Assessing physical activity in people with mental illness: 23-country reliability and validity of the simple physical activity questionnaire (SIMPAQ).

BACKGROUND: Physical inactivity is a key contributor to the global burden of disease and disproportionately impacts the wellbeing of people experiencing mental illness. Increases in physical activity are associated with improvements in symptoms of mental illness and reduction in cardiometabolic risk. Reliable and valid clinical tools that assess physical activity would improve evaluation of intervention studies that aim to increase physical activity and reduce sedentary behaviour in people living with mental illness. METHODS: The five-item Simple Physical Activity Questionnaire (SIMPAQ) was developed by a multidisciplinary, international working group as a clinical tool to assess physical activity and sedentary behaviour in people living with mental illness. Patients with a DSM or ICD mental illness diagnoses were recruited and completed the SIMPAQ on two occasions, one week apart. Participants wore an Actigraph accelerometer and completed brief cognitive and clinical assessments. RESULTS: Evidence of SIMPAQ validity was assessed against accelerometer-derived measures of physical activity. Data were obtained from 1010 participants. The SIMPAQ had good test-retest reliability. Correlations for moderate-vigorous physical activity was comparable to studies conducted in general population samples. Evidence of validity for the sedentary behaviour item was poor. An alternative method to calculate sedentary behaviour had stronger evidence of validity. This alternative method is recommended for use in future studies employing the SIMPAQ. CONCLUSIONS: The SIMPAQ is a brief measure of physical activity and sedentary behaviour that can be reliably and validly administered by health professionals.

Association between obesity and risk of chronic kidney disease: A nationwide Cohort study in Taiwan.

BACKGROUND AND AIMS: Increased body fat relates to enhanced inflammatory cytokine production, which, in turn, activates the renin-angiotensin-aldosterone system and increases the risk of chronic kidney disease (CKD). Herein, we aimed to examine the association between obesity and the risk of CKD in a population-representative cohort in Taiwan. METHODS AND RESULTS: A multistage systematic sampling process was applied in the National Health Interview Survey (NHIS) 2000, 2005, and 2009. Participants were interviewed by a standardized face-to-face questionnaire to obtain information on their demographics, socioeconomic status, lifestyle factors, and body mass index (BMI). The BMI values were classified as follows: underweight (<18.5 kg/m2), normal (18.5-23.9 kg/m2), overweight (24-26.9 kg/m2), and obesity (≥27 kg/m2). The NHIS dataset was linked to National Health Insurance claims data to identify the incidence of CKD. Univariate and multivariate Cox proportional hazard models with competing risks were used to investigate the association between BMI and CKD incidence. We analyzed 45,012 subjects (mean age, 42.03 years; 50.09% males). During 374,254 person-years of follow-up, a total of 1913 new-onset CKD cases were identified. Kaplan-Meier curves comparing the four BMI groups revealed a significant difference (p < 0.01, log-rank test). After controlling for confounding factors, the relative risk of incident CKD was significantly higher in the obese group compared to the normal-weight group (adjusted hazard ratio = 1.32; 95% confidence interval: 1.17-1.49), with a significant linear trend (p < 0.01). CONCLUSION: Obesity was suggested as an independent risk factor for CKD. Further studies focusing on the effect of losing weight on CKD prevention are warranted.

Obesity/overweight reduces the risk of active tuberculosis: a nationwide population-based cohort study in Taiwan.

BACKGROUND: Obesity affects immune function by increasing the number of T helper lymphocytes, which may reduce the risk of tuberculosis (TB) infection. However, the effect of obesity on TB development has not been extensively studied. This nationwide population-based cohort study investigated the effect of obesity on TB development in Taiwanese adults. METHODS: We included 46 028 adult participants (age ⩾18 years) from three rounds (2001, 2005 and 2009) of the Taiwan National Health Interview Survey. Obesity and overweight were defined as a body mass index (BMI) ⩾27 and 24-26.9 (kg/m2), respectively. Data on BMI and other covariates at baseline were collected by in-person interviews. Incident cases of active TB were identified from the National Health Insurance database. Multivariable logistic regression was used to estimate the associations of obesity and overweight with active TB, with adjustment for age, sex, smoking, alcohol consumption, socioeconomic status and other covariates. RESULTS: In total, 241 new cases of active TB occurred during the study period. Obesity (adjusted odds ratio [AOR], 0.43; 95% confident interval [CI], 0.28-0.67) and overweight (AOR, 0.67; 95% CI, 0.49-0.91) were associated with lower risk of incident TB, after adjusting for demographic characteristics and comorbidities. There was a linear dose-response relation of BMI with active TB incidence (AOR per unit change in BMI, 0.92; 95% CI, 0.88-0.95; P <0.001). CONCLUSION: Obesity and overweight are associated with lower risk of active TB. Future studies should investigate the underlying mechanisms and clinical and epidemiological consequences of these findings.

Association between actigraphy-derived physical activity and cognitive performance in patients with schizophrenia.

BACKGROUND: An association between low levels of physical activity and impaired cognitive performance in schizophrenia has been proposed, but most studies have relied on self-report measures of activity. This study examined the association between actigraphy-derived physical activity and cognitive performance adjusting for multiple covariates in patients with schizophrenia. METHOD: Patients with schizophrenia (n = 199) were recruited from chronic psychiatric wards, and 60 age-, sex- and body mass index-matched comparison participants were recruited from the staff of two hospitals and universities. Physical activity was assessed objectively for 7 days using an ActiGraph. Cognitive performance was assessed with the Cognitrone test from the Vienna Test System and the Grooved Pegboard Test. Demographic variables, metabolic parameters, positive and negative symptoms, duration of illness and hospitalization, and medication use were included as covariates. Pearson correlations and multivariable linear regressions were conducted to examine the associations between physical activity levels and cognitive performance. RESULTS: Patients with schizophrenia were less physically active and had poorer performance on attention/concentration and speed of processing than the comparison group. Patients with schizophrenia who spent more time in light physical activity showed better performance on attention/concentration (ß = 0.198, p = 0.020) and speed of processing (ß= -0.169, p = 0.048) tasks than those who were less active. Cognitive performance was also associated with moderate-vigorous physical activity, but the effect was no longer significant once light physical activity had been taken into account. CONCLUSIONS: This study provides evidence for a positive association between objectively measured light physical activity and cognitive performance in people with schizophrenia, after adjustment for multiple confounders.

Modelling the vicious circle between obesity and physical activity in children and adolescents using a bivariate probit model with endogenous regressors.

The increasing prevalence of obesity in children and adolescents has become one of the most important public health issues around the world. Lack of physical activity is a risk factor for obesity, while being obese could reduce the likelihood of participating in physical activity. Failing to account for the endogeneity between obesity and physical activity would result in biased estimation. This study investigates the relationship between overweight and physical activity by taking endogeneity into consideration. It develops an endogenous bivariate probit model estimated by the maximum likelihood method. The data included 4008 boys and 4197 girls in the 5th-9th grades in Taiwan in 2007-2008. The relationship between overweight and physical activity is significantly negative in the endogenous model, but insignificant in the comparative exogenous model. This endogenous relationship presents a vicious circle in which lower levels of physical activity lead to overweight, while those who are already overweight engage in less physical activity. The results not only reveal the importance of endogenous treatment, but also demonstrate the robust negative relationship between these two factors. An emphasis should be put on overweight and obese children and adolescents in order to break the vicious circle. Promotion of physical activity by appropriate counselling programmes and peer support could be effective in reducing the prevalence of obesity in children and adolescents.