Remission of obesity among a nationally representative sample of US children.

BACKGROUND: Little is known about the incidence and natural history of obesity remission among children outside of weight loss programmes. OBJECTIVES: The objectives are to characterize and identify sociodemographic and early life predictors of obesity remission between kindergarten and eighth grade among a nationally representative sample of US children. METHODS: The sample included children with obesity [age-specific and gender-specific body mass index percentile (BMI) ≥95] at the spring kindergarten assessment of the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99. Weight categories across 8 years of follow-up were used to identify three transition patterns: persistent obesity remission, non-persistent obesity remission and non-remission. Weight, height and BMI changes between remission categories were examined and predictors of persistent remission were identified. RESULTS: One-third of children with obesity in kindergarten experienced remission during follow-up and 21.6% of children experienced persistent remission through eighth grade. Female gender and high socio-economic status predicted persistent remission; these associations were attenuated after accounting for baseline BMI. Children experiencing persistent remission gained less weight across waves than those experiencing non-remission. CONCLUSIONS: A meaningful proportion of young children with obesity experience remission by eighth grade. Further study is needed to identify factors that support obesity remission among children outside of treatment contexts.

Depression, anxiety and telomere length in young adults: evidence from the National Health and Nutrition Examination Survey.

Telomere length has been hypothesized to be a marker of cumulative exposure to stress, and stress is an established cause of depression and anxiety disorders. The aim of this study was to examine the relationship between depression, anxiety and telomere length, and to assess whether this relationship is moderated by race/ethnicity, gender and/or antidepressant use. Data were from the 1999-2002 National Health and Nutrition Examination Survey. Telomere length was assessed using the quantitative PCR method of telomere length relative to standard reference DNA. Past-year major depression (MD), generalized anxiety disorder (GAD) and panic disorder (PD), as well as depressed affect and anxious affect, were assessed using the Composite International Diagnostic Inventory (N=1290). Multiple linear regression was used to assess the relationship between depression and anxiety disorders and telomere length. Among women, those with GAD or PD had shorter telomeres than those with no anxious affect (ß: -0.07, P<0.01), but there was no relationship among men (ß: 0.08, P>0.05). Among respondents currently taking an antidepressant, those with MD had shorter telomeres than those without (ß: -0.26, P<0.05), but there was no association between MD and telomere length among those not using antidepressants (ß: -0.00, P>0.05). Neither depressive nor anxiety disorders were directly associated with telomere length in young adults. There was suggestive evidence that pharmacologically treated MD is associated with shorter telomere length, likely reflecting the more severe nature of MD that has come to clinical attention.

Exposure to peer deviance during childhood and risk for drug abuse: a Swedish national co-relative control study.

BACKGROUND: Peer deviance (PD) is associated with risk for drug abuse (DA). Is this association causal? METHOD: DA was recorded in official records. PD was defined as the percentage of peers residing in small communities with future DA registrations. We examined offspring in families whose community PD changed when the offspring was 0-15 years of age and then examined families where cousins or siblings differed in their years of exposure to low or high PD communities. RESULTS: The duration of exposure to PD was strongly associated with future DA. Co-relative analyses for families whose exposure to PD declined suggested that the PD-DA association was largely non-causal. Within full-sibling pairs in such families, the length of exposure to low PD environments was unrelated to risk for DA. By contrast, co-relative analyses in families where exposure to PD increased over time indicated that the PD-DA association was largely causal. In such families, siblings who differed in the duration of their exposure to high PD differed in their risk for subsequent DA. These results were replicated in families whose PD changed because they moved or because of changes in the community in which they resided. CONCLUSIONS: Within families whose social environment is improving over time, the association between PD exposure and offspring DA outcomes is not causal but is due to familial confounding. Within families whose social environment is deteriorating, the PD-DA association seems to be largely causal. Our measure of PD may also reflect broader aspects of the community environment beyond peers.

Association between duration and quality of sleep and the risk of pre-diabetes: evidence from NHANES.

