Associations of salivary cortisol levels with inflammatory markers: the Multi-Ethnic Study of Atherosclerosis.

Socioeconomic and psychosocial factors have been found to be associated with systemic inflammation. Although stress is often proposed as a contributor to these associations, no population studies have investigated the links between inflammation and biomarkers of stress. The current study examines associations between daily cortisol profiles and inflammatory markers interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor (TNF-a) in a population-based sample of 869 adults with repeat measures of cortisol over multiple days. Persons with higher levels of IL-6 had a less pronounced cortisol awakening response, a less steep daily decline, and higher cortisol area under the curve for the day with associations persisting after controls for risk factors and other cytokines. Persons with higher levels of TNF-a had lower cortisol levels upon waking, and flatter daily decline, although associations with decline were attenuated when controlling for inflammatory risk factors. Higher levels of IL-10 were associated with marginally flatter daily cortisol decline (p<.10). This study is the first to identify associations of basal cortisol activity and inflammatory markers in a population based sample. Findings are consistent with the possibility that HPA axis activity may mediate associations between psychosocial stressors and inflammatory processes. Additional prospective data are necessary to clarify the directionality of associations between cortisol and inflammatory markers.

Associations of salivary cortisol levels with metabolic syndrome and its components: the multi-ethnic study of atherosclerosis.

CONTEXT: Prior research has identified associations between social-environmental factors and metabolic syndrome (MetS) components. The physiological mechanisms underlying these associations are not fully understood, but alterations in activity of the hypothalamic-pituitary-adrenal axis, a stress-responsive biological system, have been hypothesized to play a role. OBJECTIVE: The aim of the study was to determine whether MetS diagnosis and specific clusters of MetS components (waist circumference, high-density lipoproteins, glucose, and blood pressure) are associated with cortisol levels. DESIGN AND SETTING: We conducted cross-sectional analyses of data from the Multi-Ethnic Study of Atherosclerosis (MESA) study in the general community. PATIENTS OR OTHER PARTICIPANTS: We studied a population-based sample of 726 adults (ages 48 to 89 yr) who do not have clinical diabetes. INTERVENTION(S): There were no interventions. MAIN OUTCOME MEASURE(S): Cortisol awakening response, cortisol decline across the waking day, and total cortisol output were analyzed (using 18 timed measures of salivary cortisol over 3 d). RESULTS: Overall, we found little evidence that the presence of MetS or its components is related to cortisol output or patterns. Contrary to expectation, the presence of MetS was associated with lower rather than higher area under the curve, and no consistent pattern was observed when MetS components or subsets of components were examined in relation to cortisol. CONCLUSIONS: Our findings do not support the hypothesis that differences in level or diurnal pattern of salivary cortisol output are associated with MetS among persons without clinical diabetes.

Do the wealthy have a health advantage? Cardiovascular disease risk factors and wealth.

The use of wealth as a measure of socioeconomic status (SES) remains uncommon in epidemiological studies. When used, wealth is often measured crudely and at a single point in time. Our study explores the relationship between wealth and three cardiovascular disease (CVD) risk factors (smoking, obesity and hypertension) in a US population. We improve upon existing literature by using a detailed and validated measure of wealth in a longitudinal setting. We used four waves of data from the Panel Study of Income Dynamics (PSID) collected between 1999 and 2005. Inverse probability weights were employed to control for time-varying confounding and to estimate both relative (risk ratio) and absolute (risk difference) measures of effect. Wealth was defined as inflation-adjusted net worth and specified as a six category variable: one category for those with less than or equal to zero wealth and quintiles of positive wealth. After adjusting for income and other time-varying confounders, as well as baseline covariates, the risk of becoming obese was inversely related to wealth. There was a 40%-89% higher risk of becoming obese among the less wealthy relative to the wealthiest quintile and 11 to 25 excess cases (per 1000 persons) among the less wealthy groups over six years of follow up. Smoking initiation had similar but more moderate effects; risk ratios and differences both revealed a smaller magnitude of effect compared to obesity. Of the three CVD risk factors examined here, hypertension incidence had the weakest association with wealth, showing a smaller increased risk and fewer excess cases among the less wealthy groups. In conclusion, this study found a strong inverse association between wealth and obesity incidence, a moderate inverse association between wealth and smoking initiation and a weak inverse association between wealth and hypertension incidence after controlling for income and other time-varying confounders.

