Factors associated with change and stability in adherence to muscle-strengthening guidelines among young Australian adults: A longitudinal study.

OBJECTIVES: The 2014 Australian Physical Activity and Sedentary Behaviour Guidelines (Adults) recommend muscle-strengthening activities ≥2 days/week. This study aimed to identify factors associated with 5-year change and stability in adherence to these guidelines. DESIGN: Two adult follow-ups of the Childhood Determinants of Adult Health (CDAH) Study. Participants (n = 1510) were 26-36 years (CDAH-1, 2004-06) and 31-41 years (CDAH-2, 2009-11). METHODS: Information on muscle-strengthening activities, sociodemographics, health, physical activity and sedentary behaviour was collected. Participants reporting muscle-strengthening activities ≥2 days/week 'met guidelines', with change and stability categorised as 'persistent adherence', 'increasing adherence', 'decreasing adherence' and 'persistent non-adherence'. Differences in sociodemographic, health and behavioural factors were analysed using log multinomial regression. RESULTS: Between 15-21% of women (CDAH-1: 14.5%, 95% confidence interval = 12.5-16.9; CDAH-2: 20.7%, 95% confidence interval = 18.3-23.4) and ~21% of men (CDAH-1: 22.2%, 95% confidence interval = 19.0-26.0; CDAH-2: 21.0%, 95% confidence interval = 17.8-24.7) met muscle-strengthening guidelines, but only 8.5% (95% confidence interval = 7.2-10.1) of participants were persistently adherent. Remaining in or moving from a major city, CDAH-1 weight status, cumulative self-rated health and vigorous physical activity were positively associated with persistent adherence (relative risk range = 1.51-3.92), while female gender, becoming partnered and having children at any timepoint were negatively associated with persistent adherence (relative risk range = 0.38-0.58). CONCLUSIONS: Adherence - particularly persistent adherence - to muscle-strengthening guidelines in this sample was low. Gender, marital status, weight status, BMI, self-rated health, urban-rural status, parental status, physical activity and sedentary behaviour were associated with adherence, and should be considered in intervention development to maximise effectiveness.

Youth diet quality and hazard of mood disorder in adolescence and adulthood among an Australian cohort.

BACKGROUND: Prospective studies on youth diet and mood disorders outcomes are limited. We examined if youth diet quality was associated with mood disorder onset over a 25-year follow-up period. METHODS: In 1985, Australian participants (aged 10-15 years) completed a 24-hour food record. A validated 100-point Dietary Guidelines Index (DGI) assessed diet quality. In 2009-11, 1005 participants (aged 33-41 years) completed the lifetime Composite International Diagnostic Interview for age of first DSM-IV defined mood disorder (depression or dysthymia). Cox proportional hazards regression estimated hazard of mood disorder during the 25-year follow-up according to baseline DGI score. Sensitivity analyses censored the study at 5, 10, and 15 years after baseline and used log binomial regression to estimate relative risk (RR). Covariates included baseline negative affect, BMI, academic performance, smoking, breakfast eating, physical activity, and socioeconomic status. RESULTS: The mean(SD) youth DGI score was 45.0(11.5). A 10-point higher DGI was not associated with hazard of mood disorder onset over the 25-year follow-up (Hazard Ratio (HR):1.00; 95% Confidence Interval (CI):0.89-1.13). The only indication that higher DGI might be associated with lower risk of mood disorder was within the first 5 years after baseline and this was not statistically significant (RR=0.85; 95% CI:0.60-1.18). LIMITATIONS: Loss-to-follow-up. A single 24-hour food record may not represent usual diet. CONCLUSION: Youth diet did not predict mood disorders in adulthood. The suggestions of a lower risk of mood disorder during late adolescence highlights that further prospective studies are needed.

An eating pattern characterised by skipped or delayed breakfast is associated with mood disorders among an Australian adult cohort.

