Body Mass Index, Quality of Life and Activity Limitation Trajectories over 2 Years in Patients with Knee or Hip Osteoarthritis: A Dual Trajectory Approach Based on 4265 Patients Included in the AktivA Quality Register

(1) Background: Recent studies claim that weight-neutral approaches emphasizing physical activity might be as effective as weight-loss-centered approaches for improving pain and physical function in patients with knee and hip osteoarthritis. The objectives were to identify distinctive groups of individuals with similar BMI, quality of life and activity limitation trajectories over two years, to compare the overall differences between BMI trajectory groups for baseline variables and to explore the probabilities of the quality of life and activity limitation trajectory groups conditional on the BMI group. (2) Methods: Baseline data for age, gender, BMI, quality of life, activity limitations, pain, general health, knee or hip osteoarthritis and follow-up data on BMI, quality of life and activity limitations at 3, 12 and 24 months were retrieved from the "Active with osteoarthritis" (AktivA) electronic quality register. Group-based trajectory modeling was used to identify distinct trajectories for BMI, quality of life and activity limitations. (3) Results: 4265 patients were included in the study. Four distinct BMI trajectories were identified, normal weight (31%), slightly overweight (43%), overweight (20%) and obese (6%). At baseline, there were highly significant differences between all BMI groups, pain increased and age and general health decreased with higher BMI. Irrespective of weight category, minimal changes in BMI were found over the two-year follow-up period. Over 80% of the participants showed moderate-to-considerable improvements both in quality of life and activity limitations. (4) Conclusions: Almost 70% of the participants belonged to the overweight trajectories. Despite no significant weight reduction over the two years, eight in every 10 participants improved their quality of life and reduced their activity limitations after participating in the AktivA program.

Self-reported and measured anthropometric variables in association with cardiometabolic markers: A Danish cohort study

General obesity is a recognized risk factor for various metabolically related diseases, including hypertension, dyslipidemia, and pre-diabetes. In epidemiological studies, anthropometric variables such as height and weight are often self-reported. However, misreporting of self-reported data may bias estimates of associations between anthropometry and health outcomes. Further, few validation studies have compared self-reported and measured waist circumference (WC). This study aimed to quantify the agreement between self-reported and measured height, weight, body mass index (BMI), WC, and waist-to-height ratio (WHtR), and to investigate associations of these anthropometric measures with cardiometabolic biomarkers. A total of 39,514 participants aged above 18 years were included into the Diet, Cancer, and Health-Next Generation Cohort in 2015-19. Self-reported and measured anthropometric variables, blood pressure, and cardiometabolic biomarkers (HbA1c, lipid profiles, C-reactive protein and creatinine) were collected by standard procedures. Pearson correlations (r) and Lin's concordance correlations were applied to evaluate misreporting. Misreporting by age, sex and smoking status was investigated in linear regression models. Multivariable regression models and Receiver Operating Characteristic analyses assessed associations of self-reported and measured anthropometry with cardiometabolic biomarkers. Self-reported height was overreported by 1.07 cm, and weight was underreported by 0.32 kg on average. Self-reported BMI and WC were 0.42 kg/m2 and 0.2 cm lower than measured, respectively. Self-reported and measured height, weight, BMI, WC and WtHR were strongly correlated (r = 0.98, 0.99, 0.98, 0.88, 0.86, respectively). Age, sex, smoking, and BMI contributed to misreporting of all anthropometric measures. Associations between self-reported or measured anthropometric measures and cardiometabolic biomarkers were similar in direction and strength. Concordance between self-reported and measured anthropometric measures, including WC, was very high. Self-reported anthropometric measures were reliable when estimating associations with cardiometabolic biomarkers.

Comparison of Mortality Outcomes in Acute Myocardial Infarction Patients With or Without Standard Modifiable Cardiovascular Risk Factors

Background

Acute myocardial infarction (AMI) cases have decreased in part due to the advent of targeted therapies for standard modifiable cardiovascular disease risk factors (SMuRF). Recent studies have reported that ST-elevation myocardial infarction (STEMI) patients without SMuRF (termed “SMuRF-less”) may be increasing in prevalence and have worse outcomes than “SMuRF-positive” patients. As these studies have been limited to STEMI and comprised mainly Caucasian cohorts, we investigated the changes in the prevalence and mortality of both SMuRF-less STEMI and non-STEMI (NSTEMI) patients in a multiethnic Asian population.

