The association between chronotype, food craving and weight gain in pregnant women.

BACKGROUND: This cross-sectional study investigated the association between chronotype, food craving and weight gain in pregnant women. METHODS: In total, 245 pregnant women attending the public health service in Brazil were included. Chronotype was derived from the time of mid-sleep time on free days, with a further correction for calculated sleep debt, and higher scores on this variable indicate a tendency to eveningness. A Food Craving Questionnaire Trait and State assessment was performed, and weight gain was calculated. Generalised linear models were used to determine the association between the variables under analysis. RESULTS: Evening types presented higher anticipation of relief from negative states and feelings as a result of eating as a usual behaviour compared to morning (P = 0.013) and non-evening types (P = 0.028); less intense desire to eat as a sporadic behaviour compared to morning (P = 0.012) and non-evening types (P = 0.009); and less anticipation of positive reinforcement that may result from eating as a sporadic behaviour than non-evening types (P = 0.022). We also found a significant association between chronotype score and anticipation of relief from negative states and feelings as a result of eating (P = 0.004); anticipation of positive reinforcement that may result from eating (P = 0.013) as a usual behaviour; weight gain during the early gestational period (P = 0.024); and intense desire to eat (P = 0.045) as a sporadic behaviour. CONCLUSIONS: We conclude that evening chronotype was associated with the food craving trait. Pregnant women who tend to eveningness are more likely to gain weight in the early gestational period.

A link between sleep loss, glucose metabolism and adipokines

The present review evaluates the role of sleep and its alteration in triggering problems of glucose metabolism and the possible involvement of adipokines in this process. A reduction in the amount of time spent sleeping has become an endemic condition in modern society, and a search of the current literature has found important associations between sleep loss and alterations of nutritional and metabolic contexts. Studies suggest that sleep loss is associated with problems in glucose metabolism and a higher risk for the development of insulin resistance and type 2 diabetes mellitus. The mechanism involved may be associated with the decreased efficacy of regulation of the hypothalamus-pituitary-adrenal axis by negative feedback mechanisms in sleep-deprivation conditions. In addition, changes in the circadian pattern of growth hormone (GH) secretion might also contribute to the alterations in glucose regulation observed during sleep loss. On the other hand, sleep deprivation stress affects adipokines - increasing tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and decreasing leptin and adiponectin -, thus establishing a possible association between sleep-debt, adipokines and glucose metabolism. Thus, a modified release of adipokines resulting from sleep deprivation could lead to a chronic sub-inflammatory state that could play a central role in the development of insulin resistance and type 2 diabetes mellitus. Further studies are necessary to investigate the role of sleep loss in adipokine release and its relationship with glucose metabolism.

A link between sleep loss, glucose metabolism and adipokines.

The present review evaluates the role of sleep and its alteration in triggering problems of glucose metabolism and the possible involvement of adipokines in this process. A reduction in the amount of time spent sleeping has become an endemic condition in modern society, and a search of the current literature has found important associations between sleep loss and alterations of nutritional and metabolic contexts. Studies suggest that sleep loss is associated with problems in glucose metabolism and a higher risk for the development of insulin resistance and type 2 diabetes mellitus. The mechanism involved may be associated with the decreased efficacy of regulation of the hypothalamus-pituitary-adrenal axis by negative feedback mechanisms in sleep-deprivation conditions. In addition, changes in the circadian pattern of growth hormone (GH) secretion might also contribute to the alterations in glucose regulation observed during sleep loss. On the other hand, sleep deprivation stress affects adipokines - increasing tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and decreasing leptin and adiponectin -, thus establishing a possible association between sleep-debt, adipokines and glucose metabolism. Thus, a modified release of adipokines resulting from sleep deprivation could lead to a chronic sub-inflammatory state that could play a central role in the development of insulin resistance and type 2 diabetes mellitus. Further studies are necessary to investigate the role of sleep loss in adipokine release and its relationship with glucose metabolism.

Cyanobacteria and biodeterioration of cultural heritage: a review.

Growing concern for the preservation of cultural heritage has led to a greater interest in the biological attack on these buildings. The importance of cyanobacteria as deteriogens is emphasized and the traditional and more modern molecular methods used to detect these microorganisms are discussed. The development of molecular techniques for the rapid identification of cyanobacteria without need for culture and isolation is fundamental if our knowledge of these communities in biofilms on the surfaces of historic buildings is to be extended.