Sex-specific effects of age and body mass index on antibody responses to seasonal influenza vaccines in healthcare workers

Healthcare institutions with mandatory influenza vaccination policies have over 90% vaccination rates among healthcare workers (HCWs) resulting in a population that has received the influenza vaccine in many, consecutive years. This study explored the impact of sex and other host factors in pre- and post-vaccination neutralizing antibody (nAb) titers and seroconversion against the H1N1 and H3N2 influenza A viruses (IAVs) among HCWs enrolled into a cross-sectional serosurvey during the annual Johns Hopkins Hospital employee vaccination campaign in the 2017–18 and 2018–19 seasons. The study enrolled 111 participants (male = 38, female = 73) in 2017–18 and 163 (male = 44, female = 119) in 2018–19. Serum samples were collected immediately prior to vaccination and approximately 28 days later and nAb titers to vaccine strains determined. An intersectional approach was used to disaggregate the combined effects of sex with age and body mass index (BMI) in the nAb response. Differences between the pre- or post-vaccination geometric mean nAb titers between male and female HCWs were not observed. Male HCWs were 2.86 times more likely to seroconvert compared to female HCWs in 2017–2018, but the same trend was not observed in the following year. When data were disaggregated by age and sex, older female HCWs had higher H1N1 pre- and post-vaccination nAb titers compared to male HCWs in the same age group for both vaccination campaign seasons. In both years, the decline in H3N2 pre-vaccination titers with increasing BMI was greater in female than male HCW. The sex-specific effects of age and BMI on nAb responses to seasonal influenza vaccines require greater consideration.     

双生子体质指数遗传度的Meta分析

目的 采用Meta分析方法,了解双生子BMI遗传度。方法 通过检索中国知网、万方数据知识服务平台、维普数据库、PubMed和Web of Science数据库,获得截至2020年12月31日双生子BMI遗传度的研究。采用现况调查偏倚风险评价标准评价纳入文献的质量。采用Stata 16.0软件对结局指标（遗传度,95%CI）进行亚组分析,探索异质性来源和局部加权回归法拟合遗传度随年龄的变化趋势,并对纳入的文献进行发表偏倚检验和敏感性分析。结果 共纳入符合纳入排除标准的文献10篇,共纳入79个双生子BMI遗传度独立估计值。Meta分析显示,BMI遗传度合并值为0.69（95%CI：0.65~0.71）,男性合并值（0.68,95%CI：0.65~0.70）低于女性合并值（0.70,95%CI：0.68~0.72）;儿童青少年时期的BMI遗传度（0.72,95%CI：0.68~0.76）比成年时高（0.68,95%CI：0.66~0.70）;≤ 18岁的双生子BMI遗传度性别间的差异更大,男性（0.68,95%CI：0.61~0.76）低于女性（0.75,95%CI：0.69~0.81）。遗传度随年龄的变化趋势：儿童时期随年龄的增长而上升,至18岁左右达到峰值,其后随年龄的增加缓慢下降。结论 BMI遗传度受人口特征影响,特别是年龄和性别。鉴于女性青少年时期BMI遗传度估计值较高,应给予更多关注,把握健康干预的切入点。     

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3...     

Longitudinal associations of neighborhood environment features with pediatric body mass index

IntroductionIt has been posited that policies to promote child health and prevent obesity should target neighborhood environments but evidence on the impact of neighborhoods on child weight is conflicting and longitudinal studies (which have benefits for causal inference) are scarce.MethodsWe used electronic health records (2007–2016) from an urban, pediatric integrated delivery system and linked children (N = 51,873, ages 6–19 years, 77% African American) to neighborhood-level data to investigate how changes in neighborhood environments relate to changes in body mass index (BMI). Measures of neighborhood environment were resources for healthy foods and physical activity (‘resources’), greenness, violent crime rate, perceived safety and social cohesion. Fixed effects models estimated associations between changes in neighborhood environment exposures and changes in BMI z-score and whether effects differed by sex, baseline age, neighborhood socioeconomic status and population density.ResultsApproximately 22% of the cohort was obese (BMI z-score ≥ 95th percentile). In adjusted models, increases in neighborhood greenness and perceived safety were associated with decreases in BMI z-score (mean change in BMI z-score for 1-SD increase for both: -0.012; 95% CI= (−0.018, −0.007)). Increases in neighborhood safety had a stronger effect in children ages 6–10 years than in older children. Increases in social cohesion were associated with increases in BMI z-score (mean change: 0.005 95% CI = (0.003, 0.008)) especially in boys. Increases in food and physical activity resources were not associated with changes in BMI.ConclusionsThis study suggests that increasing neighborhood greenness and safety are potential approaches to reduce children's BMI.     

