Melatonin Supplementation Lowers Oxidative Stress and Regulates Adipokines in Obese Patients on a Calorie-Restricted Diet.
Oxidative medicine and cellular longevity. 2017;2017:8494107
Plain language summary
Obesity is one of the major global health problems. Melatonin is a hormone which regulates wakefulness, functions as an antioxidant and plays a role in the immune system. Previous research suggests that melatonin deficiency is associated with obesity. The aim of this study was to estimate the effect of melatonin on oxidative stress and levels of cell signalling proteins released by fat cells (adipokines) in obese patients on a calorie-restricted diet. Thirty obese patients were supplemented with a daily dose of 10 mg of melatonin or placebo for 30 days with a calorie-restricted diet. Blood levels of melatonin, adipokines and markers of oxidative stress were measured at baseline and after supplementation. Significant body weight reduction (7%) was observed only in the melatonin group. After melatonin supplementation, the adiponectin and omentin-1 levels and glutathione peroxidase activities statistically increased, whereas the malondialdehyde concentrations were reduced. In the placebo group, a significant rise in 4-hydroxynonenal and a drop in the melatonin concentrations were found. The results show evidence of increased oxidative stress accompanying calorie restriction. The authors concluded that melatonin supplementation facilitated body weight reduction, improved the antioxidant defence, and regulated adipokine secretion. The findings suggest that melatonin should be considered in the management of obesity.
undefined: Obesity is one of the major global health problems. Melatonin deficiency has been demonstrated to correlate with obesity. The aim of the study was to estimate the effect of melatonin on oxidative stress and adipokine levels in obese patients on a calorie-restricted diet. Thirty obese patients were supplemented with a daily dose of 10 mg of melatonin ( = 15) or placebo ( = 15) for 30 days with a calorie-restricted diet. Serum levels of melatonin, 4-hydroxynonenal (HNE), adiponectin, omentin-1, leptin, and resistin, as well as erythrocytic malondialdehyde (MDA) concentration and Zn/Cu-superoxide dismutase, catalase, and glutathione peroxidase (GPx) activities, were measured at baseline and after supplementation. Significant body weight reduction was observed only in the melatonin group. After melatonin supplementation, the adiponectin and omentin-1 levels and GPx activities statistically increased, whereas the MDA concentrations were reduced. In the placebo group, a significant rise in the HNE and a drop in the melatonin concentrations were found. The results show evidence of increased oxidative stress accompanying calorie restriction. Melatonin supplementation facilitated body weight reduction, improved the antioxidant defense, and regulated adipokine secretion. The findings strongly suggest that melatonin should be considered in obesity management. This trial is registered with CTRI/2017/07/009093.
The impact of sleeping with reduced glycogen stores on immunity and sleep in triathletes.
European journal of applied physiology. 2016;116(10):1941-54
Plain language summary
Endurance athletes are increasingly using training strategies focused on low glycogen availability in attempt to improve performance. It is well known, however, that increasing training stress could influence immune function and increase the risk of illness or injury. In endurance sports, training load, nutrient intake and sleep are key factors in modulating immune function. The aim of this study was to investigate the effects of a 3-week training strategy involving lowered glycogen availability overnight on immune function, upper respiratory tract infections and sleep patterns in 21 trained endurance athletes. This study found that reduced glycogen availability resulted in significantly faster 10km running times, and found no significant changes in the recorded immunity markers. Based on this study, the authors conclude that reduced glycogen availability has no deleterious impact on immune function.
