Applying principal component pursuit to investigate the association between source-specific fine particulate matter and myocardial infarction hospitalizations in New York City.

The association between fine particulate matter (PM2.5) and cardiovascular outcomes is well established. To evaluate whether source-specific PM2.5 is differentially associated with cardiovascular disease in New York City (NYC), we identified PM2.5 sources and examined the association between source-specific PM2.5 exposure and risk of hospitalization for myocardial infarction (MI). Methods: We adapted principal component pursuit (PCP), a dimensionality-reduction technique previously used in computer vision, as a novel pattern recognition method for environmental mixtures to apportion speciated PM2.5 to its sources. We used data from the NY Department of Health Statewide Planning and Research Cooperative System of daily city-wide counts of MI admissions (2007-2015). We examined associations between same-day, lag 1, and lag 2 source-specific PM2.5 exposure and MI admissions in a time-series analysis, using a quasi-Poisson regression model adjusting for potential confounders. Results: We identified four sources of PM2.5 pollution: crustal, salt, traffic, and regional and detected three single-species factors: cadmium, chromium, and barium. In adjusted models, we observed a 0.40% (95% confidence interval [CI]: -0.21, 1.01%) increase in MI admission rates per 1 µg/m3 increase in traffic PM2.5, a 0.44% (95% CI: -0.04, 0.93%) increase per 1 µg/m3 increase in crustal PM2.5, and a 1.34% (95% CI: -0.46, 3.17%) increase per 1 µg/m3 increase in chromium-related PM2.5, on average. Conclusions: In our NYC study, we identified traffic, crustal dust, and chromium PM2.5 as potentially relevant sources for cardiovascular disease. We also demonstrated the potential utility of PCP as a pattern recognition method for environmental mixtures.

The diagnosis and treatment of PCOS in adolescents: an update.

PURPOSE OF REVIEW: Polycystic ovary syndrome (PCOS) is often difficult to diagnose in adolescents. Recent recommendations and concepts regarding the diagnosis and treatment of PCOS in the adolescent girl are considered. RECENT FINDINGS: The diagnosis of PCOS in adolescents should be primarily based on clinical and biochemical signs of hyperandrogenism and presentation with irregular menses. Because of the similarity of normal pubertal development and features of PCOS, the diagnosis should be deferred until at least 2 years following menarche. For girls who do not fulfill the diagnostic criteria, the focus should be on treatment of symptoms. SUMMARY: PCOS is a complex, multifaceted disorder, and should be diagnosed and treated in adolescents after taking into consideration the patient's full diagnostic picture, metabolic risks, and individual concerns, to both avoid overdiagnosis but yet be able to provide early and meaningful interventions.

Obesity and Insulin Resistance, Not Polycystic Ovary Syndrome, Are Independent Predictors of Bone Mineral Density in Adolescents and Young Women.

INTRODUCTION: Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders that affects females of reproductive age. The characteristic features of PCOS individually have opposing effects on bone mineral density (BMD); however, their cumulative effect on BMD has not been clearly defined. Adolescence and young adulthood span a crucial period in achieving peak bone mass. Thus, a better understanding of the impact of PCOS on BMD in this age group is needed. OBJECTIVES: To determine whether BMD is different between young females with PCOS and controls and to identify factors that influence BMD in this population. METHODS: Data from four cross-sectional studies with a total of 170 females aged 12-25 years with PCOS (n = 123) and controls (n = 47) with a wide range of BMIs (18.7-53.4 kg/m2) were analyzed. Participants had fasting glucose, insulin, and free and total testosterone concentrations measured. HOMA-IR was calculated. Whole-body BMD was assessed by dual-energy X-ray absorptiometry. Multiple regression analysis for predicting BMD included PCOS status, menstrual age, obesity, HOMA-IR, and free testosterone. RESULTS: HOMA-IR and total and free testosterone were significantly higher in PCOS compared to controls but there was no difference in BMD z-score between PCOS (0.8 ± 1.0) and controls (0.6 ± 1.0) (p = 0.36). Obesity (p = 0.03) and HOMA-IR (p = 0.02) were associated with BMD z-score. CONCLUSIONS: Obesity status and insulin resistance, but not PCOS status, were each independently associated with BMD in adolescents and young women who spanned a wide range of BMIs.

Present Knowledge on the Etiology and Treatment of Adrenarche.

Premature adrenarche (PA) has been assumed to be a benign variant of normal pubertal development. Yet, current collective information suggests associations between PA and potential risks for development of polycystic ovary syndrome and adult diseases such as the metabolic syndrome. Adrenarche refers to the increased secretion of the adrenal androgen precursors DHEA, DHEAS, and androstenedione, which normally occurs in children at age 6-8 years. PA may be identified clinically by early pubarche, which is defined as the development of pubic or axillary hair before 8 years in girls or 9 years in boys. This paper will consider adrenal steroidogenesis, genetic markers, neurobiological changes, skeletal maturation, and associations with adult disorders. The differential diagnosis will be reviewed because PA remains a diagnosis of exclusion. Finally, synthesis of current knowledge regarding PA, suggestions for evaluation, management, and treatment are offered.