Fast food costs and adolescent body mass index: Evidence from panel data

This study draws on four waves of the 1997 National Longitudinal Survey of Youth and external data to examine the relationship between adolescent body mass index (BMI) and fast food prices and fast food restaurant availability using panel data estimation methods to account for individual-level unobserved heterogeneity. Analyses also control for contextual factors including general food prices and the availability of full-service restaurants, supermarkets, grocery stores, convenience stores and commercial physical activity-related facilities. The longitudinal individual-level fixed effects results confirm cross-sectional findings that the price of fast food but not the availability of fast food restaurants has a statistically significant effect on teen BMI with an estimated price elasticity of −0.08. The results suggest that the cross-sectional model over-estimates the price of fast food BMI effect by about 25%. There is evidence that the weight of teens in low- to middle-socioeconomic status families is most sensitive to fast food prices.     

Relationship between body mass index, cigarette smoking, and plasma sex steroids in normal male twins

Smoking has been observed to affect plasma sex hormones and body mass index. The relationship between smoking, body mass index, and plasma concentration of sex hormones was studied in normal adult male twins. The analyses were performed for between 150 and 159 twin pairs for whom hormonal data were available on both twins. With bivariate analysis, neither body mass index nor smoking affected estrone, luteinizing hormone, follicle-stimulating hormone, ratio of testosterone to estradiol, or ratio of testosterone to dihydrotestosterone. Body mass index significantly (P less than 0.05) affected sex hormone binding globulin, whereas smoking had no effect. The plasma contents of testosterone and dihydrotestosterone and the luteinizing hormone/testosterone ratio were affected by both body mass index and smoking, although, after allowing for body mass, smoking was less significant (0.05 less than P less than 0.10). A path model was formulated to examine the relationship of body mass and sex steroid levels. Our results suggest that body mass index affects sex steroids, since common environmental factors do not account for the strength of the relationship. The bivariate analysis suggests that the smoking effect on sex hormones (except perhaps for dihydrotestosterone) is secondary to an effect on body mass index.     

Underestimation of body mass index through perceived body image as compared to self-reported body mass index in the European Union

An observational, cross-sectional study was conducted in a representative sample of the European Union (7155 men and 8077 women) to calculate the underestimation of body weight as assessed by body image among the overweight and obese population and identify the associated factors to this behavior. Participants were older than 15 years and they were living in the 15 European Union countries. Body mass index (BMI) was grouped into 4 categories using the cutpoints established by the WHO, while perceived body image (PBI) was assessed using a nine-silhouettes drawing. The degree of underestimation between PBI as compared to BMI was identified in overweight and obesity categories of BMI. A multivariable logistic regression model for each gender was used to adjust for potentially confounding variables. Men classified themselves worse than women, being more likely to underestimate their body weight (65.2% of men underestimated their weight vs 32.2% women), regardless of other socioeconomic and attitudinal variables. The greatest degree of underestimation was observed in Mediterranean individuals (68.7% of men and 37.9% of women underestimated their weight). The subjects in the 'maintenance' stage of physical activity tended more often to wrongly select their actual image (71.8% for men and 38.7% for women).     

Height and body mass index and risk of lymphohematopoietic malignancies in two million Norwegian men and women

Reports on the association between obesity and lymphohematopoietic malignancies (LHMs) have been inconsistent. The present study aimed at exploring this association for specific disease lymphohematopoietic entities in a large Norwegian cohort. Height and weight were measured in two million Norwegian men and women aged 20-74 years during 1963-2001. During follow-up, 24,500 cases of LHMs were observed. Relative risks of disease were estimated by Cox proportional hazards regression. The risk of LHMs overall increased moderately by increasing body mass index and height in both sexes. The relative risk of LHMs per five-unit increase in body mass index was 1.11 (95% confidence interval (CI): 1.08, 1.14) in men and 1.08 (95% CI: 1.05, 1.11) in women. For each 10-cm increase in height, the relative risk was 1.19 (95% CI: 1.16, 1.22) in men and 1.16 (95% CI: 1.12, 1.20) in women. Separate analyses for different lymphohematopoietic malignancies did not reveal any group's being particularly strongly associated with body mass index. A modest increase in the risk of LHMs combined was observed with increasing height. The moderate associations between height and body mass index and LHMs found in the present study indicate that the observed increase in overweight/obesity plays only a minor role in explaining the increase in the incidence of LHMs.     

