The association between daily naps and metabolic syndrome: Evidence from a population-based study in the Middle-East

BACKGROUND

Daily naps are a common habit in many Middle Eastern and Asian countries; however, little is known about the association between daily naps and other health consequences, including the presence of metabolic syndrome (MetS).

METHODS

Participants were recruited from the Mashhad stroke and heart atherosclerotic disorders study. We defined MetS according to International Diabetes Federation criteria. Nighttime sleeping hours were categorized into three categories: <6, 6-8, and >8 hours. Using logistic regression models, we analyzed the association between the duration of night-time sleep and daily naps with MetS and its different components.

RESULTS

A total of 9652 individuals were included in the study: 3859 with MetS (40%) and 5793 without MetS (60%), as the control group. Of all, 72% participants had a regular daily nap. Those with daily naps had a higher odd of MetS [Odds ratio:1.19, confidence interval: (1.08-1.33); P < .001]. We also observed significantly higher odds of obesity, central obesity, hypertriglyceridemia, and diabetes or impaired fasting glucose in these subjects. Men sleeping <6 hours per night had a lower odd of MetS. However, we observed higher odds of cardiovascular risk factors in participants sleeping <6 hours, including obesity and diabetes or IFG.

CONCLUSION

Napping is a common habit in middle Eastern countries. Although the cross-sectional design of our study cannot prove causality, we observed a significant association between the presence of MetS and daily naps. The public should be aware of this possibility and be educated about the importance of sleeping patterns.

Tumor-derived exosomes: Potential biomarker or therapeutic target in breast cancer?

Exosomes are released by normal and tumour cells, including those involved in breast cancer, and provide a means of intercellular communications. Exosomes with diameters ranging between 30-150 nm are involved in transferring biological information, via various lipids, proteins, different forms of RNAs, and DNA from one cell to another, and this can result in reprogramming of recipient cell functions. These vesicles are present in all body fluids, for example, blood plasma/serum, semen, saliva, cerebrospinal fluid, breast milk, and urine. It has been recently reported that these particles are involved in the development and progression of different tumor types, including breast cancer. Furthermore, it has been suggested that exosomes have the potential to be used as drug transporters, or as biomarkers. This review highlights the potential roles of exosomes in normal and breast cancer cells and their potential applications as biomarkers with special focus on their potential applications in treatment of breast cancer.

Genetic and epigenetic factors influencing vitamin D status

The global prevalence of vitamin D deficiency appears to be increasing, and the impact of this on human health is important because of the association of vitamin D insufficiency with increased risk of osteoporosis, cardiovascular disease and some cancers. There are few studies on the genetic factors that can influence vitamin D levels. In particular, the data from twin and family-based studies have reported that circulating vitamin D concentrations are partially determined by genetic factors. Moreover, it has been shown that genetic variants (e.g., mutation) and alteration (e.g., deletion, amplification, inversion) in genes involved in the metabolism, catabolism, transport, or binding of vitamin D to it receptor, might affect vitamin D level. However, the underlying genetic determinants of plasma 25-hydroxyvitamin D3 [25(OH)D] concentrations remain to be elucidated. Furthermore, the association between epigenetic modifications such as DNA methylation and vitamin D level has now been reported in several studies. The aim of current review was to provide an overview of the possible value of loci associated to vitamin D metabolism, catabolism, and transport as well epigenetic modification and environmental factors influencing vitamin D status.