Construct validity of the Short Form-36 Health Survey and its relationship with BMI in obese outpatients

Objective: To investigate the construct validity of the Short Form‐36 (SF‐36) Health Survey questionnaire in obese patients. Research Methods and Procedures: Our series consisted of 1735 obese patients (age, 44.7 ± 11.0 years; 1346 women) consecutively enrolled in the QUOVADIS study, an observational multicenter study of obese treatment‐seeking outpatients. The construct validity of the SF‐36 was assessed by main component analysis. Age‐, gender‐, and education‐adjusted general linear models were used to investigate the relationship between BMI and SF‐36 domains or factors identified by main component analysis. Results: BMI was significantly associated with poor health‐related quality of life in all eight SF‐36 domains, and the strongest association was observed with physical activity. Main components analysis generated a six‐factor solution explaining 59% of the observed variance. BMI was strongly associated with factors based on the loading of items regarding the physical activity domain and factors based on role‐physical and role‐emotional items or general health and bodily pain items. In contrast, mental health‐, vitality‐, and social functioning‐based factors were not related to BMI. Discussion: In obese treatment‐seeking outpatients, the clustering of SF‐36 items in main components is not significantly different from the domain‐based approach generally used, thus confirming the robustness of such a generic questionnaire in this specific condition. However, the peculiar clustering of some SF‐36 items and their relationship with BMI suggest that the health‐related quality of life profile of subjects belonging to that population may be better described with alternative aggregations of the SF‐36 items or with disease‐tailored questionnaires.     

Oxidative Stress in Normal‐Weight Obese Syndrome

The normal‐weight obese (NWO) syndrome was identified in women whose body weight (BW) and BMI are normal but whose fat mass (FM) is >30%. In these subjects, an early inflammatory status has been demonstrated. The aim was to verify whether oxidative stress occurs in NWO. Sixty age‐matched white Italian women were studied and subdivided as follows: 20 normal‐weight individuals (NW) (BMI <25 kg/m²; FM% <30%); 20 NWO (BMI <25 kg/m²; FM% >30%); 20 preobese‐obese (OB) (BMI >25 kg/m²; FM% >30%). Anthropometric, body composition (by dual‐energy X‐ray absorptiometry) variables, plasma levels of some cytokines, reduced glutathione (GSH), lipid hydroperoxide (LOOH), nitric oxide (NO) metabolites (NO₂^?/NO₃^?), antioxidant nonproteic capacity (ANPC) were measured and compared between groups. Glucose and lipid metabolism parameters were assessed. GSH and NO₂^?/NO₃^? levels resulted lower in OB and NWO compared to NW (P < 0.01). LOOH levels resulted higher in OB and NWO (P < 0.01). ANPC in NWO was lower than NW but higher with respect to OB (P < 0.01). Correlation analysis revealed strong associations between GSH levels and BW, BMI, FM% (R = ?0.45, at least P < 0.05); waist circumference (W) (R = ?0.33, P < 0.05); FFM% (R = 0.45, P < 0.01); IL‐1α, IL‐6, IL‐10, IL‐15 (R = ?0.39, ?0.33, ?0.36 ?0.34, respectively, P < 0.05); triglycerides (R = ?0.416, P < 0.05). LOOH levels were negatively related to FFM% (R = ?0.413, P < 0.05) and positively to FM%, IL‐15, TNF‐α, insulin, total cholesterol, low‐density lipoprotein cholesterol, and triglycerides (R = 0.408, R = 0.502, R = 0.341, R = 0.412, R = 0.4036, R = 0.405, R = 0.405, respectively, P < 0.05). The study clearly indicates that NWO, besides being in early inflammatory status, are contextually exposed to an oxidative stress related to metabolic abnormalities occurring in obesity.     

