Diet and physical activity as possible mediators of the association between educational attainment and body mass index gain among Australian adults.

OBJECTIVES: To quantify the mediating role of leisure time physical activity (LTPA) and five dietary behaviours on educational differences in 13-year body mass index (BMI) gain across adulthood. METHODS: Participants from the Melbourne Collaborative Cohort Study (4791 women; 3103 men) who maintained or gained BMI over 1990-1994 to 2003-2007 and met our inclusion criteria were selected. Education, potential mediators and confounders (age, alcohol, and smoking) were measured at baseline. We conducted sex-specific multiple mediation analyses using MacKinnon's product of coefficients method. RESULTS: A higher educational attainment was associated with a 0.27 kg m-2 (95% CI 0.14, 0.39) lesser 13-year BMI gain among women only. We observed significant indirect effects of educational attainment on 13-year BMI gain through LTPA and nutrient-rich foods (each associated with a higher educational attainment and lesser 13-year BMI gain) and diet soft drink (associated with a lower educational attainment and greater 13-year BMI gain), which mediated 10, 15 and 20% of this relationship, respectively (45% in total). CONCLUSIONS: Nutrient-rich foods, LTPA and diet soft drink may represent effective public health targets to reduce inequities in excess weight across adulthood.

The relationship between excessive daytime sleepiness, disability, and mortality, and implications for life expectancy.

OBJECTIVE: To assess the relationship between excessive daytime sleepiness (EDS), disability, mortality, and life expectancy (with and without disability) in a cohort of middle-aged American adults. METHODS: The Wisconsin Longitudinal Study, a life-course study on 10,317 high school graduates from Wisconsin, was used to assess the odds ratio (OR) between EDS in 2004 for prevalent and incident disability to 2011 through multiple logistic regression, and to estimate the hazard ratio (HR) of EDS in 2004 for mortality over ten years through a Cox proportional hazard model. We estimated age and sex-specific rates for mortality and disability from US nation-wide survey data in 2004. Combining these data with age-, sex- and EDS-specific mortality rates and disability prevalence estimated from our study, we constructed Sullivan life tables for those with and without EDS. Life expectancy (total, with, and without disability) from age 60 was estimated for those with and without EDS. RESULTS: The study participants were on average 64 years old and 47% were men. Those with EDS were more likely to develop disability than those without (OR 1.40, 95%CI 1.01-1.95). The HR for mortality associated with having EDS was 1.43 (95%CI 1.11-1.85). The results from life table analysis suggest that a sixty-year-old individual with EDS had a four-year decrease in disability-free life years, and no change in years lived with disability. CONCLUSIONS: EDS is associated with higher likelihood of disability, increased risk of mortality, and substantially shorter disability-free life expectancy at age 60.

The relationship between weight change and daytime sleepiness: the Sleep Heart Health Study.

OBJECTIVE: Through a causal framework, we aim to assess the association between weight change and daytime sleepiness, and the role of obstructive sleep apnoea (OSA) in this relationship. METHODS: From the Sleep Heart Health Study, we selected individuals who were: (1) 40-64 years old, with (2) body mass index (BMI) ≥18.5 kg/m2, (3) no history of stroke, treatment for OSA, and tracheostomy at baseline. We used multiple linear regression to assess the relationship between five-year weight change and daytime sleepiness (assessed through Epworth Sleepiness Scale (ESS)) at five years, adjusting for daytime sleepiness, demographics, diabetes, subjective sleep duration, sleep disturbance, smoking status, weight, and use of antidepressants and benzodiazepines at baseline, in those with complete data (N = 1468). We further assessed the potential mediating role of OSA in this relationship. RESULTS: At baseline, the study participants were on average 55 years old, 46% males, with mean BMI 28 kg/m2; and 25% had ESS>10. ESS at five years worsened by 0.36 units (95% confidence interval (CI) 0.12-0.61, p = 0.004) with every 10-kg weight gain. When stratified by sex, this relationship was only found in women (0.55, 95% CI 0.25-0.86, p < 0.001; p-interaction = 0.02). Approximately one-fifth of the relationship between weight change and daytime sleepiness was mediated by severity of OSA at five years. CONCLUSION: Weight gain has a detrimental effect on daytime sleepiness, mostly through pathways other than OSA. This study provides further evidence and understanding of the relationship between obesity and excessive daytime sleepiness.

Change in Use of Sleep Medications After Gastric Bypass Surgery or Intensive Lifestyle Treatment in Adults with Obesity.

