Underweight People Research Articles

The influence of the body mass index (BMI) on the volume of distribution of ethanol

The volume of distribution of ethanol was already established in 1930s by Widmark. However, since then the average body composition has changed considerably. The effect of the body mass index (BMI) on the volume of distribution of ethanol was evaluated in this study. Fifty healthy volunteers (23 men and 27 women), with BMI-values between 16.0 and 36.0kg/m2, were asked to drink a dose of 0.4g ethanol per kilogram body weight after an overnight fast. The ethanol content was measured by a fully validated headspace-GC-FID method. The volume of distribution of ethanol varied between 0.40 and 0.68L/kg for women, and between 0.43 and 0.73L/kg for men. For both sexes, the volume of distribution decreased with increasing BMI. Regression analysis resulted in the following equations: volume of distribution=0.8202−0.0090×BMI for men (r=0.66), and 0.7772−0.0099×BMI for women (r=0.78). Population probability prediction interval limits were also calculated. In view of the current study, fixed values for the volume of distribution of 0.7L/kg and 0.6L/kg for men and women, respectively, often applied in legal blood alcohol calculations, are mainly suited to judge underweight or normal weight people, but not obese persons.

Mortality risk associated with underweight: a census-linked cohort of 31,578 individuals with up to 32 years of follow-up.

BackgroundIn contrast to obesity, information on the health risks of underweight is sparse. We examined the long-term association between underweight and mortality by considering factors possibly influencing this relationship.MethodsWe included 31,578 individuals aged 25–74 years, who participated in population based health studies between 1977 and 1993 and were followed-up for survival until 2008 by record linkage with the Swiss National Cohort (SNC). Body Mass Index (BMI) was calculated from measured (53% of study population) or self-reported height and weight. Underweight was defined as BMI < 18.5 kg/m2. Cox regression models were used to determine mortality Hazard Ratios (HR) of underweight vs. normal weight (BMI 18.5- < 25.0 kg/m2). Covariates were study, sex, smoking, healthy eating proxy, sports frequency, and educational level.ResultsUnderweight individuals represented 3.0% of the total study population (n = 945), and were mostly women (89.9%). Compared to normal weight, underweight was associated with increased all-cause mortality (HR: 1.37; 95% CI: 1.14-1.65). Increased risk was apparent in both sexes, regardless of smoking status, and mainly driven by excess death from external causes (HR: 3.18; 1.96-5.17), but not cancer, cardiovascular or respiratory diseases. The HR were 1.16 (0.88-1.53) in studies with measured BMI and 1.59 (1.24-2.05) with self-reported BMI.ConclusionsThe increased risk of dying of underweight people was mainly due to an increased mortality risk from external causes. Using self-reported BMI may lead to an overestimation of mortality risk associated with underweight.

Mortality Risk of Obesity and Underweight Is Overestimated with Self-Reported Body Mass Index