PURPOSE We investigated the effects of a 3-week dietary periodization on immunity and sleep in triathletes. METHODS 21 triathletes were divided into two groups with different nutritional guidelines during a 3-week endurance training program including nine twice a day sessions with lowered (SL group) or maintained (CON group) glycogen availability during the overnight recovery period. In addition to performance tests, sleep was monitored every night. Systemic and mucosal immune parameters as well as the incidence of URTI were monitored every week of the training/nutrition protocol. Two-ways ANOVA and effect sizes were used to examine differences in dependent variables between groups at each time point. RESULTS The SL group significantly improved 10 km running performance (-1 min 13 s, P < 0.01, d = 0.38), whereas no improvement was recorded in the CON group (-2 s, NS). No significant changes in white blood cells counts, plasma cortisol and IL-6 were recorded over the protocol in both groups. The vitamin D status decreased in similar proportions between groups, whereas salivary IgA decreased in the SL group only (P < 0.05, d = 0.23). The incidence of URTI was not altered in both groups. All participants in both groups went to bed earlier during the training program (SL -20 min, CON -27 min, P < 0.05, d = 0.28). In the SL group, only sleep efficiency slightly decreased by 1.1 % (P < 0.05, d = 0.25) and the fragmentation index tended to increase at the end of the protocol (P = 0.06). CONCLUSION Sleeping and training the next morning regularly with reduced glycogen availability has minimal effects on selected markers of immunity, the incidence of URTI and sleeping patterns in trained athletes.
The microbiome: A key regulator of stress and neuroinflammation.
Neurobiology of stress. 2016;4:23-33
Plain language summary
This study discusses the concept of intestinal microbiota as the key regulator involved in energy regulation, gut barrier function, protection from pathogens, and immune system function amongst others. The gut microbiota is the complex community of microorganisms that lives in the digestive tracts of humans. The main aim of this study is to summarise the role of gastrointestinal microbiota in fundamental physiological and pathophysiological processes and thereafter to understand and treat a range of stress and immune-related disorders. This review outlines the numerous complex relationships between gastrointestinal microbiota, stress and immune responses at the three critical stages of life The authors concluded that the evidence from this study suggests that resilience to stress and immune-related disorders and dysfunction of stress and immune systems may be dependent on the diversity and complexity of gastrointestinal microbiota. However, gut microbiota mediated relationship to stress and neuro-inflammation is still unconfirmed as previous studies mostly, have largely been, preclinical and further studies are warranted.
There is a growing emphasis on the relationship between the complexity and diversity of the microorganisms that inhabit our gut (human gastrointestinal microbiota) and health/disease, including brain health and disorders of the central nervous system. The microbiota-gut-brain axis is a dynamic matrix of tissues and organs including the brain, glands, gut, immune cells and gastrointestinal microbiota that communicate in a complex multidirectional manner to maintain homeostasis. Changes in this environment can lead to a broad spectrum of physiological and behavioural effects including hypothalamic-pituitary-adrenal (HPA) axis activation, and altered activity of neurotransmitter systems and immune function. While an appropriate, co-ordinated physiological response, such as an immune or stress response are necessary for survival, a dysfunctional response can be detrimental to the host contributing to the development of a number of CNS disorders. In this review, the involvement of the gastrointestinal microbiota in stress-mediated and immune-mediated modulation of neuroendocrine, immune and neurotransmitter systems and the consequential behaviour is considered. We also focus on the mechanisms by which commensal gut microbiota can regulate neuroinflammation and further aim to exploit our understanding of their role in stress-related disorders as a consequence of neuroinflammatory processes.
Multiple risk-behavior profiles of smokers with serious mental illness and motivation for change.
Health psychology : official journal of the Division of Health Psychology, American Psychological Association. 2014;33(12):1518-29
Plain language summary
Individuals with serious mental illness (SMI) are at greater risk for chronic disease, which are largely preventable through health behaviour change. Within this population tobacco use is a major health concern and recent trials have demonstrated treating tobacco dependence supports mental health recovery. As risk behaviours tend to co-occur, the aim of this study was to examine the behavioural risk profiles of adult smokers with SMI to further understand frequencies and patterns of risks in order to best inform interventional programmes. In the context of a tobacco-treatment trial, 693 adult smokers from inpatient psychiatry wards were recruited. The Staging Health Risk Assessment was used which screens for risk status and readiness to change 11 health behaviours. The findings of this study showed that most smokers with SMI engage in multiple risks including poor diet, inadequate sleep, physical inactivity and marijuana use. This study can help prioritise health intervention programme targets and provide further benefit for this population.
