Body mass index,waist circumference and waist–hip ratio: which is the better discriminator of cardiovascular disease mortality risk? Evidence from an individual‐participant meta‐analysis of 82 864 participants from nine cohort studies

Few studies have examined both the relative magnitude of association and the discriminative capability of multiple indicators of obesity with cardiovascular disease (CVD) mortality risk. We conducted an individual‐participant meta‐analysis of nine cohort studies of men and women drawn from the British general population resulting in sample of 82 864 individuals. Body mass index (BMI), waist circumference (WC) and waist‐to‐hip ratio (WHR) were measured directly. There were 6641 deaths (1998 CVD) during a mean of 8.1 years of follow‐up. After adjustment, a one SD higher in WHR and WC was related to a higher risk of CVD mortality (hazard ratio [95% CI]): 1.15 (1.05–1.25) and 1.15 (1.04–1.27), respectively. The risk of CVD mortality also increased linearly across quintiles of both these abdominal obesity markers with a 66% increased risk in the highest quintile of WHR. In age‐ and sex‐adjusted models only, BMI was related to CVD mortality but not in any other analyses. No major differences were revealed in the discrimination capabilities of models with BMI, WC or WHR for cardiovascular or total mortality outcomes. In conclusion, measures of abdominal adiposity, but not BMI, were related to an increased risk of CVD mortality. No difference was observed in discrimination capacities between adiposity markers.     

Optimum waist circumference‐height indices for evaluating adult adiposity: An analytic review

Phenotyping adults for excess adiposity and related health risks usually include three body size measurements: height, weight and waist circumference (WC). Height and weight are now widely used as components of the body shape measure, body mass index (BMI, weight/height²), with the height power referred to as the scaling factor, α. At present, WC is usually not adjusted for height or is expressed as WC/height in which α = 1. Although other α values have been proposed, a critical review of these shape measures is lacking. Here, we examine classical pathways by which the scaling exponent for height used in BMI was developed and then apply this strategy to identify the optimum WC index characteristic of adult shape. Our analyses explored anthropometric, body composition and clinically‐relevant data from US and Korean National Health and Nutrition Surveys. Our findings provide further support for the WC index of WC/height^0.5 as having the strongest associations with adiposity while having the weakest correlations with height across non‐Hispanic white and black, Mexican American and Korean men and women. The WC index, defined as WC/height^0.5, when combined with BMI, can play an important role when phenotyping adults for excess adiposity and associated health risks in research and clinical settings.     

Is the relationship between sedentary behaviour and cardiometabolic health in adolescents independent of dietary intake? A systematic review

Screen time, but not overall sedentary behaviour, is consistently related to cardiometabolic health in adolescents. Because of the associations screen time has with dietary intake, diet may be an important factor in the screen time and health relationship; however, evidence has not previously been synthesized. Thus, the aim of this systematic review was to explore whether the associations between various sedentary behaviours and cardiometabolic risk markers are independent of dietary intake in adolescents. Online databases and personal libraries were searched for peer‐reviewed original research articles published in English before March 2014. Included studies assessed associations between sedentary behaviour and cardiometabolic markers in 12‐ to 18‐year‐olds and adjusted for dietary intake. Twenty‐five studies met the inclusion criteria. From the 21 studies examining sedentary behaviour and adiposity, the majority found significant positive associations between television viewing, screen time and self‐reported overall sedentary behaviour with markers of adiposity, independent of dietary intake. No significant associations between screen time with blood pressure and cholesterol were reported. Sedentary behaviour appears to be associated with adiposity in adolescents, irrespective of dietary intake. However, the variability of dietary variables between studies suggests further work is needed to understand the role of dietary intake when examining these associations in youth.     