BACKGROUND: Meal timing may influence food choices, neurobiology and psychological states. Our exploratory study examined if time-of-day eating patterns were associated with mood disorders among adults. METHODS: During 2004-2006 (age 26-36 years) and 2009-2011 (follow-up, age 31-41 years), N = 1304 participants reported 24-h food and beverage intake. Time-of-day eating patterns were derived by principal components analysis. At follow-up, the Composite International Diagnostic Interview measured lifetime mood disorder. Log binomial and adjacent categories log-link regression were used to examine bidirectional associations between eating patterns and mood disorder. Covariates included sex, age, marital status, social support, education, work schedule, body mass index and smoking. RESULTS: Three patterns were derived at each time-point: Grazing (intake spread across the day), Traditional (highest intakes reflected breakfast, lunch and dinner), and Late (skipped/delayed breakfast with higher evening intakes). Compared to those in the lowest third of the respective pattern at baseline and follow-up, during the 5-year follow-up, those in the highest third of the Late pattern at both time-points had a higher prevalence of mood disorder [prevalence ratio (PR) = 2.04; 95% confidence interval (CI) 1.20-3.48], and those in the highest third of the Traditional pattern at both time-points had a lower prevalence of first onset mood disorder (PR = 0.31; 95% CI 0.11-0.87). Participants who experienced a mood disorder during follow-up had a 1.07 higher relative risk of being in a higher Late pattern score category at follow-up than those without mood disorder (95% CI 1.00-1.14). CONCLUSIONS: Non-traditional eating patterns, particularly skipped or delayed breakfast, may be associated with mood disorders.

The Association of Type 2 Diabetes Mellitus with Cerebral Gray Matter Volume Is Independent of Retinal Vascular Architecture and Retinopathy.

It is uncertain whether small vessel disease underlies the relationship between Type 2 Diabetes Mellitus (T2DM) and brain atrophy. We aimed to study whether retinal vascular architecture, as a proxy for cerebral small vessel disease, may modify or mediate the associations of T2DM with brain volumes. In this cross-sectional study using Magnetic Resonance Imaging (MRI) scans and retinal photographs in 451 people with and without T2DM, we measured brain volumes, geometric measures of retinal vascular architecture, clinical retinopathy, and MRI cerebrovascular lesions. There were 270 people with (mean age 67.3 years) and 181 without T2DM (mean age 72.9 years). T2DM was associated with lower gray matter volume (p = 0.008). T2DM was associated with greater arteriolar diameter (p = 0.03) and optimality ratio (p = 0.04), but these associations were attenuated by adjustments for age and sex. Only optimality ratio was associated with lower gray matter volume (p = 0.03). The inclusion of retinal measures in regression models did not attenuate the association of T2DM with gray matter volume. The association of T2DM with lower gray matter volume was independent of retinal vascular architecture and clinical retinopathy. Retinal vascular measures or retinopathy may not be sufficiently sensitive to confirm a microvascular basis for T2DM-related brain atrophy.

Childhood fitness reduces the long-term cardiometabolic risks associated with childhood obesity.

OBJECTIVE: The objective of this study was to examine whether childhood cardiorespiratory fitness attenuates or modifies the long-term cardiometabolic risks associated with childhood obesity. DESIGN AND METHODS: The study consisted of a 20-year follow-up of 1792 adults who participated in the 1985 Australian Schools Health and Fitness Survey when they were 7-15 years of age. Baseline measures included a 1.6-km run to assess cardiorespiratory fitness and waist circumference to assess abdominal adiposity. At follow-up, participants attended study clinics where indicators of Metabolic Syndrome (MetS) (waist circumference, blood pressure, fasting blood glucose and lipids) were measured and cardiorespiratory fitness was reassessed using a submaximal graded exercise test. RESULTS: Both high waist circumference and low cardiorespiratory fitness in childhood were significant independent predictors of MetS in early adulthood. The mutually adjusted relative risk of adult MetS was 3.00 (95% confidence interval: 1.85-4.89) for children in the highest (vs lowest) third of waist circumference and 0.64 (95% confidence interval: 0.43-0.96) for children with high (vs low) cardiorespiratory fitness. No significant interaction between waist circumference and fitness was observed, with higher levels of childhood fitness associated with lower risks of adult MetS among those with either low or high childhood waist circumference values. Participants who had both high waist circumference and low cardiorespiratory fitness in childhood were 8.5 times more likely to have MetS in adulthood than those who had low waist circumference and high cardiorespiratory fitness in childhood. Regardless of childhood obesity status, participants with low childhood fitness who increased their relative fitness by adulthood had a substantially lower prevalence of MetS than those who remained low fit. CONCLUSIONS: Childhood waist circumference and cardiorespiratory fitness are both strongly associated with cardiometabolic health in later life. Higher levels of cardiorespiratory fitness substantially reduce the risk of adult MetS, even among those with abdominal obesity in childhood.

