Ana Harb

Night eating patterns and chronotypes: A correlation with binge eating behaviors

This cross-sectional study examined the association between the morningness/eveningness dimension and eating patterns. The sample consists of 100 subjects who were screened at a nutrition clinic and was composed of 77% women; mean age was 39.5 (±11.7) years; and 66% were overweight. Significant bivariate correlations were found between the Morningness-Eveningness Questionnaire (MEQ) total score and the Binge Eating Scale (BES) and the Night Eating Questionnaire (NEQ). The NEQ and BES were also significantly correlated. Body mass index (BMI) was correlated with the NEQ and BES, but it was not a confounding variable as no associations were found between the MEQ and BMI. To control for potential multicollinearity effects among variables, we also used multivariate regression analysis in which the values of the correlation coefficients were adjusted. Only the BES remained statistically associated with the MEQ. In conclusion, these results suggest that the study of chronotype may be an important issue to be considered when characterizing disordered eating. This study serves as an impetus for examining circadian intake patterns in more detail between those with binge eating disorder (BED) and night eating syndrome (NES) to help discern these important nosological questions.

Síndrome do comer noturno: aspectos conceituais, epidemiológicos, diagnósticos e terapêuticos

Behavior and eating patterns are complex, involve metabolic, physiological and environmental aspects and have inherited and species-specific circadian rhythmicity, with humans being essentially diurnal. The aim of this study is to describe the night eating syndrome, characterized by a delay of the circadian eating patterns and mediated by neuroendocrine stress. A review of the literature found in the Pubmed, Lilacs and Sirus databases published between 1955 and 2007 was done. The keywords used were: night eating syndrome, sleep, circadian rhythm, appetite, nocturnal eating. A total of 74 articles were found of which 26 were selected, whose central theme was the night eating syndrome. Despite all the studies done, there is still long way to go to understand the genesis of the night eating syndrome and its intrinsic relation with other physiological and pathogenic processes. Given that this syndrome is linked to the control of hunger and satiety and to the desynchronization between the eating rhythm and sleep / wake rhythm, understanding its genetic process can reveal the impact that the desynchronization of circadian eating rhythms has on the health-disease process and help understand the factors involved in the rising rates of obesity in modern society.

Circadian Rhythm of Energy Expenditure and Oxygen Consumption

BACKGROUND This study aimed to evaluate the effect of continuous and intermittent methods of enteral nutrition (EN) administration on circadian rhythm. MATERIALS AND METHODS Thirty-four individuals, aged between 52 and 80 years, were fed through a nasoenteric tube. Fifteen individuals received a continuous infusion for 24 hours/d, and 19 received an intermittent infusion in comparable quantities, every 4 hours from 8:00 to 20:00. In each patient, 4 indirect calorimetric measurements were carried out over 24 hours (A: 7:30, B: 10:30, C: 14:30, and D: 21:30) for 3 days. RESULTS Energy expenditure and oxygen consumption were significantly higher in the intermittent group than in the continuous group (1782 ± 862 vs 1478 ± 817 kcal/24 hours, P = .05; 257 125 vs 212 117 ml/min, P = .048, respectively). The intermittent group had higher levels of energy expenditure and oxygen consumption at all the measured time points compared with the continuous group. energy expenditure and oxygen consumption in both groups were significantly different throughout the day for 3 days. CONCLUSION There is circadian rhythm variation of energy expenditure and oxygen consumption with continuous and intermittent infusion for EN. This suggests that only one indirect daily calorimetric measurement is not able to show the patients true needs. Energy expenditure is higher at night with both food administration methods. Moreover, energy expenditure and oxygen consumption are higher with the intermittent administration method at all times.

A chronobiological policy to decrease the burden of hypertension and obesity in low- and middle-income population

The cardiovascular structure is temporally organized in both health and disease. The link between obesity and hypertension is elevated sympathetic nervous system activity and hormonal activity which present a clear rhythmicity, with the pineal, corticosteroid and leptin systems being those most implicated. Also, genetic mutations or deletions have implicated peripheral clock genes in the regulation of glucose homeostasis, lipid synthesis and adipogenesis, which are associated with obesity and type 2 diabetes mellitus. As hypertension and obesity are related, and the treatments of these disorders are well established but sometimes ineffective, this review focuses on chronobiological contributions to decrease the burden of hypertension and obesity in low- and middle-income groups of individuals. MEDLINE, Pubmed and SUMSearch sites (2001–2011) were used in the search strategy, together with the keywords: “antihypertensive drugs”; “arterial hypertension”; “circadian rhythms”; “obesity”; and “sleep quality”. Eighty-six articles were found and 50 articles from these were selected. A link between the circadian clock and hypertension has recently been described in animal models, using Clock-mutant mice that display metabolic syndrome. Experimental evidence clearly implicates circadian rhythms in the mechanisms that underlie the regulation of the blood pressure (BP) rhythm. Most clinical studies of BP focus on some pathological situation, such as hypertension, cardiovascular disease, sleep disorders, obesity, diabetes or pregnancy with blood biomarker alterations. However, epidemiological evidence for the role of circadian rhythms in hypertension has been lacking until recently. In Brazil, in an epidemiological, cross-sectional study, changed sleep quality and an earlier phase of mid-sleep were found in those using antihypertensive drugs. Moreover, some pharmacological studies support a circadian- and dose-dependent relationship in the use of antihypertensive drugs for the 24-h control of BP. In low- and middle-income areas, cost-effectiveness of any intervention is fundamental to the implementation of any kind of public-health policy. Therefore, improvements in diagnosis, effectiveness and implementing prevention measures to control the risk of disease are all necessary, and there is evidence that chronobiology has an important role to play. Consequently, it is important to provide guidelines to monitor BP to reduce cardiovascular risk that include chronobiological aspects of the problem.

Chronobiological Aspects of Mood Disorders

Mood disorders, especially those related to depression, are among the most prevalent mental impairments. Therefore, understanding their etiology is important for prevention and improving therapy. Sub-clinical depressive symptoms, which predict the onset of mood and anxiety disorders (Gentil et al., 2007), are correlated with slow information processing, poor memory functioning (Simons et al., 2009) and cardiovascular dysfunction (Taillard et al., 1993; Wassertheil-Smoller et al., 2004 ).