中国成年双生子体质指数的分布特征

目的 描述中国双生子登记系统（CNTR）成年双生子BMI的分布特征,探索BMI在双生子人群中的特殊分布规律,为超重及肥胖高危因素分析和制定防制策略提供线索和基础资料。方法 选自CNTR中2010-2018年完成问卷调查的双生子对,纳入≥ 18岁具有完整双生子对登记信息,且身高、体重等关键变量无缺失或异常者进行分析,共计32 725对成年双生子。描述CNTR项目成年双生子BMI的人群、地区分布特征及双生子对内成员BMI差异的分布现况。结果 研究对象年龄（34.6±12.4）岁,同性别双生子对79.7%。研究对象平均BMI为22.5 kg/m²,超重率为23.7%,肥胖率为4.9%。男性、50~59岁组、北方地区、低文化程度者、在婚者的双生子超重率和肥胖率相对更高（P<0.001）。同卵和异卵间差异无统计学意义,但先出生的双生子超重和肥胖率略高于后出生者（P<0.05）。同性别双生子对内分析发现,对内BMI差异与年龄呈正相关（趋势性检验P<0.001）,异卵差异高于同卵,且卵型间差异随年龄增长发生变化。BMI一致率存在卵型差异（P<0.05）,同卵高于异卵。结论 本研究的双生子人群BMI的分布存在人群和地区差异;BMI为可遗传的性状,且遗传作用可能随年龄而变化。     

中国18岁以下双生子出生体重与超重/肥胖的关联分析

目的 分析出生体重与儿童时期超重/肥胖间的关联。方法 使用中国双生子登记系统基线调查的<18岁双生子人群(共8267对),采用双生子对内对照设计方法,探索出生体重与儿童青少年时期BMI及超重/肥胖之间的关联。结果 调整性别和卵型的影响后,出生体重每增加0.5 kg,超重/肥胖的风险:幼儿及学龄前期(≥ 2且<6岁)儿童增加0.87倍,学龄期(≥ 6且<12岁)儿童增加0.69倍,青春期(≥ 12且<18岁)青少年增加0.28倍。结论 双生子出生体重与幼儿及学龄期超重/肥胖存在正向关联,但在指导实施公共卫生干预措施时仍需谨慎。     

出生队列效应对体质指数遗传度的影响

目的 探索不同出生队列BMI遗传度的变化情况。方法 基于中国双生子登记系统丽水和青岛两个时点的双生子,按照出生年份分为1958年及以前出生、1959-1961年出生、1962-1970年出生和1971年及以后出生的4个出生队列,在各个时点分别拟合结构方程,计算不同出生队列在不同年龄的遗传度。结果 每个出生队列中,2012年时的体重、BMI高于2001年;出生于1971年及以后的双生子无论体重和BMI均低于其余出生队列。遗传因素能解释BMI的表型变异为54%~76%;出生于1959-1961年的双生子,BMI的遗传度随年龄上升,其余出生队列遗传度较为稳定。结论 BMI受遗传因素影响较大,出生于1959-1961年的双生子,随着年龄增长,遗传因素对BMI的影响增加。     

中国成年人代谢异常相关的体质指数和腰围切点研究

目的 研究中国成年人BMI和腰围与各项代谢危险因素之间的相关性,确定超重肥胖的适宜BMI和腰围切点。方法 中国慢性病前瞻性研究于2004-2008年进行基线调查,并于2013-2014年随机抽取了5%的研究对象进行第2次重复调查。本研究剔除体格指标或代谢危险因素变量缺失或极端值、自报患有恶性肿瘤者,基线纳入501 201人,第2次重复调查纳入19 201人。比较不同BMI和腰围下代谢危险因素异常率,通过受试者工作特征（ROC）曲线分析,确定预测高血压、糖尿病、血脂异常和危险因素聚集的适宜BMI和腰围切点。结果 随BMI或腰围的增加,高血压、糖尿病、血脂异常和危险因素聚集患病率均呈现上升的趋势。依据正确指数最大的原则选取BMI超重切点和腰围切点,男性和女性BMI超重切点均接近24.0 kg/m²,男性腰围切点接近85 cm,女性腰围切点约为80~85 cm。男性和女性中,检出各项代谢危险因素特异度达到90%的BMI切点范围为27.0~28.9 kg/m²,多数接近28.0 kg/m²,以28.0 kg/m²作为肥胖切点。结论 本研究在更新开展的大样本调查中进一步验证了中国肥胖问题工作组2002年推荐的超重和肥胖标准,超重和肥胖的BMI切点分别为24.0和28.0 kg/m²;中心性肥胖的腰围适宜切点男性为85 cm,女性为80~85 cm。     