探讨老年人适宜的体质量指数

老年人的体质量管理作为健康管理的基础应受到广大医务工作者的重视,然而,我国老年人适宜的体质量指数是多少,目前尚无统一结论。本文通过复习国内外近年老年人体质量以及老年肥胖问题的相关文献,探讨我国老年人适宜的体质量指数。较多文献显示老年人的体质量指数在超重和轻度肥胖范围或许是最佳的体质量状态。     

Relation of height and body mass index to renal cell carcinoma in two million Norwegian men and women

A positive association between body mass index (BMI) and renal cell carcinoma (RCC) has been observed. The association between height and RCC has been less clear. The authors explored these relations in a very large Norwegian cohort. Height and weight were measured in two million Norwegian men and women aged 20-74 years during 1963-2001. During follow-up, 6,453 cases of RCC were registered in the national cancer database. Measurements were also performed in 227,000 adolescents aged 14-19 years, and 154 cases of RCC were registered. Relative risks for RCC were estimated using Cox proportional hazards regression. The risk of RCC increased with increasing BMI among both adults and adolescents. Among adults, the relative risk associated with a one-unit increase in BMI was 1.05 (95% confidence interval (CI): 1.04, 1.06) in both sexes. The relative risk associated with a 10-cm increase in height was 1.19 (95% CI: 1.13, 1.26) in men and 1.17 (95% CI: 1.09, 1.26) in women. In a subgroup analysis, the relation between BMI and RCC was most pronounced in men and women who were never smokers, and the relation between height and RCC was confined to ever smokers. The authors conclude that elevated BMIs are associated with RCC risk in both males and females across a wide age range.     

苏州儿童青少年体质量指数与血压水平非线性效应分析

探讨6~17岁正常体重儿童和青少年体质量指数(BMI)对高血压前期和高血压的非线性效应,为控制儿童青少年血压水平并制定针对性的干预措施提供参考.方法 排除肥胖、超重和信息不完整者之后,共有522 646名苏州地区2017年中小学生健康体检者被纳入分析.根据2010年中国学生体质与健康调研报告中分年龄和性别的结果计算BMI标准分.高血压前期和高血压根据近期针对6~17岁正常体重儿童和青少年确立的血压参考标准进行确定.BMI对高血压前期和高血压的非线性效应根据限制性立方样条模型进行分析,采用立方样条Logistic回归估计发生风险,并且根据年龄、性别进行分层分析.结果 与BMI得分为0相比,BMI得分为-2.0,-1.5,-1.O,-0.5,0.5,0.8和1.O相对应的高血压前期的OR值(OR值95%CI)分别为0.58(0.56~0.61),0.67(0.65~0.69),0.77(0.75 ~ 0.78),0.88(0.87~0.89),1.12(1.11~1.13),1.20(1.18~ 1.22)和1.26(1.23~ 1.28),相对应的高血压的OR值(OR值95%CI)分别为0.51(0.49~0.53),0.60(0.59~0.62),0.72(0.70~0.73),0.85(0.84~0.86),1.17(1.16~1.18),1.29(1.27~ 1.31)和1.37(1.34~ 1.40).结论 正常体重儿童和青少年BMI对高血压前期和高血压的效应为非线性.相对超重和肥胖者,血压控制在正常体重儿童和青少年人群中仍需引起关注.     

Associations between blood pressure and overweight defined by new standards for body mass index in childhood

BACKGROUND: Using data from a longitudinal study of young Australians, we applied recent international standards for overweight and obesity to examine associations with blood pressure (BP) and to determine the prevalence and degree of tracking of overweight and obesity. We also aimed to examine socioeconomic status in relation to these variables. METHODS: BP, height, and weight were measured at 3-year intervals from age 9 to 18, and then at 25 years of age in a Western Australian cohort. At these stages, data were available for 1,036, 1,310, 618, 615 and 600 individuals, respectively. RESULTS: We found 10% of 9-year-old males to be overweight or obese, while among 12-year-olds, 13% were overweight or obese; at age 15, and still at age 18, overweight or obesity was registered in 17% of this population and it rose to 42% among the 25-year-old young men. The percentage of overweight or obese females at these stages was initially 8, then 12 (at age 12), 11 (at age 15), 14 (at age 18) and finally 32. Overweight or obesity tracked to young adult life in 16% of those overweight or obese at 9, 24% at 12, 34% at 15 and 35% at 18 years. Systolic BP was significantly higher in the overweight or obese except in 12-year-olds. At the age of 25 years, 53% of men had high normal BP or were hypertensive. CONCLUSIONS: Increasing overweight or obesity in young Australians, consistent with international trends, has serious health implications. Overweight and obesity show tracking and are predictors of higher blood pressure, except in early adolescence.     