Does youth adiposity, or change in adiposity from youth to adulthood, predict metabolically healthy obesity in adulthood?

BACKGROUND: Individuals with metabolically healthy obesity (MHO) do not have the metabolic complications usually associated with obesity. OBJECTIVE: To examine whether youth adiposity, or change in adiposity from youth to adulthood, predicts MHO 20 years later. METHODS: A national sample of 2410 Australian participants had height, weight and waist circumference (WC) measured in 1985 (7-15 years old) and 2004-2006 (26-36 years old). A fasting blood sample was taken in 2004-2006. MHO was defined as body mass index (BMI) ≥30 kg m(-2) , normal fasting glucose (<5.6 mmol L(-1) ), triglycerides (<1.695 mmol L(-1) ), high-density lipoprotein-cholesterol (>1.036 mmol L(-1) men, > 1.295 mmol L(-1) women), blood pressure (<130/85 mmHg) and no medication for these conditions. Relative risks (RR) were calculated using log binomial regression and expressed per unit of youth BMI (or WC) z-score or change in BMI (or WC) z-score from youth to adulthood, adjusted for sex and youth age. RESULTS: In total 323 individuals were obese at follow-up, 79 (24.5%) were MHO. Adult MHO was not associated with youth BMI (RR: 1.00, 95%CI: 0.85-1.19) or WC (RR: 0.93, 95%CI: 0.79-1.11). Individuals were less likely to be MHO if they had larger increases in BMI (BMI RR: 0.74, 95%CI: 0.57-0.97) or WC (RR: 0.70, 95%CI: 0.55-0.90) from youth to adulthood. CONCLUSIONS: Change in adiposity from youth to adulthood predicted adult MHO better than youth adiposity alone.

Longitudinal investigation of adenovirus 36 seropositivity and human obesity: the Cardiovascular Risk in Young Finns Study.

BACKGROUND/OBJECTIVES: Adenovirus-36 (Adv-36) infection is associated with exaggerated adipogenesis in cell culture and the development of obesity in animal models and humans, but a causal relationship remains unproven. Our objective was to determine whether serological evidence of Adv-36 infection in childhood and/or adulthood is associated with adult obesity. SUBJECTS/METHODS: Paired plasma concentrations of Adv-36 antibodies were measured by a novel enzyme-linked immunosorbent assay in a subgroup (n=449) of the Cardiovascular Risk in Young Finns Study in childhood (mean age 11.9 years) and adulthood (mean age 41.3 years). The study group included (1) individuals who had maintained normal-weight status (2) those who became obese adults from a normal-weight status in childhood and (3) those that were overweight/obese as a child and obese as an adult. RESULTS: Mean (s.d.) time between baseline and follow-up was 29.4 (3.2) years (range 21-31 years). A total of 24.4% of individuals who were normal weight throughout life were seropositive for Adv-36 during child and/or adulthood as compared with 32.3% of those who became obese adults (P=0.11). Those who became obese in adulthood were more likely to be Adv-36 seropositive as adults compared with those who maintained normal weight (21.3% vs. 11.6%, P=0.02). This difference was mediated by a decline in Adv-36 seropositivity between child and adulthood in those maintaining normal weight. No differences were observed in body mass index across the life course, nor in waist circumference in adult life, between those who were Adv-36 seronegative or seropositive at any age. CONCLUSIONS: Individuals who gained weight across the life course were more likely to be Adv-36 seropositive in adult life than those who did not gain weight. However, analysis of change in weight status in relation to Adv-36 positivity did not support a causal role for Adv-36 in the development of obesity.

