Browsing by Subject "Circadian"

Now showing 1 - 4 of 4
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    Children with obesity have poorer circadian health as assessed by a global circadian health score
    (Springer, 2024-06-08) Rodríguez‑Martín, María; Martínez‑Lozano, Nuria; Santaclara‑Maneiro, Vicente; Gris‑Peñas, Antonio; Salmerón, Diego; Ríos, Rafael; Tvarijonaviciute, Asta; Garaulet, Marta; Ciencias Sociosanitarias
    Background Circadian health refers to individuals’ well-being and balance in terms of their circadian rhythm. It is infuenced by external cues. In adults, a close relationship between circadian-related alterations and obesity has been described. How ever, studies in children are scarce, and circadian health and its association with obesity have not been evaluated globally. We aimed to assess whether circadian health difered between children with and without obesity as determined by a global circadian score (GCS) in a school-age population. Methods Four hundred and thirty-two children (7–12 years) were recruited in Spain. Non-invasive tools were used to calcu late the GCS: (1) 7-day rhythm of wrist temperature (T), activity (A), position (P), an integrative variable that combines T, A, and P (TAP); (2) cortisol; and (3) 7-day food and sleep records. Body mass index, body fat percentage, waist circumference (WC), melatonin concentration, and cardiometabolic marker levels were determined. Results Circadian health, as assessed by the GCS, difered among children with obesity, overweight, and normal weight, with poorer circadian health among children with obesity. Children with obesity and abdominal obesity had 3.54 and 2.39 greater odds of having poor circadian health, respectively, than did those with normal weight or low WC. The percentage of rhythmicity, a marker of the robustness of the TAP rhythm, and the amplitude, both components of the GCS, decreased with increasing obesity. Diferent lifestyle behaviors were involved in the association between circadian health and obesity, particularly protein intake (P=0.024), physical activity level (P=0.076) and chronotype (P=0.029). Conclusions The GCS can capture the relationship between circadian health and obesity in school-age children. Protein intake, physical activity level, and chronotype were involved in this association. Early intervention based on improving circadian health may help to prevent childhood obesity.
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    Living without temporal cues: a case study
    (Frontiers Media, 2020-02-07) Revell, Victoria L.; Cook, Tom J.; Welch, Thomas R. E.; Rol, Maria-Angeles; Skene, Debra J.; Madrid, Juan Antonio; Bonmatí Carrión, María de los Ángeles; Anatomía Humana y Psicobiología
    Isolation from external time cues allows endogenous circadian rhythmicity to be demonstrated. In this study, also filmed as a television documentary, we assessed rhythmic changes in a healthy man time isolated in a bunker for 9 days/nights. During this period the lighting conditions were varied between: (1) self-selected light/dark cycle, (2) constant dim light, and (3) light/dark cycle with early wake up. A range of variables was assessed and related to the sleep-wake cycle, psychomotor and physical performance and clock-time estimation. This case study using modern non-invasive monitoring techniques emphasizes how different physiological circadian rhythms persist in temporal isolation under constant dim light conditions with different waveforms, free-running with a period (τ) between 24 and 25 h. In addition, a significant correlation between time estimation and mid-sleep time, a proxy for circadian phase, was demonstrated.
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    Melatonin and cancer: a polyhedral network where the source matters
    (MDPI, 2021-02-01) Tomas-Loba, Antonia; Bonmatí Carrión, María de los Ángeles; Anatomía Humana y Psicobiología
    Melatonin is one of the most phylogenetically conserved signals in biology. Although its original function was probably related to its antioxidant capacity, this indoleamine has been “adopted” by multicellular organisms as the “darkness signal” when secreted in a circadian manner and is acutely suppressed by light at night by the pineal gland. However, melatonin is also produced by other tissues, which constitute its extrapineal sources. Apart from its undisputed chronobiotic function, melatonin exerts antioxidant, immunomodulatory, pro-apoptotic, antiproliferative, and anti-angiogenic effects, with all these properties making it a powerful antitumor agent. Indeed, this activity has been demonstrated to be mediated by interfering with various cancer hallmarks, and different epidemiological studies have also linked light at night (melatonin suppression) with a higher incidence of different types of cancer. In 2007, the World Health Organization classified night shift work as a probable carcinogen due to circadian disruption, where melatonin plays a central role. Our aim is to review, from a global perspective, the role of melatonin both from pineal and extrapineal origin, as well as their possible interplay, as an intrinsic factor in the incidence, development, and progression of cancer. Particular emphasis will be placed not only on those mechanisms related to melatonin’s antioxidant nature but also on the recently described novel roles of melatonin in microbiota and epigenetic regulation.
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    Timing of chocolate intake affects hunger, substrate oxidation, and microbiota: a randomized controlled trial
    (2021-06-23) Hernández-González, Teresa; Escobar, Carolina; Madrid, J.A.; Periago, María Jesús; Collado, María Carmen; Scheer, Frank. A.J.L.; Garaulet, Marta; González-Barrio, Rocío; Tecnología de Alimentos, Nutrición y Bromatología
    Eating chocolate in the morning or in the evening/at night, may differentially affect energy balance and impact body weight due to changes in energy intake, substrate oxidation, microbiota (composition/function), and circadian-related variables. In a randomized controlled trial, postmenopausal females (n = 19) had 100 g of chocolate in the morning (MC), in the evening/at night (EC), or no chocolate (N) for 2 weeks and ate any other food ad libitum. Our results show that 14 days of chocolate intake did not increase body weight. Chocolate consumption decreased hunger and desire for sweets (P < .005), and reduced ad libitum energy intake by ~300 kcal/day during MC and ~150 kcal/day during EC (P = .01), but did not fully compensate for the extra energy contribution of chocolate (542 kcal/day). EC increased physical activity by +6.9%, heat dissipation after meals +1.3%, and carbohydrate oxidation by +35.3% (P < .05). MC reduced fasting glucose (4.4%) and waist circumference (−1.7%) and increased lipid oxidation (+25.6%). Principal component analyses showed that both timings of chocolate intake resulted in differential microbiota profiles and function (P < .05). Heat map of wrist temperature and sleep records showed that EC induced more regular timing of sleep episodes with lower variability of sleep onset among days than MC (60 min vs 78 min; P = .028). In conclusion, having chocolate in the morning or in the evening/night results in differential effects on hunger and appetite, substrate oxidation, fasting glucose, microbiota (composition and function), and sleep and temperature rhythms. Results highlight that the “when” we eat is a relevant factor to consider in energy balance and metabolism.