Body Mass Index and Physical Function in Older Women

Objective: We modified existing standardized measurement tools in the Physical Performance Test and tasks from the Frailty and Injuries: Cooperative Studies of Intervention Technique Study to evaluate physical function in older women. Our objectives were (1) to characterize physical function themes based on combinations of tasks (deriving factors or components) and (2) to quantify the correlation between derived factors and body mass index (BMI). Research Methods and Procedures: Nutrition risk screens from enrollees in a Medicare‐managed risk program served as the sampling frame. To obtain adequate representation for a range of BMI, a random sample was obtained of 90 women from the following BMI strata: BMI, 22 to <27 kg/m²; BMI, 27 to <30 kg/m²; and BMI, ≥30 kg/m². Subjects were asked to perform a series of 18 functional tasks during a home visit. Results: The mean age was similar in the three BMI groups with an overall mean age of 71 ± 4.9 years (SD). Factors characterized by lower‐body function, upper‐body function, coordination, and strength were responsible for 30%, 11%, 9%, and 9% of the variance in task scores, respectively. BMI, controlling for age, explained 5%, 14%, 3%, and 0% of the variation in these factors, respectively. Higher BMI is associated significantly with poorer upper‐ and lower‐body function but is not associated significantly to strength or coordination. Discussion: Higher BMI seems to differentially impede specific aspects of physical function, especially upper‐body function, and to a lesser extent, lower‐body function. BMI does not seem to be associated with levels of coordination or strength. Better understanding of how BMI impacts physical function will aid in the design of interventions to promote independent living in elderly, obese women.     

Purification and Characterisation of the Enantiospecific Dioxygenases from Delftia acidovorans MC1 Initiating the Degradation of Phenoxypropionate and Phenoxyacetate Herbicides

After cultivation on (R,S)‐2‐(2,4‐dichlorophenoxy)propionate, two α‐ketoglutarate‐dependent dioxygenases were isolated and purified from Delftia acidovorans MC1, catalysing the cleavage of the ether bond of various phenoxyalkanoate herbicides. One of these enzymes showed high specificity for the cleavage of the R‐enantiomer of substituted phenoxypropionate derivatives: the K_m values were 55 μM and 30 μM, the k_cat values 55 min^–1 and 34 min^–1 with (R)‐2‐(2,4‐dichlorophenoxy)propionate [(R)‐2,4‐DP] and (R)‐2‐(4‐chloro‐2‐methylphenoxy)propionate, respectively. The other enzyme predominantly utilised the S‐enantiomers with K_m values of 49 μM and 22 μM, and k_cat values of 50 min^–1 and 46 min^–1 with (S)‐2‐(2,4‐dichlorophenoxy)propionate [(S)‐2,4‐DP] and (S)‐2‐(4‐chloro‐2‐methylphenoxy)propionate, respectively. In addition, it cleaved phenoxyacetate herbicides (i.e. 2,4‐dichlorophenoxyacetate: K_m = 123 μM, k_cat = 36 min^–1) with significant activity. As the second substrate, only α‐ketoglutarate served as an oxygen acceptor for both enzymes. The enzymes were characterised by excess substrate inhibition kinetics with apparent K_i values of 3 mM with (R)‐2,4‐DP and 1.5 mM with (S)‐2,4‐DP. The reaction was strictly dependent on the presence of Fe²⁺ and ascorbate; other divalent cations showed inhibitory effects to different extents. Activity was completely extinguished within 2 min in the presence of 100 μM diethylpyrocarbonate (DEPC).     