心血管病高危人群腰围和体重变化与血压水平变化关系的随访研究

目的 探讨心血管病高危人群中腰围和体重变化与血压水平变化的关系,为高血压及心血管病防治提供理论依据和参考。方法 选取2016年纳入随访调查的12 931名心血管病高危人群作为研究对象,将其2017-2019年长期随访数据纳入分析。统计学分析采用t检验、χ²检验和广义估计方程。结果 在心血管病高危人群中,腰围、体重和BMI增加,血压水平升高的风险高;腰围、体重和BMI减少,血压水平升高的风险低。腰围每增加1 cm,SBP增加0.200（95%CI：0.164~0.236） mmHg,DBP增加0.085（95%CI：0.066~0.105） mmHg;体重每增加1 kg,SBP增加0.355（95%CI：0.289~0.421） mmHg,DBP增加0.182（95%CI：0.144~0.220）mmHg;BMI每增加1 kg/m²,SBP增加1.100（95%CI：1.194~1.258） mmHg,DBP增加0.365（95%CI：0.273~0.456） mmHg。心血管病高危人群中农村居民相对于城市居民,SBP随腰围和体重变化更大,DBP随腰围变化更大（交互作用P<0.05）;随访高血压不患病相对于随访高血压患病人群,SBP随腰围和BMI变化更大,DBP随BMI变化更大（交互作用P<0.05）。结论 在心血管病高危人群中,腰围、体重和BMI的变化与血压水平的变化均存在正向线性相关。     

中国1995－2012年双生子出生体重变化趋势分析

目的 描述分析中国双生子出生体重变化趋势。方法 使用中国双生子登记系统在中国8个省份收集的1995-2012年出生的双生子人群(共10 827对),采用病例回顾方法分析出生体重各指标情况和变化趋势。结果 调整性别、卵型、出生地区后,出生年份每推迟5年,双生子出生体重平均值降低0.01 kg(P=0.041).随着时间变化,双生子优势方出生体重、劣势方出生体重均不同程度地降低,出生体重相对差与出生体重不一致率在2007年以后有升高趋势。结论 1995-2012年中国双生子出生体重呈下降趋势,出生体重不一致率逐渐上升。考虑到出生体重不一致与某些不良健康结局的风险存在关联,应对双生子出生体重不一致予以重视。     

中国成年人体质指数和腰围与主要慢性病风险的关联研究

目的 分析中国成年人BMI与主要慢性病发病及全死因死亡风险的关联。方法 本研究基于中国慢性病前瞻性研究,基线时测量研究对象的身高、体重和腰围。分析中剔除基线现患冠心病、脑卒中、恶性肿瘤、COPD和糖尿病者,纳入428 113名研究对象。使用Cox比例风险回归模型分析BMI和腰围与主要慢性病（包括心血管疾病、恶性肿瘤、COPD、2型糖尿病）发病及全死因死亡的关联。结果 在平均10年随访期间,共有131 454人发生≥ 1种上述慢性病,26 892人死亡。主要慢性病发病风险随BMI增加而升高,与正常体重（18.5 ≤ BMI<24.0 kg/m²）者相比,超重（24.0 ≤ BMI < 28.0 kg/m²）和肥胖（BMI > 28.0 kg/m²）者的风险比分别为1.26（95% CI：1.24~1.27）和1.59（95% CI：1.57~1.62）。BMI过低或过高均与全死因死亡风险升高有关。腰围与主要慢性病发病及全死因死亡风险呈正向关联。按照中国人群体重标准,将体重控制在正常范围可以减少约12%主要慢性病发病。结论 一般性肥胖和中心性肥胖是中国成年人主要慢性病发病的危险因素。     

