Alice Pik Shan Kong

The Effect of Weekend and Holiday Sleep Compensation on Childhood Overweight and Obesity

OBJECTIVES: A growing trend in childhood sleep habits is to compensate for the weekday sleep deficit by longer weekend and holiday sleep duration. We aimed to investigate the effect of weekend/holiday sleep compensation in relation to childhood overweight and obesity. METHODS: This is a community-based cross-sectional study with 5159 children (49.6% boys), mean age of 9.25 years (SD: 1.78), from 13 primary schools in Hong Kong. Data on sleep patterns, lifestyle, body weight, and height of children were obtained from questionnaires. Sleep durations during weekdays, weekends, and holidays were predictor variables. BMI z scores and obesity/overweight status were the outcome measures. RESULTS: Children slept significantly longer during holidays (mean [SD]: 10.20 (0.92) hours) and weekends (school terms) (10.07 [0.93] hours) than during school weekdays (9.18 [0.95] hours). Children with shorter sleep duration had higher BMI z scores regardless of the sleep parameters used in the analysis. Among children who slept <8 hours during weekdays, those children who did not compensate for their sleep deficit during weekends or holidays had significantly increased risk of overweight/obesity compared with those children with sleep compensation (odds ratios: 2.59 [95% confidence interval: 1.22–5.48] and 2.32 [95% confidence interval: 1.00–5.53], respectively). CONCLUSIONS: There was a prominent difference in sleep duration between weekdays and weekends/holidays among school children. Short sleep duration was associated with higher BMI, but compensation of sleep during weekends/holidays may partly ameliorate the risk of childhood overweight/obesity. Further prospective and interventional study is needed to delineate the risk-benefit effect of these increasingly common sleep habits among children and adolescents.

Glucose Intolerance and Cardiometabolic Risk in Adolescents Exposed to Maternal Gestational Diabetes: A 15-year follow-up study

OBJECTIVE Adolescent offspring of women with a history of gestational diabetes (GD) were evaluated for their cardiometabolic risks at a mean age of 15 years. RESEARCH DESIGN AND METHODS One hundred and twenty-nine adolescents who were assessed for their cardiometabolic risks at 8 years of age were reassessed at 15 years of age. RESULTS Adolescent offspring of mothers with GD had similar blood pressure, plasma lipid profile, and a rate of abnormal glucose tolerance as control subjects. In utero hyperinsulinemia was associated with a 17-fold increase in metabolic syndrome and a 10-fold increase in overweight at adolescence, independent of birth weight, Tanner stage, maternal GD status, and mothers BMI. CONCLUSIONS In utero environment of hyperinsulinemia, irrespective of the degree of maternal GD, was associated with increased risk of overweight and metabolic syndrome during early adolescence in the offspring.

Testosterone level in men with type 2 diabetes mellitus and related metabolic effects: A review of current evidence

A significant proportion of patients with type 2 diabetes mellitus have a low testosterone level relative to reference ranges based on healthy young men. Only a small number of these patients suffer from classical hypogonadism as a result of recognizable hypothalamic–pituitary–gonadal axis pathology. The cut‐off value of the serum testosterone level in men without obvious hypothalamic–pituitary–gonadal axis pathology is controversial. It is unclear to what extent a low serum testosterone level causally leads to type 2 diabetes and/or the metabolic syndrome. From a theoretical standpoint, there can be complex interactions among the hypothalamic–pituitary–gonadal axis, body composition and insulin resistance, which can be further influenced by intrinsic and extrinsic factors to give rise to metabolic syndrome, glucose intolerance, and low‐grade inflammation to increase the risk of cardiovascular disease. Although a low serum testosterone level frequently coexists with cardiometabolic risk factors and might serve as a biomarker, more studies are required to clarify the causal, mediating or modifying roles of low serum testosterone level in the development of adverse clinical outcomes. Currently, there are insufficient randomized clinical trial data to evaluate the effects of testosterone replacement therapy on meaningful clinical outcomes. The risk‐to‐benefit ratio of testosterone therapy in high‐risk subjects, such as those with type 2 diabetes, also requires elucidation. The present article aims to review the current evidence on low serum testosterone levels in patients with type 2 diabetes, and its implications on cardiovascular risk factors, metabolic syndrome and adverse clinical outcomes.

