Sleep patterns in Spanish adolescents: associations with TV watching and leisure-time physical activity

We aimed to describe the sleep patterns in Spanish adolescents and to examine the relationships of sleep duration and morning tiredness with participation in leisure-time physical-sporting activities (LT-PA) and television (TV) watching. Sleep duration, morning tiredness, participation in LT-PA and time spent on watching TV were reported by 2,179 (1,139 females) Spanish adolescents (AVENA study). Data were analyzed by binary logistic regression. One-fifth of the adolescents reported insufficient night sleep (<8 h) on school days. The review of the literature (30 studies) showed that the Spanish adolescents sleep as long as adolescents from central Europe, and longer than those from other Mediterranean countries, South Africa, Asia and North America. Insufficient sleep duration doubled the odds of excessive TV watching (≥3 h/day) in males, regardless of morning tiredness (OR 2.15, 95% CI 1.42–3.27). Morning tiredness reduced the odds of participating in any LT-PA in both males and females (0.49, 0.34–0.70 and 0.49, 0.35–0.69, respectively), and increased the odds of excessive TV watching in females, regardless of sleep duration (2.49, 1.64–3.79). We conclude that non-participation in LT-PA is associated with morning tiredness in male and female adolescents, while excessive TV watching is more associated with short sleep or morning tiredness depending on gender.     

Association of angiotensin-converting enzyme 2 (ACE2) gene polymorphisms with parameters of left ventricular hypertrophy in men

Angiotensin-converting enzyme (ACE) activity is considered to be of major importance for the conversion of angiotensin (Ang) I to Ang II. Recently, a second ACE, named ACE2, has been identified. Experimental data provide evidence that ACE2 might be involved in modulating cardiac structure and function. In the present explorative study, we assessed whether polymorphisms in the ACE2 gene are related to echocardiographically determined parameters of left ventricular mass, structure or function in the general population. Five intronic single nucleotide polymorphisms (SNPs) were genotyped using the 5'-exonuclease activity (TaqMan) assay in the echocardiographic substudy of the third MONICA Augsburg survey. As ACE2 is located on the X chromosome, women and men were analysed separately. Four SNPs showed high pairwise linkage disequilibrium (rs4646156, rs879922, rs4240157 and rs233575). The minor alleles of these four SNPs were associated with higher left ventricular mass index (LVMI) and higher septal wall thickness (SWT) in men. Likewise, male carriers of a common haplotype (frequency 29.9%) consisting of the minor alleles of these four SNPs displayed higher values for LVMI and SWT than non-carriers (LVMI: TGGC 98.8+/-1.52 vs non-TGGC 94.8+/-0.99 g/m(2), p=0.027; SWT: TGGC 11.5+/-0.14 vs non-TGGC 11.1+/-0.09 mm, p=0.019). Furthermore, this haplotype was associated with an increased odds ratio (OR) for left ventricular hypertrophy (OR 3.10, p=0.006). In women, similar but less pronounced and consistent trends were observed. No association was observed between any of these SNPs and parameters of left ventricular systolic or diastolic function nor with blood pressure levels. This study provides evidence that genetic variants in the ACE2 gene may be associated with left ventricular mass, SWT and left ventricular hypertrophy in hemizygous men.     

GDF5基因rs224331多态性与汉族青少年体格发育指标关联分析

目的探讨中国汉族青少年GDF5基因rs224331位点多态性与身高、体重和BMI的相关性。方法采集江苏省某技校1790名17～22岁青少年的身高、体重指标并计算BMI。采用Taqman探针real-timePCR方法检测GDF5基因rs224331位点的单核苷酸多态性,并分析该基因位点与男女生身高、体重和BMI的相关性。结果 97.9%（1754/1790名）基因分型成功,男生859名,女生895名。rs224331位点频率最高的基因型为AA（51.7%）,其次为AC（39.6%）,CC最少（8.7%）。rs224331的基因型分布与男生、女生的身高无显著关联（P分别为0.728和0.723）;rs224331不同基因型间的男生体重和BMI差异均有统计学意义（P均〈0.01）,男生AC基因型体重和BMI均显著高于AA基因型（P=0.002）,女生中未发现类似的相关性（P分别为0.713和0.921）。结论 GDF5基因rs224331位点多态性在本研究的汉族人群中与身高无明显关联,提示该多态性位点可能存在种族特异性。rs224331位点多态性与男生体重和BMI存在相关性。     