AIMS: To examine the association between duration and quality of sleep and the prevalence of undiagnosed and clinically identified diabetes mellitus and pre-diabetes in a nationally representative sample. METHODS: Cross-sectional study of 2285 participants ≥ 30 years old and without diagnosed sleep disorders from the National Health and Nutrition Examination Survey (2005-2008). The primary exposures were sleep duration and quality. Sleep quality was assessed by questionnaire using trouble initiating sleep, trouble maintaining sleep, and waking up too early. The primary outcomes were clinically identified and undiagnosed pre-diabetes and diabetes as defined by the American Diabetes Association using fasting plasma glucose (5.6-6.9 mmol/l = pre-diabetes; ≥ 7.0 mmol/l = diabetes). Multivariate logistic regression was used to test the association between sleep quality, sleep duration and glycaemic status. RESULTS: After adjustment for socio-demographic characteristics and health behaviors, sleeping ≤ 5 h/night was associated with clinically identified pre-diabetes (odds ratio 2.06, 95% CI 1.00-4.22 vs. 7 h). Both trouble maintaining sleep ≥ 5 times/month (odds ratio 3.50, 95% CI 1.30-9.45) and waking up too early ≥ 5 times/month (odds ratio 2.69, 95% CI 1.21-5.98) were also significantly associated with increased risk of clinically identified pre-diabetes. Trouble initiating sleep and sleeping ≥ 9 h/night were not found to be associated with having diabetes. CONCLUSIONS: Only clinically identified pre-diabetes was associated with trouble maintaining sleep, waking up too early, and short sleep. No other relations were found to be significant. Findings suggest that poor sleep quality and short sleep duration were more strongly associated with clinically identified pre-diabetes than 7-8 hours per day.

Examining variation in depressive symptoms over the life course: a latent class analysis.

BACKGROUND: Older adults have the lowest prevalence and incidence of major depressive disorder, although it has been hypothesized that this finding is due in part to differences in expression of psychopathology in later life. The aim of this study was to examine variation in depressive symptomatology in the general population across the lifespan. METHOD: Data came from three sites of the Epidemiologic Catchment Area (ECA) Project (n=10 529). Depressive symptoms during the past 6 months were assessed using the Diagnostic Interview Schedule (DIS). Latent class analysis (LCA) was used to identify homogeneous groups of depressive symptomatology based on 16 individual symptoms, and to examine variation in the prevalence and composition of depression classes across age groups. RESULTS: The DIS symptoms fit a four-class model composed of non-depressed (83.2%), mild depression (11.6%), severe depression (1.9%), and despondent (3.2%) groups. Relative to the non-depressed class, older age was inversely associated with being in the mild or severe depression class. The profile of the latent classes was similar across age groups with the exception of the despondent class, which was not well differentiated among the youngest adults and was not inversely associated with age. CONCLUSIONS: The symptom profiles of depression are similar across age with the exception of the despondent class, which is more differentiated from severe depression among older adults. The findings demonstrate the benefit of examining individual symptoms rather than broad symptom groups for understanding the natural history of depression over the lifespan.

Depression and osteoporosis: epidemiology and potential mediating pathways.

INTRODUCTION: There have been numerous studies examining the association between depression and bone mineral density (BMD), but the underlying nature of this relationship remains unclear. Independent of this association, there is a growing body of evidence that depression impacts the risk for fracture in older adults. This article reviews the current epidemiological evidence regarding comorbidity of depression, low bone mineral density, and fracture. METHODS: A review of the literature on depression, depressive symptoms, low BMD, osteoporosis, and fracture using electronic databases. RESULTS: We reviewed 20 studies of the association between depression and BMD and five reports of the relationship between depression and fractures. Potential mediating mechanisms (both physiological and behavioral) are discussed, as well as potential confounding influences (e.g., medication use). CONCLUSIONS: Most studies support the finding that depression is associated with increased risk for both low BMD and fractures, but variation in study design, sample composition, and exposure measurement make comparisons across studies difficult. Researchers should be aware of potential confounders, such as medication use, that may influence results. Future research should focus on identifying mediating pathways and targets for intervention in the relationships between depression, low BMD, and fracture.

Prevalence and incidence of depressive disorder: the Baltimore ECA follow-up, 1981-2004.

OBJECTIVE: To describe trends in prevalence and incidence of depressive disorder in a cohort from Eastern Baltimore. METHOD: Twenty-three-year-old longitudinal cohort, the Baltimore Epidemiologic Catchment Area Follow-up. Participants were selected probabilistically from the household population in 1981, and interviewed in 1981, 1993, and 2004. Diagnoses were made via the Diagnostic Interview Schedule according to successive editions of the American Psychiatric Association Diagnostic and Statistical Manual. RESULTS: Older age, lower education, non-White race, and cognitive impairment are independent predictors of attrition due to death and loss of contact, but depressive disorder is not related to attrition. Prevalence rates rise for females between 1981, 1993, and 2004. Incidence rates in the period 1993-2004 are lower than the period 1981-1993, suggesting the rise in prevalence is due to increasing chronicity. CONCLUSION: There has been a rise in the prevalence of depression in the prior quarter century among middle-aged females.