Obese persons (those with a body mass index [BMI] ≥30 kg/m2) tend to underestimate their weight, leading to an underestimation of their true (measured) BMI and obesity prevalence.1,2 In contrast, underweight people (BMI <18.5 kg/m2) tend to report themselves heavier, resulting in a higher BMI compared with measured BMI and an underestimation of underweight prevalence.1 Less is known about biases in the estimate of mortality risk associated with these body weight categories using self-reported data. It has been shown that the mortality risk of obesity based on self-report can be overestimated, ie, biased away from the null.3,4 Underweight is associated with an increased mortality risk5 and, because underweight persons tend to overestimate BMI, one might intuitively expect that the mortality risk of underweight based on self-reported BMI would be underestimated, ie, biased toward the null (the opposite of the effect in obese persons). Is that a misleading intuition? Consider a cohort of 1000 men, of whom 10% were underweight at baseline, 70% had normal weight or were overweight, and 20% were obese, based on measured BMI. After 5 years, 36 men died (Table). The relative risk (RR) of death was higher in underweight (RR = 2.0) and obese men (RR = 1.5) compared with that in normal weight and overweight men combined. We assumed that the mortality risk was higher in the lowest (<17.5 kg/m2) category among underweight persons and in the highest BMI category (≥31 kg/m2) among obese persons.TABLE: Hypothetical Cohort with 1000 Men Providing Measured and Self-Reported Weight and Height to Compute Body Mass Index (BMI)Participants also reported their weight and height at baseline to compute self-reported BMI. We assume that underweight men (measured BMI <18.5 kg/m2) overestimated their BMI by 1 unit, on average. Consequently, men with measured BMI 17.5–18.4 kg/m2 were classified as “normal weight” based on self-reported BMI, while in truth they were underweight (eAppendix, eFigure, https://links.lww.com/EDE/A735). Thus, using self-reported data, the prevalence of underweight was underestimated. Men with self-reported BMI <18.5 kg/m2 had a measured BMI <17.5 kg/m2. Therefore, these men had a higher mortality compared with men with true BMI <18.5 kg/m2 (8% vs. 6%). We assume that obese men underestimated their BMI by 1 unit, on average. Therefore, men with true BMI 30.0–31.0 kg/m2 were classified as normal weight/overweight based on self-reported BMI although they were in truth obese. Using self-reported data, the prevalence of obesity was underestimated. Men with self-reported BMI ≥30.0 kg/m2 had a measured BMI ≥31.0 kg/m2. Accordingly, they had a higher mortality compared with men with true BMI ≥30.0 kg/m2 (6% vs. 4.5%). Using self-reported BMI to define body weight categories, the risk of underweight relative to normal/overweight was (4/50)/[(2 + 21 + 3)/(50 + 700 + 100)] = 2.6, which was higher than the RR (2.0) obtained with measured BMI. The RR of obesity was (6/100)/[(2 + 21 + 3)/(50 + 700 + 100)] = 2.0, which was also higher than the RR (1.5) obtained with measured BMI. Although self-reports lead to an overestimation of BMI by underweight persons and an underestimation by obese persons,1 the mortality (or disease) risk in both obese and underweight persons is likely overestimated when self-reported data are used to categorize people. Our assumptions are simplistic. The errors in weight estimations depend on sex, age, and other characteristics,2,6 and the direction of the bias will depend on how people in the various categories estimate their weight. The possible effects of exposure misclassification on the estimation of RR are complex and barely generalizable.7 Still, as shown, the effects of such misclassification can be counterintuitive. Direction and magnitude of bias should be evaluated carefully for each situation.7 The overestimation of obesity risk based on self-reports has been demonstrated3,4 and recently corroborated in a meta-analysis.8 Research is needed to confirm the bias entailed by defining underweight with self-reported data. David Faeh Lucienne Roh Institute of Social and Preventive Medicine (ISPM), University of Zurich, Zurich, Switzerland, [email protected] Fred Paccaud Arnaud Chiolero Institute of Social and Preventive Medicine (IUMSP), University Hospital Center of Lausanne, Lausanne, Switzerland

Overweight People Have Low Levels of Implicit Weight Bias, but Overweight Nations Have High Levels of Implicit Weight Bias

Although a greater degree of personal obesity is associated with weaker negativity toward overweight people on both explicit (i.e., self-report) and implicit (i.e., indirect behavioral) measures, overweight people still prefer thin people on average. We investigated whether the national and cultural context – particularly the national prevalence of obesity – predicts attitudes toward overweight people independent of personal identity and weight status. Data were collected from a total sample of 338,121 citizens from 71 nations in 22 different languages on the Project Implicit website (https://implicit.harvard.edu/) between May 2006 and October 2010. We investigated the relationship of the explicit and implicit weight bias with the obesity both at the individual (i.e., across individuals) and national (i.e., across nations) level. Explicit weight bias was assessed with self-reported preference between overweight and thin people; implicit weight bias was measured with the Implicit Association Test (IAT). The national estimates of explicit and implicit weight bias were obtained by averaging the individual scores for each nation. Obesity at the individual level was defined as Body Mass Index (BMI) scores, whereas obesity at the national level was defined as three national weight indicators (national BMI, national percentage of overweight and underweight people) obtained from publicly available databases. Across individuals, greater degree of obesity was associated with weaker implicit negativity toward overweight people compared to thin people. Across nations, in contrast, a greater degree of national obesity was associated with stronger implicit negativity toward overweight people compared to thin people. This result indicates a different relationship between obesity and implicit weight bias at the individual and national levels.

