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Scholarly Works (356 results)

  • Article
  • Peer Reviewed
UC San Diego Previously Published Works (2018)

Objective

This study examined the associations between abdominal IMAT area and density with inflammatory markers associated with cardiometabolic disease.

Methods

1897 participants enrolled in the Multi-Ethnic Study of Atherosclerosis underwent computed tomography to quantify body composition and measurements of adiponectin, leptin, interleukin-6 (IL-6), C-reactive protein (CRP), and resistin.

Results

The mean age and body mass index of participants was 65years and 28kg/m2, respectively, and 50% were female. After adjustment for age, sex, and race/ethnicity, as IMAT area increased and density decreased from the first to fourth quartile, markers of inflammation increased linearly (p<0.01). Using linear regression, and with adjustment for demographics, cardiovascular disease risk factors, and abdominal muscle area and density, a 1-standard deviation (SD) increase in total abdominal IMAT area was associated with a 21%, 36% and 20% higher IL-6, leptin, and CRP, respectively, and 19% lower adiponectin (p<0.001). With similar adjustment, a 1-SD decrease in total abdominal IMAT density was associated with a 14%, 32%, and 15% higher IL-6, leptin, and CRP, respectively, and 22% lower adiponectin (p<0.001). These associations were attenuated with the addition of visceral fat (p>0.05).

Conclusions

Abdominal IMAT area and density are associated with inflammatory markers, with these associations attenuated by central adiposity.
    Cover page: Associations of abdominal intermuscular adipose tissue and inflammation: The Multi-Ethnic Study of Atherosclerosis
    • Thesis
    • Peer Reviewed
    UC San Diego Electronic Theses and Dissertations (2020)

    Background: Cardiovascular disease (CVD) is the leading cause of mortality among US women. CVD risk factors emerge well before onset of clinical disease, requiring a life course approach to prevention. Women of reproductive age are a targeted demographic due to growing burden of CVD risk in this group, and because poor preconception cardiovascular health may cause worse pregnancy outcomes. Few studies have evaluated associations between prospectively measured preconception cardiometabolic risk factors and birth outcomes. Methods: This dissertation includes three studies. Study 1 leverages data from the National Health and Nutrition Examination Surveys administered between 1988 and 2016 to describe trends in the burden of metabolic syndrome-- a clustering of CVD risk factors---among US women ages 18 to 44. Studies 2 and 3 use data from Add Health, a cohort study that recruited and followed US adolescents through adulthood, to evaluate effects of preconception blood pressure (Study 2) and preconception glycemia (Study 3) on two birth outcomes: preterm birth and birthweight. Study 3 additionally examines healthcare and racial and ethnic disparities in preconception hyperglycemia and preterm birth. Results: The prevalence of metabolic syndrome among US women ages 18-44 increased between 1988-94 (14%) and 1999-2004 (21%) and has since plateaued. The prevalence of two metabolic syndrome components, elevated waist circumference and elevated fasting glucose, have increased dramatically with persistent disparities by race/ethnicity (Study 1). Higher preconception blood pressure and higher preconception glycemia were associated with increased risk of preterm birth, even at levels below clinical cutoffs for hypertension and diabetes (Study 2, 3). Women with limited access and utilization of healthcare experienced a disproportionate burden of preconception hyperglycemia and preterm birth (Study 3). Conclusions: The proportion of women entering pregnancy with existing cardiometabolic risk factors like hypertension and diabetes is rising. Interventions to optimize maternal health prior to pregnancy, and to better manage these conditions during pregnancy, could greatly improve health outcomes for women and children.