A School-Based Sleep Education Program for Adolescents: A Cluster Randomized Trial

OBJECTIVES: To evaluate the effectiveness of a multilevel and multimodal school-based education program. METHODS: A cluster randomized controlled trial with 14 secondary schools in Hong Kong and a total of 3713 students (intervention: 1545 vs control: 2168; 40.2% boys; mean age ± SD: 14.72 ± 1.53 years) were included in the final analysis. The intervention included a town hall seminar, small class workshops, a slogan competition, a brochure, and an educational Web site. Their parents and teachers were offered sleep education seminars. The control schools did not receive any sleep program. Data were collected before and 5 weeks after the intervention. RESULTS: The students in the intervention group had significantly improved sleep knowledge compared with the control group (mean difference: 3.64 [95% confidence interval (CI): 3.21 to 4.07]; Cohen’s d = 0.51) as measured by using a sleep knowledge questionnaire. Weekday sleep duration was reduced in both groups, and the significant difference in weekday sleep duration was lost in the intention-to-treat analysis (mean difference: 0:01 [95% CI: –0:00 to 0:04]). In addition, the intervention group had a lower incidence of consuming caffeine-containing energy drinks (adjusted odds ratio: 0.46 [95% CI: 0.22 to 0.99]) and had better behavioral (mean difference: –0.56 [95% CI: –1.02 to –0.10]; Cohen’s d = 0.13) and mental health (mean difference: –0.30 [95% CI: –0.15 to –0.46]; Cohen’s d = 0.11) outcomes. CONCLUSIONS: A school-based sleep education program was effective in enhancing sleep knowledge and improving behavioral and mental health, but it had no significant impact on sleep duration or pattern among adolescents.

Association between sleep architecture and glucose tolerance in children and adolescents 儿童及青少年的睡眠结构与糖耐量的关系

Short sleep duration is a contributing factor for decreased insulin sensitivity and hyperglycemia. Sleep architecture represents a cyclical pattern of sleep that shifts between sleep Stages N1, N2, N3 (slow wave sleep) and Stage R (rapid eye movement sleep). The aim of the present study was to examine the association between sleep architecture and glucose and insulin metabolism in both normal weight and overweight/obese children and adolescents.

Restless legs symptoms in adolescents: Epidemiology, heritability, and pubertal effects

AIMSnWe aimed to determine the prevalence, pubertal effect, familial aggregation, and heritability of restless legs (RLS) symptoms in Chinese adolescents. In addition, the correlates and consequences of RLS symptoms were examined.nnnMETHODSnThis was a population-based family study that involved 1549 adolescents (probands), their parents and siblings. RLS symptoms were assessed by a single question measuring the core features of RLS. Subjects with RLS symptoms for at least once per week were considered as abnormal. Impairment of daytime functions, behavioral problems, health status, and lifestyle practice were also documented.nnnRESULTSnThe prevalence of RLS symptoms was 2.8% in adolescents and 7.4% in their parents with female preponderance. Gender difference of RLS symptoms emerged in mid-pubertal adolescents (Tanner stage 3 or above). RLS symptoms were closely associated with various sleep problems (range of ORs=2.24 to 32.5, p<0.05), except habitual snoring. They were also independently associated with impairment of daytime functions, poor general health and frequent temper outbursts but not caffeine or alcohol intake or cigarette smoking after adjustment for age, sex, and other comorbid sleep problems. RLS symptoms presented with a modest familial aggregation and heritability (h²±SE=0.17±0.04, p<0.001).nnnINTERPRETATIONnRLS symptoms are common in Chinese adolescents with significant health repercussions. Puberty plays a critical role in the emergence of gender difference of RLS symptoms, which are accounted for by both genetic and environmental factors.

Emergence of Sex Differences in Insomnia Symptoms in Adolescents: A Large-Scale School-Based Study

STUDY OBJECTIVESnThis study aimed to explore the moderation of pubertal status on the onset of sex differences in the prevalence of insomnia symptoms and their health correlates.nnnMETHODSnA total of 7,507 children and adolescents (weighted percentage of female: 48.5%) aged between 6-17 y were recruited from thirty-one primary and secondary schools. Participants with difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and/or early morning awakening (EMA) ≥ 3 times/week in the past month were considered as having insomnia symptoms. The severity of insomnia was measured by the Insomnia Severity Index (ISI).nnnRESULTSnThe prevalence of insomnia symptoms increased from 3.4% to 12.2% in girls (3.6-fold) and from 4.3% to 9.1% in boys (2.1-fold) from Tanner stage 1 to 5. There was a significant interaction between sex and Tanner stage in the prevalence of insomnia (P < 0.001) with an emergence of female preponderance at Tanner stage 4 even after controlling for age, family income, and school start time. Similar sex-Tanner stage interactions were found in DIS, DMS, and ISI total score but not EMA. Insomnia symptoms were strongly associated with behavioral problems, poor mental health, and poor general health in both sexes. Boys with insomnia would report more maladaptive lifestyles (smoking, alcohol, and energy drinks) whereas girls with insomnia were more susceptible to emotional and relationship difficulties.nnnCONCLUSIONSnPubertal maturation was associated with a progressive increase in the prevalence of insomnia symptoms with the emergence of female preponderance in both the prevalence and severity of insomnia symptoms at late puberty.nnnCLINICAL TRIALS REGISTRATIONnChinese Clinical Trial Register, http://www.chictr.org.cn, ID: ChiCTR-TRC-12002798.

