Optimising nucleic acid recovery from rapid antigen tests for whole genome sequencing of respiratory viruses.

BACKGROUND: Whole genome sequencing (WGS) of respiratory viruses from rapid antigen tests (RAT-WGS) is a novel approach to expanding genomic surveillance of respiratory infections. To date however, there are limited data on the genomic stability of these viruses on RATs. In this study, we investigated the effect of storage conditions and nucleic acid preservatives on the ability to enhance stability and improve recovery of respiratory virus genomes from RATs. METHODS: A mixture of common respiratory viruses was used to inoculate RATs at different environmental temperatures (4°C, 20°C and 36°C), with two preservative reagents (RNALater and DNA/RNA shield) Nucleic acid was extracted from RATs at two different timepoints (72 h and seven days) and subject to real-time multiplex respiratory PCR to detect a range of respiratory viruses. WGS was performed using target-enrichment with the TWIST Comprehensive Viral Research Panel. Defined metrics from an automated in-house bioinformatic pipeline were used to assess and compare viral genome recovery under different conditions. RESULTS: Nucleic acid degradation (indicated by relative change in PCR cycle threshold and WGS-based metrics) was most notable at 20 °C and 36 °C. Storage in either RNALater or DNA / RNA shield improved genome recovery for respiratory viruses across all temperature conditions, although this was most pronounced for RNALater. Subtyping of Influenza viruses demonstrated the applicability of RAT-WGS in downstream genomic epidemiological surveillance. CONCLUSIONS: Under simulated conditions, RAT-WGS demonstrated that (i) viral genomes were generally stable at 4°C at 72 h and 1 week, (ii) RNALater has a more significant preservation of nucleic acids compared to DNA/RNA Shield and (iii) genome recovery can be achieved using a sequencing depth of 500,000 reads per sample in RNALater, across all respiratory viruses and conditions.

Longitudinal evaluation of laboratory-based serological assays for SARS-CoV-2 antibody detection.

Serological assays for SARS-CoV-2 infection are now widely available for use in diagnostic laboratories. Limited data are available on the performance characteristics in different settings, and at time periods remote from the initial infection. Validation of the Abbott (Architect SARS-CoV-2 IgG), DiaSorin (Liaison SARS-CoV-2 S1/S2 IgG) and Roche (Cobas Elecsys Anti-SARS-CoV-2) assays was undertaken utilising 217 serum samples from 131 participants up to 7 months following COVID-19 infection. The Abbott and DiaSorin assays were implemented into routine laboratory workflow, with outcomes reported for 2764 clinical specimens. Sensitivity and specificity were concordant with the range reported by the manufacturers for all assays. Sensitivity across the convalescent period was highest for the Roche at 95.2-100% (95% CI 81.0-100%), then the DiaSorin at 88.1-100% (95% CI 76.0-100%), followed by the Abbott 68.2-100% (95% CI 53.4-100%). Sensitivity of the Abbott assay fell from approximately 5 months; on this assay paired serum samples for 45 participants showed a significant drop in the signal-to-cut-off ratio and 10 sero-reversion events. When used in clinical practice, all samples testing positive by both DiaSorin and Abbott assays were confirmed as true positive results. In this low prevalence setting, despite high laboratory specificity, the positive predictive value of a single positive assay was low. Comprehensive validation of serological assays is necessary to determine the optimal assay for each diagnostic setting. In this low prevalence setting we found implementation of two assays with different antibody targets maximised sensitivity and specificity, with confirmatory testing necessary for any sample which was positive in only one assay.

Protein adhesins as vaccine antigens for Group A Streptococcus.

Group A Streptococcus (GAS) is a globally important human pathogen that causes a broad spectrum of disease ranging from mild superficial infections to severe invasive diseases with high morbidity and mortality. Currently, there is no vaccine available for human use. GAS produces a vast array of virulence factors including multiple adhesin molecules. These mediate binding of the bacteria to host tissues and are essential in the initial phases of infection. Prophylactic vaccination with adhesins is a promising vaccine strategy and many GAS adhesins are currently in development as vaccine candidates. The most advanced candidates, having entered clinical trials, are based on the M protein, while components of the pilus and a number of fibronectin-binding proteins are in pre-clinical development. Adhesin-based vaccines aim to induce protective immunity via two main mechanisms: neutralisation where adhesin-specific antibodies block the ability of the adhesin to bind to host tissue and opsonisation in which adhesin-specific antibodies tag the GAS bacteria for phagocytosis. This review summarises our current knowledge of GAS adhesins and their structural features in the context of vaccine development.

