Julie A. Phillips

Cholesterol Efflux Capacity, High-Density Lipoprotein Function, and Atherosclerosis

BACKGROUND High-density lipoprotein (HDL) may provide cardiovascular protection by promoting reverse cholesterol transport from macrophages. We hypothesized that the capacity of HDL to accept cholesterol from macrophages would serve as a predictor of atherosclerotic burden. METHODS We measured cholesterol efflux capacity in 203 healthy volunteers who underwent assessment of carotid artery intima-media thickness, 442 patients with angiographically confirmed coronary artery disease, and 351 patients without such angiographically confirmed disease. We quantified efflux capacity by using a validated ex vivo system that involved incubation of macrophages with apolipoprotein B-depleted serum from the study participants. RESULTS The levels of HDL cholesterol and apolipoprotein A-I were significant determinants of cholesterol efflux capacity but accounted for less than 40% of the observed variation. An inverse relationship was noted between efflux capacity and carotid intima-media thickness both before and after adjustment for the HDL cholesterol level. Furthermore, efflux capacity was a strong inverse predictor of coronary disease status (adjusted odds ratio for coronary disease per 1-SD increase in efflux capacity, 0.70; 95% confidence interval [CI], 0.59 to 0.83; P<0.001). This relationship was attenuated, but remained significant, after additional adjustment for the HDL cholesterol level (odds ratio per 1-SD increase, 0.75; 95% CI, 0.63 to 0.90; P=0.002) or apolipoprotein A-I level (odds ratio per 1-SD increase, 0.74; 95% CI, 0.61 to 0.89; P=0.002). Additional studies showed enhanced efflux capacity in patients with the metabolic syndrome and low HDL cholesterol levels who were treated with pioglitazone, but not in patients with hypercholesterolemia who were treated with statins. CONCLUSIONS Cholesterol efflux capacity from macrophages, a metric of HDL function, has a strong inverse association with both carotid intima-media thickness and the likelihood of angiographic coronary artery disease, independently of the HDL cholesterol level. (Funded by the National Heart, Lung, and Blood Institute and others.).

The new labor market: Immigrants and wages after IRCA

We examine the effect of the Immigration Reform and Control Act (IRCA) on migrants ’ wages using data gathered in 39 Mexican communities and their U.S. destination areas. We examine changes in the determinants of wages before and after the passage of IRCA, as well as the effects of its massive legalization program. Migrants ’ wages deteriorated steadily between 1970 and 1995, but IRCA did not foment discrimination against Mexican workers per se. Rather, it appears to have encouraged greater discrimination against undocumented migrants, with employers passing the costs and risks of unauthorized hiring on to the workers. Although available data do not permit us to eliminate competing explanations entirely, limited controls suggest that the post-IRCA wage penalty against undocumented migrants did not stem from an expansion of the immigrant labor supply, an increase in the use of labor subcontracting, or a deterioration of the U.S. labor market.

Understanding Recent Changes in Suicide Rates among the Middle-Aged: Period or Cohort Effects?:

Objective. We examined trends in suicide rates for U.S. residents aged 40 to 59 years from 1979 to 2005 and explored alternative explanations for the notable increase in such deaths from 1999 to 2005. Methods. We obtained information on suicide deaths from the National Center for Health Statistics and population data from the U.S. Census Bureau. Age- and gender-specific suicide rates were computed and trends therein analyzed using linear regression techniques. Results. Following a period of stability or decline, suicide rates have climbed since 1988 for males aged 40–49 years, and since 1999 for females aged 40–59 years and males aged 50–59 years. A crossover in rates for 40- to 49-year-old vs. 50- to 59-year-old males and females occurred in the early 1990s, and the younger groups now have higher suicide rates. The post-1999 increase has been particularly dramatic for those who are unmarried and those without a college degree. Conclusions. The timing of the post-1999 increase coincides with the complete replacement of the U.S. populations middle-age strata by the postwar baby boom cohorts, whose youngest members turned 40 years of age by 2005. These cohorts, born between 1945 and 1964, also had notably high suicide rates during their adolescent years. Cohort replacement may explain the crossover in rates among the younger and older middle-aged groups. However, there is evidence for a period effect operating between 1999 and 2005, one that was apparently specific to less-protected members of the baby boom cohort.