The association of angiotensin converting enzyme (ACE) polymorphisms with sleep apnea and hypertension

STUDY OBJECTIVES: To identify the role of polymorphisms in the angiotensin-converting enzyme (ACE) gene in modulating susceptibility to hypertension in sleep apnea. DESIGN: Observational cross-sectional study. PARTICIPANTS: Nine hundred seventy-two participants of the Cleveland Family Study who underwent home sleep studies, blood pressure assessments, and genotyping. RESULTS: After controlling for age, sex, race, and obesity, hypertension risk was reduced in participants who possess the ACE deletion (D) polymorphism with an odds ratio = 0.63 (95% confidence interval: 0.41-0.96) comparing those with 2 versus no D alleles. In analyses stratified by apnea severity, the protective effect of the D allele was most evident in those with severe apnea. Among subjects with severe apnea, the odds ratios for hypertension were 0.47 (0.22-1.00) for 1 D allele and 0.57 (0.26-1.24) for 2 D alleles. CONCLUSIONS: The ACE deletion allele may protect against hypertension in the setting of obstructive sleep apnea. Further research into the potential role of angiotensin in modulating the hypertensive effect of sleep apnea is needed.     

Relationships of physical activity and somatic characteristics with physical fitness and motor skill in prepubertal girls

The purpose of this study was to examine the relationships between physical activity and somatic growth with motor skill and physical fitness in prepubertal girls. The subjects were 215, 7–10-year-old girls. Somatic characteristics included 15 dimensions. Physical fitness was assessed by the EUROFIT battery of 9 tests. Motor skill development was based on quantitative and qualitative assessment of the overhand throw. Physical activity was assessed by parental seven-day physical activity recall for the child. Sum of five skinfolds was significantly negatively related with motor fitness after controlling for the effects of physical activity (r = −0.27 to −0.39). Somatic characteristics were not significantly related with fitness items and throwing stage after controlling for physical activity. Age-specific partial correlations between physical activity, fitness items, quantitative, and qualitative characteristics of the overhand throw, were not significant. After controlling for body size and subcutaneous fatness, aerobic fitness was significantly related with physical activity of moderate to high intensity. Am. J. Hum. Biol. 9:513–521, 1997. © 1997 Wiley-Liss, Inc.     

The association between parenting behavior and somatization in adolescents explained by physiological responses in adolescents

Introduction

This study adds to the knowledge on somatization in adolescents by exploring its relation with parenting behavior and the mediating/moderating role of physiological responses in adolescents to parenting behavior.

Method

Eighteen adolescents with high and 18 adolescents with low somatization scores and their mothers completed a discussion task, from which observed parenting behavior scores were derived. Skin conductance in adolescents was measured before and during the discussion.

Results

For adolescents with high levels of physiological responses, unadaptive parenting was related to a higher chance of high somatization scores. For low physiologically responsive adolescents, the relation between parenting behavior and somatization was not significant.

Conclusion

Parenting behavior is not univocally related to somatization in adolescents, but the association depends on physiological responses in adolescents.     

Renin,ANP, ACE polymorphisms,blood pressure and age in American Samoans: Preliminary data

Molecular studies have identified numerous candidate genes that may influence interindividual variation in physiologically important endpoints. Among these are molecular variants of three proteins associated with blood pressure regulation, renin, atrial natriuretic peptide (ANP), and angiotensin-converting enzyme (ACE). These loci are polymorphic in all populations examined. The purpose of this study was to determine gene and genotype frequencies at these three loci in a sample of American Samoans and to examine associations of the various genotypes with blood pressure, hypertension, and age. Genotype frequencies of a BglI restriction fragment length polymorphisms (RFLP) at the renin locus were slightly out of Hardy-Weinberg expectations (P ⩽ 0.025). Frequencies of a BglI RFLP at the ANP locus and of the insertion/deletion polymorphism at the ACE locus approximated Hardy-Weinberg expectations (P ⩾ 0.10). These frequencies differed from those reported in “Afro-Caribbean” and “Caucasian” samples from London. Neither average blood pressures nor the frequencies of either systolic or diastolic hypertension differed significantly across genotypes at the ANP or ACE loci. However, systolic pressure was elevated among those heterozygous for the renin BglI cut site (P = 0.07). Mean age was 34.4 years among individuals heterozygous for the ANP BglI cut site, while it was 46.0 years for homozygotes without the site (P = 0.04). After dividing the sample at its median age (45 years), 31.8% of younger, but only 8.7% of older participants were ANP BglI heterozygotes (G = 9.48; P = 0.005). Am. J. Hum. Biol. 10:439–449, 1998. © 1998 Wiley-Liss, Inc.     

