The diurnal pattern of moderate-to-vigorous physical activity and obesity: a cross-sectional analysis.

OBJECTIVE: Moderate-to-vigorous physical activity (MVPA) is obesity-protective. However, the optimal time of the day to engage in MVPA for weight management is controversial. This study is designed to investigate the influence of the diurnal pattern of MVPA on the association between MVPA and obesity. METHODS: A total of 5285 participants in the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES) were cross-sectionally analyzed. The diurnal pattern of objectively measured MVPA was classified into three clusters by K-means clustering analysis: morning (n = 642); midday (n = 2456); and evening (n = 2187). The associations of MVPA level and the diurnal pattern with obesity were tested. RESULTS: A strong linear association between MVPA and obesity was found in the morning group, whereas a weaker curvilinear association between MVPA and obesity was observed in the midday and evening groups, respectively. Among those who met the physical activity guidelines, the adjusted means for BMI were 25.9 (95% CI: 25.2-26.6), 27.6 (95% CI: 27.1-28.1), and 27.2 (95% CI: 26.8-27.7) kg/m2 in the morning, midday, and evening groups, respectively, and for waist circumference were 91.5 (95% CI: 89.4-93.6), 95.8 (95% CI: 94.7-96.9), and 95.0 (95% CI: 93.9-96.1) cm, respectively. CONCLUSIONS: The diurnal pattern of MVPA influences the association between MVPA and obesity. The promising role of morning MVPA for weight management warrants further investigation.

Association of Time-of-Day Physical Activity With Incident Cardiovascular Disease: The UK Biobank Study.

INTRODUCTION: Early morning is characterized by an increased risk of cardiovascular events, a sudden rise in blood pressure, impaired endothelial function, and exacerbated hemodynamic changes during physical activity. The study aims to examine whether the time of day of physical activity is associated with incident cardiovascular disease (CVD). METHODS: We prospectively analyzed 83,053 participants in the UK Biobank with objectively measured physical activity and initially free of CVD. Based on the diurnal patterns of physical activity, participants were categorized into 4 groups: early morning (n = 15,908), late morning (n = 22,371), midday (n = 24,764), and evening (n = 20,010). Incident CVD was defined as the first diagnosis of coronary heart disease or stroke. RESULTS: During 197.4 million person-years of follow-up, we identified 3454 CVD cases. After adjusting for the overall acceleration average, the hazard ratios and 95% confidence intervals were 0.95 (0.86-1.07) for late morning, 1.15 (1.03-1.27) for midday, and 1.03 (0.92-1.15) for evening, as compared with the early morning group. In the joint analyses, higher levels of physical activity were associated with a lower risk of incident CVD in a similar manner across the early morning, late morning, and evening groups. However, the beneficial association was attenuated in the midday group. CONCLUSION: In conclusion, early morning, late morning, and evening are all favorable times of day to engage in physical activity for the primary prevention of CVD, while midday physical activity is associated with an increased risk of CVD compared with early morning physical activity after controlling for the levels of physical activity.

Association of the time of day of peak physical activity with cardiovascular mortality: Findings from the UK Biobank study.

Cardiovascular physiology and pathophysiology display pronounced circadian rhythms. The study is designed to examine whether the time of day of physical activity is associated with cardiovascular mortality. We analyzed 94,489 UK Biobank adults with objectively measured physical activity, including 53,328 morning-type participants and 30,962 evening-type participants based on self-reported chronotypes. The time of day of peak physical activity was categorized using a machine learning algorithm: early morning (n = 18,477), late morning (n = 25,700), midday (reference) (n = 27,803), and night (n = 22,509). Hazard ratios of cardiovascular mortality were examined using the Cox proportional hazards model. During a median follow-up of 6.9 years (interquartile range, 6.3-7.4 years), we identified 629 cardiovascular deaths. The hazard of cardiovascular mortality was elevated in the early morning group (hazard ratio = 1.56, 95% Confidence Interval [1.23-1.98]) and night group (1.49, [1.18-1.88]) but not in the late morning group (1.21, [0.98-1.47]) compared to the referent midday group. In the chronotype-stratified analysis, the increased cardiovascular mortality in the morning group was only observed in the evening-type participants, while the increased cardiovascular mortality in the night group was only observed in the morning-type participants. In conclusion, optimizing the timing of peak physical activity according to cardiovascular circadian rhythms and individual chronotypes could be a potential therapeutic target that brings additional health benefits.

Efficacy and feasibility of a 12-week Tai Chi training for the prophylaxis of episodic migraine in Hong Kong Chinese women: A randomized controlled trial.

