Acute melatonin administration in humans impairs glucose tolerance in both the morning and evening.
Ontology highlight
ABSTRACT: Study objectives
To study the effect of melatonin administration on glucose metabolism in humans in the morning and evening.Design
Placebo-controlled, single-blind design.Setting
Laboratory assessments.Participants
21 healthy women (24 ± 6 y; body mass index: 23.0 ± 3.3 kg/m(2)).Interventions
Glucose tolerance was assessed by oral glucose tolerance tests (OGTT; 75 g glucose) on 4 occasions: in the morning (9 AM), and evening (9 PM); each occurring 15 minutes after melatonin (5 mg) and placebo administration on 4 non-consecutive days.Measurements and results
Melatonin administration impaired glucose tolerance. When administered in the morning, melatonin significantly increased the incremental area under the curve (AUC) and maximum concentration (Cmax) of plasma glucose following OGTT by 186% and 21%, respectively, as compared to placebo; while in the evening, melatonin significantly increased glucose AUC and Cmax by 54% and 27%, respectively. The effect of melatonin on the insulin response to the OGTT depended on the time of day (P < 0.05). In the morning, melatonin decreased glucose tolerance primarily by decreasing insulin release, while in the evening, by decreasing insulin sensitivity.Conclusions
Acute melatonin administration in humans impairs glucose tolerance in both the morning and evening. When administering melatonin, the proximity to meal timing may need to be considered, particularly in those at risk for glucose intolerance.
SUBMITTER: Rubio-Sastre P
PROVIDER: S-EPMC4173928 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:ObjectiveStudies suggest that bedtime dosing of an angiotensin-converting enzyme (ACE)-inhibitor or angiotensin receptor blocker shows a more sustained and consistent 24-h antihypertensive profile, including greater night-time blood pressure (BP) reduction. We compared the antihypertensive effects of morning (a.m.) and evening (p.m.) dosing of valsartan on 24-h BP.MethodsThis 26-week, multicentre, randomized, double-blind study evaluated the efficacy and safety of valsartan 320 mg, dosed a.m. or p.m., versus lisinopril 40 mg (a.m.), a long-acting ACE-inhibitor, in patients with grade 1-2 hypertension and at least one additional cardiovascular risk factor. Patients (n = 1093; BP = 156 ± 11/91 ± 8 mmHg; 62 years, 56% male, 99% white) received (1 : 1 : 1) valsartan 160 mg a.m. or p.m. or lisinopril 20 mg a.m. for 4 weeks, then force-titrated to double the initial dose for 8 weeks. At Week 12, hydrochlorothiazide (HCTZ) 12.5 mg was added for 14 weeks if office BP was more than 140/90 mmHg and/or ambulatory BP more than 130/80 mmHg.ResultsMean 24-h ambulatory SBP change from baseline to Weeks 12 and 26 was comparable between valsartan a.m. (-10.6 and -13.3 mmHg) and p.m. (-9.8 and -12.3 mmHg) and lisinopril (-10.7 and -13.7 mmHg). There was no benefit of valsartan p.m. versus a.m. on night-time BP, early morning BP and morning BP surge. Evening dosing also did not improve BP lowering in patients requiring add-on HCTZ or in nondippers at baseline. All treatments were well tolerated.ConclusionOnce-daily dosing of valsartan 320 mg results in equally effective 24-h BP efficacy, regardless of dosing time.Trial registrationClinicalTrials.gov Identifier: NCT00241124.