OBJECTIVE Individuals with serious mental illness (SMI) are dying on average 25 years prematurely. The leading causes are chronic preventable diseases. In the context of a tobacco-treatment trial, this exploratory study examined the behavioral risk profiles of adults with SMI to identify broader interventional needs. METHOD Recruited from five acute inpatient psychiatry units, participants were 693 adult smokers (recruitment rate = 76%, 50% male, 45% Caucasian, age M = 39, 49% had income < $10,000) diagnosed with mood disorders (71%), substance-use disorders (63%), posttraumatic stress disorder (39%), psychotic disorders (25%), and attention deficit-hyperactivity disorder (25%). The Staging Health Risk Assessment, the primary measure used in this study, screened for risk status and readiness to change 11 health behaviors, referencing the period prior to acute hospitalization. RESULTS Participants averaged 5.2 (SD = 2.1) risk behaviors, including smoking (100%), high-fat diet (68%), inadequate fruits/vegetables (67%), poor sleep (53%), physical inactivity (52%), and marijuana use (46%). The percent prepared to change ranged from 23% for tobacco and marijuana to 76% for depression management. Latent class analysis differentiated three risk groups: the global higher risk group included patients elevated on all risk behaviors; the global lower risk group was low on all risks; and a mood and metabolic risk group, characterized by inactivity, unhealthy diet, sleep problems, and poor stress and depression management. The global higher risk group (11% of sample) was younger, largely male, and had the greatest number of risk behaviors and mental health diagnoses; had the most severe psychopathologies, addiction-treatment histories, and nicotine dependence; and the lowest confidence for quitting smoking and commitment to abstinence. CONCLUSION Most smokers with SMI engaged in multiple risks. Expanding targets to treat co-occurring risks and personalizing treatment to individuals' multibehavioral profiles may increase intervention relevance, interest, and impact on health.
Sleep restriction for 1 week reduces insulin sensitivity in healthy men.
Plain language summary
Short sleep duration is associated with an increased risk of many chronic diseases including diabetes, however the effects of sleep restriction on insulin sensitivity have not yet been established. The aim of study was to assess the effects of decreased sleep duration on insulin sensitivity in a controlled environment. This 12-day inpatient study included 20 healthy men who were randmoised to receive a wakefulness-promoting drug, modafinil, or placebo during the sleep restriction phase. This study showed that sleep restriction for one week significantly reduces insulin sensitivity. These findings raise concerns about chronic insufficient sleep on the development of metabolic diseases and promote further research into these effects.
OBJECTIVE Short sleep duration is associated with impaired glucose tolerance and an increased risk of diabetes. The effects of sleep restriction on insulin sensitivity have not been established. This study tests the hypothesis that decreasing nighttime sleep duration reduces insulin sensitivity and assesses the effects of a drug, modafinil, that increases alertness during wakefulness. RESEARCH DESIGN AND METHODS This 12-day inpatient General Clinical Research Center study included 20 healthy men (age 20-35 years and BMI 20-30 kg/m(2)). Subjects spent 10 h/night in bed for >or=8 nights including three inpatient nights (sleep-replete condition), followed by 5 h/night in bed for 7 nights (sleep-restricted condition). Subjects received 300 mg/day modafinil or placebo during sleep restriction. Diet and activity were controlled. On the last 2 days of each condition, we assessed glucose metabolism by intravenous glucose tolerance test (IVGTT) and euglycemic-hyperinsulinemic clamp. Salivary cortisol, 24-h urinary catecholamines, and neurobehavioral performance were measured. RESULTS IVGTT-derived insulin sensitivity was reduced by (means +/- SD) 20 +/- 24% after sleep restriction (P = 0.001), without significant alterations in the insulin secretory response. Similarly, insulin sensitivity assessed by clamp was reduced by 11 +/- 5.5% (P < 0.04) after sleep restriction. Glucose tolerance and the disposition index were reduced by sleep restriction. These outcomes were not affected by modafinil treatment. Changes in insulin sensitivity did not correlate with changes in salivary cortisol (increase of 51 +/- 8% with sleep restriction, P < 0.02), urinary catecholamines, or slow wave sleep. CONCLUSIONS Sleep restriction (5 h/night) for 1 week significantly reduces insulin sensitivity, raising concerns about effects of chronic insufficient sleep on disease processes associated with insulin resistance.
