The association of chronotype and social jet lag with body composition in German students: The role of physical activity behaviour and the impact of the pandemic lockdown

Adolescents' chronotype and its association with obesity-related outcomes: The EHDLA study

OBJECTIVE

This study aimed to assess associations between chronotype and obesity-related indicators in a sample of Spanish adolescents.

METHODS

This cross-sectional study used data from The Eating Healthy and Daily Life Activities (EHDLA) Study, which included a representative sample of adolescents from Spain. A total of 820 adolescents (54.7% girls) aged 12-17 years were included in the analyses. The adolescents' chronotype was determined using the Morningness/Eveningness Scale in Children. Obesity-related indicators included body mass index, waist circumference, waist-to-height ratio, triceps and medial calf skinfolds, sum of skinfolds, and body fat percentage. Generalized linear models were used to examine the relationship between the Morningness-Eveningness score and chronotype status and the above-mentioned obesity-related indicators in adolescents. All analyses were adjusted for sex, age, socioeconomic status, sleep duration, physical activity, sedentary behaviour, adherence to the Mediterranean diet, and energy intake.

RESULTS

The morningness chronotype was associated with higher abdominal obesity (odds ratio [OR] = 1.67, 95% confidence interval (CI) 1.12 to 2.50; p = 0.001), waist-to-height ratio (unstandardized beta coefficient [B] = 0.01, 95% CI 0.01 to 0.05; p = 0.029) and skinfold calves (B = 1.04 95% CI 0.24 to 1.94; p = 0.011), compared with the intermediate chronotype.

CONCLUSION

Adolescents with a morningness chronotype may be more prone to abdominal obesity than their counterparts with an intermediate chronotype. Effective intervention-related approaches can be applied to those with a morningness chronotype.

Association between social jetlag and leisure-time physical activity and muscle strengthening exercise in young adults: findings from a nationally representative sample in South Korea

OBJECTIVES

Social jetlag (SJL), which is characterised by a misalignment between biological and social time, is associated with cardiometabolic risk factors. This study investigated the relationship between SJL, leisure-time physical activity (LTPA) and muscle strengthening exercise (MSE) in young adults.

STUDY DESIGN

This was a cross-sectional study.

METHODS

This cross-sectional study included a nationally representative sample of young adults aged 19-29 years (n = 2113). SJL was calculated as the difference in the midpoint of sleep onset and offset time between weekdays and weekends. The dependent variables were engagement in ≥150 min/week of moderate-to-vigorous LTPA and engagement in MSE ≥2 days/week based on guidelines provided by the World Health Organisation. Logistic regression analysis was performed to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Non-linear relationships were estimated using restricted cubic spline regression.

RESULTS

The study population comprised 975 men and 1138 women. Among participants, 4.6% had <0 min, 41.9% had 0-59 min, 25.7% had 60-119 min and 27.7% had ≥120 min SJL. Those with ≥120 min SJL had a reduced likelihood of achieving the recommended level of LTPA (OR: 0.71, 95% CI: 0.52-0.95) and MSE (OR: 0.73, 95% CI: 0.55-0.97). In the non-linear model, an inverse U-shaped association was observed, wherein the highest probability of meeting the recommended level of LTPA and MSE was observed in those with 45 min SJL, decreasing after this threshold.

CONCLUSIONS

Individuals with ≥120 min SJL were less likely to engage in the recommended level of both aerobic and anaerobic exercise. Although future studies using a longitudinal design are required to elucidate the causal relationship between SJL and physical activity, the current findings suggest that physical inactivity during leisure time may play an important role in the increased risk of cardiometabolic abnormalities in young adults with SJL.

Chronotype is associated with Mediterranean dietary adherence and environmental footprints

This cross-sectional study was carried out to determine the relationship between nutrition according to chronotype and the Mediterranean diet and environmental footprints. "Morningness Eveningness Questionnaire" was used to determine the chronotype classification, and "Mediterranean Diet Adherence Screener" was used to evaluate adherence to the Mediterranean diet. In addition, the food consumption record of the participants was taken and the carbon and water footprints were calculated. A total of 472 adults with a mean age of 22.7 ± 5.0 years participated in the study. Accordingly, 61.0% of the participants were morning type, 15.7% were intermediate type, and 23.3% were evening type. Individuals with higher chronotype values (morning) tended to be more adherent to the Mediterranean diet and had lower environmental (carbon and water) footprints (p < 0.05). The results of this study; showed that diet according to chronotype affects adherence to the Mediterranean diet and environmental footprints.