广州市中老年人体脂率与常规肥胖指标相关性及其对应值的研究

目的 探讨广州市中老年人体脂率（BFP）与BMI、腰围（WC）和腰臀比（WHR）等常规肥胖指标的相关性,并推算BFP相应切点值。方法 基于“广州生物库队列研究”（GBCS）平台,选择3 490名50岁及以上相对健康者随机分成两组,一组用于曲线拟合分析,确定BFP与BMI、WC和WHR间的相关方程,然后再引入性别、年龄、体力运动、吸烟、饮酒等因素进行逐步回归分析,建立预测方程,进而推算反映肥胖程度的BMI、WC、WHR各切点值对应的BFP切点值,然后与另一组进行验证。结果 BFP随BMI、WC和WHR的增加而增加,与WC、WHR相比,BMI能更好预测BFP,其回归方程为BFP=（-23.47-8.87×性别）+2.94×（BMI）-0.024×（BMI）²,决定系数R²=0.805。根据回归方程,超重（24 kg/m²≤BMI < 28 kg/m²）对应的BFP分别男性为24.3%≤BFP < 31.1%,女性为33.2%≤BFP < 40.0%。与WC、WHR对应的BFP判定肥胖的一致性相比,BMI所对应的BFP判定肥胖的一致性较好,其ROC曲线下面积最大,男性为0.909,女性为0.919,灵敏度和特异度分别男性为70.3%、85.5%;女性为75.2%、93.0%。结论 BFP与BMI的相关性较好。广州市中老年人BFP对应于超重/肥胖（BMI≥24 kg/m²）的切点值男性为24.0%,女性为33.0%。     

中国成年人文化程度与体格指标的长期变化关系

目的 分析中国慢性病前瞻性研究（CKB）人群文化程度与成年人不同阶段体格测量指标及其长期变化之间的关系。方法 本研究在参加第2次重复调查的研究对象中,剔除调查时年龄>65岁者、体格测量指标缺失或极端值者、基线或重复调查时自报患有重大慢性病者。分析研究对象的文化程度与25岁、基线调查时（2004-2008年）和重复调查时（2013-2014年）BMI和腰围、及每5年体重与腰围的变化值的关系。结果 纳入分析3 427名男性和6 320名女性。研究对象的体重和腰围都随年龄增长逐渐增加。从25岁到基线调查[年龄（45.2±6.5）岁],男性和女性每5年体重变化值分别为（1.70±2.63）和（1.27±2.10）kg。从基线到重复调查[年龄（53.2±6.5）岁],男性和女性每5年体重变化值分别为（1.12±2.61）和（0.90±2.54）kg,每5年腰围变化值分别为（3.20±3.79）和（3.83±3.85）cm。无论是25岁、基线还是重复调查时,文化程度低的女性BMI和腰围都更大。而在男性中,25岁时文化程度越低的男性BMI略大;到了基线和重复调查时,不同文化程度者间的BMI差异消失,但初、高中文化程度者的腰围及其增幅略高于其他文化程度者。结论 无论男性或女性,随年龄增长,体重和腰围都在不断增加。文化程度与BMI和腰围的关系存在性别差异。     

基于中国双生子人群的冠心病遗传-BMI交互作用研究

目的 分析冠心病患病的遗传-BMI交互作用。方法 利用中国双生子登记系统募集的20 340对≥ 25岁的同性别双生子,构建单变量遗传-环境交互作用模型,通过评估BMI对冠心病遗传效应的修饰作用反映冠心病的遗传-BMI交互作用。结果 调整年龄后,在男性中发现BMI对冠心病患病受到的遗传效应有负向修饰作用,遗传效应修饰系数（β_a）及95% CI为-0.14（-0.22~-0.04）,说明log-BMI每增加1个标准差,冠心病的遗传通径系数减小0.14,从而导致冠心病的遗传效应减小。而且低BMI（<24.0 kg/m²）男性冠心病患病的遗传度为0.77（0.65~0.86）,而高BMI（≥ 24.0 kg/m²）组对应模型中的遗传度为0.56（0.33~0.74）。在女性中未观察到冠心病的遗传-BMI交互作用。结论 中国成年男性双生子人群中发现冠心病患病的遗传-BMI交互作用,且遗传因素在低BMI组冠心病患病中发挥更重要的作用。     