Unravelling the association between accelerometer‐derived physical activity and adiposity among preschool children: A systematic review and meta‐analyses

Evidence on the association between physical activity (PA) and adiposity in young children is inconclusive. A systematic review and meta‐analyses were conducted to examine associations between accelerometer‐derived PA and varying adiposity outcomes in preschool children. Searches were conducted in Embase, MEDLINE and Web of Science to identify studies on the association between total PA, sedentary behaviour or different PA intensities and adiposity in children aged 2 to 7 years. Separate random effects meta‐analyses were performed for varying PA intensities and adiposity outcomes. Fifty‐six articles were included in the review and 48 in the meta‐analyses. There was substantial evidence of an inverse association between moderate‐to‐vigorous‐ or vigorous PA and body fat percentage (stdβ [SE] = ?0.162[0.041]; 5 studies), weight status (r = ?0.120, P<.001; 11 studies), fat mass (stdβ [SE] = ?0.103[0.051]; 5 studies), fat mass index (stdβ [SE] = ?0.121[0.036]; 2 studies) and skinfold thickness (stdβ [SE] = ?0.145[0.036]; 4 studies). However, total PA, sedentary behaviour, and different PA intensities were not associated with body mass index (BMI) or waist circumference. Adiposity levels were lower among preschool children engaged in more (moderate‐to‐) vigorous PA compared with their peers, but no associations between PA and BMI or waist circumference were found.     

Alcohol and adiposity: effects of quantity and type of drink and time relation with meals

BACKGROUND: It has been suggested that the effects of alcohol on body weight and fat distribution may be influenced by the quantity and type of drink and may differ according to whether the alcohol is consumed with meals or not. OBJECTIVE: We have examined the cross-sectional association between alcohol intake, patterns of drinking and adiposity (body mass index (BMI), waist-to-hip ratio (WHR), waist circumference (WC) and percentage body fat (%BF)). METHODS: We studied 3327 men aged 60-79 y with no history of myocardial infarction, stroke or diabetes drawn from general practices in 24 British towns. RESULTS: BMI, WHR, WC and %BF increased significantly with increasing alcohol intake even after adjustment for potential confounders (all P < 0.0001), although the effects were stronger for WC and WHR (measures of central adiposity). Men who consumed > or = 21 units/week showed higher levels of central adiposity (WHR, WC) and general adiposity (BMI, %BF) than nondrinkers and lighter drinkers, irrespective of the predominant type of drink consumed (wine, beer, spirits or mixed). The positive association was most clearly seen in beer and spirit drinkers; positive but weaker associations were seen for wine. Among drinkers, a positive association was seen between alcohol intake and the adiposity variables irrespective of whether the alcohol was drunk with or separately from meals. CONCLUSION: Higher alcohol consumption (> or = 21 units/week) is positively associated with general and to a greater extent with central adiposity, irrespective of the type of drink and whether the alcohol is drunk with meals or not.     

Adiposity measures and pre‐diabetes or diabetes in adults with hypertension in Singapore polyclinics

Identification of hypertensive patients with pre‐diabetes or diabetes is important for timely prevention of complications including vascular disease. We aimed to compare the association and discrimination of central obesity measures (waist circumference [WC] and waist‐to‐height ratio [WHtR]) with generalized obesity measure (body mass index [BMI]) in relation to pre‐diabetes and diabetes among a group of Asian hypertensive patients for the first time. We used the baseline data of 925 subjects aged 40 years or older with uncontrolled hypertension recruited at eight primary care clinics in Singapore. Information on height, weight, WC, fasting blood glucose, and hemoglobin A1c (HbA1c) was collected. Pre‐diabetes or diabetes was defined as having reported physician‐diagnosed diabetes or taking anti‐diabetes medication, fasting blood glucose ≥ 5.6 mmol/dL or HbA1c ≥ 5.7%. Among 925 subjects, 495 (53.5%) had pre‐diabetes or diabetes. In logistic regression models, BMI was not associated with pre‐diabetes or diabetes after adjusting for WC or WHtR, while a positive association remained with both WC and WHtR after adjustment of BMI. Both WC and WHtR had significantly better discrimination than BMI (respective area under ROC curve: 0.63 for WC, 0.63 for WHtR, and 0.60 for BMI; P = 0.019), and adding WC or WHtR on top of BMI further correctly reclassified 42.7% and 38.7% hypertensive patients to the right risk group of pre‐diabetes or diabetes indicated by net reclassification improvement. However, WHtR was not superior to WC. In conclusion, our results suggested that central obesity has stronger association with and better discrimination for pre‐diabetes or diabetes than generalized obesity.     