Relevance of high glycaemic index breakfast for heart rate variability among collegiate students with early and late chronotypes

Plasma glucose spikes affect cardiac autonomic modulation resulting in a decrease of heart rate variability (HRV). We hypothesize that a later chronotype or a higher morning plasma melatonin level is associated with larger decreases of HRV following an early high glycaemic index (GI) breakfast. In persons with an early (n = 21) or a late (n = 15) chronotype who consumed a high GI breakfast at 7 a.m. glucose data were continuously monitored. Time domain HRV parameters were calculated from blood volume pulses derived by wireless wrist worn multisensor. HRV changes (values after minus values before breakfast) were associated with chronotype by multivariable linear regression adjusted for age, sex and baseline levels. Morning plasma melatonin levels were determined from samples drawn on the run-in day. Time domain parameters indicate a higher HRV before high GI breakfast in both chronotypes. A later chronotype tended to be associated with smaller decreases of mean interbeat intervals (p = 0.08) only; no associations were seen with morning melatonin levels. This exploratory analysis in a small sample provides a first indication that in young healthy adults later chronotype might be associated with reduced ANS activation following a high GI breakfast. Future studies should elucidate whether this indicates parasympathetic or sympathetic inhibition.

Social Jetlag on Obesity-Related Outcomes in Spanish Adolescents: Cross-Sectional Evidence from the EHDLA Study

PURPOSE

This study aimed to investigate the association between social jetlag (SJL) and obesity-related outcomes among adolescents from Valle de Ricote (Region of Murcia, Spain). We explored the relationship between SJL and body mass index (BMI) z-score, waist circumference, and body fat percentage, as well as the odds of having excess weight, obesity, and abdominal obesity in a sample of Spanish adolescents.

METHODS

A cross-sectional study was conducted using data from the Eating Healthy and Daily Life Activities (EHDLA) project, which included 847 Spanish adolescents aged 12-17 years. SJL was assessed based on the differences in sleep patterns between weekdays and weekends. Obesity-related indicators such as BMI z-score, waist circumference, body fat percentage, excess weight, obesity, and abdominal obesity were measured. Generalized linear models with a Gaussian or binomial distribution were used to analyze the associations between SJL and obesity-related outcomes, adjusting for potential confounders.

RESULTS

The analysis revealed significant associations between SJL and BMI z-score (unstandardized beta coefficient [B] = 0.15, 95% CI: 0.05 to 0.25, p = 0.003), waist circumference (B = 1.03, 95% CI: 0.39 to 1.67, p = 0.002), and body fat percentage (B = 0.83, 95% CI: 0.31 to 1.43, p = 0.008). Additionally, the odds ratios (ORs) for excess weight (OR = 1.35, 95% CI: 1.16 to 1.57; p < 0.001), obesity (OR = 1.59, 95% CI: 1.26 to 2.00; p < 0.001), and abdominal obesity (OR = 1.46, 95% CI: 1.23 to 1.72; p < 0.001) increased significantly with each 60 min increment in SJL.

CONCLUSIONS

This study pointed out that the misalignment of sleeping times during weekdays and weekends (SJL) is significantly associated with higher BMI z-scores, waist circumference, body fat percentage, and higher odds of excess weight, obesity, and abdominal obesity among adolescents, being more significant in boys than in girls. These findings highlight the importance of addressing circadian misalignment in the prevention and management of obesity and its related metabolic disorders in this population.

The effect of circadian timing program for evening-chronotype individuals with obesity on obesity management and sleep quality: A randomized controlled trial

OBJECTIVES

The study aimed to investigate the effect of the circadian timing program (SİZAP) developed for evening-chronotype individuals with obesity on obesity management and sleep quality.