Statistical Analysis of the Korean National Health and Nutrition Examination Survey Using Poisson Regression - Focusing on Obesity, Cancer, and Adult Disease

Obesity indicates not only excessive body weight, but excessive accumulation of fat in the body, which is known to be the main reason of a variety of adult diseases such as cancer, high blood pressure, and diabetes. In this study, we have empirically examined data gathered by the Korean National Health and Nutrition Examination Survey. As a result, statistically significant increase in high blood pressure, diabetes, and cancer has been shown for past five years. Next, it is shown that obesity has a statistically meaningful relationship with high blood pressure, diabetes, and cancer. That is, compared with underweight people, the proportion of normal or overweight people suffering from adult illnesses is much higher, which is statistically meaningful, empirically verifying the fact that adult diseases have much to do with obesity.

VARIATION IN HEIGHT AND BMI OF ADULT INDIANS

It is well known that height and weight are interrelated, and that both are related to socioeconomic variables. The objective of this study was to assess the effect of socioeconomic variables on the heights and weights of different groups of people, formed according to different levels of heights and weights, and to see whether there are sex differences in the variations in heights and weights. Data for adults aged 15-49 years were taken from the India National Family Health Survey-3 and descriptive studies and multiple linear regression analyses carried out. A clear positive association was found for height and BMI with economic level (except for overweight females in the case of BMI). In the case of BMI, it is age that seems to be the most influential factor. Surprisingly, the observed changes in height and BMI are not as expected for short and tall or underweight and overweight people; these sometimes behave in the opposite directions to that of normal height and weight people. The basic assumption of multivariate normality is not valid due to changing relations at different height and BMI levels.

RRH: envenoming syndrome due to 200 stings from Africanized honeybees

Envenoming syndrome from Africanized bee stings is a toxic syndrome caused by the inoculation of large amounts of venom from multiple bee stings, generally more than five hundred. The incidence of severe toxicity from Africanized bee stings is rare but deadly. This report reveals that because of the small volume of distribution, having fewer stings does not exempt a patient from experiencing an unfavorable outcome, particularly in children, elderly people or underweight people.

PS41 Characteristics Associated with Statin Prescribing for Primary Prevention of Cardiovascular Disease Among People with Diabetes

BackgroundDiabetes is a risk factor for cardiovascular disease (CVD) and guidelines recommend that people with diabetes ought to have their blood lipid levels monitored and, if necessary, controlled to ensure...

Results of Epidemiological Studies of Blood Pressure Are Biased by Continuous Variation in Arm Size Related to Body Mass

In cross-sectional epidemiological studies, blood pressure (BP) is often found to be positively correlated with fatness. Usually sphygmomanometers with only one cuff size for adults are used to measure BP while arm circumference (AC) influences BP readings. We have studied cross-sectional anthropometric and BP data of adult men and women from three populations: Cook Islanders (n = 259), Papua New Guinean: Purari (n = 295), and Ok Tedi (n = 274). These were selected because of their diverse socio-economic, anthropometric, and BP characteristics. Partial correlations and regressions were used to analyze these data. Systolic and diastolic pressures (SBP, DBP) showed dependence on AC, body mass index (BMI), and skinfold thickness. Stature had some effect on SBP and DBP, independent of BMI and AC. When effects of AC and stature were statistically controlled, BMI did not correlate with either SBP or DBP. People of larger body mass have greater AC, and this biases BP readings. Average values of SBP and DBP in groups of underweight, normal, overweight, and obese people predicted by AC (sex, age, and BMI being statistically controlled) closely matched observed SBP and DBP averages in those groups. Out of 24 pairwise comparisons (3 samples from different populations × 4 groups of BMI × 2 pressure readings) of predicted and actual BP, only two produced statistically significant differences while 21 of the differences were 5 mm Hg or less. Correlations between BP and obesity found in epidemiological studies may be severely biased by effects of variation in AC. Sphygmomanometric measurements of BP should be corrected for continuous variation in AC.