Group‐based trajectory modelling for BMI trajectories in childhood: A systematic review

Childhood obesity is an important public health issue. We aimed to systematically review studies that used group‐based trajectory modelling approaches to investigate body mass index (BMI) trajectories in early childhood, explore associated determinants, and the association with body composition outcomes. Five databases were searched systematically for studies using group‐based trajectory modelling approaches to track BMI trajectories from birth. Fourteen studies using latent class growth analysis or growth mixture modelling to track BMI trajectories were identified. Three or four trajectories were identified in most studies. High maternal pre‐pregnancy BMI was the most frequently identified risk factor for membership of a rapid gain trajectory. Significant associations between rapid weight gain and stable high trajectories and body measures at follow‐up were identified by several studies. Relatively similar trajectories were identified across studies. Trajectories characterized by rapid weight gain were associated with several predictors, as well as body measures at follow‐up, however not with great consistency. Similar associations with body measure outcomes were found for stable high and rapid gain trajectories, suggesting that long‐term outcomes do not differ greatly between children with consistently high BMI and children with rapid increases in BMI. As the shape and timing of the trajectories differed between studies, it is difficult to draw conclusions.     

The association of differing measures of overweight and obesity with prevalent atherosclerosis: the Dallas Heart Study.

OBJECTIVES: This study sought to evaluate the associations between different measures of obesity and prevalent atherosclerosis in a large population-based cohort. BACKGROUND: Although obesity is associated with cardiovascular mortality, it is unclear whether this relationship is mediated by increased atherosclerotic burden. METHODS: Using data from the Dallas Heart Study, we assessed the association between gender-specific obesity measures (i.e., body mass index [BMI]; waist circumference [WC]; waist-to-hip ratio [WHR]) and prevalent atherosclerosis defined as coronary artery calcium (CAC) score >10 Agatston units measured by electron-beam computed tomography and detectable aortic plaque measured by magnetic resonance imaging. RESULTS: In univariable analyses (n = 2,744), CAC prevalence was significantly greater only in the fifth versus first quintile of BMI, whereas it increased stepwise across quintiles of WC and WHR (p trend <0.001 for each). After multivariable adjustment for standard risk factors, prevalent CAC was more frequent in the fifth versus first quintile of WHR (odds ratio 1.91, 95% confidence interval 1.30 to 2.80), whereas no independent positive association was observed for BMI or WC. Similar results were observed for aortic plaque in both univariable and multivariable-adjusted analyses. The c-statistic for discrimination of prevalent CAC was greater for WHR compared with BMI and WC in women and men (p < 0.001 vs. BMI; p < 0.01 vs. WC). CONCLUSIONS: We discovered that WHR was independently associated with prevalent atherosclerosis and provided better discrimination than either BMI or WC. The associations between obesity measurements and atherosclerosis mirror those observed between obesity and cardiovascular mortality, suggesting that obesity contributes to cardiovascular mortality via increased atherosclerotic burden.     

Objectively measured physical activity and obesity prevention in children,adolescents and adults: a systematic review of prospective studies

This study aimed at synthesizing the prospective associations between measured physical activity (PA) and change in adiposity in children, adolescents and adults following from two previous reviews. Search terms were adapted and a systematic literature search was conducted (January 2000–September 2008) and later updated (up to October 2009), considering observational and intervention studies of weight gain that measured both PA and body composition. Sixteen observational studies (six comprising adults) and five trials (one comprising adults) were eligible. For consistency, whenever possible either baseline PA energy expenditure or accelerometer output (counts min^?1) and change in per cent body fat were the extracted exposure and outcome measures. Results of observational studies suggest that PA is not strongly prospectively related with adiposity: five studies on children and three on adults reported no association between baseline PA and change in adiposity, one study found a weak positive association and the other studies observed a weak negative association. Negative associations were more frequently observed in studies that analysed the association between change in the exposure and outcome. Intervention studies show generally no effect on either PA or adiposity. In conclusion, despite the well‐established health benefits of PA, it may not be a key determinant of excessive gain in adiposity.     