ADAM33 polymorphisms and phenotype associations in childhood asthma

BACKGROUND: A disintegrin and metalloproteinase (ADAM) 33 has been implicated as an asthma susceptibility gene by using a positional cloning approach. However, genetic linkage of asthma phenotypes to chromosome 20p13 (the location of ADAM33) has not been observed in most asthma genome scans, and it is unclear whether these associations with ADAM33 are broadly generalizable. OBJECTIVE: To examine whether ADAM33 is associated with asthma in a North American population of childhood asthmatic patients. METHODS: We performed a family-based association study by using 652 nuclear families ascertained through asthmatic subjects enrolled in a large randomized clinical trial. Seventeen ADAM33 single nucleotide polymorphisms (SNPs; including 9 associated with asthma in the initial report) were genotyped by mass spectrometry. Single-SNP and haplotype association analysis was performed. RESULTS: Among white and African American subjects, no single-SNP association with asthma was observed. However, a common 16-SNP haplotype (frequency, 14.6% in white subjects) was associated with asthma (P=.006). Two SNPs in strong linkage disequilibrium (T1 and T+1) were marginally associated with asthma in the Hispanic cohort (P=.04). These data provide marginal support for an asthma locus in the ADAM33 genomic region. However, the magnitudes of the observed associations are modest at best and are inconsistent with the original report. CONCLUSIONS: We conclude that either ADAM33 has only modest effects on asthma susceptibility, and the initial reports of association were a result of analysis in a selected population, or the initial findings were a result of chance. It is also possible that the true asthma susceptibility locus in this genomic region is near, but not at, ADAM33.     

Angiotensin I-converting enzyme polymorphisms, ACE level and blood pressure among Nigerians, Jamaicans and African-Americans

The genes in the renin-angiotensin system are important physiologic candidates in studies of the genetic susceptibility to hypertension. Limited information has been available in most studies on the extent of variation in the candidate loci or the modifying effects of different environmental settings. We consequently genotyped 13 polymorphisms at the angiotensin I-converting enzyme (ACE) locus at an average distance of 2 kb in 2776 family members from Nigeria, Jamaica and an African-American community in the US. Allele and haplotype frequencies were similar in the three populations, with modest evidence of European admixture in the US. Two markers were consistently associated with ACE level in the three samples and the proportion of variance accounted for by ACE8 was similar in the three groups. No evidence of consistent association of single markers was noted with blood pressure across the three population samples, however. Likewise, in a haplotype-based analysis, despite significant associations within each population, the findings were not replicated consistently across all three samples. We did observe, however, that the overtransmitted haplotypes among hypertensives were drawn from a single clade, suggesting that susceptibility may cluster in patterns not captured directly by our markers.     

The interaction of growth hormone secretion and gonadal function in adolescents with delayed physical development

The studies conducted in adolescents with physical underdevelopment allowed a conclusion on reduced anabolic processes particularly growth process at the expense of both STH and sex steroids: T and E2. Studies of sex steroid and gonadotrophic hormone concentrations in blood serum revealed dysfunction of the hypothalamo-hypophyseal-gonadal system in this group of patients. Evaluation of androgen receptor level in protein cytosol fraction from the pubic skin of undersized youths with delayed sexual development demonstrated its significant reduction against the control group that may be explained by incomplete ability for androgen receptor synthesis due to relatively low T-level and its biologically active free fraction and low sensitivity of target tissues to androgens as a result of dissociation between functional activity of STH and T.     