How many illnesses does one emergency department visit represent? Using a population-based telephone survey to estimate the syndromic multiplier.

INTRODUCTION: Syndromic surveillance monitors trends in nonspecific health indicator data to detect disease outbreaks in a timely manner; however, only a limited percentage of persons with mild illness might exhibit behaviors that could be detected by syndromic surveillance. OBJECTIVES: The objectives of this study were to 1) examine the demographic characteristics of New Yorkers with recent flu-like or diarrheal illness, 2) describe behaviors associated with having flu-like illness, and 3) estimate the citywide burden for selected illnesses by calculating the syndromic multiplier (i.e., the number of citywide illnesses represented by each visit to an emergency department [ED]). METHODS: A cross-sectional telephone survey of 2,433 adult residents of New York City (NYC) was conducted during March 19-March 31, 2003, and October 27-November 23, 2003. Respondents were asked about flu-like illness, behaviors related to flu-like illness, and diarrheal illness during the 30 days before the interview. Estimated numbers of citywide illnesses were compared with ED visits for flu-like and diarrheal illnesses that were recorded by the NYC syndromic surveillance system for the same periods. RESULTS: Every ED visit for flu-like illness represented approximately 60 illnesses among city residents; every visit for diarrheal illness represented approximately 251 illnesses. Among adults who reported a recent flu-like illness, 53.2% purchased over-the-counter (OTC) medications; 32.6% reported missing school or work; 29.1% visited a physician; 21.4% called a physician for advice; 8.8% visited an ED; and 3.8% called a nurse or health hotline for advice. Of those who reported multiple behaviors, respondents most commonly reported purchasing OTC medications as their first response to a flu-like illness. CONCLUSIONS: Population-based survey data can be used in conjunction with syndromic surveillance data to better understand the relation between nonspecific health indicators and the burden of certain illnesses in the community, and to assess the representativeness of different syndromic data sources.

Health outcomes among Hispanic subgroups: data from the National Health Interview Survey, 1992-95.

BACKGROUND: Within the next 50 years, Hispanics will become the largest minority group in the United States. The largest Hispanic subgroups are those of Mexican, Cuban, and Puerto Rican descent. The Hispanic population is heterogeneous in terms of culture, history, socioeconomic status (SES) and health status. In this report, various health status measures are compared across Hispanic subgroups in the United States. METHODS: National Health Interview Survey (NHIS) data aggregated from 1992 through 1995 were analyzed. NHIS is one of the few national surveys that has a sufficiently large sample size to adequately compare the different subgroups. Data are presented for four Hispanic origin subgroups--Mexican, Cuban, Puerto Rican, and "other Hispanic" persons--for the Hispanic population as a whole and for the non-Hispanic white and non-Hispanic black populations. These groups are compared with respect to several health status outcomes, providing both age-adjusted and unadjusted estimates. RESULTS: The health indicators for Puerto Rican persons are significantly worse than for the other Hispanic origin subgroups. For example, about 21% of Puerto Rican persons reported having an activity limitation, compared with about 15% of Cuban and Mexican persons and 14% of "other Hispanic" persons. In contrast, the health indicators of Cuban persons are often better than those of the other subgroups. For example, Cuban persons reported an average of 3 days per year lost from school or work, compared with about 6 days for Mexican and Puerto Rican persons and 7 days for "other Hispanic" persons. Mexican persons fare better than Puerto Rican persons on measures such as restricted activity days, bed disability days and hospitalizations. CONCLUSION: These data demonstrate clear differences in health status as well as indicators of socioeconomic status across Hispanic subgroups in the United States. Data on Hispanic subgroups facilitate the planning of public health services for various underserved populations.