      Cover page: Preconception Cardiometabolic Health and Risk of Adverse Birth Outcomes among US Women
      • Article
      • Peer Reviewed
      UC San Diego Previously Published Works (2021)
      The role of ectopic adipose tissue infiltration into skeletal muscle (i.e., myosteatosis) for metabolic disorders has received considerable and increasing attention in the last 10 years. The purpose of this review was to evaluate and summarize existing studies focusing on computed tomography (CT)-derived measures of myosteatosis and metabolic disorders. There is consistent evidence that CT-derived myosteatosis contributes to dysglycemia, insulin resistance, type 2 diabetes mellitus, and inflammation, and, to some extent, dyslipidemia, independent of general obesity, visceral fat, and other relevant risk factors, suggesting that it may serve as a tool for metabolic risk prediction. Identification of which muscles should be examined, and the standardized CT protocols to be employed, are necessary to enhance the applicability of findings from epidemiologic studies of myosteatosis. Additional and longer longitudinal studies are necessary to confirm a role of myosteatosis in the development of type 2 diabetes mellitus, and examine these associations in a variety of muscles across multiple race/ethnic populations. Given the emerging role of myosteatosis in metabolic health, well-designed intervention studies are needed to investigate relevant lifestyle and pharmaceutical approaches.
        Cover page: Computed Tomography-Derived Myosteatosis and Metabolic Disorders
        • Article
        • Peer Reviewed
        UC San Diego Previously Published Works (2018)
        BACKGROUND AND AIMS:Renal artery calcium (RAC) has been linked to several cardiovascular disease (CVD) risk factors, including age, male gender, and hypertension. The purpose of this study was to determine whether anthropometric measures of obesity are associated with presence of RAC. METHODS:We studied 1287 community-dwelling adults enrolled in the Multi-Ethnic Study of Atherosclerosis. Logistic regression models adjusted for CVD risk factors were used to examine body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR) as primary predictors of RAC. RESULTS:Study participants had a mean age of 67.7 years, 55.7% were female, and 36.8% were non-Hispanic White. Prevalence of RAC was 33.3%. WC and WHR as continuous variables were not significant with adjustment. Subjects with high WC, as defined by World Health Organization cut-offs, had significantly higher odds for RAC in the fully adjusted model. BMI and HC were not significantly associated with RAC in any models. CONCLUSIONS:In this community-based sample of older adults, higher levels of WC are significantly associated with RAC independently of CVD risk factors. Adults who meet World Health Organization criteria for high WC may be at higher risk for complications of calcified atherosclerosis in the renal arteries.
          Cover page: Anthropometric measures of obesity and renal artery calcification: Results from the Multi-Ethnic Study of Atherosclerosis
          • Article
          • Peer Reviewed
          UC San Diego Previously Published Works (2018)

          Objective

          This study examined the associations of muscle area and radiodensity with adiponectin and leptin.

          Methods

          A total of 1,944 participants who enrolled in the Multi-Ethnic Study of Atherosclerosis underwent computed tomography to quantify body composition and measurements of adiponectin, leptin, interleukin-6, C-reactive protein, and resistin.

          Results

          The mean age and BMI of participants were 64.7 years and 28.1 kg/m2 and 49% were female. With adjustment for age, gender, race/ethnicity, traditional cardiovascular disease risk factors, inflammatory biomarkers, physical activity, and sedentary behavior, a 1-SD increment in total abdominal, stability, and locomotor muscle area was associated with a 19%, 17%, and 12% lower adiponectin level, respectively (P < 0.01 for all) but not leptin (P > 0.05). Muscle radiodensity was more robustly associated with adiponectin and leptin in the multivariable linear regression models. That is, with full adjustment for all covariates, a 1-SD increment in total abdominal, stability, and locomotor muscle radiodensity was associated with a 31%, 31%, and 18% lower adiponectin level (P < 0.01 for all) and a 6.7%, 4.6%, and 8.1% higher leptin level (P < 0.05 for all), respectively.

