A two-step gas chromatography-tandem mass spectrometry method for measurement of multiple environmental pollutants in human plasma.

Individuals are exposed to a wide variety of chemicals over their lifetime, yet current understanding of mixture toxicology is still limited. We present a two-step analytical method using a gas chromatograph-triple quadrupole mass spectrometer that requires less than 1 mL of sample. The method is applied to 183 plasma samples from a study population of children with autism spectrum disorder, their parents, and unrelated neurotypical children. We selected 156 environmental chemical compounds and ruled out chemicals with detection rates less than 20% of our study cohort (n = 61), as well as ones not amenable to the selected extraction and analytical methods (n = 34). The targeted method then focused on remaining chemicals (n = 61) plus 8 additional polychlorinated biphenyls (PCBs). Persistent pollutants, such as p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and PCB congeners 118 and 180, were detected at high frequencies and several previously unreported chemicals, including 2,4,6-trichlorophenol, isosafrole, and hexachlorobutadiene, were frequently detected in our study cohort. This work highlights the benefits of employing a multi-step analytical method in exposure studies and demonstrates the efficacy of such methods for reporting novel information on previously unstudied pollutant exposures.

Exposure to Persistent Organic Pollutants (POPs) and Their Relationship to Hepatic Fat and Insulin Insensitivity among Asian Indian Immigrants in the United States.

Persistent organic pollutants (POPs), such as dichlorodiphenyltrichloroethane (DDT) and other organochlorine compounds, are abundant in the environment and in foodstuffs from the Indian subcontinent. These environmental contaminants have been associated with a higher risk of diabetes in numerous studies. Asian Indians are well known to have a high risk of diabetes compared with other populations, and this risk is also found in migrant populations of Asian Indians in the United States, Europe, and elsewhere. We hypothesized that high plasma concentrations of POPs in Asian Indian migrants are linked to a variety of diabetes-related pathologies and explored the mechanism for the induction of these effects. We measured 30 environmental pollutants in plasma samples obtained from 147 participants in the Metabolic syndrome and Atherosclerosis in South Asians Living in America pilot study using a gas chromatography-tandem mass spectrometry analytical method that uses less than 0.5 mL of plasma. We found that plasma levels of o,p'-DDT and p,p'-DDT were independently associated with both body mass index (BMI) and waist circumference. Doubling the levels of the sums of these DDTs was associated with insulin insensitivity (-0.38 Matsuda index, p = 0.001), increased adiposity (1.26 kg/m2 BMI and 3.58 cm waist circumference increase, p < 0.0001), circulating insulin (12.9 mIU/L, p = 0.002), hepatic fat (-0.051 HU, p = 0.001), as well as increased odds of obesity (OR = 2.17, p < 0.001, BMI-based; OR = 2.37, p = 0.001, waist-based), prediabetes (OR = 1.55, p = 0.02), diabetes (OR = 1.72, p = 0.01), and fatty liver (OR = 1.66, p = 0.01) in multivariable models accounting for confounding by age, sex, years in the US, education, and fish protein. Furthermore, levels of DDTs were associated with increased hepatic fat and circulating insulin, independent of obesity and confounders. These findings suggest that exposure to DDTs may contribute to the risk of metabolic disease among Asian Indians by affecting hepatic fat levels independent of obesity.

Family satisfaction predicts life satisfaction trajectories over the first 5 years after traumatic brain injury.

OBJECTIVES: Examined the influence of functional impairment, stable marital status, and family satisfaction on life satisfaction trajectories for 609 individuals (435 men, 174 women) over the first 5 years after traumatic brain injury (TBI). MEASURES: Participants completed the Family Satisfaction Scale (FSS), Functional Independence Measure (FIM), and the Life Satisfaction Index (LSI) at years 1, 2, 4, and 5 after sustaining a TBI. RESULTS: Trajectory modeling revealed that higher family satisfaction was associated with increases in life satisfaction for individuals with less functional impairment. Stable marital status was not significantly associated with life satisfaction trajectories. IMPLICATIONS: Family satisfaction appears to have pronounced beneficial effects on life satisfaction for persons with less functional impairment after TBI regardless of marital status. In contrast, a stable marriage appears to have no apparent benefits to self-reported life satisfaction over the first 5 years post-TBI. Theoretical and clinical implications of these results are discussed.

Trajectories of life satisfaction in the first 5 years following traumatic brain injury.

OBJECTIVES: The trajectories of life satisfaction for 609 individuals who sustained a traumatic brain injury (TBI) were studied. Hierarchical linear modeling analysis examined individual level growth trends over the first 5 years following TBI using gender, functional independence, age, and time to estimate life satisfaction trajectories. MEASURES: Participants completed the Functional Independence Measure and the Life Satisfaction Inventory at years 1, 2, 4, and 5 after sustaining TBI. RESULTS: Participants who reported higher functional independence at year 1 also had higher life satisfaction at year 1. Participants with lower functional independence across the 5-year period had life satisfaction trajectories that decreased at significantly greater rates than the individuals with more functional independence. The life satisfaction trajectory declined for the sample, but participants reporting lower cognitive and motor functional independence had significantly greater declines in life satisfaction trajectories. Age and gender were not significant factors in predicting life satisfaction trajectories following TBI. IMPLICATIONS: Individuals with greater cognitive and motor impairments following TBI are likely to experience significant declines in life satisfaction within 5 years of living with TBI.