The role of pharmacotherapy in the prevention and treatment of paediatric metabolic syndrome--Implications for long-term health: part of a series on Pediatric Pharmacology, guest edited by Gianvincenzo Zuccotti, Emilio Clementi, and Massimo Molteni.

The metabolic syndrome (MetS) is defined as a clustering of risk factors predisposing to the future development of cardiovascular disease and Type 2 diabetes mellitus (T2DM). Its clinical relevance, above and beyond recognition and treatment of each of the component parts, is still hotly debated--especially within paediatric medicine. Prevention and treatment strategies for adult MetS focus on weight management, as obesity and insulin resistance are known to be at the central axis of the definition, alongside pharmacotherapy of integrally linked conditions such as hypertension and dyslipidaemia. In children and adolescents, however, opportunities for pharmacotherapy are currently limited and interventions aimed at weight management remain the sole treatment paradigm in the majority of cases. This is primarily due to a lack of long-term data relating to the degree of cardiovascular disease and T2DM risk from paediatric MetS, as well as concerns relating to safety and side effect profiles of currently available pharmacotherapies in those who are still growing and developing. Coupled with continuing concern about the recently recognised adverse effects of past and proposed anti-obesity drugs, this indicates that a new era of pharmacotherapy for paediatric MetS is unlikely to be imminent. In fact, the overall paucity of effective current interventions for paediatric MetS is concerning, especially given the fact that approximately 25-33% of all obese paediatric patients likely harbour the condition. It is therefore essential at the present time to concentrate efforts on properly testing the safety and efficacy of currently available products in well-constructed randomised controlled trials in obese adolescents. However, not all obese children and adolescents appear equally at-risk of long-term, weight-related morbidity and a change in emphasis is possibly warranted--one that moves away from simple weight reduction for all and more to a model of reducing long-term risk of cardiovascular disease and T2DM in those at greatest metabolic risk.

Predictive associations between alternative measures of childhood adiposity and adult cardio-metabolic health.

OBJECTIVE: To estimate associations between alternative measures of childhood adiposity and indicators of cardio-metabolic health in adulthood, both unadjusted and adjusted for changes in adiposity from childhood to adulthood. DESIGN AND METHODS: The study consisted of a 20-year follow-up of 2188 adults who had participated in the 1985 Australian Schools Health and Fitness Survey when they were between 7 and 15 years of age. Baseline and follow-up measures of body composition included height and weight, waist and hip circumferences and skinfold thicknesses at four sites. At follow-up, participants attended study clinics where component indicators of the metabolic syndrome (MetS) (waist circumference, blood pressure, fasting blood glucose and lipids) were measured. RESULTS: Waist circumference and skinfold measures were the strongest predictors of subsequent MetS (2009 Joint Scientific Statement definition) in early adulthood. For example, relative risks (RRs) for children in the highest (vs lowest) quarter of waist circumference were 4.8 (95% confidence interval (CI): 2.5-9.2) for males and 5.8 (95% CI: 2.4-14.2) for females. After adjusting for change in waist circumference from childhood to adulthood, each 10 cm increase in childhood waist circumference was associated with an approximate twofold increase in risk for adult MetS (RR = 2.1 (95% CI: 1.7-2.7) among males and RR = 2.3 (95% CI: 1.6-3.4) among females). CONCLUSION: Elevated waist circumference and skinfold thickness measures in childhood appear to be the strongest predictors of subsequent MetS in early adulthood. The increased risk associated with higher waist circumference in childhood appears to be independent of changes in waist circumference from childhood to adulthood.