Suicide and the Great Recession of 2007-2009: the role of economic factors in the 50 U.S. states

After several decades of decline, U.S. suicide rates have risen since 2005, a trend driven largely by increases among those aged 45-64 that began in 1999. A prominent explanation for this pattern relates to deteriorating economic conditions, especially the sharp rise in unemployment associated with the Great Recession of 2007-2009. We pool data from 1997 to 2010 on the 50 U.S. states to examine the role of economic factors in producing the recent rise in suicide rates. Unlike prior studies, we examine trends in the total suicide rate and in the rate disaggregated by sex, age group and time period and include a number of important confounding factors in a multivariate analysis. We find a strong positive association between unemployment rates and total suicide rates over time within states. The association appears stronger in states that had higher female labor force participation rates over the period, suggesting that the Great Recession may generate greater levels of anomie in this context. Once we consider contextual factors such as female labor force participation, we find that rising unemployment had a similar adverse effect on male and female suicide rates. A positive effect of unemployment on temporal variation in middle-aged suicide exists but not for other age groups. Other economic characteristics, such as percent of manufacturing jobs and per capita income, are not associated with temporal variation in suicide rates within states but are associated with variation between states in suicide rates. The findings suggest that the following may be important components of effective prevention strategies: 1) specifically targeting employers and workplaces as important stakeholders in the prevention of suicide, 2) disseminating information about health risks tied to un/employment, and 3) linking the unemployed to mental health resources.

A changing epidemiology of suicide? The influence of birth cohorts on suicide rates in the United States

The increases in suicide among middle-aged baby boomers (born between 1946 and 1964) in the United States since 1999 suggest a changing epidemiology of suicide. Using data from 1935 to 2010, this paper conducts age-period-cohort analyses to determine the impact of cohorts in shaping temporal patterns of suicide in the United States. The analysis demonstrates that age, period and cohort effects are all important in determining suicide trends. Net of age and period effects, the cohort pattern of suicide rates is U-shaped, with cohorts born between 1915 and 1945 possessing among the very lowest suicide rates. Suicide rates begin to rise with boomers and subsequent cohorts exhibit increasingly higher rates of suicide. The general pattern exists for both men and women but is especially pronounced among males. The average suicide rate over the entire period for males is about 28 per 100,000, 95% CI [27.4, 28.7]. For males born in 1930-34, the suicide rate is estimated to be 17.4 per 100,000, 95% CI [15.9, 18.8]; for males born between 1955 and 1959, the rate is essentially the same as the average for the period while for males born between 1985 and 1989, the suicide rate is estimated to be 37.8 per 100,000, 95% CI [33.1, 43.4]. The results dispute popular claims that boomers exhibit an elevated suicide rate relative to other generations, but boomers do appear to have ushered in new cohort patterns of suicide rates over the life course. These patterns are interpreted within a Durkheimian framework that suggests weakened forms of social integration and regulation among postwar cohorts may be producing increased suicide rates.

Factors Associated With Temporal and Spatial Patterns in Suicide Rates Across U.S. States, 1976–2000

Using pooled cross-sectional time-series data for the 50 U.S. states over a 25-year period, this article examines how well four conceptual groups of social correlates—demographic, economic, social, and cultural factors—are associated with the 1976–2000 patterns in overall suicide rates and suicide by firearms and other means. Unlike past research that typically considers only one dimension, this analysis differentiates between spatial and temporal variation in suicide rates to determine whether and how social correlates operate differently in these two contexts. Results indicate that suicide rates correspond closely to social correlates. Within U.S. states, lower overall suicide rates between 1976 and 2000 were associated with demographic change (e.g., larger numbers of foreign-born) as well as with fewer numbers of Episcopalians. Across U.S. states, variation in overall suicide rates over the period was related to demographic (percentage male), economic (per capita income), social (percentage divorced), and cultural (alcohol consumption and gun ownership) factors. However, findings differ importantly by type of suicide, and across time and space. Reasons for these distinct patterns are discussed.