Impact of a modest delay in school start time in Hong Kong school adolescents

OBJECTIVEnTo examine the effects of a modest delay (15xa0min) in school start time (SST) on adolescent sleep patterns, mood, and behaviors.nnnMETHODSnTwo secondary schools in Hong Kong with a total of 1173 students (intervention: nxa0=xa0617; comparison school nxa0=xa0556) completed both baseline and follow-up questionnaires. School start time was delayed by 15xa0min, from 7:45 a.m. to 8:00 a.m., in the intervention school. The comparison school maintained their regular SST at 7:55 a.m. Students sleep-wake patterns, daytime sleepiness, and mental and behavioral aspects were assessed by validated questionnaires before and after the intervention.nnnRESULTSnStudents in the intervention school significantly delayed their weekday wake-up time (pxa0<xa00.001) and increased their total time in bed (pxa0<xa00.001) when compared to students in the comparison school. Both groups experienced a delay in their weekday bedtime. The students in the intervention school showed improved mental health [General Health Questionnaire (GHQ) score, pxa0=xa00.015], better prosocial behaviors (pxa0=xa00.009), better peer relationships (pxa0<xa00.001), greater attentiveness (pxa0<xa00.001), less emotional problems (pxa0=xa00.002), and less behavioral difficulties (pxa0<xa00.001) as measured by Strengths and Difficulties Questionnaire (SDQ).nnnCONCLUSIONSnA modest delay (15xa0min) in school start time can increase adolescent sleep with corresponding improvement in mood and behaviors. Current findings have significant implications for education policy, suggesting that school administrators and policy makers should systematically consider delaying school start time to promote sleep and health among school-aged adolescents.nnnCLINICAL TRIAL REGISTRATIONnChiCTR-TRC-12002798. The trial protocol can be accessed at: http://www.chictr.org/en/proj/show.aspx?proj=3955.

Familial young-onset diabetes, pre-diabetes and cardiovascular disease are associated with genetic variants of DACH1 in Chinese.

In Asia, young-onset type 2 diabetes (YOD) is characterized by obesity and increased risk for cardiovascular disease (CVD). In a genome-wide association study (GWAS) of 99 Chinese obese subjects with familial YOD diagnosed before 40-year-old and 101 controls, the T allele of rs1408888 in intron 1 of DACH1(Dachshund homolog 1) was associated with an odds ratio (OR) of 2.49(95% confidence intervals:1.57–3.96, Pu200a=u200a8.4×10−5). Amongst these subjects, we found reduced expression of DACH1 in peripheral blood mononuclear cells (PBMC) from 63 cases compared to 65 controls (Pu200a=u200a0.02). In a random cohort of 1468 cases and 1485 controls, amongst top 19 SNPs from GWAS, rs1408888 was associated with type 2 diabetes with a global P value of 0.0176 and confirmation in a multiethnic Asian case-control cohort (7370/7802) with an OR of 1.07(1.02–1.12, Pmetau200a=u200a0.012). In 599 Chinese non-diabetic subjects, rs1408888 was linearly associated with systolic blood pressure and insulin resistance. In a case-control cohort (nu200a=u200a953/953), rs1408888 was associated with an OR of 1.54(1.07–2.22, Pu200a=u200a0.019) for CVD in type 2 diabetes. In an autopsy series of 173 non-diabetic cases, TT genotype of rs1408888 was associated with an OR of 3.31(1.19–9.19, Pu200a=u200a0.0214) and 3.27(1.25–11.07, Pu200a=u200a0.0184) for coronary heart disease (CHD) and coronary arteriosclerosis. Bioinformatics analysis revealed that rs1408888 lies within regulatory elements of DACH1 implicated in islet development and insulin secretion. The T allele of rs1408888 of DACH1 was associated with YOD, prediabetes and CVD in Chinese.

Effects of systolic and diastolic blood pressures on incident coronary heart disease and all-cause death in Chinese women with Type 2 diabetes: the Hong Kong Diabetes Registry.

Background:u2002 Elevated blood pressure (BP) is an important risk factor for the development of coronary heart disease (CHD), although the threshold above which the risk increases has not been clearly defined. The aim of the present study was to examine the full‐range association between BP and CHD.