Methods

We evaluated 23,922 STEMI and 62,631 NSTEMI patients from a national multiethnic registry. Short-term cardiovascular and all-cause mortalities in SMuRF-less patients were compared to SMuRF-positive patients.

Results

The proportions of SMuRF-less STEMI but not of NSTEMI have increased over the years. In hospitals, all-cause and cardiovascular mortality and 1-year cardiovascular mortality were significantly higher in SMuRF-less STEMI after adjustment for age, creatinine, and hemoglobin. However, this difference did not remain after adjusting for anterior infarction, cardiopulmonary resuscitation (CPR), and Killip class. There were no differences in mortality in SMuRF-less NSTEMI. In contrast to Chinese and Malay patients, SMuRF-less patients of South Asian descent had a two-fold higher risk of in-hospital all-cause mortality even after adjusting for features of increased disease severity.

Conclusion

SMuRF-less patients had an increased risk of mortality with STEMI, suggesting that there may be unidentified nonstandard risk factors predisposing SMuRF-less patients to a worse prognosis. This group of patients may benefit from more intensive secondary prevention strategies to improve clinical outcomes.

A comparison of measured versus self-reported anthropometrics for assessing obesity in adults: a literature review

Aims: Up-to-date information on the accuracy between different anthropometric data collection methods is vital for the reliability of anthropometric data. A previous review on this matter was conducted a decade ago. Our aim was to conduct a literature review on the accuracy of self-reported height, weight, and body mass index (BMI) against measured values for assessing obesity in adults. To obtain an overview of the present situation, we included studies published after the previous review. Differences according to sex, BMI groups, and continents were also assessed. Methods: Studies published between January 2006 and April 2017 were identified from a literature search on PubMed. Results: Our search retrieved 62 publications on adult populations that showed a tendency for self-reported height to be overestimated and weight to be underestimated when compared with measured values. The findings were similar for both sexes. BMI derived from self-reported height and weight was underestimated; there was a clear tendency for underestimation of overweight (from 1.8%-points to 9.8%-points) and obesity (from 0.7%-points to 13.4%-points) prevalence by self-report. The bias was greater in overweight and obese participants than those of normal weight. Studies conducted in North America showed a greater bias, whereas the bias in Asian studies seemed to be lower than those from other continents. Conclusions: With globally rising obesity rates, accurate estimation of obesity is essential for effective public health policies to support obesity prevention. As self-report bias tends to be higher among overweight and obese individuals, measured anthropometrics provide a more reliable tool for assessing the prevalence of obesity.

Measured versus self-reported body height and body mass in patients after an acute coronary syndrome

The basic anthropometric data describing a person in the broadest context are body weight and height, two of the most frequently analyzed somatometric parameters. The same is true I in relation to clinical patients. The aim of the present study was to compare the self-reported and actual body weight, height and BMI in patients suffering from coronary artery disease and undergoing cardiac rehabilitation. The study sample consisted of 100 patients treated for coronary artery disease. The patients were asked to state their body weight and height. At the same time a three-person study team took measurements, which were later the basis for verification and objective assessment of the data provided by the patients. Statistical analysis was performed with Statistics 11.0 PL software. The analysis of mean results for the assessed group of patients has shown the presence of statistically significant differences between declared and actual data. The differences were observed for both male and female study population. It has been proven that the subjects declare greater body height (mean value 1.697 m vs. 1.666 m) and lower body weight (80.643 kg vs. 82.051 kg). Based on the data from surveys and direct measurements, the body mass index for the self-reported and actual data was calculated. A comparison of these values has shown considerable statistically significant differences. The differences between declared and actual data point to highly subjective self-assessment, which disqualifies the declared data in the context of monitoring of treatment and rehabilitation processes. The authors believe that actual data should be used in direct trial examination of patients suffering from coronary artery disease who presented with acute coronary syndrome.

Modifiable Healthy Lifestyle Behaviors: 10-Year Health Outcomes From a Health Promotion Program

INTRODUCTION

Previous studies have examined the impact of healthy lifestyle choices on health-related outcomes; however, given their fragmented, often cross-sectional nature, assessing the relative impact of daily modifiable behaviors on overall long-term outcomes, particularly for a diverse working adult population, remains challenging.

