Chronomics, human time estimation, and aging

Franz Halberg, Robert B Sothern, Germaine Cornélissen, Jerzy Czaplicki1Halberg Chronobiology Center, University of Minnesota, Minneapolis, MN, USA; 1Institut de Pharmacologie et de Biologie Structurale CNRS, Université Paul Sabatier, Toulouse, FranceBackground: Circadian rhythm stage affects many outcomes, including those of mental aging.Methods: Estimations of 1 minute ∼5 times/day for a year, 25 years apart, by a healthy male biomedical scientist (RBS), are analyzed by the extended cosinor.Results: Cycles of a half-week, a week, ∼30 days, a half-year and a year, in self-assessed 1-minute estimation by RBS between 25 and 60 years of age in health, are mapped for the first time, compared and opposite effects are found. For RBS at 60 vs at 25 years of age, it takes less time in the morning around 10:30 (P < 0.001), but not in the evening around 19:30 (P = 0.956), to estimate 1 minute.Discussion: During the intervening decades, the time of estimating 1 minute differed greatly, dependent on circadian stage, being a linear decrease in the morning and increase in the evening, the latter modulated by a ∼33.6-year cycle.Conclusion: Circadian and infradian rhythm mapping is essential for a scrutiny of effects of aging. A ∼30-day and a circannual component apparent at 25 years of age are not found later; cycles longer than a year are detected. Rhythm stages await tests as markers for timing therapy in disease.Keywords: circadian rhythm, mental function, time estimatio

Transdisciplinary unifying implications of circadian findings in the 1950s

A few puzzles relating to a small fraction of my endeavors in the 1950s are summarized herein, with answers to a few questions of the Editor-in-Chief, to suggest that the rules of variability in time complement the rules of genetics as a biological variability in space. I advocate to replace truisms such as a relative constancy or homeostasis, that have served bioscience very well for very long. They were never intended, however, to lower a curtain of ignorance over everyday physiology. In raising these curtains, we unveil a range of dynamics, resolvable in the data collection and as-one-goes analysis by computers built into smaller and smaller devices, for a continued self-surveillance of the normal and for an individualized detection of the abnormal. The current medical art based on spotchecks interpreted by reference to a time-unqualified normal range can become a science of time series with tests relating to the individual in inferential statistical terms. This is already doable for the case of blood pressure, but eventually should become possible for many other variables interpreted today only based on the quicksand of clinical trials on groups. These ignore individual differences and hence the individual's needs. Chronomics (mapping time structures) with the major aim of quantifying normalcy by dynamic reference values for detecting earliest risk elevation, also yields the dividend of allowing molecular biology to focus on the normal as well as on the grossly abnormal

Protocol for: Sheffield Obesity Trial (SHOT): A randomised controlled trial of exercise therapy and mental health outcomes in obese adolescents [ISRCNT83888112]

Background While obesity is known to have many physiological consequences, the psychopathology of this condition has not featured prominently in the literature. Cross-sectional studies have indicated that obese children have increased odds of experiencing poor quality of life and mental health. However, very limited trial evidence has examined the efficacy of exercise therapy for enhancing mental health outcomes in obese children, and the Sheffield Obesity Trial (SHOT) will provide evidence of the efficacy of supervised exercise therapy in obese young people aged 11–16 years versus usual care and an attention-control intervention. Method/design SHOT is a randomised controlled trial where obese young people are randomised to receive; (1) exercise therapy, (2) attention-control intervention (involving body-conditioning exercises and games that do not involve aerobic activity), or (3) usual care. The exercise therapy and attention-control sessions will take place three times per week for eight weeks and a six-week home programme will follow this. Ninety adolescents aged between 11–16 years referred from a children's hospital for evaluation of obesity or via community advertisements will need to complete the study. Participants will be recruited according to the following criteria: (1) clinically obese and aged 11–16 years (Body Mass Index Centile > 98th UK standard) (2) no medical condition that would restrict ability to be active three times per week for eight weeks and (3) not diagnosed with insulin dependent diabetes or receiving oral steroids. Assessments of outcomes will take place at baseline, as well as four (intervention midpoint) and eight weeks (end of intervention) from baseline. Participants will be reassessed on outcome measures five and seven months from baseline. The primary endpoint is physical self-perceptions. Secondary outcomes include physical activity, self-perceptions, depression, affect, aerobic fitness and BMI