The accuracy of self‐reported pregnancy‐related weight: a systematic review

Self‐reported maternal weight is error‐prone, and the context of pregnancy may impact error distributions. This systematic review summarizes error in self‐reported weight across pregnancy and assesses implications for bias in associations between pregnancy‐related weight and birth outcomes. We searched PubMed and Google Scholar through November 2015 for peer‐reviewed articles reporting accuracy of self‐reported, pregnancy‐related weight at four time points: prepregnancy, delivery, over gestation and postpartum. Included studies compared maternal self‐report to anthropometric measurement or medical report of weights. Sixty‐two studies met inclusion criteria. We extracted data on magnitude of error and misclassification. We assessed impact of reporting error on bias in associations between pregnancy‐related weight and birth outcomes. Women underreported prepregnancy (PPW: ?2.94 to ?0.29 kg) and delivery weight (DW: ?1.28 to 0.07 kg), and over‐reported gestational weight gain (GWG: 0.33 to 3 kg). Magnitude of error was small, ranged widely, and varied by prepregnancy weight class and race/ethnicity. Misclassification was moderate (PPW: 0–48.3%; DW: 39.0–49.0%; GWG: 16.7–59.1%), and overestimated some estimates of population prevalence. However, reporting error did not largely bias associations between pregnancy‐related weight and birth outcomes. Although measured weight is preferable, self‐report is a cost‐effective and practical measurement approach. Future researchers should develop bias correction techniques for self‐reported pregnancy‐related weight.     

Value of body fat mass vs anthropometric obesity indices in the assessment of metabolic risk factors

OBJECTIVE: To compare the value of body fat mass (%FM) to indirect measures of general (body mass index (BMI)) and central adiposity (waist circumference (WC); waist-to-height ratio (WC/ht)) for the prediction of overweight- and obesity-related metabolic risk in a study population with a high prevalence of metabolic syndrome (MSX). METHODS: BMI, WC, WC/ht, body composition (by air-displacement plethysmography) and metabolic risk factors: triglycerides, cholesterol, HDL-cholesterol (HDL-C), uric acid, systolic blood pressure (BPsys), insulin resistance by homeostasis model assessment (HOMA-IR) and C-reactive protein (CRP) were measured in 335 adults (191 women, 144 men; mean age 53 +/-13.9 years, prevalence of MSX 30%). RESULTS: When compared with BMI and WC, %FM showed weaker associations with metabolic risk factors, except for CRP and BPsys in men. In women, HDL-C and HOMA-IR showed the closest correlations with BMI. For all other risk factors, WC or WC/ht were the best predictors in both sexes. Differences in the strength of correlations between an obesity index and different risk factors exceeded the differences observed between all obesity indices within one risk factor. In stepwise multiple regression analyses, WC/ht was the main predictor of metabolic risk in both sexes combined. However, analysis of the area under receiver operating characteristic curves for prediction of the prevalence of >or=2 component traits of the MSX revealed a similar accuracy of all obesity indices. CONCLUSIONS: At the population level, measurement of body FM has no advantage over BMI and WC in the prediction of obesity-related metabolic risk. Although measures of central adiposity (WC, WC/ht) tended to show closer associations with risk factors than measures of general adiposity, the differences were small and depended on the type of risk factor and sex, suggesting an equivalent value of methods.     