METHODS

Relationships between ten self-reported healthy lifestyle behaviors and health outcomes during the subsequent 9 years in a cohort of 10,248 participants enrolled during 2003 in a voluntary workplace wellness program were assessed. Cox proportional-hazards models computed hazard ratios (HRs) for lifestyle characteristics associated with time to one of seven self-reported chronic diseases or death. Data were collected between 2003 and 2012 and analyzed between 2014 and 2016.

RESULTS

Behaviors that most significantly affected future outcomes were low-fat diet, aerobic exercise, nonsmoking, and adequate sleep. A dose-response effect was seen between dietary fat intake and hypertension, obesity, diabetes, heart disease, and hypercholesterolemia. After dietary fat intake, aerobic exercise was the next most significant behavior associated with development of outcomes. Compared with sedentary participants, those who exercised 4 days per week were less likely to develop new-onset diabetes (HR=0.31, 95% CI=0.20, 0.48); heart disease (HR=0.46, 95% CI=0.27, 0.80); and hypercholesterolemia (HR=0.61, 95% CI=0.50, 0.74). Low-fat diet and adequate sleep were more significant than commonly promoted healthy behaviors, such as eating a daily breakfast.

CONCLUSIONS

Modifiable lifestyle behaviors targeted in health promotion programs should be prioritized in an evidence-based manner. Top priorities for workplace health promotion should include low-fat diet, aerobic exercise, nonsmoking, and adequate sleep.

Validity of self-reported versus actual age in Nepali children and young people

•

Self-reported age is a potential source of misclassification bias in International Surveys.

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We compare objectively recorded age with self-reported age at mean age 11.5 years in 3943 children in rural Nepal.

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There was high agreement between actual and self-reported age with an error rate of 7%.

The association between weight perception and BMI: report and measurement data from the growing up in Ireland Cohort Study of 9-year olds

BACKGROUND

The gold standard for categorisation of weight status is clinically measured body mass index (BMI), but this is often not practical in large epidemiological studies.

OBJECTIVES

To determine if a child's weight perception or a mother's perception of a child's weight status is a viable alternative to measured height and weight in determining BMI classification. Secondary outcomes are to determine the influence of a mother's BMI on her ability to categorise the child's BMI and a child's ability to recognise his/her own BMI.

METHODS

Cross-sectional analysis of the growing up in Ireland cohort study, a nationally representative cohort of 8568 9-year-old children. The variables considered for this analysis are the child's gender, BMI (International Obesity Taskforce grade derived from measured height and weight) and self-perceived weight status, and the mother's weight perception of the child, BMI (derived from measured height and weight) and self-perceived weight status. Cohen's weighted-kappa was used to evaluate the strength of the agreement between pairwise combinations of the BMI variables. Cumulative and adjacent categories logistic regression were used to predict how likely a person rates themselves as under, normal or overweight, based on explanatory variables.

RESULTS

Mothers are more accurate at correctly classifying their child's BMI (κ=0.5; confidence intervals (CI) 0.38-0.51) than the children themselves (κ=0.25; CI 0.23-0.26). Overweight mothers are better raters of their child's BMI (κ=0.51; CI 0.49-0.54), compared with normal (κ=0.44; CI 0.41-0.47) or underweight mothers (κ=0.4; CI 0.22-0.58), regardless of whether the mother's BMI is derived from measured height and weight or self-perceived. The mother's perception of the child's weight status is not an influencing factor on the child's ability to correctly classify him/herself, but the child's self-perceived weight status influences the mother's ability to correctly classify the child.

CONCLUSIONS

A mother's BMI classification of her child is a viable alternative to BMI measurement in large epidemiological studies.

Validity of self-reported body mass index among middle-aged participants in the Norwegian Women and Cancer study

Background

Body mass index (BMI) based on self-reported height and weight has been criticized as being biased because of an observed tendency for overweight and obese people to overestimate height and underestimate weight, resulting in higher misclassification for these groups. We examined the validity of BMI based on self-reported values in a sample of Norwegian women aged 44–64 years.