Modeling the Impact of Adjustable Gastric Banding on Survival in Patients with Morbid Obesity

Objective: Morbid obesity is associated with premature death. Adjustable gastric banding may lead to substantial weight loss in patients with morbid obesity. Little is known about the impact of weight loss on survival after adjustable gastric banding. We therefore developed a mathematical model to estimate life expectancy in patients with a body mass index (BMI) ≥40 kg/m² undergoing bariatric surgery. Research Methods and Procedures: We developed a nonhomogeneous Markov chain consisting of five states: the absorbing state (“dead”) and the four recurrent states BMI ≥40 kg/m², BMI 36 to 39 kg/m², BMI 32 to 35 kg/m², and BMI 25 to 31 kg/m². Scenarios of weight loss and age‐ and sex‐dependent risk of death, as well as BMI‐dependent excess mortality were extracted from life tables and published literature. All patients entered the model through the state of BMI ≥40 kg/m². Results: In men aged either 18 or 65 years at the time of surgery, who moved from the state BMI ≥40 kg/m² to the next lower state of BMI 36 to 39 kg/m², life expectancy increased by 3 and 0.7 years, respectively. In women aged either 18 or 65 years at the time of surgery, who moved from the state BMI ≥40 kg/m² to the next lower state BMI 36 to 39 kg/m², life expectancy increased by 4.5 and 2.6 years, respectively. Weight loss to lower BMI strata resulted in further gains of life expectancy in both men and women. Discussion: Within the limitations of the modeling study, adjustable gastric banding in patients with morbid obesity may substantially increase life expectancy.     

Impact of cardiometabolic risk factor clusters on health-related quality of life in the U.S

Objective: Research has shown that risk factors for cardiovascular disease often cluster together, most notably overweight/obesity, diabetes, hyperlipidemia, and hypertension. The impact of cardiometabolic risk factor clusters on health‐related quality of life (HRQL) is not well understood. The purpose of this study was to examine and quantify the impact of cardiometabolic risk factor clusters on HRQL as measured by the SF (Short Form)‐12 Mental Component Scale (MCS‐12), SF‐12 Physical Component Scale (PCS‐12), EQ‐5D index (a generic quality of life index), and Visual Analogue Scale. Research Methods and Procedures: The Medical Expenditure Panel Survey is a nationally representative survey of the U.S. population. From 2000 to 2002, detailed information on sociodemographic characteristics and health conditions were collected for 36,697 adults with complete responses. Controlling for comorbidity and sociodemographic characteristics, this study estimated the marginal impact of cardiometabolic risk factor clusters on MCS‐12, PCS‐12, EQ‐5D index, and Visual Analogue Scale scores. Cardiometabolic risk factor clusters were defined as the presence of BMI ≥25 kg/m² and at least two of the following: diabetes, hyperlipidemia, and hypertension. Using BMI ≥30 kg/m² as the cut‐off was also examined. Results: The marginal impact of cardiometabolic risk factor clusters was highly statistically significant across all four HRQL measures and seemed to be clinically significant for all but the MCS‐12. The PCS‐12 showed a greater decrease in HRQL associated with physical function compared with mental function‐related domains of the MCS‐12. Discussion: Common cardiometabolic risk factor clusters such as overweight/obesity, diabetes, hypertension, and hyperlipidemia have a significant and negative impact on HRQL in the United States.     

Mediating Effects of Inflammatory Biomarkers on Insulin Resistance Associated with Obesity

Objective: Obesity is associated with elevated levels of biomarkers of inflammation and endothelial dysfunction [including C‐reactive protein (CRP), E‐selectin, and intercellular adhesion molecule‐1], as well as insulin resistance (IR) and type 2 diabetes. We tested the hypothesis that these biomarkers mediate associations among obesity, IR, and risk of diabetes. Research Methods and Procedures: We stratified 510 initially non‐diabetic women in the Nurses’ Health Study cohort into four phenotypes above/below median BMI (27 kg/m²) and waist circumference (81 cm): low BMI‐low waist (LBLW; N = 190), low BMI‐high waist (LBHW; N = 74), high BMI‐low waist (HBLW; N = 27), and high BMI‐high waist (HBHW; N = 219). Results: In models assessing associations of weight phenotype with IR [fasting insulin (FI)], adjusted for age and diabetes risk factors, mean FI was higher comparing HBHW women (13.6 μU/mL, p < 0.0001) and LBHW (11.5 μU/mL, p = 0.02) with LBLW women (8.6 μU/mL); HBLW and LBLW women were not significantly different. Differences in FI levels were most strongly attenuated after adjustment for E‐selectin comparing LBHW with LBLW women (11.7 vs. 9.7 μU/mL, p = 0.2). Discussion: In logistic regression models, LBHW predicted diabetes (risk factor‐adjusted relative risk 2.06, 1.05 to 6.40), compared with LBLW, but was no longer significant after adjustment for E‐selectin or CRP. After adjusting for CRP and E‐selectin, only HBHW and E‐selectin were significantly associated with risk of diabetes. In women with central adiposity and low BMI, endothelial dysfunction and inflammation may mediate the relationship among central fat, IR, and incident diabetes.     