| S-EPMC4284009 | biostudies-literature
Project description:Binge alcohol consumption elicits acute and robust increases of muscle sympathetic nerve activity (MSNA), yet the impact of evening binge drinking on morning-after MSNA is unknown. The present study examined the effects of evening binge alcohol consumption on polysomnographic sleep and morning-after MSNA. We hypothesized that evening binge drinking (i.e. 4-5 drink equivalent in <2 h) would reduce sleep quality and increase morning-after blood pressure (BP) and MSNA. Following a familiarization night within the sleep laboratory, 22 participants (12 men, 10 women; 25 ± 1 yr) were examined after simulated binge drinking or fluid control (randomized, crossover design). Morning MSNA was successfully recorded across both conditions in 16 participants (8 men, 8 women) during a 10-min baseline and three Valsalva's maneuvers (VM). Binge drinking reduced rapid eye movement (REM) sleep (15 ± 1 vs. 20 ± 1%, P = 0.003), increased stage II sleep (54 ± 1 vs. 51 ± 1%, P = 0.002), and increased total urine output (2.9 ± 0.2 vs. 2.1 ± 0.1 liters, P < 0.001) but did not alter morning-after urine specific gravity. Binge drinking increased morning-after heart rate [65 (54-72) vs. 58 (51-67) beats/min, P = 0.013] but not resting BP or MSNA. Binge drinking elicited greater sympathoexcitation during VM (38 ± 3 vs. 43 ± 3 bursts/min, P = 0.036). Binge drinking augmented heart rate (P = 0.002), systolic BP (P = 0.022), and diastolic BP (P = 0.037) reactivity to VM phase IV and blunted cardiovagal baroreflex sensitivity during VM phases II (P = 0.028) and IV (P = 0.043). In conclusion, evening binge alcohol consumption disrupted REM sleep and morning-after autonomic function. These findings provide new mechanistic insight into the potential role of binge drinking on cardiovascular risk.NEW & NOTEWORTHY Chronic binge alcohol consumption is associated with future cardiovascular disease (CVD) risk in both men and women. In addition, binge alcohol consumption is known to disrupt normal sleep quality during the early morning hours, coinciding with the morning sympathetic surge. In the present study, an evening of binge alcohol consumption increased baseline morning heart rate and cardiovascular reactivity during the Valsalva maneuver (VM) strain. Specifically, muscle sympathetic nerve activity and phase IV hemodynamic responses increased during VM the morning after binge alcohol consumption. The autonomic dysfunction and increased cardiovascular reactivity during VM suggests a contributing mechanism to CVD risk present in individuals who binge drink.
| S-EPMC7864252 | biostudies-literature
Project description:Brain recovery after prolonged wakefulness is characterized by increased density, amplitude and slope of slow waves (SW, <4 Hz) during non-rapid eye movement (NREM) sleep. These SW comprise a negative phase, during which cortical neurons are mostly silent, and a positive phase, in which most neurons fire intensively. Previous work showed, using EEG spectral analysis as an index of cortical synchrony, that Morning-types (M-types) present faster dynamics of sleep pressure than Evening-types (E-types). We thus hypothesized that single SW properties will also show larger changes in M-types than in E-types in response to increased sleep pressure. SW density (number per minute) and characteristics (amplitude, slope between negative and positive peaks, frequency and duration of negative and positive phases) were compared between chronotypes for a baseline sleep episode (BL) and for recovery sleep (REC) after two nights of sleep fragmentation. While SW density did not differ between chronotypes, M-types showed higher SW amplitude and steeper slope than E-types, especially during REC. SW properties were also averaged for 3 NREM sleep periods selected for their decreasing level of sleep pressure (first cycle of REC [REC1], first cycle of BL [BL1] and fourth cycle of BL [BL4]). Slope was significantly steeper in M-types than in E-types in REC1 and BL1. SW frequency was consistently higher and duration of positive and negative phases constantly shorter in M-types than in E-types. Our data reveal that specific properties of cortical synchrony during sleep differ between M-types and E-types, although chronotypes show a similar capacity to generate SW. These differences may involve 1) stable trait characteristics independent of sleep pressure (i.e., frequency and durations) likely linked to the length of silent and burst-firing phases of individual neurons, and 2) specific responses to increased sleep pressure (i.e., slope and amplitude) expected to depend on the synchrony between neurons.
