Mechanisms and risk factors of metabolic syndrome in children and adolescents

Metabolic syndrome (MetS) is a complex disorder characterized by abdominal obesity, elevated blood pressure, hyperlipidemia, and elevated fasting blood glucose levels. The diagnostic criteria for MetS in adults are well-established, but there is currently no consensus on the definition in children and adolescents. The etiology of MetS is believed to involve a complex interplay between genetic predisposition and environmental factors. While genetic predisposition explains only a small part of MetS pathogenesis, modifiable environmental risk factors play a significant role. Factors such as maternal weight during pregnancy, children's lifestyle, sedentariness, high-fat diet, fructose and branched-chain amino acid consumption, vitamin D deficiency, and sleep disturbances contribute to the development of MetS. Early identification and treatment of MetS in children and adolescents is crucial to prevent the development of chronic diseases later in life. In this review we discuss the latest research on factors contributing to the pathogenesis of MetS in children, focusing on non-modifiable and modifiable risk factors, including genetics, dysbiosis and chronic low-grade inflammation.

Sleep-associated insulin resistance promotes neurodegeneration

Lifestyle modification can lead to numerous health issues closely associated with sleep. Sleep deprivation and disturbances significantly affect inflammation, immunity, neurodegeneration, cognitive depletion, memory impairment, neuroplasticity, and insulin resistance. Sleep significantly impacts brain and memory formation, toxin excretion, hormonal function, metabolism, and motor and cognitive functions. Sleep restriction associated with insulin resistance affects these functions by interfering with the insulin signalling pathway, neurotransmission, inflammatory pathways, and plasticity of neurons. So, in this review, We discuss the evidence that suggests that neurodegeneration occurs via sleep and is associated with insulin resistance, along with the insulin signalling pathways involved in neurodegeneration and neuroplasticity, while exploring the role of hormones in these conditions.

The association between rest-activity parameters and hemoglobin A1c in patients with prediabetes

Circadian abnormalities can adversely affect glucose metabolism. This study determined whether behavioral circadian parameters, as assessed by rest-activity rhythm, were predictors of glycemic control in patients with prediabetes. Seventy-nine patients with prediabetes participated. Nonparametric rest-activity rhythm parameters, sleep duration and efficiency were obtained from 7-d actigraphy recordings. Sleep-disordered breathing severity was assessed using a home sleep apnea test. Hemoglobin A1c (HbA1c) was obtained to evaluate glycemic control. The results revealed that shorter sleep duration, lower relative amplitude and higher L5 (average activity of the least active 5-h period) were associated with higher HbA1c, while other sleep variables were not related to HbA1c. Multiple stepwise regression analysis adjusting for age, sex, body mass index and sleep duration revealed that lower relative amplitude, but not L5, was independently associated with higher HbA1c (B = -0.027, p = 0.031). In summary, among patients with prediabetes, an abnormal circadian rhythm was associated with higher HbA1c, implying a greater risk of developing diabetes. These results support the role of circadian rhythmicity in glucose control among those with prediabetes.

Does Insufficient Sleep Increase the Risk of Developing Insulin Resistance: A Systematic Review

It has been recommended that adults sleep a minimum of seven hours of sleep every night to maintain holistic health and well-being. A considerable fraction of the adult population suffers from sleep deprivation and related disorders. The stress of modern-day living may be the cause of this curtailment of sleep duration. The primary purpose of this study was to investigate the effects of reduced sleep on the development of insulin resistance and explore the possible mechanisms linking the two. We utilized databases like such as PubMed, PubMed Central (PMC), and Medical Literature Analysis and Retrieval System Online (MEDLINE) to systematically screen papers using keywords and Medical Subject Heading (MeSH) terms. A few articles were also retrieved from Cochrane Library. We applied inclusion/exclusion criteria after screening papers via title and abstracts. A quality appraisal check was doneperformed, and ten 10 related studies were strictly reviewed.

Short sleep duration was significantly associated with insulin resistance. Inflammatory markers such as C-reactive protein (CRP) and serum amyloid A (SAA), biomarkers such as glucagon-like peptide-1 (GLP-1), and circadian misalignment may play a significant role in the pathogenesis of this association. To prevent metabolic complications such as type- 2 diabetes, adequate sleep (more than seven hours per night) is required in the adult population. The causal relationship between sleep deprivation and insulin resistance is multifactorial, and further studies are warranted to understand these mechanisms better.