Background: Tai Chi has been broadly applied as alternative treatment for many neurological and psychological disorders. Whereas no study using Tai Chi as prophylactic treatment for migraine. The purpose of this study was to preliminarily examine the efficacy and feasibility of a 12-week Tai Chi training on migraine attack prevention in a sample of Chinese women. Methods: A two-arm randomized controlled trial was designed. Women aged 18 to 65 years and diagnosed with episodic migraine were randomized to either Tai Chi group (TC group) or the waiting list control group. A modified 33-short form Yang-style Tai Chi training with 1 h per day, 5 days per week for 12 weeks was implemented in the TC group, with a 12-week follow up period. The control group received a "delayed" Tai Chi training at the end of the trial. The primary outcome was the differences in attack frequency between 4 weeks before baseline and at the 9-12 weeks after randomization. The intensity and duration of headache were also measured. The feasibility was evaluated by the maintenance of Tai Chi practice and satisfactory level of the participants toward training. Results: Eighty-two women were randomized, finally 40 in TC group and 33 in control group were involved in the analysis. On average, women in TC group had 3.0 times (95% CI: -4.0 to -2.0, P < 0.01) and 3.6 days (95% CI: -4.7 to -2.5, P < 0.01) reduction of migraine attack per month. Compared with the control group, the differences were statistically significant (-3.7 attacks/month, 95% CI: -5.4 to -1.9; and -3.0 migraine days/month, 95% CI: -4.5 to -1.5; both P < 0.001). The intensity and duration of headache had 0.6 (95% CI: -1.2 to -0.0, P < 0.05) units and 1.2 (IQR: -5.0 to 1.1, P < 0.05) hours reduction in TC group, respectively. Most of the participants (69.2%-97.4%) were satisfied with the training. At the end of 24 weeks, on average, the participants maintained 1.5 times of practice per week and 20 min for each practice. Conclusion: The 12-week Tai Chi training significantly decreased the frequency of migraine attack. It was acceptable and practicable among female migraineurs. Clinical trial registration: www.ClinicalTrials.gov, identifier: NCT03015753.

Effectiveness of Tai Chi on Blood Pressure, Stress, Fatigue, and Sleep Quality among Chinese Women with Episodic Migraine: A Randomised Controlled Trial.

The beneficial effects of Tai Chi on the cardiovascular risk profile and the migraine trigger factors among female migraineurs remain unknown. This study aimed to evaluate the effectiveness of a 12-week Tai Chi training on blood pressure (BP) and migraine-related trigger factors, including stress, fatigue, and sleep quality among Chinese women with episodic migraine. In this study, eligible Hong Kong Chinese women aged 18-65 years were randomly assigned to the Tai Chi group adopting a modified 33-short form of Yang style Tai Chi training for 12 weeks, followed by additional 12 weeks of self-practice or the waiting list control group that maintained the usual lifestyle for 24 weeks. The primary outcome was the changes in BP from the baseline to 12 and 24 weeks. The secondary outcomes included the stress level, fatigue, and sleep quality measured by the perceived stress scale (PSS), the numeric rating scale-fatigue (NRS-fatigue), and the Pittsburgh sleep quality index (PSQI), respectively. Significant between-group differences were found in systolic BP (-6.8 mmHg at 24 weeks, P=0.02), and a decreasing trend was significant across baseline, 12 weeks, and 24 weeks between groups (P < 0.05). The 12-week Tai Chi training significantly reduced the BP level and moderately improved stress level, fatigue status, and sleep quality among Chinese women with episodic migraine. Therefore, Tai Chi could be considered a promising mind-body exercise with good feasibility for migraineurs in the future. This trial is registered with registration number NCT03015753.

Time-of-day moderate-to-vigorous physical activity and all-cause mortality in individuals with type 2 diabetes.

There is no clear evidence for the best time of day for physical activity in benefitting health among individuals with type 2 diabetes. This study was aimed to examine whether there is an optimal time of day for physical activity to increase longevity. In this cohort study of 904 patients with type 2 diabetes, we fitted a Cox model with restricted cubic spline to examine the association of moderate-to-vigorous physical activity (MVPA) and time of day with all-cause mortality. Compositional data analysis was used to examine the association of time spent in sedentary behaviour (SB), light-intensity physical activity (LIPA), morning MVPA, and evening MVPA with all-cause mortality. MVPA was inversely associated with all-cause mortality in a curvilinear manner (P-value for nonlinearity<0.0001). The interaction between MVPA and time of day was not significant (P-value for interaction=0.11). Substituting evening MVPA with morning MVPA was not associated with appreciable changes in all-cause mortality. There is no evidence that the time of day moderates the association of MVPA with all-cause mortality. Patients with higher levels of MVPA had lower mortality regardless of the timing of MVPA. Patients with type 2 diabetes should engage in regular physical activity whenever possible.

Why are physical activity breaks more effective than a single session of isoenergetic exercise in reducing postprandial glucose? A systemic review and meta-analysis.

