Circadian desynchrony and glucose metabolism.

The circadian timing system controls glucose metabolism in a time-of-day dependent manner. In mammals, the circadian timing system consists of the main central clock in the bilateral suprachiasmatic nucleus (SCN) of the anterior hypothalamus and subordinate clocks in peripheral tissues. The oscillations produced by these different clocks with a period of approximately 24-h are generated by the transcriptional-translational feedback loops of a set of core clock genes. Glucose homeostasis is one of the daily rhythms controlled by this circadian timing system. The central pacemaker in the SCN controls glucose homeostasis through its neural projections to hypothalamic hubs that are in control of feeding behavior and energy metabolism. Using hormones such as adrenal glucocorticoids and melatonin and the autonomic nervous system, the SCN modulates critical processes such as glucose production and insulin sensitivity. Peripheral clocks in tissues, such as the liver, muscle, and adipose tissue serve to enhance and sustain these SCN signals. In the optimal situation all these clocks are synchronized and aligned with behavior and the environmental light/dark cycle. A negative impact on glucose metabolism becomes apparent when the internal timing system becomes disturbed, also known as circadian desynchrony or circadian misalignment. Circadian desynchrony may occur at several levels, as the mistiming of light exposure or sleep will especially affect the central clock, whereas mistiming of food intake or physical activity will especially involve the peripheral clocks. In this review, we will summarize the literature investigating the impact of circadian desynchrony on glucose metabolism and how it may result in the development of insulin resistance. In addition, we will discuss potential strategies aimed at reinstating circadian synchrony to improve insulin sensitivity and contribute to the prevention of type 2 diabetes.

Effect of Postmenopausal Hormone Therapy on Glucose Regulation in Women With Type 1 or Type 2 Diabetes: A Systematic Review and Meta-analysis.

BACKGROUND: Blood glucose regulation in women with diabetes may change during and after menopause, which could be attributed, in part, to decreased estrogen levels. PURPOSE: To determine the effect of postmenopausal hormone therapy (HT) on HbA1c, fasting glucose, postprandial glucose, and use of glucose-lowering drugs in women with type 1 and women with type 2 diabetes. DATA SOURCES: We conducted a systematic search of MEDLINE, Embase, Scopus, the Cochrane Library, and the ClinicalTrials.gov registry to identify randomized controlled trials (RCTs). STUDY SELECTION: We selected RCTs on the effect of HT containing estrogen therapy in postmenopausal women (≥12 months since final menstrual period) with type 1 or type 2 diabetes. DATA EXTRACTION: Data were extracted for the following outcomes: HbA1c, fasting glucose, postprandial glucose, and use of glucose-lowering medication. DATA SYNTHESIS: Nineteen RCTs were included (12 parallel-group trials and 7 crossover trials), with a total of 1,412 participants, of whom 4.0% had type 1 diabetes. HT reduced HbA1c (mean difference -0.56% [95% CI -0.80, -0.31], -6.08 mmol/mol [95% CI -8.80, -3.36]) and fasting glucose (mean difference -1.15 mmol/L [95% CI -1.78, -0.51]). LIMITATIONS: Of included studies, 50% were at high risk of bias. CONCLUSIONS: When postmenopausal HT is considered for menopausal symptoms in women with type 2 diabetes, HT is expected to have a neutral-to-beneficial impact on glucose regulation. Evidence for the effect of postmenopausal HT in women with type 1 diabetes was limited.

Skills or Pills: Randomized Trial Comparing Hypnotherapy to Medical Treatment in Children With Functional Nausea.

BACKGROUND & AIMS: The potential effectiveness of gut-directed hypnotherapy (HT) is unknown for pediatric chronic nausea. This randomized controlled trial compared HT with standard medical treatment (SMT). METHODS: One hundred children (ages, 8-18 y) with chronic nausea and fulfilling functional nausea (FN) or functional dyspepsia (FD) criteria were allocated randomly (1:1) to HT or SMT, with a 3-month intervention period. Outcomes were assessed at baseline, at the halfway point, after treatment, and at the 6- and 12-month follow-up evaluation. Children scored nausea symptoms in a 7-day diary. The primary outcome was treatment success, defined as a reduction in nausea of 50% or more, at the 12-month follow-up evaluation. Secondary outcomes included adequate relief of nausea. RESULTS: After treatment and at the 6-month follow-up evaluation, there was a trend toward higher treatment success in the HT group compared with the SMT group (45% vs 26%, P = .052; and 57% vs 40%, P = .099, respectively). At 12 months, treatment success was similar in both groups (60% in the HT group and 55% in the SMT group; P = .667). In the FN group, significantly higher success rates were found for HT, but no differences were found in patients with FD. Adequate relief was significantly higher in the HT group than in the SMT group at the 6-month follow-up evaluation (children: 81% vs 55%, P = .014; parents: 79% vs 53%; P = .016), but not at the 12-month follow-up evaluation. CONCLUSIONS: HT and SMT were effective in reducing nausea symptoms in children with FN and FD. In children with FN, HT was more effective than SMT during and after the first 6 months of treatment. Therefore, HT and SMT, applied separately or in combination, should be offered to children with FN as a treatment option (Clinical trials registration number: NTR5814).

Gut-directed hypnotherapy versus standard medical treatment for nausea in children with functional nausea or functional dyspepsia: protocol of a multicentre randomised trial.

INTRODUCTION: The treatment of chronic functional nausea or nausea due to functional dyspepsia in children is generally symptomatic. Moreover, these disorders pose a risk for worse psychosocial and health outcomes in children. Hypnotherapy (HT), by its ability to positively influence gastrointestinal and psychosocial functioning, may be an effective treatment for chronic nausea. METHODS AND ANALYSIS: To test efficacy, this multicentre, parallel, randomised controlled, open label trial evaluates whether gut-directed HT is superior to standard medical treatment (SMT) for reducing nausea. The study will be conducted at eleven academic and non-academic hospitals across the Netherlands. A total of 100 children (8-18 years), fulfilling the Rome IV criteria for chronic idiopathic nausea or functional dyspepsia with prominent nausea, will be randomly allocated (1:1) to receive HT or SMT. Children allocated to the HT group will receive six sessions of HT during 3 months, while children allocated to the SMT group will receive six sessions of SMT+supportive therapy during the same period. The primary outcome will be the difference in the proportion of children with at least 50% reduction of nausea, compared with baseline at 12 months' follow-up. Secondary outcomes include the changes in abdominal pain, dyspeptic symptoms, quality of life, anxiety, depression, school absences, parental absence of work, healthcare costs and adequate relief of symptoms, measured directly after treatment, 6 and 12 months' follow-up. If HT proves effective for reducing nausea, it may become a new treatment strategy to treat children with chronic functional nausea or functional dyspepsia with prominent nausea. ETHICS AND DISSEMINATION: Results of the study will be publicly disclosed to the public, without any restrictions, in peer-reviewed journal and international conferences. The study is approved by the Medical Research Ethics Committees United (MEC-U) in the Netherlands. TRIAL REGISTRATION NUMBER: NTR5814.