          Conclusions

          The data suggest that increases in muscle area and radiodensity may have positive impacts on chronic inflammation and, in turn, reduce the risk of cardiometabolic disease.
            Cover page: Associations of Abdominal Muscle Area and Radiodensity with Adiponectin and Leptin: The Multiethnic Study of Atherosclerosis
            • Article
            • Peer Reviewed
            UC San Diego Previously Published Works (2016)
            BACKGROUND:With increasing age, a downward shift of the aorto-iliac bifurcation relative to the lumbar spine occurs. A lower bifurcation position is an independent marker for adverse vascular aging and is associated with increased burden of cardiovascular disease (CVD) risk factors; however, the associations between lower bifurcation position and CVD events remain unknown. METHODS:Abdominal computed tomography scans were used to measure the aorto-iliac bifurcation distance (AIBD, distance from the aorto-iliac bifurcation to the L5/S1 disc space). Cox proportional hazard analysis was used to determine the independent hazard of a lower bifurcation position (smaller AIBD) for incident coronary heart disease (CHD, defined as myocardial infarction, resuscitated cardiac arrest, or sudden cardiac death), CVD (CHD plus stroke or stroke death), and all-cause mortality (ACM). RESULTS:In the 1,711 study participants (51% male), the mean AIBD was 26 ± 15 mm. After a median follow-up of 10 years, 63 (3.7%) developed CHD, 100 (5.8%) developed CVD, and 129 (7.5%) were deceased. Compared to the 4th quartile of AIBD (highest bifurcation position), participants in the 1st quartile (lowest bifurcation position) had increased risk for CHD (hazard ratio (HR) = 1.5, 95% confidence interval (CI): 0.8-3.0, P = 0.2), CVD (HR = 1.8, 95% CI: 0.9-2.7, P = 0.1), and ACM (HR = 2.2, 95% CI: 1.3-3.6, P = 0.01). After adjustments for CVD risk factors, the HR for ACM was no longer significant. CONCLUSION:Despite being an independent marker for adverse vascular changes in the aorta, a lower aorto-iliac bifurcation position was not independently associated with future CVD events. The opposing effects of atherosclerosis and stiffness in the aorta may, in part, explain our null findings.
              Cover page: Lower Aorto-Iliac Bifurcation Position and Incident Cardiovascular Disease: A Multi-Ethnic Study of Atherosclerosis (MESA)
              • Article
              • Peer Reviewed
              UC San Diego Previously Published Works (2022)

              Background

              Using data from a multiethnic cohort, the authors tested associations of multiple types and intensities of physical activity (PA) with abdominal muscle area and density.

              Methods

              1895 Multiethnic Study of Atherosclerosis participants (mean age 64.6 [9.6] y) completed health history and PA questionnaires and computed tomography to quantify body composition and measurements of cardiovascular and inflammatory biomarkers. Analyses included multivariable regression.

              Results

              Compared with those not meeting PA guidelines for Americans, those meeting the guidelines had higher total abdominal muscle area (odds ratio, 95% confidence interval 1.60, 1.20 to 2.15), stability muscle area (1.68, 1.28 to 2.20), and stability muscle density (1.35, 1.03 to 1.76). After adjustment for relevant covariates, each SD increase in total moderate to vigorous PA was associated with a higher total abdominal (β, 95% confidence interval = 0.068, 0.036 to 0.173), stability (0.063, 0.027 to 0.099), and locomotor (0.069, 0.039 to 0.099) muscle area and higher locomotor muscle density (0.065, 0.022 to 0.108, P < .01). Only intentional and conditioning exercise were associated with total abdominal and stability muscle density (P < .05). Light PA and walking were not associated with muscle area or density.

              Conclusions

              Most types of PA are positively associated with abdominal muscle area and density across functional categories, independent of relevant covariates. These results provide additional evidence for promoting PA for healthy muscle aging.
                Cover page: Physical Activity Type and Intensity Are Associated With Abdominal Muscle Area and Density: The Multiethnic Study of Atherosclerosis.
                • Article
                • Peer Reviewed
                UC San Diego Previously Published Works (2023)
                Mechanistic research suggests using Cannabis sativa L. (cannabis or marijuana) may increase the risk of cardiometabolic disease, but observational studies investigating associations between cannabis use and myocardial infarction (MI) have reported inconsistent results. Cross-sectional National Health and Nutrition Examination Survey data from five 2-year cycles between 2009 and 2018 and representing 9,769 middle-aged adults (35 to 59 years old) were analyzed. Multivariable logistic regression models accounting for sampling weights and adjusting for cardiovascular risk factors were used to assess associations between a history of monthly cannabis use before MI and a subsequent MI. A quarter of respondents (n = 2,220) reported a history of monthly use >1 year before an MI. A history of MI was reported by 2.1% of all respondents and 3.2.% of those who reported a history of monthly use. In fully adjusted multivariable models, and compared with never use, a history of monthly cannabis use preceding an MI was not associated with an MI (odds ratio [OR] 0.78, 95% confidence interval [CI] 0.35 to 1.71). However, when stratified by recent use, the odds of MI were threefold greater (OR 2.98, 95% CI 1.08 to 8.60) when no use was reported within the past month than when use was reported within the past month. Duration of monthly use was also not significantly associated with MI, including monthly use >10 years (OR 0.78, 95% CI 0.30 to 2.01). In conclusion, in a representative sample of middle-aged US adults, a history of monthly cannabis use >1 year before an MI was not associated with a subsequent physician-diagnosed MI, except for threefold greater odds when cannabis was not used within the past month.
                  Cover page: Associations Between Monthly Cannabis Use and Myocardial Infarction in Middle-Aged Adults: NHANES 2009 to 2018, Corroon et al
                  • Article
                  • Peer Reviewed
                  UC San Diego Previously Published Works (2023)