Joint effects of adiposity and physical activity on incident mobility limitation in older adults

OBJECTIVES: To examine joint associations of physical activity and adiposity measures (body mass index (BMI), waist circumference, percentage body fat) with incident mobility limitation. DESIGN: Prospective observational cohort study. SETTING: Memphis, Tennessee and Pittsburgh, Pennsylvania. PARTICIPANTS: Two thousand nine hundred and eighty‐two black and white men and women aged 70 to 79 participating in the Health, Aging and Body Composition (Health ABC) study. MEASUREMENTS: Mobility limitation was defined as reported difficulty walking one‐quarter of a mile or climbing 10 steps during two consecutive semiannual assessments over 6.5 years. Three measures of adiposity were included in this study: BMI, total percentage body fat, and waist circumference. Physical activity was assessed using a modified leisure‐time physical activity questionnaire. RESULTS: Forty‐six percent of the cohort developed mobility limitation. White and black men with a high BMI (≥30 kg/m²), high total percentage body fat (>31.3%), or high waist circumference (≥102 cm) had an approximately 60%, 40%, and 40%, respectively, higher risk of incident mobility limitation than those with low adiposity. In women, high adiposity was also associated with a significantly higher mobility limitation risk than in those with low adiposity. Low physical activity (lowest quartile) was associated with a 70% higher risk of mobility limitation in all groups. Persons with high adiposity and low physical activity were at particularly high risk of mobility limitation. People with high adiposity who were physically active had an equally high risk of mobility limitation as inactive people with low adiposity. CONCLUSION: High adiposity and low self‐reported physical activity predicted the onset of mobility limitation in well‐functioning older persons. Preventing weight gain in old age and promoting physical activity in obese and non‐obese older persons may therefore be effective strategies to prevent mobility loss and future disability.     

Body mass index, sexual difficulties and sexual satisfaction among people in regular heterosexual relationships: a population-based study

Background/Aims: The aims of this study were to clarify the relationship between body mass index (BMI) and sexual difficulties and to investigate if BMI influenced sexual satisfaction, over and above the effects of sexual difficulties. Methods: Cross‐sectional analyses of a nationally representative computer‐assisted telephone interview. Eight thousand, six hundred and fifty‐six respondents were recruited by random digit dialling in 2004–2005. Only those in a sexually active, heterosexual relationship were included in the current analyses. Results: After adjustments for demographic factors, both overweight and obese male and female participants were more likely to report worrying during sex about whether their body was unattractive. Among women, associations were also found between higher BMI and lack of interest in sex. No other significant associations between BMI and sexual difficulties were evident. There was an association between BMI and extreme physical pleasure for women but not men over and above the effects of sexual difficulties, with obese women being more likely than normal weight women to report extreme physical pleasure. No associations were found for either men or women between BMI and whether or not they reported extreme emotional or sexual satisfaction with their relationship. Conclusions: With the exception of body image difficulties, there is little association between BMI and self‐reported sexual difficulties. Furthermore, extreme sexual and emotional satisfaction appeared to be associated with the presence or absence of sexual difficulties and not overly influenced by BMI. Overall, clinicians and patients should be aware that being overweight is not necessarily detrimental to sexual functioning.     

Size at birth and abdominal adiposity in adults: a systematic review and meta‐analysis

We performed a systematic literature review on the associations between birth size and abdominal adiposity in adults, while also investigating the role of the adjustment for adult body mass index (BMI). MEDLINE, Scopus, Web of Science, LILACS and SciELO databases were searched for articles published up to February 2013. Only prospective studies were included. After screening 2,570 titles, we selected 31 publications for the narrative synthesis, of which 13 were considered to be of high methodological quality. Six main indicators of birth size were identified, and birth weight (BW) was the most extensively studied. Most studies relied on anthropometric measurements as proxies for abdominal fatness or as indicators of body fat distribution. Few studies assessed abdominal adiposity through imaging methods, generally with small sample sizes. Eleven articles could be included in the meta‐analyses. BW was found to be positively associated with waist circumference in adulthood, but the association disappeared after adjustment for adult BMI. In contrast, there was no association between BW and waist‐to‐hip ratio, whereas a strong negative association became evident after controlling for adult BMI. In conclusion, BW seems to be associated with larger adult size in general, including both waist and hip circumferences. The marked change in coefficients after adjustment for adult BMI suggests that post‐natal growth strongly affects relative central adiposity, whereas BW per se does not play a role. Given the potential impact of post‐natal growth, further research is needed to identify different growth trajectories that lead to abdominal adiposity, as well as studies on interactions of foetal and post‐natal growth patterns.     