Prediabetes Is Associated with Increased Prevalence of Sleep-Disordered Breathing

Type 2 diabetes leads to severe nocturnal hypoxemia, with an increase in apnea events and daytime sleepiness. Hence, we assessed sleep breathing parameters in the prediabetes stage. A cross-sectional study conducted on 966 middle-aged subjects without known pulmonary disease (311 patients with prediabetes and 655 controls with normal glucose metabolism) was conducted. Prediabetes was defined by glycated hemoglobin (HbA1c), and a nonattended overnight home sleep study was performed. Participants with prediabetes (n = 311) displayed a higher apnea−hypopnea index (AHI: 12.7 (6.1;24.3) vs. 9.5 (4.2;19.6) events/h, p < 0.001) and hypopnea index (HI: 8.4 (4.0;14.9) vs. 6.0 (2.7;12.6) events/h, p < 0.001) than controls, without differences in the apnea index. Altogether, the prevalence of obstructive sleep apnea was higher in subjects with prediabetes than in controls (78.1 vs. 69.9%, p = 0.007). Additionally, subjects with prediabetes presented impaired measurements of the median and minimum nocturnal oxygen saturation, the percentage of time spent with oxygen saturations below 90%, and the 4% oxygen desaturation index in comparison with individuals without prediabetes (p < 0.001 for all). After adjusting for age, sex, and the presence of obesity, HbA1c correlated with the HI in the entire population (r = 0.141, p < 0.001), and the presence of prediabetes was independently associated with the AHI (B = 2.20 (0.10 to 4.31), p = 0.040) as well as the HI (B = 1.87 (0.61 to 3.14), p = 0.004) in the multiple linear regression model. We conclude that prediabetes is an independent risk factor for an increased AHI after adjusting for age, sex, and obesity. The enhanced AHI is mainly associated with increments in the hypopnea events.

Tooth loss as a potential risk factor for deficient sleep: an analysis of a nationally representative sample of adults in the USA

PURPOSE

Sleep deficiency is implicated as a risk factor for several systemic conditions. Loss of teeth has a profound effect on the individual's physiologic and psychologic health and quality of life. This study aimed to assess the association between tooth loss and sleep duration and determine if anterior and/or posterior tooth loss is a significant predictor.

METHODS

A total of 22,483 individuals ≥ 18 years who participated in the United States National Health and Nutrition Examination Survey (NHANES) 2005-2016 cycles were included. Multinomial logistic regression adjusted for age, gender, race/ethnicity, smoking, diabetes, body mass index, socioeconomic level, education, alcohol, and depression was performed to examine the association between sleep duration and tooth loss.

RESULTS

Compared to individuals with > 20 remaining teeth, those who were completely edentulous, had 1-10 or 11-20 teeth remaining were more likely to be in the deficient sleep category (OR [95% CI] = 1.59 [1.35-1.87], 1.29 [1.07-1.54], and 1.26 [1.11-1.43], respectively). When the numbers of both missing anterior and posterior teeth were entered in the model, only posterior teeth were significant. There was a 4% increase in the odds of being in the deficient sleep category for each missing posterior tooth (OR [95% CI] = 1.04 [1.02-1.05]).

CONCLUSIONS

Tooth loss was significantly associated with deficient sleep and posterior tooth loss appeared to be the main contributor. Although further research is needed to clarify the nature of this association, our results suggest that improving oral health might have an impact on overall health and quality of life.

Severe sleep restriction suppresses appetite independent of effects on appetite regulating hormones in healthy young men without obesity

OBJECTIVE

Several nights of moderate (4-5 hr/night) sleep restriction increases appetite and energy intake, and may alter circulating concentrations of appetite regulating hormones. Whether more severe sleep restriction has similar effects is unclear. This study aimed to determine the effects of severe, short-term sleep restriction on appetite, ad libitum energy intake during a single meal, appetite regulating hormones, and food preferences.

METHODS

Randomized, crossover study in which 18 healthy men (mean ± SD: BMI 24.4 ± 2.3 kg/m², 20 ± 2 yr) were assigned to three consecutive nights of sleep restriction (SR; 2 hr sleep opportunity/night) or adequate sleep (AS; 7-9 hr sleep opportunity/night) with controlled feeding and activity designed to maintain energy balance throughout the 3-day period. On day 4, participants consumed a standardized breakfast. Appetite, assessed by visual analogue scales, and circulating ghrelin, peptide-YY (PYY), glucagon-like peptide (GLP-1), insulin, and glucose concentrations were measured before and every 20-60 min for 4hr after the meal. Ad libitum energy and macronutrient intakes were then measured at a provided buffet lunch. Food preferences were measured by Leeds Food Preference Questionnaire (LFPQ) administered before and after the lunch.