Results of Epidemiological Studies of Blood Pressure Are Biased by Continuous Variation in Arm Size Related to Body Mass

In cross-sectional epidemiological studies, blood pressure (BP) is often found to be positively correlated with fatness. Usually sphygmomanometers with only one cuff size for adults are used to measure BP while arm circumference (AC) influences BP readings. We have studied cross-sectional anthropometric and BP data of adult men and women from three populations: Cook Islanders (n = 259), Papua New Guinean: Purari (n = 295), and Ok Tedi (n = 274). These were selected because of their diverse socio-economic, anthropometric, and BP characteristics. Partial correlations and regressions were used to analyze these data. Systolic and diastolic pressures (SBP, DBP) showed dependence on AC, body mass index (BMI), and skinfold thickness. Stature had some effect on SBP and DBP, independent of BMI and AC. When effects of AC and stature were statistically controlled, BMI did not correlate with either SBP or DBP. People of larger body mass have greater AC, and this biases BP readings. Average values of SBP and DBP in groups of underweight, normal, overweight, and obese people predicted by AC (sex, age, and BMI being statistically controlled) closely matched observed SBP and DBP averages in those groups. Out of 24 pairwise comparisons (3 samples from different populations × 4 groups of BMI × 2 pressure readings) of predicted and actual BP, only two produced statistically significant differences while 21 of the differences were 5 mm Hg or less. Correlations between BP and obesity found in epidemiological studies may be severely biased by effects of variation in AC. Sphygmomanometric measurements of BP should be corrected for continuous variation in AC.

Body &amp; brain: Brain plays role in extreme eating: Same regions involved for obese and underweight people

Body &amp; brain: Brain plays role in extreme eating: Same regions involved for obese and underweight people

SP6-16 The association of BMI with self-rated health and functional capacity among community-living Japanese people age over 75 years

ObjectiveIncreasing age is strongly associated with poor nutritional status, hence approaching the risk of poor nutrition in the elderly people is important. This study aimed to identify the associated factors...

Distribution of body mass index in the forensic victim population: Comparison with the general population and relation to manner of death

Despite a dramatic increase in the worldwide prevalence of overweight and obese people in recent years, the implication of this epidemic on forensic practice has barely been studied. Over a one-year period, all autopsy cases performed on adult victims in the province of Quebec (Canada) were retrospectively reviewed (582 cases). In the forensic population, manner of death differed in relation to BMI: underweight people most commonly died of natural causes, whereas normal weight, overweight and obese individuals most commonly died as the result of an accident. Results also revealed an over-representation of underweight victims and under-representation of overweight victims in the forensic population compared to the population of both Quebec and Canada. The latter is particularly worrisome considering it suggests that overweight corpses are less frequently referred for an autopsy. It is important to emphasize to forensic teams that just because an obese person is more likely to suffer from health problems that can lead to death, does not mean a natural death has occurred. Obese people are equally susceptible to unnatural causes of death and it is crucial to maintain an adequate level of suspicion while investigating the cases of these individuals.

Associations between body mass index and health-related quality of life among Australian adults

To assess the relationship between body mass index (BMI) and health-related quality of life (HQoL), as measured by the Short Form Health Survey (SF-36) within a sample with broad population coverage. Survey data incorporating the SF-36 questionnaire, height and weight were obtained from a nationally representative sample of 9,771 Australians aged 21 or older (4,649 men and 5,122 women). Linear multiple regression methods were employed to estimate the magnitude of association between BMI classes and HQoL variables, adjusting for disability and other covariates. Less than 1% of men and just 3.5% of women were classified as underweight while 52.2% of women and 65.9% of men were classified as overweight or obese. For all SF-36 health dimensions, people with BMI scores in the healthy range reported, on average, higher health-related HQoL scores than underweight and obese people, and HQoL scores decreased with the degree of obesity. Although overweight and obesity were associated with decreasing levels of both physical and emotional well-being, the deterioration in health status was significantly more evident in the physical than in the mental, social or emotional dimensions. Low and high BMIs were associated with decreasing levels of both physical and emotional well-being, but the deterioration in health status was more consistent in the physical than in other dimensions.