Comparison of Overall Obesity and Body Fat Distribution in Predicting Risk of Mortality

Results of studies comparing overall obesity and abdominal adiposity or body fat distribution with risk of mortality have varied considerably. We compared the relative importance and joint association of overall obesity and body fat distribution in predicting risk of mortality. Participants included 5,799 men and 6,429 women aged 30–102 years enrolled in the third National Health and Nutrition Examination Survey who completed a baseline health examination during 1988–1994. During a 12‐year follow‐up (102,172 person‐years), 1,188 men and 925 women died. In multivariable‐adjusted analyses, waist‐to‐thigh ratio (WTR) in both sexes (P_trend <0.01 for both) and waist‐to‐hip ratio (WHR) in women (P_trend 0.001) were positively associated with mortality in middle‐aged adults (30–64 years), while BMI and waist circumference (WC) exhibited U‐ or J‐shaped associations. Risk of mortality increased with a higher WHR and WTR among normal weight (BMI 18.5–24.9 kg/m²) and obese (BMI ≥30.0 kg/m²) adults. In older adults (65–102 years), a higher BMI in both sexes (P_trend <0.05) and WC in men (P_trend 0.001) were associated with increased survival, while remaining measures of body fat distribution exhibited either no association or an inverse relation with mortality. In conclusion, ratio measures of body fat distribution are strongly and positively associated with mortality and offer additional prognostic information beyond BMI and WC in middle‐aged adults. A higher BMI in both sexes and WC in men were associated with increased survival in older adults, while a higher WHR or WTR either decreased or did not influence risk of death.     

Correlates of health-related quality of life in overweight and obese adults with type 2 diabetes

Objective: This paper describes and examines conceptually relevant correlates of health‐related quality of life (HRQL) in overweight or obese persons with type 2 diabetes. Research Design and Procedures: The investigation was a cross‐sectional study of 5145 overweight or obese adults with type 2 diabetes between the ages of 45 and 74 years. Analyses examined the relationship that demographic characteristics, disease burden, and cardiovascular fitness had with HRQL: the Short Form 36 (SF‐36) and the Beck Depression Inventory (BDI) II. Results: Means for the SF‐36 physical component summary (PCS) scores, the mental component summary scores, and the BDI‐II were as follows: 47.0, 54.0, and 5.7. Less desirable PCS scores were related to several comorbidities, insulin use, physical complaints, a high BMI, low metabolic equivalent (MET) capacity, and lower education. Interactions between categories of obesity and MET capacity revealed that greater BMI was related to lower PCS scores when individuals had lower MET capacities yet was absent for those individuals who had higher MET capacities. In addition, although greater BMI was associated with more severe depressive symptomatology, this association was the most dramatic for those with class III obesity who had low MET capacity. Discussion: Although participants in Look AHEAD had a favorable profile on the SF‐36 and the BDI‐II at baseline, lower PCS scores were related to disease severity and the presence of other comorbidities. More important, although the temporal ordering of associations cannot be determined in a cross‐sectional design, the interactions between obesity class and MET capacity suggest that the adverse effect of BMI on PCS and BDI‐II scores may be buffered by higher MET capacities.     