Methods

The study sample of 1,837 participants in the Norwegian Women and Cancer study self-reported height and weight, and then, within 1 year, either self-reported anthropometric again, or were measured by medical staff. Demographic and anthropometric were compared using t-tests and chi-square tests of independence. Misclassification of BMI categories was assessed by weighted Cohen’s kappa and Bland–Altman plot.

Results

On average, the two measurements were taken 8 months apart, and self-reported weight increased by 0.6 kg (P<0.05), and BMI by 0.2 kg/m² (P<0.05). The distribution of BMI categories did not differ between self-reported and measured values. There was substantial agreement between self-reported values and those measured by medical staff (weighted kappa 0.73). Under-reporting resulting in misclassification of BMI category was most common among overweight women (36%), but the highest proportion of extreme under-reporting was found in obese women (18% outside the 95% limits of agreement). The cumulative distribution curves for the measured and self-reported values closely followed each other, but measurements by medical staff were shifted slightly toward higher BMI values.

Conclusion

While there was substantial agreement between self-reported and measured BMI values, there was small but statistically significant under-reporting of weight and thus self-reported BMI. The tendency to under-report was largest among overweight women, while the largest degree of under-reporting was found in the obese group. Self-reported weight and height provide a valid ranking of BMI for middle-aged Norwegian women.

Potential role of age, sex, body mass index and pain to identify patients with knee osteoarthritis

AIM

To evaluate the potential role of age, sex, body mass index (BMI), radiographic features and pain in knee osteoarthritis (OA) case ascertainment.

METHODS

A cross-sectional study was performed using information from the EPIPorto cohort; social, demographic, behavioral and clinical data was obtained. Pain was assessed using a pain frequency score (regarding ever having knee pain, pain in the last year, in the last 6 months and in the last month). Knee radiographs were classified using the Kellgren-Lawrence scale (0-4). Path analysis was used to assess the plausibility of the causal assumptions and a classification tree to identify characteristics that could improve the identification of patients with radiographic OA.

RESULTS

Higher age and higher BMI were associated with higher radiographic score, but sex had no statistical association. Females, higher age, higher BMI and higher radiographic score were statistically associated with higher pain scores. For both genders, the classification tree estimated age as the first variable to identify individuals with knee radiographic features. In females older than 56 years, pain frequency score is the second discriminator characteristic, followed by age (> 65 years) and (BMI > 30 kg/m² ). Higher pain frequency and BMI > 29 kg/m² were relevant for identifying OA in men with ages between 43.5 and 55.5 years.

CONCLUSIONS

Age, BMI and pain frequency are independently associated with radiographic OA and the use of information on these characteristics can improve the identification of patients with knee OA. Beyond age, pain complaints are particularly relevant but the level of pain is different by sex.

The incidence of acute myocardial infarction in relation to overweight and obesity: a meta-analysis

INTRODUCTION

Epidemiological evidence suggests that overweight and obesity have been associated with acute myocardial infarction (AMI). However, data on this issue are controversial. This study aims to use meta-analysis to determine whether overweight and obesity are related to AMI.

MATERIAL AND METHODS

We searched PubMed and Embase databases up to October 23(rd), 2013 for related literature. The association of overweight and obesity with AMI was assessed by odd ratio (OR) with 95% confidence interval (CI) as the effect size. Then subgroup analysis was performed according to gender, area and study type.

RESULTS

Five primary studies (one cohort study and four case-control studies) were included in this meta-analysis involving 36 803 participants, 14 883 of whom had an AMI. There was a significant association between overweight and AMI (OR = 1.27, 95% CI: 1.21-1.33, p < 0.001). Similar results revealed a relation between obesity and AMI (OR = 1.22, 95% CI: 1.07-1.40, p = 0.003). Subgroup analysis showed that overweight and obesity were positively associated with AMI risk except for obese subjects in Europe. There was no publication bias (Begg's test p = 0.972, Egger's test p = 0.858).

CONCLUSIONS

Both overweight and obesity increased the incidence of AMI, and it is necessary to control weight to prevent AMI. A large number of studies is needed to explore the mechanisms that link overweight and obesity with AMI.

Disparity between reported and measured patient weight: can it affect planning in breast reduction surgery?