Estimating the likely true changes in rheumatic fever incidence using two data sources.

Acute rheumatic fever (ARF) continues to produce a significant burden of disease in New Zealand (NZ) Maori and Pacific peoples. Serious limitations in national surveillance data mean that accurate case totals cannot be generated. Given the changing epidemiology of ARF in NZ and the major national rheumatic fever prevention programme (2012-2017), we updated our previous likely true case number estimates using capture-recapture analyses. Aims were to estimate the likely true incidence of ARF in NZ and comment on the changing ability to detect cases. Data were obtained from national hospitalisation and notification databases. The Chapman Estimate partially adjusted for bias. An estimated 2342 likely true new cases arose from 1997 to 2015, giving a mean annual incidence of 2·9 per 100 000 (95% CI 2·5-3·5). Compared with the pre-intervention (2009-2011) baseline incidence (3·4 per 100 000, 95% CI 2·9-4·0), the likely true 2015 incidence declined 44%. Large gaps in data completeness are slowly closing. During the period 2012-2015, 723 cases were identified; 83·8% of notifications were matched to hospitalisation data, and 87·2% of hospitalisations matched to notifications. Despite this improvement, clinicians need to remain aware of the need to notify atypical patients. A possible unintended consequence of the national ARF prevention programme is increased misdiagnosis.

Markers of dietary protein intake are associated with successful weight loss in the POUNDS Lost trial.

To assess the association of markers for dietary protein intake, measures of dietary adherence and demographic variables with weight loss in the POUNDS Lost study over the first 6 months and again between 6 and 24 months using data from those who completed each period. This is a secondary analysis of pooled data on completers assigned to one of four diets: 65%C/15%P/20%F (AP/LF), 55%C/25%P/20%F (HP/LF), 45%C/15%P/40%F (AP/HF) or 35%C/25%P40%F (HP/HF) in the POUNDS Lost study. Urinary nitrogen excretion, dietary adherence measured by 24-h recall and attendance at sessions, age (above and below 50 years), gender, race/ethnicity and activity by pedometry were analysed. Increased spread between protein intake at baseline and protein at 6 or 24 months, assessed by urinary nitrogen excretion, was associated with greater weight loss from baseline to 2 years. At 6 and 24 months, older age, male gender, body mass index > 30 kg m-2 and adherence to the fat and protein diets were associated with more weight loss. None of these variables was associated with a regain from 6 to 24 months. Weight regain for women in the highest carbohydrate (65%) group was significantly greater (-4.4 kg [95% CI: -5.9, -3.0]) than for women in the lowest carbohydrate group (-1.8 kg [95% CI: -3.2, -0.4 kg]) (P for interaction = 0.012). An increased spread in the difference between baseline and follow-up protein intake was associated with greater weight loss, consistent with the 'protein spread theory'. Women eating the highest carbohydrate diet regained more weight from 6 to 24 months.

Asymptomatic and symptomatic urethral gonorrhoea in men who have sex with men attending a sexual health service.

OBJECTIVES: Guidelines regarding whether men who have sex with men (MSM) without symptoms of urethritis should be screened for urethral gonorrhoea differ between countries. We examined the rate of asymptomatic urethral gonorrhoea in MSM using sensitive nucleic acid amplification testing. METHODS: This study was conducted on consecutive MSM attending the Melbourne Sexual Health Centre between July 2015 and May 2016 for sexually transmitted infections screening. Gonorrhoea testing with the Aptima Combo 2 (AC2) assay was performed on all urine specimens obtained from MSM, whether symptoms of urethritis were present or not. Men were classified as having: typical discharge if they reported symptoms suggesting purulent discharge; other symptoms if they reported other symptoms of urethritis; and no symptoms if they reported no urethral symptoms. RESULTS: During the study period, there were 7941 clinic visits by 5947 individual MSM with 7090 urine specimens obtained from 5497 individual MSM tested with the AC2 assay. Urethral gonorrhoea was detected in 242 urine specimens from 228 individual MSM. The majority (189/242, 78%, 95% CI 73-83) reported typical discharge, 27/242 (11%, 95% CI 8-16) reported other urethral symptoms, and 26/242 (11%, 95% CI 7-15) reported no symptoms on the day of presentation and testing. Among men with urethral gonorrhoea, the proportions with concurrent pharyngeal or rectal gonorrhoea were 32% (134/210) and 64% (74/235), respectively. The mean interval between last reported sexual contact and onset of typical urethral discharge, where present, was 3.9 days. CONCLUSION: The findings from our study lend support to guidelines that recommend screening asymptomatic MSM for urethral gonorrhoea.