| S-EPMC3150370 | biostudies-literature
Project description:BackgroundVariation in blood pressure levels display circadian rhythms. The morning surge in blood pressure is known to increase the risk of myocardial events in the first several hours post awakening. A systematic review of the administration-time-related-effects of evening versus morning dosing regimen of antihypertensive drugs in the management of patients with primary hypertension has not been conducted.ObjectivesTo evaluate the administration-time-related-effects of antihypertensive drugs administered as once daily monotherapy in the evening versus morning administration regimen on all cause mortality, cardiovascular morbidity and reduction of blood pressure in patients with primary hypertension.Search strategyWe searched Cochrane CENTRAL on Ovid (4th Quarter 2009), Ovid MEDLINE (1950 to October 2009), EMBASE (1974 to October 2009), the Chinese Biomedical literature database (1978 to 2009) and the reference lists of relevant articles. No language restrictions were applied.Selection criteriaRandomized controlled trials comparing the administration-time-related effects of evening with morning dosing monotherapy regimens in patients with primary hypertension were included. Patients with known secondary hypertension, shift workers or white coat hypertension were excluded.Data collection and analysisTwo authors independently extracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Data synthesis and analysis were done using RevMan 5.1. Random effects meta-analysis and sensitivity analysis were conducted.Main results21 randomized controlled trials (RCTs) in 1,993 patients with primary hypertension met the inclusion criteria for this review - ACEIs (5 trials), CCBs (7 trials), ARBs (6 trials), diuretics (2 trials), alpha-blockers (1 trial), and beta-blockers (1 trial). Meta-analysis showed significant heterogeneity across trials.No RCT reported on all cause mortality, cardiovascular mortality, cardiovascular morbidity and serious adverse events.There was no statistically significant difference for overall adverse events (RR=0.78, 95%CI: 0.37 to 1.65) and withdrawals due to adverse events (RR=0.53, 95%CI: 0.26 to 1.07).No significant differences were noted for morning SBP (-1.62 mm Hg, 95% CI: -4.19 to 0.95) and morning DBP (-1.21 mm Hg, 95% CI: -3.28 to 0.86); but 24-hour BP (SBP: -1.71 mm Hg, 95% CI: -2.78 to -0.65; DBP: -1.38 mm Hg, 95% CI: -2.13 to -0.62) showed a statistically significant difference.Authors' conclusionsNo RCT reported on clinically relevant outcome measures - all cause mortality, cardiovascular morbidity and morbidity. There were no significant differences in overall adverse events and withdrawals due to adverse events among the evening versus morning dosing regimens. In terms of BP lowering efficacy, for 24-hour SBP and DBP, the data suggests that better blood pressure control was achieved with bedtime dosing than morning administration of antihypertensive medication, the clinical significance of which is not known.
| S-EPMC9040377 | biostudies-literature
Project description:AimsThe common MTNR1B genetic variant rs10830963 is associated with an increased risk of type 2 diabetes (T2D). To date, no experimental study has tested the effect of the MTNR1B variant on glucose metabolism in humans during exposure of the melatonin receptors to their ligand. The aim of this study was to investigate whether this MTNR1B variant influenced the effect of melatonin (5mg) on glucose tolerance assessed by an oral glucose tolerance test (OGTT; 75 g) at different times of the day (morning and evening) as compared to a placebo.MethodsSeventeen normoglycemic women (24 ± 6 years; BMI 23.0 ± 3.3 kg/m(2)) completed the study (11 carriers of the risk allele [CG] and 6 noncarriers [CC]).ResultsThe effect of melatonin on glucose tolerance depended on the genotype. In the morning, the effect of melatonin (melatonin-placebo) on the glucose area under the curve (AUC) above baseline differed significantly (P=0.036) between the carriers and noncarriers. This effect of melatonin in the carriers was six times as large as that in the noncarriers. The MTNR1B SNP explained over one-quarter (26%) of the inter-individual differences in the effect of melatonin on glucose AUC. However, in the evening, the effect of melatonin on glucose AUC of the carriers and noncarriers did not differ significantly (P>0.05).ConclusionsMTNR1B rs10830963 risk variant worsens the effect of melatonin on glucose tolerance, suggesting the importance of genotyping and personalized recommendations, especially in people consuming food when melatonin levels are elevated. Large-scale studies in vulnerable populations are necessary to translate these results into real-world, clinically relevant recommendations.
| S-EPMC4856010 | biostudies-literature
Project description:It has been posited that a critical function of sleep is synaptic renormalization following a net increase in synaptic strength during wake. We hypothesized that wake would alter the resting-state functional organization of the brain and increase its metabolic cost. To test these hypotheses, two experiments were performed. In one, we obtained morning and evening resting-state functional MRI scans to assess changes in functional brain organization. In the second experiment, we obtained quantitative positron emission tomography measures of glucose and oxygen consumption to assess the cost of wake. We found selective changes in brain organization. Most prominently, bilateral medial temporal regions were locally connected in the morning but in the evening exhibited strong correlations with frontal and parietal brain regions involved in memory retrieval. We speculate that these changes may reflect aspects of memory consolidation recurring on a daily basis. Surprisingly, these changes in brain organization occurred without increases in brain metabolism.