BACKGROUND

Patient weights are frequently used in surgery for essential calculations including preoperative surgical planning, dosing of medications, and qualification for insurance reimbursement. Often, there is a disparity between patient-reported and actual measured weights. This study examines differences between self-reported and measured weights and implications in breast reduction surgery.

METHODS

A review was performed of 197 consecutive women who presented for breast surgery at an academic institution. Self-reported weights were recorded during the initial encounter, and the patients were subsequently weighed on the same day. A paired t-test was used to compare the self-reported and actual measured weights and stratified analysis performed based on body mass index (BMI). The Schnur sliding scale was used to estimate resection weights for reduction mammaplasty.

RESULTS

The overall mean difference in reported and measured weight was 3.0 lbs standard deviation (SD) 8.9 (P < 0.0001) with a maximum overestimation of 25 lb and underestimation of 80 lb. Statistically significant differences were found when stratified analysis was performed based on BMI as mean differences in the overweight (BMI 25-30) and obese (BMI > 30) groups were 1.7 lb SD 5.5 (P < 0.026) and 4.9 lbs SD 11.8 (P < 0.0002), respectively. Significant differences in calculated breast reduction resection weights, based on the Schnur sliding scale, were also found when comparing self-reported and measured weights in all groups.

CONCLUSIONS

Significant disparities between self-reported and measured weights were identified in patients presenting for breast surgery. These differences can influence important calculations of resection weights for breast reduction surgery. These differences may also affect dosing of medications and preoperative planning.

The effect of depressive symptoms on the association between radiographic osteoarthritis and knee pain: a cross-sectional study

BACKGROUND

The progressive nature of knee osteoarthritis (OA) leads to not only to physical but also to psychosocial decline; this aspect can influence knee pain experience, manifestations and inevitably diagnostic accuracy.

METHODS

Data on 663 subjects was obtained by interview using a structured questionnaire on social, demographic, behavioural and clinical data. Painful knee was assessed regarding having pain: ever, in the last year, in the last 6 months and in the last month. Using factor analysis, participants were graded using a knee pain score, with higher scores representing more symptomatology. Depressive symptoms were evaluated with the Beck Depressive Inventory (BDI), and radiographic knee OA was classified using the Kellgren Lawrence (KL) scale; those with KL ≥ 2 were considered as having radiographic OA.

RESULTS

Knee pain was reported by 53.2% of those with radiographic KL ≥ 2 and by 33.2% of those with radiographic KL < 2. The prevalence of depressive symptoms (BDI > 14) was 19.9% among participants with radiographic KL ≥ 2 and 12.6% among those with radiographic KL < 2 (p = 0.01). The association of knee pain with radiographic knee OA was higher in higher pain scores and in participants without depressive symptoms. Among participants with BDI ≤ 14 the likelihood ratio to identify patients with radiographic knee OA increased with increased pain scores: 1.02 for score 1; 2.19 for score 2 and 7.34 when participants responded positively to all pain questions (score 3). Among participants with depressive symptoms (BDI > 14) likelihood ratios were 0.51, 1.92, 1.82, respectively. The results were similar for both genders.

CONCLUSIONS

Knee pain scores increased ability to identify participants with radiographic KL ≥ 2 in both sexes. However, the presence of depressive symptoms impairs the ability of knee pain complaints to identify patients with radiographic OA.

Health risk factor modification predicts incidence of diabetes in an employee population: results of an 8-year longitudinal cohort study

OBJECTIVE

To understand risk factor modification effect on Type 2 diabetes incidence in a workforce population.

METHODS

Annual health risk assessment data (N = 3125) in years 1 through 4 were used to predict diabetes development in years 5 through 8.

RESULTS

Employees who reduced their body mass index from 30 or more to less than 30 decreased their chances of developing diabetes (odds ratio = 0.22, 95% confidence interval: 0.05 to 0.93), while those who became obese increased their diabetes risk (odds ratio = 8.85, 95% confidence interval: 2.53 to 31.0).

CONCLUSIONS

Weight reduction observed over a long period can result in clinically important reductions in diabetes incidence. Workplace health promotion programs may prevent diabetes among workers by encouraging weight loss and adoption of healthy lifestyle habits.