Frailty, Body Mass Index, and Abdominal Obesity in Older People

Frailty has been conceptualized as a wasting disorder with weight loss as a key component. However, obesity is associated with disability and with physiological markers also recently linked with frailty, for example, increased inflammation and low antioxidant capacity. We aimed to explore the relationship between frailty and body mass index (BMI) in older people. Data were from 3,055 community-dwelling adults aged 65 years and older who participated in the English Longitudinal Study of Ageing. Frailty was defined both by an index of accumulated deficits and by the Fried phenotype. BMI was divided into five categories, and waist circumference 88 cm or more (for women) and 102 cm or more (for men) was defined as high. Analyses were adjusted for sex, age, wealth, level of education, and smoking status. The association between BMI and frailty showed a U-shaped curve. This relationship was consistent across different frailty measures. The lowest frailty index (FI) scores and lowest prevalence of Fried frailty were in those with BMI 25-29.9. At each BMI category, and using either measure of frailty, those with a high waist circumference were significantly more frail. Both the phenotypic definition of frailty and the FI show increased levels of frailty among those with low and very high BMIs. In view of the rise in obesity in older populations, the benefits and feasibility of diet and exercise for obese older adults should be a focus of urgent inquiries. The association of frailty with a high waist circumference, even among underweight older people, suggests that truncal obesity may be an additional target for intervention.

Body Mass Index, Disability, and 13-Year Mortality in Older French Adults

To investigate the relationship between mortality and BMI in older people, taking into account other established mortality risk factors. A total of 3,646 French community dwellers aged 65 years and older from PAQUID cohort study were included. Cox proportional-hazards analysis was used to assess association between BMI and mortality. Death occurred in 54.1% of the cohort more than 13 years: 68.99% of the underweight (BMI <19), 52.13% of the obese (BMI >30), 51.66% of the overweight (BMI 25-30), and 51.79% of the reference participants (BMI 22-25) died.The relative risk of death as a function of BMI, adjusted for gender and age, formed a U-shaped pattern, with larger risks associated with lower BMI (<22.0) and for BMI of 25.0 to 30.0 and BMI >/=30. (BMI 22.0-24.9 was the reference.) After adjustment for demographic factors, smoking history, and comorbidity, increased mortality risk persisted in underweight older people, BMI <18.5 and BMI 18.5-22 (respectively, HR = 1.45, 95% CI 1.17-1.78; HR = 1.27, 95% CI 1.12-1.43) compared with reference. Overweight (BMI 25-29.9) and obesity (>/=30) were not associated with increased mortality compared with the reference category (respectively, HR = 0.98, 95% IC 0.88-1.10; HR = 1.06, 95% IC 0.89-1.27). Similar relationships persisted for disabled participant. For nondisabled participant disability did not alter the associations for BMI of 25.0 and higher but for BMI less than 22.0, the risks become insignificantly different from those for the reference group. BMI below 22 kg/ m(2) is a risk factor for 13-year mortality in older people, but our findings suggest that overweight and obesity may not be associated to mortality after adjustment for established mortality risk factors.

Study on the relationship between body mass index and health-related quality of life in middle-aged or older Chinese adults

To study the association between body mass index (BMI) and the health-related quality of life (HRQOL) in the middle-aged and older Chinese people. Data of 9539 middle-aged and older adults was collected from a cross-sectional survey performed in 9 provinces of China (Jiangsu, Anhui, Gansu, Qinghai, Fujian, Beijing, Jilin, Jiangxi and Henan province). MOS SF-36 was used to measure HRQOL. BMI classification was in accordance with the criteria recommended by the Ministry of Health of China. Rank sum test was used to compare HRQOL between subjects with normal weight and those with different BMI classification. Multiple logistic regression analysis was used to assess the association of HRQOL with BMI after adjusted for sex, age, marital, education, physical activity status and chronic diseases. When compared with middle-aged and older adults at normal weight range (18.5< or =BMI<24), data on physical domain (P<0.001), mental domain (P< 0.01) and 8 dimensions of HRQOL (physical functioning, mental health, P<0.05; role-physical, bodily pain, general health, vitality, social functioning, role-emotional, P<0.01) among subjects with underweight (BMI<18.5) were significantly lower while mental component summary (P<0.05) of overweight subjects (24< or =BMI<28) was significantly higher. Obese subjects (BMI> or =28) had worse physical function (physical functioning, P<0.01) but better mental health (mental health, P<0.01; mental component summary, P<0.05). After adjusting for other factors, and compared to middle aged and older adults with normal weight, data on odds ratios (ORs) of impaired HRQOL in physical domain (OR=1.67, 95% CI: 1.35-2.06), mental domain (OR=1.39, 95% CI: 1.13-1.70) and 8 dimensions increased among underweight subjects while ORs of impaired HRQOL in mental domain (OR=0.86, 95% CI: 0.78-0.95) and role-physical, vitality, social functioning, role-emotional and mental health dimensions decreased among overweight subjects. ORs increased (OR= 1.51, 95% CI: 1.27-1.80) in impaired HRQOL in physical functioning dimension but decreased in mental domain (OR=0.71, 95% CI: 0.60-0.85) as well as vitality, role-emotional and mental health dimensions among obese subjects. HRQOL of each domain were different among middle aged and older adults with different BMI classification. Underweight people had poor HRQOL in both physical domain and psychological domain, and obese people had poor physical function but good mental health condition.