| S-EPMC3602835 | biostudies-literature
Project description:BackgroundThe aging population is associated with increased multimorbidity and polypharmacy. Older adults are at a higher risk of adverse events and reduced therapeutic response. This phenomenon is partially explained by drug interactions and treatment adherence. Most randomized clinical trials have found no significant differences between morning and evening levothyroxine (LT4) administration in young adults, but there is little evidence regarding alternative LT4 regimens in older populations. Thus, the MONIALE trial aims to test an alternative schedule for LT4 administration in older adults.Methods/designThis randomized crossover clinical trial will include participants aged 60 years or older with primary hypothyroidism. The trial groups will consist of morning LT4 intake (60 min before breakfast) or evening LT4 intake (60 min after supper). The primary outcome will be variation in serum thyrotropin (TSH) levels after 24 weeks of the LT4 protocol. The secondary outcomes will be the prevalence of drugs that potentially interact with LT4 and hypothyroidism control according to interaction status. The sample size was calculated to detect a minimum mean difference of 1 mUI/L in serum TSH level between the groups with 80% power and a 5% probability of type I error, resulting in 91 patients per group. The project was approved by the Hospital de Clínicas de Porto Alegre Ethics Committee.DiscussionConsidering the aging population, the increased prevalence of multimorbidity and polypharmacy, as well as potential drug interactions and treatment adherence difficulties, an alternative LT4 protocol could be useful for hypothyroidism treatment in the elderly. Prior studies comparing alternative LT4 administration protocols have mainly included young adult populations and have not addressed potential drug interactions.Trial registrationClinicalTrials.gov, NCT03614988. Registered 30 July 2018.
| S-EPMC6918562 | biostudies-literature
Project description:Social media manipulation poses a significant threat to cognitive autonomy and unbiased opinion formation. Prior literature explored the relationship between online activity and emotional state, cognitive resources, sunlight and weather. However, a limited understanding exists regarding the role of time of day in content spread and the impact of user activity patterns on susceptibility to mis- and disinformation. This work uncovers a strong correlation between user activity time patterns and the tendency to spread potentially disinformative content. Through quantitative analysis of Twitter (now X) data, we examine how user activity throughout the day aligns with diurnal behavioural archetypes. Evening types exhibit a significantly higher inclination towards spreading potentially disinformative content, which is more likely at night-time. This knowledge can become crucial for developing targeted interventions and strategies that mitigate misinformation spread by addressing vulnerable periods and user groups more susceptible to manipulation.
| S-EPMC11364767 | biostudies-literature
Project description:A great deal of evidence has been gathered on the use of creatine as an ergogenic supplement. Recent studies show greater benefits when creatine ingestion is performed close in time to training, but few studies tackle the way that circadian rhythms could influence creatine consumption. The aim of this study was therefore to observe the influence circadian rhythms exert on sports performance after creatine supplementation. Our method involved randomly assigning fourteen women players of a handball team into two groups in a single-blind study: one that consumed the supplement in the morning and one that consumed it in the evening, with both groups following a specific training program. After twelve weeks, the participants exhibited a decreased fat percentage, increased body weight and body water, and improved performance, with these results being very similar in the two groups. It is therefore concluded that, although circadian rhythms may influence performance, these appear not to affect creatine supplementation, as creatine is stored intramuscularly and is available for those moments of high energy demand, regardless of the time of day.
| S-EPMC8744932 | biostudies-literature
Project description:ContextFatigue is the most common symptom in oncology patients during chemotherapy. Little is known about the predictors of interindividual variability in initial levels and trajectories of morning fatigue severity in these patients.ObjectivesAn evaluation was done to determine which demographic, clinical, and symptom characteristics were associated with initial levels as well as the trajectories of morning fatigue and to compare findings with our companion paper on evening fatigue.MethodsA sample of outpatients with breast, gastrointestinal, gynecological, and lung cancer (n = 586) completed demographic and symptom questionnaires a total of six times over two cycles of chemotherapy. Fatigue severity was evaluated using the Lee Fatigue Scale. Hierarchical linear modeling was used to answer the study objectives.ResultsA large amount of interindividual variability was found in the morning fatigue trajectories. A piecewise model fit the data best. Patients with higher body mass index, who did not exercise regularly, with a lower functional status, and who had higher levels of state anxiety, sleep disturbance, and depressive symptoms reported higher levels of morning fatigue at enrollment. Variations in the trajectories of morning fatigue were predicted by the patients' ethnicity and younger age.ConclusionThe modifiable risk factors that were associated with only morning fatigue were body mass index, exercise, and state anxiety. Modifiable risk factors that were associated with both morning and evening fatigue included functional status, depressive symptoms, and sleep disturbance. Using this information, clinicians can identify patients at higher risk for more severe morning fatigue and evening fatigue, provide individualized patient education, and tailor interventions to address the modifiable risk factors.
| S-EPMC4526314 | biostudies-literature