Introduction: Poor quality of sleep is a distressing and worrying condition that can disturb academic performance of medical students. Sleep hygiene practices are one of the important variables that affect sleep quality. The objective of this study was to assess association between sleep hygiene practices and sleep quality of medical students in Qazvin University of Medical Sciences. Methods:In this descriptive-correlational study, a total of 285 medical students completed a self-administered questionnaire. Demographic data, sleep-wake schedule in weekday and weekend, and sleep duration were collected. Students' sleep quality was assessed by Pittsburg Sleep Quality Index (PSQI). Data were analyzed by SPSS Ver 13. Results: Overall, 164 (57.5) of students had poor sleep quality. Mean global PSQI score and average score of four subscales were significantly higher in male than female. Regression analysis showed that male students (β=-0.85, P<0.05), students at senior level (β=-0.81, P<0.05), married students (β=-0.45, P<0.05), and those with improper sleep hygiene practices slept worse. Conclusion: The findings of this study showed that the prevalence of poor sleep quality in medical students is high. Improper sleep hygiene behaviors might be a reason for poor quality of sleep in medical students.

SUMMARYPoor sleep quality and inadequate sleep in adolescents are a rising trend globally. The Theory of Planned Behaviour (TPB)-which centres on an individual's attitude toward performing the behaviour, subjective norms and perceived behavioural control-has been applied to examine sleep hygiene behaviours in young adults. We expanded on prior works by using a longitudinal design to examine the effects of TPB factors, together with sleep hygiene knowledge and planning constructs, on sleep hygiene behaviours and on sleep quality and health in a group of Iranian adolescents. A total of 1822 healthy adolescents (mean age = 13.97) from 25 high schools in Qazvin, Iran, completed a selfreported survey at baseline and 6 months later. Structural equation modelling (SEM) was used to delineate the pathway from adolescents' sleep hygiene knowledge, TPB constructs of their behavioural intentions and sleep hygiene behaviours and their sleep quality and self-reported health. The SEM model demonstrated that although behavioural intention, coping planning and action planning predicted the sleep hygiene behaviours positively 6 months later with acceptable model fit [comparative fit index (CFI) = 0.936; Tucker-Lewis index (TLI) = 0.902; root mean square error of approximation (RMSEA) = 0.080; standardized root mean square residual (SRMR) = 0.044], sleep hygiene knowledge did not predict behavioural intentions significantly. Sleep hygiene behaviours were associated with sleep quality and psychiatric wellbeing. Thus, the TPB, combined with coping and action planning, is useful in understanding the sleep hygiene behaviours of adolescents. Health-care providers may want to emphasize TPB constructs and coping and action planning to improve adolescents' sleep hygiene behaviours, rather than rely solely upon increasing adolescents' sleep hygiene knowledge.

Using BEARS (Bedtime problems, Excessive sleepiness, Awakenings during the night, Regularity of sleep, Snoring), and CSHQ (Children's Sleep Habits Questionnaires) screening tools with 224 participants revealed that Iranian children have shorter night sleep duration than expected (9.54 vs 12 h) for their age group. Earlier sleepers had longer night sleep duration (10:36 ± 1:12; 9:12 ± 1:06 h, P < 0.001), and total daily sleep time (11:36 ± 1:42; 10:36 ± 1:30 h, P= 0.005) than late sleepers. A majority (85%) of nap‐takers had sleep bedtime of 22:00 or later. The poor sleep quality of Iranian preschool children is probably due to cultural characteristics, climate differences, or harmful sleep habits.

Little is known about the effect of birth weight, birth order and number of siblings on the nutritional status in children in Iran, especially in Qazvin province. The aim of this study was to provide the current data on malnutrition and birth related determinants among children in Qazvin, Iran. This study was conducted in six cities of Qazvin province (Iran), during December 2009-December 2010. Data on age, weight and height were taken and birth weight, number of children in family, birth order, parental career and educational state and family caretaker were collected by a questionnaire that a trained team filled in. Sample size was1351, almost 225 children under 6-years-old from each city participated in the study (692 boys and 659 girls). In each city, subjects were randomly selected among children who had profiles at health centers. The overall prevalence of wasting, stunting and underweight was 10.3%, 5.8% and 4.8% respectively. There was association between 'birth weight' and wasting ( P = 0.022), stunting ( P = 0.032) and underweight ( P < 0.001). A non-significant association was obtained between factors 'number of children at home' and 'birth order' with wasting, stunting and underweight. These data suggest that birth weight can influence malnutrition indicators; therefore, knowing risk factors of malnutrition in population subgroups is important for planners in country because it helps the future studies concentrate on the most determining ones.

PurposeThe purpose of this study was to estimate the presence of metabolic syndrome (MS) in a group of children and adolescents with a body mass index (BMI) above the 85th percentile for their age and sex in Qazvin Province, Iran; to evaluate the relationship between obesity and metabolic abnormalities; and to compare two proposed definitions of MS.Patients and methodsThe study was conducted on 100 healthy subjects aged between 6 and 16 years (average age, 10.52 ± 2.51 years) with a high BMI for their age and sex. Fifty- eight percent of subjects were female. Physical examination including evaluation of weight, height, BMI, and blood pressure measurement was performed (“overweight” was defined as a BMI between the 85th and 95th percentiles for children of the same age and sex; “obese” was defined as a BMI over the 95th percentile for children of the same age and sex). Blood levels of glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and uric acid were measured after a 12-hour overnight fast. The authors used and compared two definitions of MS: the National Cholesterol Education Program’s Adult Treatment Panel III (NCEP ATP III) criteria and a modified definition by Weiss et al. Variables were compared using the Student’s t-test and chi-square and Mann-Whitney U tests, and agreement between the two definitions was analyzed using kappa values.ResultsThe subjects had a mean BMI of 26.02 ± 4.38 and 80% had obesity. Insulin resistance was found in 81% of the study population. MS was present in ten (50%) of the overweight and 53 (66.2%) of the obese subjects using the NCEP ATP III criteria. MS was present in five (25%) of the overweight and 34 (42.5%) of the obese subjects using the definition by Weiss et al. The overall kappa value for the two definitions of MS was 0.533. There were no statistically significant differences between the two definitions of MS in participants.ConclusionThe prevalence of MS in children and adolescents depends on the criteria chosen and their respective cutoff points. The NCEP ATP III criteria, the parameters of which include higher cutoff values for high-density lipoprotein cholesterol and triglycerides, detected the higher prevalence and therefore the NCEP ATP III criteria are able to diagnose a larger number of children and adolescents at metabolic risk.