OBJECTIVE: To examine the change in use of hypnotics and/or sedatives after gastric bypass surgery or intensive lifestyle modification in adults with obesity. METHODS: Adults with obesity who underwent gastric bypass surgery or initiated intensive lifestyle modification between 2007 and 2012 were identified through the Scandinavian Obesity Surgery Registry and a Swedish commercial weight loss database. The two cohorts were matched on BMI, age, sex, education, history of hypnotics and/or sedatives use, and treatment year (surgery n = 20,626; lifestyle n = 11,973; 77% women, mean age 41 years, mean BMI 41 kg/m2 ). The proportion of participants with filled hypnotics and/or sedatives prescriptions was compared yearly for 3 years. RESULTS: In the matched treatment cohorts, 4% had filled prescriptions for hypnotics and/or sedatives during the year before treatment. At 1 year follow-up, following an average weight loss of 37 kg and 18 kg in the surgery and intensive lifestyle cohorts, respectively, this proportion had increased to 7% in the surgery cohort but remained at 4% in the intensive lifestyle cohort (risk ratio 1.7; 95% CI: 1.4-2.1); at 2 years, the proportion had increased to 11% versus 5% (risk ratio 2.0; 95% CI: 1.7-2.4); and at 3 years, it had increased to 14% versus 6% (risk ratio 2.2; 95% CI: 1.9-2.6). CONCLUSIONS: Gastric bypass surgery was associated with increased use of hypnotics and/or sedatives compared with intensive lifestyle modification.

Trends in adult overweight and obesity prevalence in Mongolia, 2005-2013.

OBJECTIVE: To analyze trends in the prevalence of overweight and obesity among Mongolian adults during the past decade as measured by body mass index (BMI) and waist circumference (WC). METHODS: Data from the repeated cross-sectional surveys on the prevalence of noncommunicable disease risk factors conducted in 2005, 2009, and 2013 in Mongolia were used. Linear regression was used to quantify trends in mean BMI and WC, adjusted for age group, sex, and survey year. RESULTS: The age-standardized prevalence of obesity, denoted by the international BMI cutoff values, in men and women between 2005 and 2013 increased from 10.8% to 17.6% and from 18.9% to 26.4%, respectively. Using Asian-specific BMI cutoff values for men and women, the age-standardized prevalence of obesity between 2005 and 2013 increased from 20.0% to 32.8% and 33.4% to 43.7%, respectively. CONCLUSIONS: The prevalence of overweight and obesity has increased markedly between 2005 and 2013 similarly across all age groups and sexes. It is important to consider the use of Asian-specific cut-offs as the burden of obesity is twice as high as when using international BMI cutoffs. These data demonstrate the urgent need for obesity treatment, prevention, and monitoring in Mongolia.

Predictors of efficacy of GLP-1 agonists and DPP-4 inhibitors: A systematic review.

AIMS: To identify the determinants of efficacy of glucagon-like peptide-1 receptor agonists (GLP-1A) and dipeptidyl peptidase-4 inhibitors (DPP-4I). METHODS: MEDLINE and EMBASE were searched between 01/01/2011 and 15/08/2014 for randomized controlled trials of 12-52weeks' duration, which reported the change in glycated hemoglobin (HbA1c) from baseline as the primary end point, and reported data about predictors of efficacy of incretins. RESULTS: Among 4172 studies found, 77 studies reported data on baseline HbA1c, age, sex, ethnicity, body mass index (BMI), and history of diabetes in relation to change in HbA1c. For DPP-4I, 37 out of 47 studies reported a greater decrease in HbA1c among patients with higher baseline HbA1c. Most DPP-4I studies reported no variation in efficacy in regard to demographic characteristics or BMI. Among 17 studies reporting on GLP-1A, baseline higher HbA1c was reported as predictive of a greater response in 7 out of 9 studies; 13 studies reported data about other factors, without consistent findings. CONCLUSIONS: Current evidence suggests that higher baseline HbA1c is associated with a greater efficacy of both DPP-4I and GLP-1A therapies in lowering HbA1c. The roles of other potential predictors are less consistent across studies and require further investigation.

Quantifying the proportion of deaths due to body mass index- and waist circumference-defined obesity.