Accuracy of self-reported anthropometric measures — Findings from the Finnish Twin Study

ObjectiveTo determine the accuracy of self-reported height, weight, body mass index (BMI) and waist circumference (WC) compared to the measured values, and to assess the similarity between self-reported and measured values within dizygotic (DZ) and monozygotic (MZ) twin pairs.MethodsThe data on self-reported and measured height, weight and WC values as well as measured hip circumference (HC) were collected from 444 twin individuals (53–67 years old, 60% women). Accuracies between self-reported and measured values were assessed by Pearson’s correlation coefficients, Cohen’s kappa coefficients and Bland-Altman 95% limits of agreement. Intra-class correlation was used in within-pair analyses.ResultsThe correlations between self-reported and measured values were high for all variables (r = 0.86–0.98), although the agreement assessed by Bland-Altman 95% limits had relatively wide variation. The degree of overestimating height was similar in both sexes, whereas women tended to underestimate and men overestimate their weight. Cohen’s kappa coefficients between self-reported and measured BMI categories were high: 0.71 in men and 0.70 in women. Further, the mean self-reported WC was less than the mean measured WC (difference in men 2.5 cm and women 2.6 cm). The within-pair correlations indicated a tendency of MZ co-twins to report anthropometric measures more similarly than DZ co-twins.ConclusionsSelf-reported anthropometric measures are reasonably accurate indicators for obesity in large cohort studies. However, the possibility of more similar reporting among MZ pairs should be taken into account in twin studies exploring the heritability of different phenotypes.     

Perinatal and early adulthood factors associated with adiposity

We used body mass index (BMI) and waist circumference (WC) as fat indicators to assess whether perinatal and early adulthood factors are associated with adiposity in early adulthood. We hypothesized that risk factors differ between men and women and are also different when WC is used for measuring adiposity as opposed to BMI. We conducted a longitudinal study based on a sample of 2,063 adults from the 1978/1979 Ribeir?o Preto birth cohort. Adjustment was performed using four sequential multiple linear regression models stratified by sex. Both perinatal and early adulthood variables influenced adulthood BMI and WC. The associations differed between men and women and depending on the measure of abdominal adiposity (BMI or WC). Living with a partner, for both men and women, and high fat and alcohol intake in men were factors that were consistently associated with higher adulthood BMI and WC levels. The differences observed between sexes may point to different lifestyles of men and women, suggesting that prevention policies should consider gender specific strategies.     

The Impact of Body Mass Index and Waist Circumference on Health-related Quality of Life Among Colorectal Cancer Survivors: Results from the PROFILES Registry

Background: We aimed to assess the association of waist circumference (WC) and body mass index (BMI) with health-related quality of life (HRQL) among colorectal cancer (CRC) survivors. Methods: CRC survivors diagnosed between 2000 and 2009 completed questionnaires in August 2013 (with self-reported weight, height, and self-assessed WC) and January 2014 (with HRQL using the EORTC-QLQ-C30). Clinical characteristics were retrieved from the Netherlands Cancer Registry. In multivariable linear regression analyses associations of BMI only, WC only and both BMI and WC with HRQL outcomes were assessed. Results: 1,111 CRC survivors were included of whom 34% had a normal weight (18.5 ≤ BMI < 25 kg/m²), 49% had overweight (25 ≤ BMI < 30 kg/m²), 17% had obesity (BMI ≥ 30 kg/m²), and 44% had an increased WC (i.e., >102 and >88 cm for men and women, respectively). Both BMI and WC were separately associated with worse global health status, functioning, and more symptoms of fatigue. Increased WC was associated with lower physical, role and emotional functioning, regardless of BMI, with average differences ranging between 3 and 5 points. Conclusion: Future research on HRQL among CRC survivors should consider both BMI and WC. Furthermore, weight reduction trials should not only focus on general weight loss but also on the loss of abdominal fat.     