RESULTS

Area under the curve (AUC) of postprandial hunger (-23%), desire to eat (-23%), and prospective consumption (-18%) ratings were all lower, and postprandial fullness AUC (25%) was higher after SR relative to after AS (p ≤ 0.02). Ad libitum energy intake at the lunch meal was 332 kcal [95% CI: -479, -185] (p<0.001) lower after SR relative to after AS, but relative macronutrient intakes and LFPQ scores did not differ. Postprandial glucose, insulin, PYY, GLP-1, and ghrelin AUCs did not differ between phases. However, mean concentrations of PYY (-11%) and GLP-1 (-4%) over the 4-hr testing period were lower, and glucose concentrations were 6% higher, after SR relative to after AS (p ≤ 0.01).

CONCLUSION

In contrast with reported effects of moderate sleep restriction, severe sleep restriction reduced appetite and energy intake, had no impact food preferences, and had little impact on appetite regulating hormones. Findings suggest that severe sleep restriction may suppress appetite and food intake, at least at a single meal, by a mechanism independent of changes in food preference or appetite regulating hormones.

Obesity and the Lung: What We Know Today

Obesity is becoming more and more prevalent especially in Western industrial nations. The understanding of adipose tissue as an endocrine organ as well as the detection of adipocytokines - hormones that are secreted from the adipose tissue - gave reason to examine the interactions between adipose tissue and target organs. These efforts have been intensified especially in the context of bariatric surgery as promising weight loss therapy. Interactions between the lung and adipose tissue have rarely been investigated and are not well understood. There are obvious mechanical effects of obesity on lung function explaining the associations between obesity and lung diseases, in particular obesity hypoventilation syndrome, obstructive sleep apnea syndrome, asthma, and chronic obstructive pulmonary disease. The rise in the prevalence of obesity affects the epidemiology of pulmonary diseases as well. The aim of this review is to summarize the current knowledge on interactions, associations, and consequences of obesity and weight loss on lung function and lung diseases. Based on these data, areas for future research are identified.

Sleep apnea in men is associated with altered lipid metabolism, glucose tolerance, insulin sensitivity, and body fat percentage

PURPOSE

Obstructive sleep apnea (OSA) is associated with obesity and risk for type 2 diabetes. In this community-based study, we thoroughly investigated fatty acid metabolism, incretin response, glucose tolerance, insulin secretion and insulin sensitivity, and autonomic nerve activity in men with or without OSA.

METHODS

Fifteen men without diabetes but with signs of severe OSA, defined as apnea-hypopnea index (AHI) >30, and 15 age- and BMI-matched men without OSA (AHI < 5) were recruited from a community-based cohort. Assessments included clinical and anthropometric measurements, a 2-h oral glucose tolerance test (OGTT), and autonomic nerve activity using heart rate variability (HRV).

RESULTS

Men with OSA had higher body fat % than BMI-matched men without OSA (p = 0.046) and it was associated with markers of insulin resistance. The area under the curve for nonesterified fatty acids (NEFA) during OGTT was higher in men with OSA (p = 0.021) and fasting NEFA levels were numerically higher (p = 0.097). The plasma glucose at fasting and during OGTT was higher in men with OSA (p < 0.001). Incretin response was similar between groups. Fasting and OGTT-derived indices indicated impaired insulin sensitivity in men with OSA. Compared with men without OSA, Matsuda index (p = 0.068) and Gutt index (p < 0.01) were lower in men with OSA. The HRV measures did not differ between groups.

CONCLUSIONS

Our study suggests that fatty acid handling, glucose tolerance, and insulin sensitivity are impaired in men with severe OSA. This might partly be explained by the increased body fat percentage.

Clinical and psychological characteristics of liraglutide treatment among patients with type 2 diabetes

Aim:

This study aimed to evaluate the glycemic control, quality of life (QOL), and sleep quality in type 2 diabetes mellitus (T2DM) patients who are treated with liraglutide and to investigate whether the QOL and sleep quality were correlated with the glycemic control of this population.

