Adiponectin levels and sleep deprivation in patients with endocrine metabolic disorders

SUMMARY BACKGROUND: Sleep abnormalities are frequent in patients with endocrine metabolic disorders (EMD) such as arterial hypertension, diabetes and obesity. Adiponectin is a peptide largely secreted by adipocytes and has various properties e.g. anti-inflammatory, antioxidant, antiatherogenic, pro-angiogenic, vasoprotective and insulin-sensitizing. Adiponectin inversely relates to body weight and when its concentration decreases, the resistin concentration increases resulting in greater insulin resistance. OBJECTIVE: The objective of this study is to examine factors influencing adiponectin levels in a population with EMD. METHODS: This was a cross-sectional evaluation of 332 patients (18 to 80y) presenting arterial hypertension, pre-diabetes, diabetes, and/or obesity. Investigation included clinical evaluation of comorbidities, general blood tests and adiponectin measures (ELISA). Chronic sleep deprivation was determined if habitual sleep was <6 hours >4 days/week. RESULTS: Arterial hypertension (78.5%), type-2 diabetes (82.3%), and overweight (45.0%)/obesity (38.8%) were frequent. Patients with type-2 diabetes tended to have more chronic sleep deprivation (p=0.05). Adiponectin levels increased with age and were inversely correlated with sagittal abdominal diameter (p=0.04) and fasting insulin (p=0.001). Chronic sleep deprivation was associated with higher adiponectin concentration [OR=1.34; CI=1.13-1.58; p<0.005] and this was maintained after adjustment for gender, age, body mass index, menopause, arterial hypertension, American Diabetes Association classification and physical exercise levels [OR=1.38; 0=1.14-1.66: p=0.001]. CONCLUSION: In patients with EMD, adiponectin is influenced not only by obesity but also by age and sleep deprivation. The latter finding may be explained by a compensatory effect or a counter regulation to minimize the harmful effects of sleep deprivation.

RESUMO INTRODUÇÃO: Problemas de sono são frequentes em pacientes com distúrbios endócrino-metabólicos (DEM), como hipertensão arterial, diabetes e obesidade. A adiponectina é um peptídeo segregado por adipócitos e apresenta diversas propriedades, como por exemplo, anti-inflamatória, antioxidante, antiaterogênica, pró-angiogênica e vasoprotetora. A adiponectina relaciona-se inversamente com o peso corporal. OBJETIVO: Examinar os fatores que influenciam os níveis de adiponectina em uma população com DEM. MÉTODOS: Trata-se de uma avaliação transversal com 332 pacientes (18 a 80 anos) apresentando hipertensão arterial, pré-diabetes, diabetes e/ou obesidade. A investigação incluiu avaliação clínica de comorbidades, exames de sangue e medidas de adiponectina (Elisa). A restrição crônica do sono foi determinada com o sono habitual <6 horas >4 dias/semana. RESULTADOS: Doenças como hipertensão arterial (78,5%), diabetes tipo 2 (82,3%) e sobrepeso (45,0%)/obesidade (38,8%) foram frequentes. Pacientes com diabetes tipo 2 apresentaram uma tendência na restrição crônica do sono (p=0,05). Os níveis de adiponectina aumentaram com a idade e foram inversamente correlacionados com o diâmetro abdominal sagital (p=0,04) e com a insulina em jejum (p=0,001). A restrição crônica do sono foi associada à maior concentração de adiponectina [OR=1,34; CI=1,13-1,58; p<0,005] e isso foi mantido após ajuste por gênero, idade, índice de massa corporal, menopausa, hipertensão arterial, classificação dos níveis da American Diabetes Association e exercício físico [OR=1,38; CI=1,14-1,66: p=0,001]. CONCLUSÕES: Em pacientes com DEM, a adiponectina é influenciada não apenas pela obesidade, mas também pela idade e pela restrição de sono. O último achado pode ser explicado por um efeito compensatório ou por um regulamento contrário para minimizar os efeitos nocivos da restrição do sono.

Influence of food restriction on lipid profile and spontaneous glucose levels in male rats subjected to paradoxical sleep deprivation

OBJECTIVES: The purpose of this study was to determine the paired consequences of food restriction and paradoxical sleep deprivation on lipid profile and spontaneous glucose levels in male rats. METHOD: Food restriction began at weaning, with 6 g of food being provided per day, which was subsequently increased by 1 g per week until reaching 15 g per day by the eighth week. At adulthood, both rats subjected to food restriction and those fed ad libitum were exposed to paradoxical sleep deprivation for 96 h or were maintained in their home-cage groups. RESULTS: Animals subjected to food restriction exhibited a significant increase in high-density lipoprotein levels compared to animals that were given free access to food. After the paradoxical sleep deprivation period, the foodrestricted animals demonstrated reduced concentrations of high-density lipoprotein relative to their respective controls, although the values for the food-restricted animals after sleep deprivation were still higher than those for the ad libitum group. The concentration of low-density lipoproteins was significantly increased in sleep-deprived animals fed the ad libitum diet. The levels of triglycerides, very low-density lipoproteins, and glucose in foodrestricted animals were each decreased compared to both ad libitum groups. CONCLUSION: These results may help to illustrate the mechanisms underlying the relationship between sleep curtailment and metabolism and may suggest that, regardless of sleep deprivation, dietary restriction can minimize alterations in parameters related to cardiovascular risk.

La reducción del sueño como factor de riesgo para obesidad / Sleep deprivation as a risk factor for obesity

Nocturnal sleep patterns may be a contributing factor for the epidemic of obesity. Epidemiologic ana experimental studies have reported that sleep restriction is an independent risk factor for weight gain and obesity. Moreover, sleep restriction is significantly associated with incidence and prevalence of obesity and several non-transmissible chronic diseases. Experimental sleep restriction is related to altered plasma leptin and ghrelin concentrations. Both hormones are directly related to appetite and satiety mechanisms. Also, a higher activity of the orexin/hypocretin system has been reported, as well as changes in glucose metabolism and autonomic nervous system. Some studies indicate that these endocrine changes could be associated with a higher diurnal food intake and preference for energy- dense foods. All these changes could result in a positive energy balance, leading to weight gain and a higher obesity risk in the long-term. The present article summarizes the epidemiologic and experimental evidence related to sleep deprivation and higher obesity risk. The possible mechanisms are highlighted.

Paradoxical sleep deprivation increases plasma endothelin levels

The endothelins (ET-1, 2 and 3) constitute a family of 21 amino acid peptides with potent biological activities. ET-1 is one of the most potent endogenous vasoconstrictors so far identified and its increased concentration in plasma appears to be closely related to the pathogenesis of arterial hypertension as well as to obstructive sleep apnea (OSA). OSA patients exhibit repetitive episodes of apnea and hypopnea that result in hypoxia and consecutive arousals. These patients are chronically sleep deprived, which may aggravate the hypertensive features, since literature data show that sleep deprivation results in hypertension both in humans and in animals. Based on the reported relationship between ET-1, hypertension and sleep deprivation consequences, the purpose of the present study was to determine plasma ET concentrations in paradoxical sleep-deprived animals. Male Wistar rats, 3 to 4 months old (N = 10 per group), were deprived of sleep for 24 and 96 h by the platform technique and plasma ET-1/2 was measured by radioimmunoassay. Analysis of plasma revealed that 96 h of sleep deprivation induced a significant increase in ET-1/2 release (6.58 fmol/ml) compared to control (5.07 fmol/ml). These data show that sleep deprivation altered plasma ET-1/2 concentrations, suggesting that such an increase may participate in the genesis of arterial hypertension and cardiorespiratory changes observed after sleep deprivation