Rising suicide among adults aged 40-64 years: the role of job and financial circumstances

INTRODUCTION Suicide rates among middle-aged men and women in the U.S. have been increasing since 1999, with a sharp escalation since 2007. PURPOSE To examine whether suicides with circumstances related to economic crises increased disproportionately among the middle-aged between 2005 and 2010. METHODS This study used the National Violent Death Reporting System (NVDRS) in 2014 to explore trends and patterns in circumstance and method among adults aged 40-64 years. RESULTS Suicide circumstances varied considerably by age, with those related to job, financial, and legal problems most common among individuals aged 40-64 years. Between 2005 and 2010, the proportion of suicides where these circumstances were present increased among this age group, from 32.9% to 37.5% of completed suicides (p<0.05). Further, suffocation is a method more likely to be used in suicides related to job, economic, or legal factors, and its use increased disproportionately among the middle-aged. The number of suicides using suffocation increased 59.5% among those aged 40-64 years between 2005 and 2010, compared with 18.0% for those aged 15-39 years and 27.2% for those aged >65 years (p<0.05). CONCLUSIONS The growth in the importance of external circumstances and increased use of suffocation jointly pose a challenge for prevention efforts designed for middle-aged adults. Suffocation is a suicide method that is highly lethal, requires relatively little planning, and is readily available. Efforts that target employers and workplaces as important stakeholders in the prevention of suicide and link the unemployed to mental health resources are warranted.

Racial and ethnic differences in risk factors associated with suicidal behavior among young adults in the USA.

Objective. The objectives of this study are to examine racial and ethnic differences in suicidal behaviour, its main risk factors, and the effect of the risk factors on suicidal behaviour in young adults in the United States. Design. Using nationally representative data (n = 10,585) from Add Health, we calculate the prevalence of suicidal behavior and associated risk factors for non-Hispanic White, non-Hispanic Black, and Hispanic youth (aged 18–26) using logistic regression models of suicidal ideation stratified by race. Results. Non-Hispanic White and Hispanic young adults have higher rates of suicidal ideation than their non-Hispanic Black counterparts, but racial/ethnic differences in attempts are not statistically significant. Non-Hispanic Whites and Hispanic young adults are more likely to possess key risk factors for suicide. With the exception of substance use variables (i.e. alcohol and marijuana use) which appear to be more conducive to suicidal ideation in non-Hispanic Black than in non-Hispanic White young adults, the effects of risk factors appear to be similar across race/ethnicity. Conclusion. The higher prevalence of suicidal ideation in non-Hispanic White and Hispanic young adults may be driven by their greater exposure to risk factors, as opposed to differences in the effects of these risk factors. More research is needed to uncover why non-Hispanic White and Hispanic young adults have higher rates of suicidal ideation than their non-Hispanic Black counterparts; yet, rates of suicide attempts are comparable and non-Hispanic White young adults have the highest rate of completed suicides.

Differences in U.S. Suicide Rates by Educational Attainment, 2000–2014

INTRODUCTION The purpose of this study was to document the association between education and suicide risk, in light of rising suicide rates and socioeconomic differentials in mortality in the U.S. METHODS Differentials and trends in U.S. suicide rates by education were examined from 2000 to 2014 using death certificate data on 442,135 suicides from the National Center for Health Statistics and Census data. Differences in the circumstances and characteristics of suicide deaths by education were investigated using 2013 data from the National Violent Death Reporting System for nine states. Analyses were conducted in 2016. RESULTS Between 2000 and 2014, men and women aged ≥25 years with at least a college degree exhibited the lowest suicide rates; those with a high school degree displayed the highest rates. Men with a high school education were twice as likely to die by suicide compared with those with a college degree in 2014. The education gradient in suicide mortality generally remained constant over the study period. Interpersonal/relationship problems and substance abuse were more common circumstances for less educated decedents. Mental health issues and job problems were more prevalent among college-educated decedents. CONCLUSIONS The findings highlight the importance of social determinants in suicide risk, with important prevention implications.

Antidepressant Use and Method of Suicide in the United States: Variation by Age and Sex, 1998–2007

This study examines the association between antidepressant use and suicide rates, by sex, age, and method of suicide, between 1998 and 2007 in the United States. Overall suicide rates for the young and elderly declined but rates for the middle-aged increased. All age groups experienced increases in antidepressant use. The elderly exhibited the largest increase in antidepressant usage and biggest declines in suicide rates. Firearm suicides for men and women declined but suicide by drug poisoning rose, particularly for women. For young males and elderly males and females, better treatment of severe depression may have contributed to declining suicide rates. However, rising rates of prescription drug use are associated with higher levels of suicide by drug poisoning.