Relationships between physical activity, obesity and meal frequency in adolescents

OBJECTIVE: The purpose of this study was to assess the associations and impact of increased meal frequency, physical activity and 'skipping' breakfast on obesity levels in a sample of urban adolescents, aged 13-17 years old, from Porto, Portugal. METHODS: Overweight and obesity were defined according to age- and sex-specific BMI cut-points. Daily meal frequency was assessed by questionnaire. Self-reported physical activity was recalled. Results: The proportion of overweight/obese girls (p < or = 0.05) and boys (p < or = 0.001) that consumed fewer than three meals was significantly higher than those reported from normal-weight counterparts. While no statistically significant differences were reported in girls, obese boys skipped breakfast significantly more (13% vs 5.6%; p < or = 0.05) than normal-weight counterparts did. Normal-weight boys but not girls were significantly more active (p < or = 0.01) than obese peers. An additional meal in boys (OR: 2.75; p < or = 0.05) and girls (OR: 1.97; p < or = 0.05) reduced the risk of being overweight/obese. Regardless of gender, breakfast skipping is not seen as a predictor of being overweight/obese. However, boys (OR: 2.10; p < 0.003), but not girls, who were moderately active were more likely to be of normal weight. CONCLUSION: The data indicate that increased meal frequency may have a beneficial effect on a reduced BMI. Physical activity and breakfast skipping may be candidate targets for prevention programmes aimed at reducing overweight/obesity among adolescents.     

Overweight and obesity in children and adolescents: relationship with blood pressure,and physical activity

OBJECTIVE: Using body mass index (BMI) quartiles, the present study's aims were (1) to describe and evaluate the relationship between overweight/obesity with cardiovascular disease (CVD) risk factors, such as systolic blood pressure (SBP), diastolic blood pressure (DBP) and physical activity; (2) to provide information on the prevalence of high blood pressure and physical activity according to BMI quartiles; and (3) to examine the relationship of risk of obesity to adverse levels of high blood pressure and physical activity. METHODS: The sample consisted of 1439 children (758 males and 681 females), 8-16 years old. Participants were classified as being at 'risk of obesity' according to age- and sex-adjusted fourth quartile of BMI values. Blood pressure was measured using the Dinamap monitor. An adapted version of the Weekly Activity Checklist was applied for the diagnosis of physical activity index (PAI). RESULTS: Systolic and diastolic blood pressures were significantly (p < 0.05) and positively related to BMI, whereas no significant associations were reported between BMI and PAI in both genders. Overall, the proportion of subjects with adverse levels of blood pressure (SBP or DBP) ranged from 21.3% in the first BMI quartile (BMI-1Q) to 30.4% in BMI-4Q (p < 0.05). The PAI ranged from 24.5% in BMI-1Q to 20.6 in BMI-4Q and no significant differences were found. Children and adolescents at 'risk of obesity' were 1.5 times as likely to have at least one risk factor (high blood pressure or low level of activity). CONCLUSIONS: Our data suggest that higher BMI is associated with higher values of SBP and DBP. Children and adolescents in the upper quartile of BMI are 1.5 times as likely to have at least one risk factor. Furthermore our data confirmed previous findings that higher levels of BMI are associated with a unfavourable risk profile for CVD risk factors.     

Overweight and obesity in children and adolescents: relationship with blood pressure,and physical activity

Objective : Using body mass index (BMI) quartiles, the present study's aims were (1) to describe and evaluate the relationship between overweight/obesity with cardiovascular disease (CVD) risk factors, such as systolic blood pressure (SBP), diastolic blood pressure (DBP) and physical activity; (2) to provide information on the prevalence of high blood pressure and physical activity according to BMI quartiles; and (3) to examine the relationship of risk of obesity to adverse levels of high blood pressure and physical activity. Methods : The sample consisted of 1439 children (758 males and 681 females), 8-16 years old. Participants were classified as being at 'risk of obesity' according to age- and sex-adjusted fourth quartile of BMI values. Blood pressure was measured using the Dinamap monitor. An adapted version of the Weekly Activity Checklist was applied for the diagnosis of physical activity index (PAI). Results : Systolic and diastolic blood pressures were significantly ( p < 0.05) and positively related to BMI, whereas no significant associations were reported between BMI and PAI in both genders. Overall, the proportion of subjects with adverse levels of blood pressure (SBP or DBP) ranged from 21.3% in the first BMI quartile (BMI-1Q) to 30.4% in BMI-4Q ( p < 0.05). The PAI ranged from 24.5% in BMI-1Q to 20.6 in BMI-4Q and no significant differences were found. Children and adolescents at 'risk of obesity' were 1.5 times as likely to have at least one risk factor (high blood pressure or low level of activity). Conclusions : Our data suggest that higher BMI is associated with higher values of SBP and DBP. Children and adolescents in the upper quartile of BMI are 1.5 times as likely to have at least one risk factor. Furthermore our data confirmed previous findings that higher levels of BMI are associated with a unfavourable risk profile for CVD risk factors.