Staphylococcus aureus 'Down Under': contemporary epidemiology of S. aureus in Australia, New Zealand, and the South West Pacific.

The clinical and molecular epidemiology of Staphylococcus aureus disease has changed considerably over the past two decades, particularly with the emergence and spread of community-associated methicillin-resistant S. aureus (CA-MRSA) clones. Indeed, some of the first global descriptions of CA-MRSA were from remote indigenous communities in Western Australia, and from Pacific Peoples in New Zealand. The epidemiology of S. aureus infections in the South West Pacific has several unique features, largely because of the relative geographical isolation and unique indigenous communities residing in this region. In particular, a number of distinct CA-MRSA clones circulate in Australia and New Zealand, such as sequence type (ST) 93 methicillin-resistant S. aureus (MRSA) (Queensland clone) and clonal complex 75 S. aureus (Staphylococcus argenteus) in Australia, and ST30 MRSA (Southwest Pacific clone) in New Zealand. In addition, there is a disproportionate burden of S. aureus disease in indigenous paediatric populations, particularly in remote Aboriginal communities in Australia, and in Pacific Peoples and Maori in New Zealand. In this review, we provide a contemporary overview of the clinical and molecular epidemiology of S. aureus disease in the South West Pacific region, with a particular focus on features distinct to this region.

Clinical and molecular epidemiology of community-onset invasive Staphylococcus aureus infection in New Zealand children.

Our aim was to describe the epidemiology and incidence of community-onset invasive S. aureus disease in children presenting to our hospital, and to compare the clonal complexes and virulence genes of S. aureus strains causing invasive and non-invasive disease. The virulence gene repertoire of invasive disease isolates was characterized using DNA microarray and compared with the virulence gene repertoire of non-invasive S. aureus isolates. Over the study period, 163 children had an invasive S. aureus infection. There was no difference in the distribution of clonal complexes or in the prevalence of genes encoding virulence factors between invasive and non-invasive isolates. Future research should include a strong focus on identifying the host and environmental factors that, along with organism virulence factors, are contributing to the patterns of invasive S. aureus disease observed in New Zealand.

Multi-profile hidden Markov model for mood, dietary intake, and physical activity in an intervention study of childhood obesity.

Motivated by an application to childhood obesity data in a clinical trial, this paper describes a multi-profile hidden Markov model (HMM) that uses several temporal chains of measures respectively related to psychosocial attributes, dietary intake, and energy expenditure behaviors of adolescents in a school setting. Using these psychological and behavioral profiles, the model delineates health states from the longitudinal data set. Furthermore, a two-level regression model that takes into account the clustering effects of students within school is used to assess the effects of school-based and community-based interventions and other risk factors on the transition between health states over time. The results from our study suggest that female students tend to decrease their physical activities despite a high level of anxiety about weight. The finding is consistent across intervention and control arms.

Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy Phase 2 (CALERIE Phase 2) screening and recruitment: methods and results.

The Comprehensive Assessment of the Long-term Effects of Reducing Intake of Energy Phase 2 (CALERIE) study is a systematic investigation of sustained 25% calorie restriction (CR) in non-obese humans. CALERIE is a multicenter (3 clinical sites, one coordinating center), parallel group, randomized controlled trial. Participants were recruited, screened, and randomized to the CR or control group with a 2:1 allocation. Inclusion criteria included ages 21-50 years for men and 21-47 years for women, and a body mass index (BMI) of 22.0 ≤ BMI < 28.0 kg/m(2). Exclusion criteria included abnormal laboratory markers, significant medical conditions, psychiatric/behavioral problems, and an inability to adhere to the rigors of the evaluation/intervention schedule. A multi-stage screening process (telephone screen and 3 in-clinic visits) was applied to identify eligible participants. Recruitment was effective and enrollment targets were met on time. 10,856 individuals contacted the clinical sites, of whom 9787 (90%) failed one or more eligibility criteria. Of the 1069 volunteers who started the in-clinic screening, 831 (78%) were either ineligible or dropped. 238 volunteers were enrolled (i.e., initiated the baseline evaluations), 220 were randomized, and 218 started the assigned intervention (2% from the first screening step). This study offered lessons for future multi-center trials engaging non-disease populations. Recruitment strategies must be tailored to specific sites. A multi-disciplinary screening process should be applied to address medical, physical, and psychological/behavioral suitability of participants. Finally, a multi-step screening process with simple criteria first, followed by more elaborate procedures has the potential to reduce the use of study resources.