                  Background

                  Observational studies investigating associations between cannabis use and blood pressure (BP)/hypertension are inconsistent.

                  Methods

                  Cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) were analyzed for five 2-year cycles between 2009 and 2018 representing 9,783 middle-aged adults (35-59 years). Hypertension was defined as systolic BP (SBP) ≥130, diastolic BP (DBP) ≥80, or a BP medication. Sample-weighted multivariable logistic regression models were used to assess associations between cannabis use and BP and hypertension.

                  Results

                  One quarter of respondents (n = 2,228) reported a history of monthly cannabis use for more than 1 year, which was consistent over the study period (P for trend = 0.75). Approximately 48% (n = 4,831) met the definition of hypertension. While a significant positive trend was seen over time for mean SBP and DBP (P = <0.01 for both), no significant trend was seen in prevalent hypertension (P for trend = 0.23). In adjusted models, compared with never use, a history of monthly cannabis use for more than 1 year was not associated with increased BP (mean SBP: 124.5 mm Hg (95% confidence interval [CI], 122.4-126.6) vs. 122.6 (95% CI, 120.9-124.2); DBP: 74.7 mm Hg (95% CI, 73.1-76.2) vs. 74.1 (95% CI, 72.8-75.4)), or prevalent hypertension (odds ratio = 0.88 (95% CI, 0.62-1.24)). Results from analyses of duration of monthly use, and recency and frequency of recent use were similar.

                  Conclusions

                  A history of monthly cannabis use for more than 1 year was not independently associated with either increased BP or prevalent hypertension in a nationally representative sample of middle-aged US adults.
                    Cover page: Trends in Cannabis Use, Blood Pressure, and Hypertension in Middle-Aged Adults: Findings From NHANES, 2009–2018
                    • Article
                    • Peer Reviewed
                    UC San Diego Previously Published Works (2018)

                    Purpose

                    Skeletal muscle is the largest regulator of glucose metabolism, but few population-based studies have examined the associations between muscle and inflammation. We studied the relationships between abdominal muscle area and density with selected adiposity-associated inflammatory mediators.

                    Methods

                    Nearly 2000 subjects underwent computed tomography of the abdomen and had venous fasting blood drawn concomitantly. The computed tomography scans were interrogated for visceral and subcutaneous fat, as well as abdominal lean muscle areas and densities. We then categorized the muscle into locomotion (psoas) and stabilization (rectus, obliques, and paraspinal) groups. Blood samples were assayed for interleukin-6 (IL-6), resistin, C-reactive protein, and TNF-α.

                    Results

                    The mean age was 64.7 yr, and 49% were female. Forty percent were white, 26% Hispanic/Latino American, 21% African American, and 13% Chinese American. The mean body mass index was 28.0 kg·m, and 30% were obese (body mass index, >30 kg·m). Using multivariable linear regression models that included adjustment for abdominal muscle area, a 1-SD increment in the mean densities for total, stabilization, and locomotive abdominal muscle were each significantly associated with lower levels of IL-6 (β = -15%, -15%, and -9%, P < 0.01 for all) and resistin (β = -0.11, -0.11, and -0.07 ng·mL, P < 0.02 for all), but not C-reactive protein or TNF-α. Conversely, muscle area was not independently associated with any of the inflammatory mediators studied.

                    Conclusions

                    Higher densities of several muscle groups in the abdomen are significantly associated with lower IL-6 and resistin levels, independent of the muscle area in these groups. Techniques that enhance muscle density may reduce levels of adiposity-associated inflammatory mediators.
                      Cover page: Abdominal Muscle Density Is Inversely Related to Adiposity Inflammatory Mediators
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