METHODS

This single-site, randomized controlled trial with an experimental research design was registered in ClinicalTrials.gov. It was reported in accordance with the "Consolidated Standards of Reporting Trials" (CONSORT) randomized controlled trial guidelines. The study sample consisted of 38 evening-chronotype individuals with first-degree obesity, with 19 individuals in each study group. The intervention group's sleep hygiene training was conducted and their lifestyle changes were ensured through SİZAP. The control group followed their normal daily lifestyle. No intervention was made in terms of the dietary practices of both groups. Study data were collected using the personal information form, the anthropometric measurement form, the Horne and Ostberg Morning and Evening Questionnaire (MEQ), the Impact of weight on quality of life-lite (IWQOL-lite), the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the sleep diary, and the data tracked via the website and smart bracelets.

RESULTS

It was determined that the participants in the SİZAP group had a statistically significant decrease in the anthropometric measurements and daytime sleepiness (p < 0.05). The sleep quality scores and the scores of the bodily functions sub-dimension of the quality of life scale were significantly better in the intervention group than in the control group (p < 0.05).

CONCLUSION

It was found that SİZAP is effective in obesity management in evening-chronotype individuals and increases weight loss success and sleep quality.

Associations of body composition with physical activity, nutritional intake status, and chronotype among female university students in Japan

BACKGROUND

Having higher muscle mass in early adulthood is an important factor in preventing sarcopenia. However, university students undergo lifestyle changes compared to their high school years, which may lead to changes in body composition, such as an increase in body fat and a decrease in muscle mass. The study aimed to investigate the association between body composition and lifestyle behaviors, including chronotype, among Japanese female university students, due to the prevalence of underweight among young females in the country.

METHODS

The physical activity level (PAL), daily dietary intake status, morningness-eveningness questionnaire (MEQ) score, and body composition of 230 students were assessed in this cross-sectional study. Body composition was measured using a multifrequency bioelectrical impedance analyzer, and body mass index (BMI), body fat percentage (%BF), and skeletal muscle mass index (SMI) were determined.

RESULTS

Individuals who were evening type (ET) had a higher %BF and lower SMI than those who were non-ET, but no differences in body weight or BMI were found. Although ET individuals had lower total energy intake, protein intake, and PALs than non-ETs, the differences were small. However, multiple regression analyses showed that SMI was significantly positively associated with MEQ and PAL, and %BF was significantly negatively associated with MEQ and PAL.

CONCLUSION

These results suggest that female university students with lateness of chronotype and low physical activity have a body composition imbalance resulting in higher body fat and lower muscle mass. Therefore, young females may need to take chronotype-specific measures (especially ET individuals) to help them maintain an appropriate body composition.

Associations between chronotype and physical activity and well-being in adults

Circadian rhythms influence a preference for people's time of activity and sleep time during the day and the hours of best performance. The aim of the study was to assess the associations between chronotype, physical activity, and well-being in adults aged 20-50. The chronotype, physical activity and well-being scores were determined based on the Composite Scale of Morningness (CSM) questionnaire, the International Physical Activity Questionnaire (IPAQ) and the Well-Being Index (WHO-5) questionnaire, respectively. Study data consisted of the answers of 213 respondents (including 64 men) who took part in an online survey. The Spearman rank correlation coefficient and the matrix scatter plots were used to check the correlations between the CSM score and quality of life parameters' values. General linear models (GLMs) were performed to find differences in quality-of-life parameters between different combinations of sex and chronotype. Morning types showed the highest value of well-being score (mean = 13.48) while evening types the lowest one (mean = 8.35). Evening types spent the most time sitting compared to other chronotypes. Results of this study revealed the significant effect of chronotype on well-being and physical activity among adults. These findings suggest that chronotype is an important factor that psychologists and personal trainers should take into account.

Does the Response to a Stressful Condition in Older Adults with Life Rhythm Dysregulations Provide Evidence of the Existence of the "Dysregulation of Mood, Energy, and Social Rhythms Syndrome"?

OBJECTIVE

The COVID-19 lockdown periods have given rise to the "Dysregulation of Mood, Energy, and Social Rhythms Syndrome" (DYMERS). This syndrome is characterized by a poor regulation of biological, social, and behavioral rhythms, including sleep, nutrition, and social contacts. The purpose of this cohort study was to examine whether older adults with pre-existing DYMERS had a more negative perception of their health-related quality of life (H-QoL) during the COVID-19 pandemic lockdown, regardless of the presence of concurrent mood disorders.