Diet type and changes in food cravings following weight loss: findings from the POUNDS LOST Trial.

Few well-controlled trials have evaluated the effects that macronutrient composition has on changes in food cravings during weight loss treatment. The present study, which was part of the Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) trial, investigated whether the fat and protein content of four different diets affected changes in specific food cravings in overweight and obese adults. A sample of 811 adults were recruited across two clinical sites, and each participant was randomly assigned to one of four macronutrient prescriptions: 1) low fat (20% of energy), average protein (15% of energy); 2) moderate fat (40%), average protein (15%); 3) low fat (20%), high protein (25%); 4) moderate fat (40%), high protein (25%). With few exceptions, the type of diet that participants were assigned did not differentially affect changes in specific food cravings. Participants assigned to the high-fat diets, however, had reduced cravings for carbohydrates at month 12 (p<0.05) and fruits and vegetables at month 24. Also, participants assigned to high-protein diets had increased cravings for sweets at month 6 and month 12 (ps<0.05). Participants in all four dietary conditions reported significant reductions in food cravings for specific types of foods (i.e., high fat foods, fast food fats, sweets, and carbohydrates/starches; all ps<0.05). Cravings for fruits and vegetables, however, were increased at month 24 (p<0.05). Calorically restricted diets (regardless of their macronutrient composition) yielded significant reductions in cravings for fats, sweets, and starches whereas cravings for fruits and vegetables were increased.

Estimation of lean body weight in older women with hip fracture.

OBJECTIVE: Lean body weight (LBW) decreases with age while total body fat increases, resulting in altered drug pharmacokinetics. A semi-mechanistic equation estimating LBW using height, weight and sex has been developed for potential use across a wide range of body compositions. The aim of this study was to determine the ability of the LBW equation to estimate dual energy x-ray absorptiometry-derived fat free mass (FFM(DXA)) in a population of older women with recent hip fracture. METHODS: Baseline, four and 12 month data obtained from 23 women enrolled in the Sarcopenia and Hip Fracture study were pooled to give 58 measurements. LBW was estimated using the equation: LBW (kg) = (9270 x Wt) / (8780 + (244 x BMI)). Body composition was classified as: 'normal' (BMI <25kg/m(2) and not sarcopenic), 'overweight-obese' (BMI >25kg/m(2) and not sarcopenic), 'sarcopenic' (sarcopenic and BMI <25kg/m(2)), or 'sarcopenic-obese' (sarcopenic and BMI >25kg/m(2)). The ability of the LBW equation to predict FFMDXA was determined graphically using Bland-Altman plots and quantitatively using the method of Sheiner and Beal. RESULTS: The mean ± SD age of female participants women was 83±7 years (n=23). Sarcopenia was frequently observed (65.2%). Bland-Altman plots demonstrated an underestimation by the LBW equation compared to FFMDXA. The bias (95% CI) and precision (95% CI) calculated using the method of Sheiner and Beal was 0.5kg (-0.7, 1.66kg) and 4.4kg (-3.7, 12.4kg) respectively for pooled data. CONCLUSION: This equation can be used to easily calculate LBW. When compared to FFMDXA, the LBW equation resulted in a small underestimation on average in this population of women with recent hip fracture. The degree of bias may not be clinically important although further studies of larger heterogeneous cohorts are needed to investigate and potentially improve the accuracy of this predictive equation in larger clinical cohorts.

Comparative epidemiology of CTX-M-14 and CTX-M-15 producing Escherichia coli: association with distinct demographic groups in the community in New Zealand.