Validation of the Activity Preference Assessment: a tool for quantifying children’s implicit preferences for sedentary and physical activities

Background High levels of sedentary behavior and low physical activity are associated with poor health, and the cognitive determinants of these behaviors in children and adolescents are not well understood. To address this gap, we developed a novel, non-verbal, computer-based assessment to quantify the degree to which youth prefer to be sedentary relative to physically active in their leisure time. Methods The Activity Preference Assessment (APA) uses a forced-choice paradigm to understand implicit decision-making processes when presented with common sedentary and physical activities. The APA bias score ranges from − 100 to + 100, with positive scores indicating a relative preference for sedentary activities, and negative scores representing a preference for physical activities. In 60 children ages 8–17 years, we assessed the validity of this behavioral task against a free-choice play observation, accelerometry-measured activity, anthropometrics and body composition, and cardiorespiratory fitness. We explored neighborhood, family, and individual-level factors that may influence implicit activity preferences. Test-retest reliability was assessed over one week. Results The majority of children (67%) preferred sedentary relative to physical activities. APA bias scores were positively associated with sedentary time during free-choice play. In girls, bias scores were negatively associated with average daily MVPA. APA bias scores were positively associated with body fat and negatively associated with cardiorespiratory fitness. These findings were independent of age, sex, and race/ethnicity. Neighborhood access to physical activity spaces, the number of people in the home, perceived physical self-competence (e.g., coordination, strength), and self-reported depressive symptoms were associated with activity preferences. The intra-class correlation for test-retest reliability was r = 0.59. Conclusions The APA shows promise as a novel tool for quantifying children’s relative preference for sedentary versus physical activities. Implicit bias scores from the APA are clinically meaningful, as shown by significant associations with adiposity and cardiorespiratory fitness. Future longitudinal studies should examine the directionality of the association between preferences and health markers, and the degree to which implicit activity preferences are modifiable. Importantly, the task only takes an average of 10 min to complete, highlighting a potential role as an efficient screening tool for the propensity to be sedentary versus physically active

Aspects of diurnal rhythmicity in pain, stiffness, and fatigue in patients with fibromyalgia

To determine diurnal rhythm characteristics of pain, stiffness, and fatigue in self-ratings performed by patients with fibromyalgia (FM).Twenty-one women with FM made self-measurements of pain, stiffness, and fatigue on 100 mm horizontal visual analog scales at 6 prespecified timepoints at home for 10 consecutive days. Linear and multiple regressions were performed on the original data and the 24-hour means vs FM classifiers (age, disease duration, tender points, dolorimetry score, Fibromyalgia Impact Questionnaire score), respectively. Data were analyzed for 24-hour and 7-day time-effects by ANOVA and for diurnal and weekly rhythms by the cosinor technique.Individual ratings for pain, stiffness, and fatigue correlated highly with each other throughout the day and over the days of the week. Of the FM classifiers, dolorimetry score was found to be inversely related to the pain, stiffness, and fatigue scores. For the group of subjects with a low dolorimetry score ( 2.25 kg), while fatigue showed the same significant diurnal pattern as in the first group. For the group as a whole, the possible presence of a weekly variation was found with ratings for pain, stiffness, and fatigue higher on Sunday and Monday and lower on Friday.Ratings of pain, stiffness, and fatigue in FM are significantly correlated, and show diurnal and possibly weekly rhythmicity, especially when pain threshold is low (dolorimetry score < 2.25 kg), and are thus predictive of each other over these time spans. This has important implications for scheduling activities of daily living, for measurement in clinical trials, and possibly for timing the administration of medications