Exposure to recurrent sleep restriction in the setting of high caloric intake and physical inactivity results in increased insulin resistance and reduced glucose tolerance.
The Journal of clinical endocrinology and metabolism. 2009;94(9):3242-50
Plain language summary
Type-2 diabetes (T2D) is a complex disease influenced by genetic, environmental, metabolic and behavioural factors and is a rising burden in Westernised societies. Whether reduced sleep duration, in the context of a Western lifestyle, is associated with an increased incidence of T2D is unclear and available evidence is limited. The aim of this crossover study was to determine whether sleep restriction may result in a decreased glucose tolerance and reduced insulin secretion in 11 healthy middle-aged adults. Participants were restricted to 5.5 hours of sleep per night and glucose challenges and circulating plasma concentrations were used to measure hormonal and metabolic parameters. This study showed that recurrent short sleep times may facilitate the development of insulin resistance and reduced glucose tolerance. These findings suggest that combining the adverse metabolic effects of a Western lifestyle with chronically reduced sleep duration may increase the long-term risk of developing T2D.
CONTEXT Epidemiological data indicate that reduced sleep duration is associated with increased incidence of type-2 diabetes. OBJECTIVE The aim of the study was to test the hypothesis that, when part of a Western-like lifestyle, recurrent bedtime restriction may result in decreased glucose tolerance and reduced insulin secretion and action. DESIGN AND SETTING We conducted a randomized crossover study at a university clinical research center and sleep research laboratory. PARTICIPANTS Eleven healthy volunteers (five females and six males) with a mean (+/-sd) age of 39 +/- 5 yr and body mass index of 26.5 +/- 1.5 kg/m(2) participated in the study. INTERVENTION The study included two 14-d periods of controlled exposure to sedentary living with ad libitum food intake and 5.5- or 8.5-h bedtimes. MAIN OUTCOME MEASURES Oral and iv glucose challenges were used to obtain measures of glucose tolerance, glucose effectiveness, insulin secretion, and insulin sensitivity at the end of each intervention. Secondary measures included circulating concentrations of the glucose counter-regulatory hormones, cortisol, GH, epinephrine, and norepinephrine. RESULTS Bedtime restriction reduced daily sleep by 122 +/- 25 min. Both study periods were associated with comparable weight gain; however, recurrent sleep restriction resulted in reduced oral glucose tolerance (2-h glucose value, 144 +/- 25 vs. 132 +/- 36 mg/dl; P < 0.01) and insulin sensitivity [3.3 +/- 1.1 vs. 4.0 +/- 1.6 (mU/liter)(-1) x min(-1); P < 0.03], and increased glucose effectiveness (0.023 +/- 0.005 vs. 0.020 +/- 0.005 min(-1); P < 0.04). Although 24-h cortisol and GH concentrations did not change, there was a modest increase in 24-h epinephrine and nighttime norepinephrine levels during the 5.5-h bedtime condition. CONCLUSIONS Experimental bedtime restriction, designed to approximate the short sleep times experienced by many individuals in Westernized societies, may facilitate the development of insulin resistance and reduced glucose tolerance.