OBJECTIVE: To determine the risk of mortality associated with and quantify the deaths attributable to combinations of body mass index (BMI) and waist circumference (WC). METHODS: This study included 41,439 participants. For the hazard ratio (HR) calculation, adiposity categories were defined as: BMI(N) /WC(N) , BMI(N) /WC(O) , BMI(O) /WC(N) , and BMI(O) /WC(O) (N = non-obese, O = obese). For the population attributable fraction analysis, obesity was classified as: (i) obese by BMI and/or WC; (ii) obese by BMI; and (iii) obese by WC. Mortality data was complete to the end of 2012. RESULTS: The prevalence of BMI(N) /WC(N) , BMI(N) /WC(O) , BMI(O) /WC(N) , and BMI(O) /WC(O) was 73%, 6%, 6%, and 15%, respectively. There was an increased risk of all-cause and cardiovascular disease (CVD) mortality in those with BMI(N) /WC(O) (HR (95% CI) 1.2 (1.2, 1.3) and 1.3 (1.1, 1.6)) and BMI(O) /WC(O) (1.3 (1.3, 1.4) and 1.7 (1.5, 1.9)) compared to those with BMI(N) /WC(N) . The estimated proportion of all-cause and CVD mortality attributable to obesity defined using WC or using BMI and/or WC was higher compared to obesity defined using BMI. CONCLUSIONS: Current population obesity monitoring misses those with BMI(N) /WC(O) who are at increased risk of mortality. By targeting reductions in population WC, the potential exists to prevent more deaths in the population than if we continue to target reductions in BMI alone.

The Immediate and Sustained long-Term Changes in Daytime Sleepiness After Participation in a Workplace Pedometer Program: A Prospective Cohort Study.

OBJECTIVE: To assess the potential benefit of a workplace physical activity program on daytime sleepiness. METHODS: A total of 685 participants of a 4-month workplace physical activity program were assessed for daytime sleepiness (Epworth Sleepiness Scale [ESS]) at baseline, 4 months (postprogram), and 12 months. Changes in ESS were analyzed using multilevel mixed linear regression. RESULTS: In the total population, no changes in ESS scores were observed; 0 to 4 months: -0.2 (95% CI: -0.5 to 0.0), 4 to 12 months: 0.1 (95% CI: -0.2 to 0.4). In participants with baseline excessive daytime sleepiness (ESS > 10, n = 109), ESS scores improved significantly by -2.2 (95% CI: -3.0 to -1.4) at 4 months, sustained at 12 months; and almost half no longer had excessive daytime sleepiness by end of program. CONCLUSIONS: This study suggests that for employees with excessive daytime sleepiness, short- and long-term improvement in daytime sleepiness may be an unforeseen benefit of workplace physical activity programs.

Estimating the proportion of metabolic health outcomes attributable to obesity: a cross-sectional exploration of body mass index and waist circumference combinations.

BACKGROUND: Recent evidence suggests that a substantial subgroup of the population who have a high-risk waist circumference (WC) do not have an obese body mass index (BMI). This study aimed to explore whether including those with a non-obese BMI but high risk WC as 'obese' improves prediction of adiposity-related metabolic outcomes. METHODS: Eleven thousand, two hundred forty-seven participants were recruited. Height, weight and WC were measured. Ten thousand, six hundred fifty-nine participants with complete data were included. Adiposity categories were defined as: BMI(N)/WC(N), BMI(N)/WC(O), BMI(O)/WC(N), and BMI(O)/WC(O) (N = non-obese and O = obese). Population attributable fraction, area under the receiver operating characteristic curve (AUC), and odds ratios (OR) were calculated. RESULTS: Participants were on average 48 years old and 50 % were men. The proportions of BMI(N)/WC(N), BMI(N)/WC(O), BMI(O)/WC(N) and BMI(O)/WC(O) were 68, 12, 2 and 18 %, respectively. A lower proportion of diabetes was attributable to obesity defined using BMI alone compared to BMI and WC combined (32 % vs 47 %). AUC for diabetes was also lower when obesity was defined using BMI alone (0.62 vs 0.66). Similar results were observed for all outcomes. The odds for hypertension, dyslipidaemia, diabetes and CVD were increased for those with BMI(N)/WC(O) (OR range 1.8-2.7) and BMI(O)/WC(O) (OR 1.9-4.9) compared to those with BMI(N)/WC(N). CONCLUSIONS: Current population monitoring, assessing obesity by BMI only, misses a proportion of the population who are at increased health risk through excess adiposity. Improved identification of those at increased health risk needs to be considered for better prioritisation of policy and resources.

The prevalence and characteristics associated with excessive daytime sleepiness among Australian workers.

OBJECTIVE: To estimate the prevalence of excessive daytime sleepiness (EDS) and its associated factors in a mixed population of employed Australian workers. METHODS: Study participants (n = 707) were volunteers from various Melbourne workplaces, participating in a workplace physical activity program in 2008. Daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS), with EDS defined as ESS scores >10. RESULTS: In this population of adult employees (40.0% male; mean age 40.2 ± 10.4 years), prevalence of EDS was 16.0%. Characteristics associated with EDS and higher ESS scores were age, higher body mass index, markers of poorer diet, and markers of poorer mental health. CONCLUSIONS: Excessive daytime sleepiness is potentially an important contributor to lower productivity and poorer mental health in the workplace. Our finding suggests that workplace health programs aimed at improving diet and body weight may also help alleviate EDS.