Association of triglyceride glucose index and its combination of obesity indices with prehypertension in lean individuals: A cross‐sectional study of Chinese adults

For normal‐weight population, the management of prehypertension may be more beneficial by identifying insulin resistance (IR) status than relying solely on traditional indicators of obesity. We investigated the association of triglyceride glucose (TyG) index, a simple surrogate marker of IR, and its combination of obesity indices with prehypertension in lean individuals. A total of 105 070 lean adults without hypertension were included in this analysis. Body mass index (BMI), waist circumference (WC), waist‐to‐height ratio (WtHR), and TyG were calculated according to the corresponding formula; TyG‐BMI, TyG‐WC, and TyG‐WHtR were calculated by multiplying the corresponding two parameters. Gardner‐Altman plots, partial correlation, and logistic regression analyses were applied to explore the associations in continuous variables and quartiles. The prehypertensive ones had higher mean values of TyG, TyG‐BMI, TyG‐WC, and TyG‐WHtR than normotensive individuals. All the four indicators showed positive correlations with systolic blood pressure and diastolic blood pressure. After full adjustment, only TyG‐BMI and TyG‐WC were significantly associated with prehypertension in both genders. Furthermore, TyG‐BMI had the highest OR for prehypertension. Our study showed that TyG‐BMI might be an accessible and complementary monitor in the hierarchical management of non‐obese prehypertensive patients.     

Associations between anthropometric indicators in early life and low-grade inflammation,insulin resistance and lipid profile in adolescence

Background and aimsThe long-term relations between excessive adiposity in early childhood and unfavourable cardiometabolic profiles in later ages are not yet completely understood. We aimed to assess the associations between birth weight (BW) and BMI from 6 months to 6 years of age, with biomarkers indicative of low-grade inflammation, insulin resistance and lipid profiles in adolescence.Methods and resultsRetrospective school-based study with 415 Portuguese adolescents (220 girls), mean age of 14.08 ± 1.6 years old. Anthropometric data from birth to 6 years old was extracted from individual child health book records. Actual weight and height were measured and BMI calculated. Participants were classified at each time point as normal weight or overweight according to WHO reference values. Biomarkers were obtained from venous blood samples. Linear regressions were used to explore the associations between the biomarkers and early life anthropometric indicators. From 2 years onwards, BMI associated positively with the inflammatory score and HOMA-IR in adolescence. Children who were overweight/obese from 2 to 6 years of age presented significantly higher inflammatory score and HOMA-IR later in adolescence. TC/HDL ratio was also positively associated with BMI from the age of 5 years onwards. The associations between BMI and cardiometabolic outcomes remained positive in adolescence, with overweight adolescents presenting a higher inflammatory score, HOMA-IR and TC/HDL than normal weight adolescents.ConclusionA high BMI from an early age was consistently associated with worse inflammatory and lipid profiles and insulin resistance in adolescence. No associations were found between BW and the same studied outcomes.     

Body composition and fat repartition in relation to structure and function of large arteries in middle-aged adults (the SU.VI.MAX study)

OBJECTIVE: To investigate associations of body composition assessed by bioimpedance analysis and anthropometric indicators of fat repartition with carotid structure and function. DESIGN: Cross-sectional epidemiological study. SUBJECTS: A total of 1014 middle-aged apparently healthy adults participating in the SU.VI.MAX study. MEASUREMENTS: Body composition (fat mass, fat-free mass) was assessed by bioimpedance analysis and anthropometric indicators of fat repartition (waist circumference (WC); waist-hip-ratio (WHR)) were simultaneously collected. Carotid ultrasound examination included measurements of intima-media thickness (IMT) at the common carotid arteries (CCA) and assessment of atherosclerotic plaques in extracranial carotid arteries. Carotid-femoral pulse-wave velocity (PWV) was used as a marker of aortic stiffness.RESULTS:In multivariate analyses adjusted for major known cardiovascular risk factors in addition to age, gender and height, fat-free mass, fat mass (FM), and WC were positively associated with CCA-IMT and lumen diameter. No significant association was found with occurrence of carotid plaques. PWV was only associated with WC. Associations of CCA-IMT and PWV with WC were not significant anymore after further adjustment on body mass index (BMI) or FM. CONCLUSION: WC was the only measurement positively associated with both early atherosclerosis markers such as CCA-IMT and arterial stiffness. Although this association depends on overall adiposity, as assessed by the BMI, it emphasizes the importance of WC in clinical practice and prevention programs as a screening tool for individuals at risk for cardiovascular disease.     