Extended spectrum beta-lactamase producing E. coli (ESBL-EC) are an emerging public health issue. In New Zealand (NZ), bla (CTX-M-14) and bla (CTX-M-15) are the most common ESBL genes. Although many studies describe risk factors for ESBL-EC, few describe risk factors for specific ESBL genes. Between January 2006 and December 2007, we characterized 108 consecutive, non-duplicate isolates of ESBL-EC at the Auckland Hospital laboratory. Demographic and clinical data were recorded. Of the 108, 54.6% (59) were CTX-M-15-EC, 26.9% (29) were CTX-M-14-EC and 12.09% were CTX-M-9 (13). The remaining seven isolates carried CTX-M-3 (3; 2.7%), CTX-M-65 (2; 1.8%), CTX-M-27 (1; 0.9%) and CTX-M-57 (1; 0.9%). CTX-M-15-EC were more likely than CTX-M-14-EC to be fluoroquinolone-resistant (86.4% versus 32.4%; p=0.006) and to be non-susceptible to amoxicillin-clavulanate (84.7% versus 41.4%; p=0.0001). Patients with CTX-M-15-EC were more likely to be of Indian ethnicity (34.5% versus 0%; p=0.0012) and to have travelled recently (31.6% versus 4%; p=0.0088). Patients with CTX-M-14-EC were more likely to have Chinese or South-East Asian ethnicity (48.1% versus 5.2%; p<0.0001) and to have no history of either travel or prior hospital admission (44% versus 8.9%; p=0.0006). These data imply that CTX-M-15 and CTX-M-14 producing E. coli are associated with distinct demographic subgroups in NZ.

Clinical failures associated with rpoB mutations in phenotypically occult multidrug-resistant Mycobacterium tuberculosis.

SETTING: Recently, Mycobacterium tuberculosis isolates have been described that test phenotypically susceptible to rifampicin (RMP) yet harbour genotypic rpoB mutations. OBJECTIVE: 1) To investigate the impact of such mutations on clinical outcomes among RMP-susceptible isolates, and 2) to determine the prevalence of rpoB mutations among isoniazid (INH) monoresistant isolates at our laboratory and to describe the association between the presence of these mutations and clinical outcomes. METHODS: M. tuberculosis isolates were screened for mutations in the rpoB gene using the Cepheid Gene-Xpert® MTB/RIF assay. Clinical correlation was made by reviewing patient case notes. RESULTS: Isolates from 94 patients were found to have INH-resistant, RMP-susceptible profiles. Clinical information was available for 52 patients, including three whose isolates had rpoB mutations. All three of these patients had treatment failures, compared to two of 49 patients whose isolates did not have rpoB mutations (P = 0.0005). DISCUSSION: We demonstrate a significant association between the presence of rpoB gene mutations that are not detected at the current RMP critical concentration and treatment failure. We suggest that a review of the current RMP critical concentration is warranted to ensure that RMP is not used inappropriately for the treatment of phenotypically occult multidrug-resistant tuberculosis.

High rates of susceptibility to ceftazidime among globally prevalent CTX-M-producing Escherichia coli: potential clinical implications of the revised CLSI interpretive criteria.

The CTX-M family of extended-spectrum ß-lactamases (ESBLs) is a significant global public health threat. The prevalence of specific bla (CTX-M) genes varies geographically, but bla (CTX-M-15) and bla (CTX-M-14) dominate in most countries. We applied the latest Clinical Laboratory Standards Institute (CLSI) interpretive criteria (M100-S20) to a diverse collection of ESBL-producing Escherichia coli strains obtained from clinical specimens in our laboratory. Whereas under previous CLSI recommendations all isolates in this strain collection would have been reported as ceftazidime-resistant, under the new recommendations, approximately 11% of CTX-M-15-producing E. coli and 93% of CTX-M-14-producing E. coli respectively tested as ceftazidime-susceptible. We also found that, whilst many CTX-M-14-producers had minimum inhibitory concentrations (MICs) less than the breakpoint of 4 mg/L, the MIC distribution for these strains was higher than that of wild-type E. coli, with one CTX-M-14-producing isolate having an MIC of >64 mg/L. Although the new CLSI recommendations imply that ceftazidime can be safely used to treat serious infections due to CTX-M-producing E. coli, clinical outcome data are lacking. Consequently, the widespread use of ceftazidime in this setting could have profound clinical implications.

Effect of calorie restriction on subjective ratings of appetite.