The relationship between body mass index and uric acid: a study on Japanese adult twins

Objectives

The present study aimed to investigate the association between body mass index (BMI) and uric acid (UA) using the twin study methodology to adjust for genetic factors.

Methods

The association between BMI and UA was investigated in a cross-sectional study using data from both monozygotic and dizygotic twins registered at the Osaka University Center for Twin Research and the Osaka University Graduate School of Medicine. From January 2011 to March 2014, 422 individuals participated in the health examination. We measured height, weight, age, BMI, lifestyle habits (Breslow’s Health Practice Index), serum UA, and serum creatinine. To investigate the association between UA and BMI with adjustment for the clustering of a twin within a pair, individual-level analyses were performed using generalized linear mixed models (GLMMs). To investigate an association with adjustment for genetic and family environmental factors, twin-pair difference values analyses were performed.

Results

In all analysis, BMI was associated with UA in men and women. Using the GLMMs, standardized regression coefficients were 0.194 (95 % confidence interval: 0.016–0.373) in men and 0.186 (95 % confidence interval: 0.071–0.302) in women. Considering twin-pair difference value analyses, standardized regression coefficients were 0.333 (95 % confidence interval: 0.072–0.594) in men and 0.314 (95 % confidence interval: 0.151–0.477) in women.

Conclusions

The present study shows that BMI was significantly associated with UA, after adjusting for both genetic and familial environment factors in both men and women.     

学龄儿童甲状腺容积相关因素分析及不同甲状腺容积指数比较

目的 分析学龄儿童甲状腺容积与体格发育的关系,比较不同甲状腺容积指数,为评价指标的选取提供参考。方法 采用分阶整群抽样方法,选定上海市闵行区某小学三至五年级共12个班级全体学生进行体格检查,测定身高、体重,计算BMI及体表面积(BSA),采用B超检查测定甲状腺容积,并分别计算不同甲状腺容积指数[身高容积指数(HVI)、体块容积指数(BMIV)、体重身高容积指数(WHVI)、体表面积容积指数(BSAV)]。采集尿样、盐样,测定尿碘及盐碘含量。分析不同测量指标与儿童生长发育指标的关联。结果 共获得485名学龄儿童甲状腺容积数据,其中男童258名(53.2%),女童227名(46.8%)。身高、体重、BMI及BSA均与年龄呈正相关(P<0.05)。相同年龄组内,甲状腺容积与体格发育指标均呈正相关。各甲状腺容积指数中,BSAV与体格发育因素之间的差异无统计学关联(与年龄、性别、身高、体重的偏相关系数分别为0.07、0.05、0.01和0.02,P>0.05),而甲状腺容积、HVI、BMIV及WHVI仍与年龄、身高、体重相关。结论 甲状腺容积受年龄、体重影响,单纯以年龄别甲状腺容积判断甲状腺肿有失偏颇;BSAV不受年龄、性别、体重、身高的影响,稳定性好,建议推荐使用。     

Birth weight and adult cardiovascular risk factors using multiple birth status as an instrumental variable in the 1958 British Birth Cohort

BackgroundBirth weight is classified as a risk factor for cardiovascular disease by the World Health Organization, but appropriate preventive interventions remain unclear because the observations have not been confirmed in experiments and appear to be contextually specific.MethodsUsing 9452 participants of the 1958 British Birth Cohort at age 42 years in 2000 (58% follow-up), we examined the credibility of multiple birth status as an instrumental variable (IV) for birth weight and, if appropriate, use it to obtain less confounded estimates of the associations of birth weight with cardiovascular disease risk factors including self-reported height, body mass index and hypertension than conventional regression in 2014.ResultsMultiple birth (203 twins and 6 triplets) was associated with older maternal age, but not with paternal occupation or maternal smoking. Multiple births had lower birth weight-for-gestational age z-score. Multiple birth status was not directly associated with height, BMI or hypertension. Using IV estimates birth weight-for-gestational age z-score was not clearly associated with height (0.99 cm, 95% confidence interval (CI) − 0.27, 2.25), body mass index (BMI) (0.42 kg/m², 95% CI − 0.17, 1.01) or hypertension (risk ratio 0.82, 95% CI 0.54, 1.23) adjusted for maternal age, with a first-stage F statistic of 145.3 from IV analysis.ConclusionsMultiple birth status is a credible IV for obtaining a less confounded estimate of the association of birth weight with height, BMI and blood pressure. Such analysis suggests that birth weight may be spuriously related to height, BMI and blood pressure, and thus not an effective target for intervention.     