Associations Between Body Mass Index,Ambulatory Blood Pressure Findings,and Changes in Cardiac Structure: Relevance of Pulse and Nighttime Pressures

Ambulatory blood pressure monitoring (ABPM) is central in the management of hypertension. Factors related to BP, such as body mass index (BMI), may differently affect particular aspects of 24‐hour ABPM profiles. However, the relevance of BMI, the most used index of adiposity, has been underappreciated in the determination of specific aspects of 24‐hour ABPM profiles in hypertension. The authors evaluated the association between BMI and aspects of ABPM together with their associations with cardiac remodeling in 1841 patients. A positive association of BMI with 24‐hour, daytime, and nighttime pulse pressure in untreated normal weight and overweight/obese hypertensive patients and a positive association of BMI with nocturnal BP parameters in treated overweight/obese hypertensive patients was observed. The clinical relevance of these findings was supported by the positive significant correlations of BMI‐related BPs with left ventricular mass and atrial diameter.     

Pulmonary function and abdominal adiposity in the general population

BACKGROUND: The prevalence of obesity is increasing, and there is evidence that obesity, in particular abdominal obesity as a marker of insulin resistance, is negatively associated with pulmonary function. The mechanism for this association and the best marker of abdominal adiposity in relation to pulmonary function is not known. STUDY OBJECTIVE: We assessed the association between pulmonary function and weight, body mass index (BMI), waist circumference, waist/hip ratio, and abdominal height as markers of adiposity and body fat distribution. We used multiple linear regression to analyze the association of pulmonary function (ie, FEV(1) and FVC) [with maneuvers performed in the sitting position] with overall adiposity markers (ie, weight and BMI) and abdominal adiposity markers, stratified by gender, and adjusted for height, age, race, smoking, and other covariates.Setting and participants: A random sample of individuals (n = 2,153) from the general population living in western New York state, 35 to 79 years of age. RESULTS: In women, abdominal height and waist circumference were negatively associated with FEV(1) percent predicted, while all five adiposity markers were negatively associated with FVC percent predicted. In men, all overall and abdominal adiposity markers were inversely associated with FEV(1) percent predicted and FVC percent predicted. CONCLUSION: These results suggest that abdominal adiposity is a better predictor of pulmonary function than weight or BMI, and investigators should consider it when investigating the determinants of pulmonary function.     

Does the relationship between waist circumference,morbidity and mortality depend on measurement protocol for waist circumference?

There is currently no consensus regarding the optimal protocol for measurement of waist circumference (WC), and no scientific rationale is provided for any of the WC protocols recommended by leading health authorities. A panel of experts conducted a systematic review of 120 studies (236 samples) to determine whether measurement protocol influenced the relationship of WC with morbidity of cardiovascular disease (CVD) and diabetes and with mortality from all causes and from CVD. Statistically significant associations with WC were reported for 65% (152) of the samples across all outcomes combined. Common WC protocols performed measurement at the minimal waist (33%), midpoint (26%) and umbilicus (27%). Non-significant associations were reported for 27% (64) of the samples. Most of these protocols measured WC at the midpoint (36%), umbilicus (28%) or minimal waist (25%). Significant associations were observed for 17 of the remaining 20 samples, but these were not significant when adjustment was made for covariates. For these samples, the most common WC protocols were the midpoint (35%) and umbilicus (30%). Similar patterns of association between the outcomes and all WC protocols were observed across sample size, sex, age, race and ethnicity. Our findings suggest that WC measurement protocol has no substantial influence on the association between WC, all-cause and CVD mortality, CVD and diabetes.