BACKGROUND: Energy or calorie restriction (CR) has consistently been shown to produce weight loss and have beneficial health effects in numerous species, including primates and humans. Most individuals, however, are unable to sustain weight losses induced through reductions in energy intake, potentially due to increased hunger levels. The effects that prolonged CR has on subjective aspects of appetite have not been well studied. Thus, the present study tested the effect of 6 months of caloric restriction on appetite in healthy, overweight men and women. METHODS: Forty-eight overweight men and women with a body mass index (BMI; kg m(-2)) between 25-29.9 took part in a 6-month study and were randomised into one of four groups: healthy diet (control); 25% CR; 12.5% CR plus exercise (12.5% increased energy expenditure; CR + EX); low-calorie diet [LCD; 3724 kJ day(-1) (890 kcal day(-1)) until 15% of initial body weight was lost, then maintenance]. Appetite markers (i.e. hunger, fullness, desire to eat, etc.) were assessed weekly during a fasting state. RESULTS: Body weight was significantly reduced in all three energy-restricted groups (CR = -10.4 +/- 0.9%; CR + EX = -10.0 +/- 0.8%; and LCD = -13.9 +/-0.7%), indicating that participants were adherent to their energy restriction regimen, whereas the healthy diet control group remained weight stable (control = -1.0 +/- 1.1%). Despite these significant weight losses, appetite ratings of participants in the three energy-restricted groups at month 6 were similar to the weight stable control group. CONCLUSIONS: CR regimens with low fat diets producing significant weight losses have similar effects on appetite markers over a 6-month time period compared to a weight stable control group.

Intervening with coaches to promote awareness and prevention of weight pressures in cheerleaders.

Research has found that athletes, particularly those involved in "aesthetically oriented" sports, experience significant pressures for thinness and are at increased risk for developing eating disorders. This study targeted cheerleading coaches as potential change agents by training them to recognize the symptoms of eating disorders and reduce the pressures for thinness among their squads. Cheerleading coaches at national or regional conferences attended an intervention workshop or a control workshop. Coaches who attended the intervention workshop received information regarding negative coaching behaviors, the symptoms of eating disorders, and ways to manage athletes with eating disorders. In addition, intervention coaches were encouraged to participate in six intervention strategies (e.g., reading materials, video, parent handouts, etc.) after attending the workshop. Eight months following the workshop, the coaches completed an assessment battery designed to test the effectiveness of the entire intervention. The results indicated that the intervention was successful in producing behavior changes in coaches. However, the intervention was less successful in producing long-term change in knowledge about eating disorders. These findings imply that interventions can be implemented by important adult figures (e.g., coaches, teachers) but the overall effectiveness of these interventions must be enhanced in order to have a significant and long-term impact.

Psychosocial and behavioral pre-treatment predictors of weight loss outcomes.

OBJECTIVE: This study tested whether baseline behavioral and psychological variables predict weight and fat loss among overweight, non-obese individuals participating in a six-month calorie restriction trial. Participants (N=48) were randomly assigned to four groups, three of which included a calorie restriction program and one of which served as a healthy diet weight maintenance control. For the purposes of this study, data were analyzed only for participants assigned to the three calorie restriction groups (n=36). Ten psychological and behavioral measures were investigated through principal components factor analysis to examine whether these measures were assessing similar or distinct psychological and behavioral constructs. Based on the obtained six-factor solution, one measure from each domain was selected for inclusion in hierarchical regression analyses, which was used to test the relative importance of psychosocial and behavioral variables in predicting percent weight and fat loss over six months. After controlling for demographic and treatment variables, the behavioral and psychological measures of negative mood states, poor psychosocial functioning, and somatic symptoms were associated with less weight loss (R2=0.68, p<0.001) and fat loss (R2=0.65, p<0.001) over six months. Among overweight individuals, poor psychological adjustment, somatic symptoms, and negative mood states appear to form a psychosocial profile that is predictive of less weight and fat loss in calorie restriction programs.

Association of depression with Body Mass Index, sedentary behavior, and maladaptive eating attitudes and behaviors in 11 to 13-year old children.

We examined the relation of different behavioral dimensions of depression with weight-related variables (BMI percentile, sedentary behavior, eating attitudes, and weight control behaviors) in children aged 11 to 13 years. Depression was assessed using the Children's Depression Inventory (CDI). Sedentary behavior was measured in 45 sixth grade students (23 boys and 22 girls) using a validated 24-hour recall instrument, the Self-Administered Physical Activity Checklist. BMI was calculated directly from measured height and weight (kg/m2). The Children's Eating Attitudes Test (ChEAT) was used to measure eating attitudes and weight control behaviors. There were not significant gender differences in reported minutes (142 vs. 91 minutes for boys vs. girls; p=0.25) of sedentary behavior (i.e., television watching and video game playing). The major finding of this study was that certain aspects of depression (i.e., interpersonal problems and feelings of ineffectiveness) were correlated with higher levels of sedentary behavior in children aged 11 to 13. A factor analysis of the study variables indicated that most dimensions of depression, sedentary behavior, and body size represent distinct but correlated behavioral dimensions. This study provides support for a link between specific aspects of depression (i.e., interpersonal problems and feelings of ineffectiveness) and sedentary behavior in children.