Previous studies revealed that interrupting sitting time with short, frequent physical activity (PA) breaks were more effective than a single session of isoenergetic exercise in reducing postprandial glucose. However, in those studies, the expected glucose-lowering effects of single-session exercises were diminished or even eliminated by exercise-induced glucose counterregulation as evidenced by the higher glucose levels during or after exercise compared to uninterrupted sitting. This study was aimed to investigate whether glucose counterregulation is a potential explanation of PA breaks being more effective than a single session of isoenergetic exercise in reducing postprandial glucose. We meta-analysed the standardized mean differences (SMD) of glucose incremental area under the curve (iAUC). PA breaks were more effective than single-session exercise in reducing glucose iAUC (5 studies, SMD = -0.581; 95% confidence interval [CI], -0.777 to -0.385; P < 0.0001) when exercise-induced glucose counterregulation occurred. There was no significant difference in glucose iAUC between PA breaks and single-session exercises (2 studies, SMD = 0.302; 95% CI, -0.107 to 0.711; P = 0.451) when glucose counterregulation did not occur. We concluded that the exercise-induced glucose counterregulation was a potential explanation of PA breaks being more effective than a single session of isoenergetic exercise in reducing postprandial glucose responses. (PROSPERO ID: CRD42020175737).

Molecular surveillance for drug resistance markers in Plasmodium vivax isolates from symptomatic and asymptomatic infections at the China-Myanmar border.

BACKGROUND: In the Greater Mekong sub-region, Plasmodium vivax has become the predominant species and imposes a major challenge for regional malaria elimination. This study aimed to investigate the variations in genes potentially related to drug resistance in P. vivax populations from the China-Myanmar border area. In addition, this study also wanted to determine whether divergence existed between parasite populations associated with asymptomatic and acute infections. METHODS: A total of 66 P. vivax isolates were obtained from patients with acute malaria who attended clinics at the Laiza area, Kachin State, Myanmar in 2015. In addition, 102 P. vivax isolates associated with asymptomatic infections were identified by screening of volunteers without signs or symptoms from surrounding villages. Slide-positive samples were verified with nested PCR detecting the 18S rRNA gene. Multiclonal infections were further excluded by genotyping at msp-3α and msp-3ß genes. Parasite DNA from 60 symptomatic cases and 81 asymptomatic infections was used to amplify and sequence genes potentially associated with drug resistance, including pvmdr1, pvcrt-o, pvdhfr, pvdhps, and pvk12. RESULTS: The pvmdr1 Y976F and F1076L mutations were present in 3/113 (2.7%) and 97/113 (85.5%) P. vivax isolates, respectively. The K10 insertion in pvcrt-o gene was found in 28.2% of the parasites. Four mutations in the two antifolate resistance genes reached relatively high levels of prevalence: pvdhfr S58R (53.4%), S117N/T (50.8%), pvdhps A383G (75.0%), and A553G (36.3%). Haplotypes with wild-type pvmdr1 (976Y/997K/1076F) and quadruple mutations in pvdhfr (13I/57L/58R/61M/99H/117T/173I) were significantly more prevalent in symptomatic than asymptomatic infections, whereas the pvmdr1 mutant haplotype 976Y/997K/1076L was significantly more prevalent in asymptomatic than symptomatic infections. In addition, quadruple mutations at codons 57, 58, 61 and 117 of pvdhfr and double mutations at codons 383 and 553 of pvdhps were found both in asymptomatic and symptomatic infections with similar frequencies. No mutations were found in the pvk12 gene. CONCLUSIONS: Mutations in pvdhfr and pvdhps were prevalent in both symptomatic and asymptomatic P. vivax infections, suggestive of resistance to antifolate drugs. Asymptomatic carriers may act as a silent reservoir sustaining drug-resistant parasite transmission necessitating a rational strategy for malaria elimination in this region.

The effect of EDTA root conditioning on periodontal surgery outcome: A meta-analysis.

OBJECTIVE: Chemical root conditioning is a procedure to remove the smear layer, which influences periodontal healing. The purpose of this study was to determine the effect of using ethylenediaminetetraacetic acid (EDTA) as a root conditioning agent on periodontal surgery outcomes. METHOD AND MATERIALS: The databases searched from their earliest records to February 2015 included Pubmed, Embase, the Cochrane library, and ISI Web of Science. Quality assessment of the methodologies of all the included studies and data was performed with Review Manager software. Probing depth (PD) and clinical attachment level (CAL) were analyzed using inverse variance. RESULTS: The evaluation of the three articles that met the inclusion criteria showed that the differences between the EDTA groups and the control groups were not statistically significant (6 months PD: mean difference [MD] = -0.15 mm, Z = 1.09, P = .27; CAL: MD = 0.15 mm, Z = 0.89, P = .37). CONCLUSION: EDTA was not able to significantly improve the PD and CAL. A positive outcome of using EDTA as a root conditioning agent was not evident. Thus, future research should focus on EDTA in combination with other drugs or a better alternative drug to EDTA.