Weighting the Weights: Agreement among Anthropometric Indicators Identifying the Weight Status of People with Intellectual Disabilities

Background The aims of this study were (1) to determine to what extent body mass index (BMI), waist circumference, fat free mass index (FFMI) and skinfold thickness are feasible measurement options in people with intellectual disabilities (ID) to measure their weight status, and (2) to assess the level of agreement among these methods.Methods BMI, waist circumference, FFMI derived from the Bioelectrical Impedance Analyser and skinfold thickness were all determined in 76 people with intellectual disabilities.Results BMI and waist circumference could be measured in all subjects. Skinfold thickness and FFMI failed in, respectively, five and 14 people. In general, intertest reliabilities were low. For underweight people, the agreement was acceptable.Conclusions BMI and waist circumference were feasible measurement options. Agreements among the methods were low. Implications of these results are discussed.

Healthy eating guidelines in the South African context

There has been a global shift of focus onto the African continent, as Africa is the only developing area in the world with increasing numbers of underweight, stunted and hungry people, while obesity rates in the more developed areas are on the increase. South Africa, faced with the consequences of the double burden of disease due to both over- and under-nutrition, is characterized by extremes of wealth and poverty. Aiming to move public health towards balanced nutrition by applying various holistic and multisectoral approaches, the South African Health sector is actively combating these nutritional imbalances. The various applications include the food based dietary guidelines (FBDGs), fortification and supplementation programs, updating of food composition data that are specific to South African foods, and the new food labeling regulations aimed at preventing misinformation and protecting the consumer. Although improvement of the South African nutrition situation is still limited despite these implemented strategies, innovative solutions should be found by all to improve persisting global malnutrition.

Underweight, overweight and obesity as risk factors for mortality and hospitalization

The prevalence of overweight and obesity is increasing in many countries. We aimed to investigate differences in mortality and severe morbidity between underweight people (body mass index (BMI)<18.5), overweight people (BMI 25 to <30), obese people (BMI> or =30), and those with normal weights (BMI 18.5 to <25). Random samples of the Swedish population aged 16-74 years in 1980-81 and 1988-89 were followed for 12 years with regard to all-cause mortality and mortality from circulatory diseases, all inpatient care, and inpatient care for circulatory and musculoskeletal diseases. Relative risks (RRs) for different levels of BMI were adjusted for age, longstanding illness, smoking, and educational level at baseline. In addition, analyses were made with delayed entry until the fourth-year after interview. Obesity and underweight, but not overweight, was associated with higher all-cause mortality. Among underweight men, the adjusted RR for all-cause mortality was 2.4 (95% confidence interval 1.6-3.6), and among underweight women it was 2.0 (1.5-2.7), but population attributable risks (PARs) were small, at 1.2% and 2.7%, respectively. Overweight was associated with increased risks for inpatient care for circulatory diseases, with PARs being 13.4% among men and 8.1% among women, and musculoskeletal diseases (PARs were 12.7% and 12.9%, respectively). Obese men and women had about 50% higher risks of all-cause mortality than normal-weight people, PARs being 3.2% and 3.8% respectively. This study supports the findings of other studies, in that overweight seems to be an exaggerated risk factor for all-cause mortality, but is related to other chronic disease. Underweight and obesity generally implies greater increases of RRs, but avoidance of overweight may have greater effect on the population level with regard to reduced cardiovascular and locomotor disease.