Height and weight bias: the influence of time

BACKGROUND

We have previously identified in a study of both self-reported body mass index (BMI) and clinically measured BMI that the sensitivity score in the obese category has declined over a 10-year period. It is known that self-reported weight is significantly lower that measured weight and that self-reported height is significantly higher than measured height. The purpose of this study is to establish if self-reported height bias or weight bias, or both, is responsible for the declining sensitivity in the obese category between self-reported and clinically measured BMI.

METHODS

We report on self-reported and clinically measured height and weight from three waves of the Surveys of Lifestyle Attitudes and Nutrition (SLÁN) involving a nationally representative sample of Irish adults. Data were available from 66 men and 142 women in 1998, 147 men and 184 women in 2002 and 909 men and 1128 women in 2007. Respondents were classified into BMI categories normal (<25 kg/m(2)), overweight (25-<30 kg/m(2)) and obese (≥30 kg/m(2)).

RESULTS

Self-reported height bias has remained stable over time regardless of gender, age or clinical BMI category. Self-reported weight bias increases over time for both genders and in all age groups. The increased weight bias is most notable in the obese category.

CONCLUSIONS

BMI underestimation is increasing across time. Knowledge that the widening gap between self-reported BMI and measured BMI is attributable to an increased weight bias brings us one step closer to accurately estimating true obesity levels in the population using self-reported data.

Ten-year trends in overweight and obesity in the adult Portuguese population, 1995 to 2005

BACKGROUND

There is little information regarding the trends in body mass index (BMI) and obesity in the overall Portuguese population, namely if these trends are similar according to educational level. In this study, we assessed the trends in the prevalence of overweight and obesity in the Portuguese population, overall and by educational level.

METHODS

Cross-sectional national health interview surveys conducted in 1995-6 (n = 38,504), 1998-9 (n = 38,688) and 2005-6 (n = 25,348). Data were derived from the population and housing census of 1991 and two geographically-based strata were defined. The sampling unit was the house, and all subjects living in the sampling unit were surveyed. Height and weight were self-reported; the effects of gender, age group and educational level were also assessed by self-reported structured questionnaires. Bivariate comparisons were performed using Chi-square or analysis of variance (ANOVA). Trends in BMI levels were assessed by linear regression analysis, while trends in the prevalence of obesity were assessed by logistic regression.

RESULTS

Mean (±standard deviation) BMI increased from 25.2 ± 4.0 in 1995-6 to 25.7 ± 4.5 kg/m² in 2005-6. Prevalence of overweight remained stable (36.1% in 1995-6 and 36.4% in 2005) while prevalence of obesity increased (11.5% in 1995-6 and 15.1% in 2005-6). Similar findings were observed according to age group. Mean age-adjusted BMI increase (expressed in kg/m²/year and 95% confidence interval) was 0.073 (0.062, 0.084), 0.016 (0.000, 0.031) and 0.073 (0.049, 0.098) in men with primary, secondary and university levels, respectively; the corresponding values in women were 0.085 (0.073, 0.097), 0.052 (0.035, 0.069) and 0.062 (0.038, 0.084). Relative to 1995-6, obesity rates increased by 48%, 41% and 59% in men and by 40%, 75% and 177% in women with primary, secondary and university levels, respectively. The corresponding values for overweight were 6%, 1% and 23% in men and 5%, 7% and 65% in women.

CONCLUSION

Between 1995 and 2005, obesity increased while overweight remained stable in the adult Portuguese population. Although higher rates were found among lesser educated subjects, the strong increase in BMI and obesity levels in highly educated subjects is of concern.

Need for weight management in Switzerland: findings from National Blood Pressure Week 2009

Background

The Swiss Health Survey (SHS) provides the only source of data for monitoring overweight and obesity in the general population in Switzerland. However, this survey reports body mass index (BMI) based on self-reported height and weight, and is therefore subject to measurement errors. Moreover, it is not possible to differentiate between overall and abdominal overweight. In this study, we aimed to gain a better understanding of the need for weight management in the general population of Switzerland by exploring and comparing prevalence rates of BMI and waist circumference (WC) based on physical measurements by trained observers, based on data from the 2009 National Blood Pressure Week (NBPW).

Methods

Sample selection was based on a one-stage cluster design. A total of 385 pharmacies representing 3,600 subjects were randomly selected from pharmacies participating in NBPW. BMI measures based on physical weight and height (NBPW) were compared with self-reported BMI measures from the SHS. BMI and WC measurements from NBPW were then used to produce population estimates of overweight and obesity.