METHOD

The entire study population (N = 93; age > 65 year) was categorized based on whether they exhibited dysregulated rhythms at the outset of the study. A comparison was made between DYMERS-positive individuals and DYMERS-negative individuals, and we assessed their H-QoL at the conclusion of the study. We also compared the H-QoL of individuals in the cohort who did not have a positive depression score to understand the impact of the rhythm dysregulation alone.

RESULTS

The frequency of individuals with a critical health-related quality of life score (SF12 < 25) was higher in the cohort with pre-existing DYMERS during lockdown (33.33% vs. 6.17%). This difference remained significant even when only individuals without depressive symptomatology were considered (27.27% vs. 2.60%).

CONCLUSION

The results of this study indicate that DYMERS can exert a substantial influence on health-related quality of life (H-QoL), even when mood disturbances are not present. Additional research is required to investigate the relationship between DYMERS and other psychiatric conditions as well as its nature as a standalone disorder.

An Examination of the Associations between Nutritional Composition, Social Jet Lag and Temporal Sleep Variability in Young Adults

While dietary intake has previously been related to various indices of poor sleep (e.g., short sleep duration, poor sleep quality), to date, few studies have examined chrononutrition from the perspectives of the relationship between dietary intake and social jet lag and temporal sleep variability. Moreover, recently it has been suggested that previous methods of measuring social jet lag have the potential to lead to large overestimations. Together, this precludes a clear understanding of the role of nutritional composition in the pathophysiology of poor sleep, via social jet lag and temporal sleep variability, or vice versa. The aim of the present study was to determine the relationships between nutrient intake and social jet lag (using a revised index, taking account of intention to sleep and sleep onset and offset difficulties), and temporal sleep variability. Using a cross-sectional survey, 657 healthy participants (mean age 26.7 ± 6.1 years), without sleep disorders, were recruited via an online platform and completed measures of weekly dietary intake, social jet lag, temporal sleep variability, stress/sleep reactivity and mood. Results showed limited associations between nutritional composition and social jet lag. However, levels of temporal sleep variability were predicted by consumption of polyunsaturated fats, sodium, chloride and total energy intake. The results suggest further examinations of specific nutrients are warranted in a first step to tailoring interventions to manage diet and temporal variabilities in sleep patterns.

The relationship between chronotype and obesity: A systematic review

Referring to the hours during a day when a person's physical and cognitive functions are active, the chronotype indicates the differences in individual preferences in sleep timing and other behaviors. The fact that the evening chronotype has been associated with adverse health outcomes has raised the issue of relationship between chronotype and obesity. This study aims to synthesize the evidence regarding the relationship between chronotype and obesity. As part of the study, the PubMed, OVID-LWW, Scopus, Taylor & Francis, ScienceDirect, MEDLINE Complete, Cochrane Library and ULAKBIM databases were screened for the articles published between January 01, 2010 and December 31, 2020. The quality of each study was assessed independently by the two researchers using the "Quality Assessment Tool for Quantitative Studies." Upon evaluating the screening results, a total of seven studies, one of high quality and six of medium quality, were included in the systematic review. The rate of the minor allele (C) genes, which have been associated with obesity, and SIRT1-CLOCK genes, which have an additional effect in favor of resistance against weight loss, is higher in individuals of evening chronotype, and such individuals have been observed to have significantly higher resistance to weight loss. The evening chronotype individuals have been associated with a higher homeostasis model assessment (HOMA) value, higher plasma ghrelin levels, and a tendency toward a higher body mass index (BMI). The evening chronotypes have been reported to adhere less to a healthy diet and have more unhealthy behaviors and eating patterns. A diet adjusted to the chronotype has been seen to be more effective than conventional hypocaloric diet therapy in terms of anthropometric parameters. Most people who eat their main meals late are of evening chronotype, and such people have been determined to lose significantly less weight than those who eat early. It has been shown that bariatric surgery is less effective in weight loss in evening chronotype patients than in morning chronotype patients. The evening chronotypes are less successful in adapting to weight loss treatments and long-term weight control than the morning chronotypes.