A major error in nomograms for estimating body mass index

The Surgeon General's Report on Nutrition and Health and Diet and Health include a nomogram for determining body mass index (BMI, in kg/m2) when the subject's weight and height are known. I regret to report that the BMI in nomograms in these books are highly inaccurate when compared with direct calculations of BMI. Anyone wishing to use a nomogram for the rapid estimation of BMI should be cautioned against relying on the versions that appear in these books.     

Body composition obtained from the body mass index

Background  Since obesity and related diseases are now considered epidemic, new and more accurate formulas for epidemiological studies are of interest to the scientific community. Several equations have been proposed to estimate the body composition simply from anthropometric measurements. However, with time, the body composition of the populations studied changes in relation to their food habits and lifestyle, and, therefore, the equations must be regularly updated and corrected. Aim of the study  The aim of the study was to develop new equations to determine the body composition among the Italian population using the body mass index and independently by variables such as age and body structure. Methods  Bioelectrical impedance and anthropometric analysis of 764 Italian Caucasian subjects (342 females and 422 males), 11 to 80 years of age, were analysed. Females and males were analysed separately. Multiple regression analyses were performed in order to estimate the body composition of the subjects. The estimated masses were then compared with the measured masses using Bland and Altman plots. We also calculated the differences between the estimated and measured masses, reported as % of the body weight, for the 95, 85 and 75° percentile of the female and male groups. Finally we compared our formulas with the Watson equations, which are used to estimate the total body water. Results  All body masses estimated were positively correlated to the measured values. Moreover, at any percentile analysed, our formulas resulted more precise than the Watson formula. Equations: Females: FM = 1.9337 BMI – 26.422; FFM = BW – FM; BCM = 0.3655 FFM + 4.865; TBW = 0.5863 FFM + 7.1732; Males: FM = 1.407 BMI – 21.389; FFM = BW – FM; BCM = 0.4485 FFM + 3.3534; TBW = 0.6997 + 1.4567. Conclusions  Although an inevitable inaccuracy must be expected in epidemiological studies, our equations are adequate to analyze the body composition state and changes occurring among the Italian population by simply considering weight and height.     

A spatial analysis of the association between restaurant density and body mass index in Canadian adults

Objective

To investigate the association between fast-food restaurant density and adult body mass index (BMI) in Canada.

Methods

Individual-level BMI and confounding variables were obtained from the 2007–2008 Canadian Community Health Survey master file. Locations of the fast-food and full-service chain restaurants and other non-chain restaurants were obtained from the 2008 Infogroup Canada business database. Food outlet density (fast-food, full-service and other) per 10,000 population was calculated for each Forward Sortation Area (FSA). Global (Moran's I) and local indicators of spatial autocorrelation of BMI were assessed. Ordinary least squares (OLS) and spatial auto-regressive error (SARE) methods were used to assess the association between local food environment and adult BMI in Canada.

Results

Global and local spatial autocorrelation of BMI were found in our univariate analysis. We found that OLS and SARE estimates were very similar in our multivariate models. An additional fast-food restaurant per 10,000 people at the FSA-level is associated with a 0.022 kg/m² increase in BMI. On the other hand, other restaurant density is negatively related to BMI.

Conclusions

Fast-food restaurant density is positively associated with BMI in Canada. Results suggest that restricting availability of fast-food in local neighborhoods may play a role in obesity prevention.     

Spouse resemblance in body mass index: effects on adult obesity prevalence in the offspring generation

Accruing evidence indicates that mate selection is promoted by similarity in body fatness. Assortative mating for obesity may contribute genetically to the obesity epidemic by increasing the risk in subsequent generations. To test this hypothesis, the authors analyzed measured and validated questionnaire data on family members, obtained between 1987 and 2000 from 7,834 obese probands and from 829 subjects randomly ascertained from the general Swedish population. Spouse correlations in body mass index were strongest among couples with the shortest duration of cohabitation. Obesity concordance in parents was associated with an obesity prevalence of 20.1% in adult offspring compared with 1.4% if parents were concordantly nonobese (odds ratio = 18.3, 95% confidence interval: 9.0, 37.4). The prevalence was 8.2% if parents were obesity discordant (odds ratio = 6.5, 95% confidence interval: 3.2, 13.2). No association was found between rearing parents' and nonbiologic offspring's body mass index. These results agree with the hypothesis that assortative mating for obesity confers a higher risk of obesity in the offspring generation and thus contributes to the obesity epidemic. Parental obesity concordance is a strong, easily identifiable genetic risk factor that should be considered in the complex network of risk factors for obesity in designing primary prevention programs.