Methods:

A cross-sectional study was carried out on T2DM patients who were treated with liraglutide. Data on body weight and glycemic control were recorded while the QOL and sleep quality were assessed using the Short-Form Health Survey (SF-36), the 5-item World Health Organization Well-Being Index (WHO-5), and the Pittsburgh Sleep Quality Index (PSQI) questionnaires.

Results:

Eighty-four T2DM patients who initiated liraglutide with a mean age of 46.7 years were included in the study. The mean hemoglobin A1c (HbA1c) was 7.76% (standard deviation [SD] =0.62), and about 88.1% of patients had HbA1c > 7%. The PSQI score showed not too bad sleep quality (mean 4.3 ± 1.9). The mean WHO-5 score of the study population showed a “moderate” QOL (12.4 ± 3). Patients had lowest SF-36 score (mean = 52.3) in the subscale of “energy and fatigue.” There was a significant positive correlation between HbA1C and the “energy and fatigue” (r = 0.232, P = 0.034) but not with the other subscales.

Conclusion:

Patients with T2DM taking liraglutide have moderate sleep difficulty and QOL score. Nonetheless, none of these outcomes was significantly correlated with glycemic control. Further well-designed studies with long-term follow-up and larger population sizes are needed to confirm our findings.

Effects of glucagon-like peptide 1 receptor agonists on comorbidities in older patients with diabetes mellitus

Elderly patients with diabetes are at high risk of polypharmacy because of multiple coexisting diseases and syndromes. Polypharmacy increases the risk of drug–drug and drug–disease interactions in these patients, who may already have age-related sensory and cognitive deficits; such deficits may delay timely communication of early symptoms of adverse drug events. Several glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have been approved for diabetes: liraglutide, exenatide, lixisenatide, dulagluatide, semaglutide, and albiglutide. Some are also approved for treatment of obesity. The current review of literature along with clinical case discussion provides evidence supporting GLP-1 RAs as diabetes medications for polypharmacy reduction in older diabetes patients because of their multiple pleiotropic effects on comorbidities (e.g. hyperlipidemia, hypertension, and fatty liver) and syndromes (e.g. osteoporosis and sleep apnea) that commonly co-occur with diabetes. Using one medication (in this case, GLP-1 RAs) to address multiple conditions may help reduce costs, medication burden, adverse drug events, and medication nonadherence.

Sleeping oxygen saturation, rapid eye movement sleep, and the adaptation of postprandial metabolic function in insulin sensitive and resistant individuals without diabetes

AIMS

Sleeping oxygen saturation (SaO₂) and sleep stage duration have been linked with prediabetic alterations but the pathogenic pathways are not well understood. This study of insulin sensitive and resistant adults examined the effect on postprandial metabolic regulation of repeated mixed-meal challenges of different carbohydrate loading. The aim was to examine whether the relationship between lower sleeping oxygen saturation (SaO₂) and poorer fasting and postprandial metabolic function may be linked with reduced slow wave sleep (SWS) and rapid eye movement (REM) duration, independent of age, sex and total adiposity.

METHODS

The 24 men and women, aged 25-54 years, had no diabetes or other diagnosed conditions, were evaluated with polysomnography to derive indices of SaO₂ and sleep architecture. In addition, an OGTT and two 14-h serial mixed-meal tests were administered over 3 successive in-patient days. The carbohydrate content of the mixed-meals was manipulated to compare a standard-load day with a double-load day (300 vs. 600 kcal/meal). Quantitative modeling was applied to derive β-cell glucose sensitivity (β-GS), early insulin secretion rate sensitivity (ESRS), and total postprandial insulinemia (AUC_INS).

RESULTS

Analyses showed that, for the 14-h tests, the SaO₂ relationship with metabolic outcomes was associated significantly with percent time spent in REM but not SWS, independent of age, sex and total adiposity. Specifically, indirect pathways indicated that lower SaO₂ was related to shorter REM duration, and shorter REM was respectively associated with higher β-GS, ESRS, and AUC_INS for the 300- and 600-load days (300 kcal/meal: β = -8.68, p < .03, β = -8.54, p < .002, and β = -10.06, p < .008; 600 kcal/meal: β = -11.45, p < .003, β = -11.44, p < .001, and β = -11.00, p < .03).

CONCLUSION

Sleeping oxygen desaturation and diminished REM duration are associated with a metabolic pattern that reflects a compensatory adaptation of postprandial insulin metabolism accompanying preclinical diabetic risk.