model). We then explored metabolic and inflammatory biomarkers as potential mediators of these relationships (additive hazards mediation). OP exposures at residential addresses were estimated with a geographic information system (GIS) based exposure assessment tool.

            Results

            Participants with high OP exposure in the five years prior to baseline experienced faster cognitive decline (β = 0.038, p = 0.02) and higher mortality over follow-up (HR = 1.91, 95% CI = 1.12, 3.26). The direct effect of OP exposure was estimated at 241 (95% CI = 27-455) additional deaths per 100,000 person-years, and the proportion mediated through the metabolic hormone adiponectin was estimated to be 4% 1.5-19.2). No other biomarkers were associated with OP exposure.

            Conclusions

            Our study provides support for the involvement of OP pesticides in cognitive decline and mortality among older Mexican Americans, possibly through biologic pathways involving adiponectin.
              Cover page: Cognitive decline, mortality, and organophosphorus exposure in aging Mexican Americans
              Top