Results

BMI-based overall prevalence of overweight and obesity was 43.6%, which was 4.7% higher than the value based on the respective SHS data. Overweight and obesity were more common in men (54.3%) than in women (33.5%). However, the overall prevalence of increased WC in the general population was estimated to be 64.4%, with more women (68.4%) than men (60.1%) exhibiting a WC above the threshold. The prevalence of subjects requiring weight management in the Swiss population remained high, even after adjusting WC for false positive and negative cases.

Conclusions

Firstly, it may be more appropriate for health promotion programs to address the wider group identified by WC, which includes subjects who need to reduce their weight, or gain no further weight. Secondly, the gender differences are reversed depending on the use of WC or BMI to identify subjects suitable for health promotion programs; more women than men are identified by WC, and more men than women using BMI. These differences should be accounted for in gender-specific health promotion programs.

Temporal trends in misclassification patterns of measured and self-report based body mass index categories--findings from three population surveys in Ireland

BACKGROUND

As the use of self-reported data to classify obesity continues, the temporal change in the accuracy of self-report measurement when compared to clinical measurement remains unclear. The objective of this study was to examine temporal trends in misclassification patterns, as well as sensitivity and specificity, of clinically measured versus self-report based body mass index (BMI) from three national lifestyle surveys over a 10-year period.

METHODS

The Surveys of Lifestyle Attitudes and Nutrition (SLÁN) were interview based cross-sectional survey/measurements involving nationally representative samples in 1998, 2002 and 2007. Data from a subsample of both self-reported and measured height and weight were available from 66 men and 142 women in 1998, 147 men and 184 women in 2002 and 909 men and 1128 women in 2007. Respondents were classified into the BMI categories normal (< 25 kg m⁻²), overweight (25- < 30 kg m⁻²) and obese (≥ 30 kg m⁻²).

RESULTS

Underreporting of BMI increased across the three surveys (14%→21%→24%; p = 0.002). Sensitivity scores for the normal category exceeded 94% in all three surveys but decreased for the overweight (75%→68%→66%) and obese categories (80%→64%→53%). Simultaneously, specificity levels remained high.

CONCLUSIONS

BMI values based on self-reported determinations of height and weight in population samples are underestimating the true prevalence of the obesity epidemic and this underestimation is increasing with time. The decreased sensitivity and consistently high specificity scores in the obese category across time, highlights the limitation of self-report based BMI classifications and the need for simple, readily comprehensible indicators of obesity.

Is participation in food and income assistance programmes associated with obesity in California adults? Results from a state-wide survey

OBJECTIVE

Public assistance programmes may increase risk of obesity among adults. The current study assessed whether participation in the Supplemental Nutrition Assistance Program (SNAP; formerly the Food Stamp Program), Supplemental Security Income (SSI) or California Work Opportunities and Responsibilities to Kids (CalWorks) was associated with obesity, independent of socio-economic status and food insecurity.

DESIGN

A cross-sectional analysis of the 2007 Adult California Health Interview Survey. Outcome measures included BMI and obesity. Distribution of BMI and prevalence of obesity were compared by participation in each programme, using weighted linear and binomial regression models in which BMI or obesity was the outcome, respectively, and programme participation was the predictor.

SETTING

A population survey of various health measures.

SUBJECTS

Non-institutionalized adults (n 7741) whose household income was ≤130% of the federal poverty level.

RESULTS

The prevalence of obesity was 27.4%. After adjusting for sociodemographic characteristics, food insecurity and participation in other programmes, the prevalence of obesity was 30% higher in SNAP participants (95% CI 6%, 59%; P=0.01) than in non-participants. This association was more pronounced among men than women. SSI participation was related to an adjusted 50% higher prevalence of obesity (95% CI 27%, 77%; P<0.0001) compared with no participation. SNAP and SSI participants also reported higher soda consumption than non-participants of any programme. CalWorks participation was not associated with obesity after multivariable adjustment.

CONCLUSIONS

Participation in SNAP or SSI was associated with obesity independent of food insecurity or socio-economic status. The suggestion that these associations may be mediated by dietary quality warrants further investigation among low-income populations.