The role of protein intake in the relationship between egg consumption and body composition in young adults. A mediation analysis

Background & aimsTo date, the literature examining the effects of whole-egg consumption on health outcomes focuses primarily on cardiovascular health markers; however, a significant gap exists in the literature about how egg consumption may influence body composition indicators. The aim of this study was to estimate the association between egg consumption and body composition indicators and to examine whether this relationship is mediated by protein intake in young adults.MethodsA cross-sectional study was conducted involving 355 first-year university students (aged 18–30 years) from a Spanish public university. Body composition was measured using bioimpedance and dual-energy X-ray absorptiometry (DXA) and fitness components were determined using the course-navette test. Egg consumption and protein intake (both in g/day/kg of body weight) were determined using a 137-item Food-Frequency Questionnaire. ANCOVA models were used to test the mean differences in body composition indicators (body mass index [BMI], ratio waist circumference/height [WC/height], body fat mass percentage, and body lean mass percentage) by egg consumption categories (<1 egg/week, 1–4 eggs/week, ≥5 eggs/week). Hayes's PROCESS macro was used for mediation analyses.ResultsParticipants reporting high egg consumption (≥5 eggs/week) showed significantly lower BMI, WC/height and body fat mass percentage values and higher body lean mass percentage values than those reporting low egg consumption (<1 egg/week) (p < 0.05). However, these relationships were not maintained after adjusting for protein intake. Protein intake acted as a full mediator of the relationships of egg consumption with BMI (indirect effect [IE] = ?1.19; 95% CI [?3.33; ?0.36]), WC/height (IE = ?0.01; 95% CI [?0.04; ?0.01]) and body lean mass percentage (IE = 2.99; 95% CI [1.26; 5.73]) as a partial mediator of the relationship be-tween egg consumption and body fat mass percentage (IE = ?2.19; 95% CI [?4.92; ?0.46]).ConclusionsThe association between egg consumption and body composition is mediated by protein intake. This finding is important from a public health perspective, suggesting that higher egg consumption (≥5 eggs/week) may lead to a healthier body composition, especially due to higher protein intake.     

Body mass index at age 25 and all-cause mortality in whites and African Americans: the Atherosclerosis Risk in Communities study

PurposeApproximately 20% of young adults in the United States are obese, and most of them gain weight between young and middle adulthood. Few studies have examined the association between elevated body mass index (BMI) in early adulthood and mortality or have examined that such effects are independent of changes in weight. To our knowledge, no such study has been conducted in African-American samples.MethodsWe used data from 13,941 African-American and white adults who self-reported their weight at the age of 25, and had weight and height measured when they were 45–64 years of age (1987–1989). Date of death was ascertained between 1987 and 2005. Hazard ratios and hazard differences for the effects of BMI at age 25 on all-cause mortality were determined using Cox proportional hazard and additive hazard models, respectively.ResultsIn the combined ethnic–gender groups, the hazard ratio associated with a 5 kg/m² increase in BMI at age 25 was 1.28 (95% confidence interval [CI]: 1.22–1.35), and the hazard difference was 2.75 (2.01–3.50) deaths/1,000 person-years. Associations were observed in all four ethnic–gender groups. Models including weight change from age 25 to age in 1987–1989 resulted in null estimates for BMI in African-American men, whereas associations were maintained or only mildly attenuated in other ethnic–gender groups.ConclusionsExcess weight during young adulthood should be avoided because it contributes to increases in death rates that may be independent of changes in weight experienced in later life. Further study is needed to better understand these associations in African-American men.