Weight Loss Intervention for Obese Older Women: Improvements in Performance and Function

Objectives: To determine the feasibility of a 3‐month weight loss program for obese older women with short‐term laboratory, performance, functional, and life quality outcomes. Research Methods and Procedures: This was a pre‐ and postintervention design. Community‐dwelling women (n = 26) ≥60 years old with BMI ≥30 were enrolled in a 3‐month weight loss program promoting prudent diet, behavior modification, and physical activity. The primary emphasis of the program was on health, function, and quality of life. The approach was specifically tailored to older subjects through use of large‐font instructional materials, supplementation of calcium and vitamin D, and moderate weight loss and physical activity goals. An initial assessment by a bariatric physician was followed by eight visits with a dietitian and a follow‐up physician visit. Measurements included anthropometrics, body composition, laboratories, pedometer, physical performance, Short‐Form 36 Health Status Survey (SF‐36), Life Space Assessment, and dietary assessment. Results: Eighteen participants completed the program. There was a significant decrease in mean body weight (100 ± 15 vs. 96 ± 18 kg, p = 0.006), with a mean weight loss of 4.3 ± 5.5 kg (range ?15.5 to +7.20 kg). Significant improvements were observed for diastolic blood pressure, total cholesterol, triglycerides, physical performance, pedometer‐measured step counts, and step climb and descent. Self‐rated physical functioning (SF‐36 subscore) and vitality (SF‐36 subscore) were also significantly improved. Discussion: It is feasible for self‐selected obese older women to achieve a moderate weight loss and increase in physical activity resulting in short‐term improvements in laboratory, physical performance, self‐reported function, vitality, and life quality outcomes.     

Redox‐triggered chiroptical switching activity of ruthenium(III)‐bis‐(β‐diketonato) complexes bearing a bipyridine‐helicene ligand

The charged, electroactive bipyridine‐helicene‐ruthenium(III) complex [ 4 ] ^{. +},PF₆^? has been prepared from 3‐(2‐pyridyl)‐4‐aza[6]helicene and a Ru‐bis‐(β‐diketonato)‐bis‐acetonitrile precursor (β‐diketonato: 2,2,6,6‐tetramethyl‐3,5‐heptanedionato). Its chiroptical properties (electronic circular dichroism and optical rotation) were studied both experimentally and theoretically and suggest the presence of 2 diastereoisomers, namely (P,Δ)‐ and (P,Λ)‐[ 4 ] ^{. +},PF₆^? (denoted jointly as (P,Δ*)‐[ 4 ] ^{. +},PF₆^?) and their mirror‐images (M,Λ)‐ and (M,Δ)‐[ 4 ] ^{. +},PF₆^? ((M,Δ*)‐[ 4 ] ^{. +},PF₆^?). The electrochemical reduction of (P,Δ*)‐[ 4 ] ^{. +},PF₆^? to neutral complex (P,Δ*)‐ 4 was performed and revealed strong changes in the UV‐vis and electronic circular dichroism spectra. A reversible redox‐triggered chiroptical switching process was then achieved.     

Familial Resemblance of 7‐Year Changes in Body Mass and Adiposity

Objective: To investigate the familial resemblance of 7‐year changes in body mass and adiposity among Canadian families. Research Methods and Procedures: The sample consisted of 655 women and 660 men from 521 families who participated in the Canada Fitness Survey in 1981 and the follow‐up Campbell's Survey in 1988. Indicators of baseline and 7‐year changes in body mass and adiposity included body mass (kilograms), body mass index (BMI; kilograms per square meter), sum of five skinfolds (SF5; millimeters), and waist circumference (WC; millimeters). The data were adjusted for the effects of age and sex, and the change scores were adjusted for baseline levels. A familial correlation model was used to determine the heritability of each phenotype using maximum likelihood techniques. Results: Significant familial resemblance was observed at baseline and for 7‐year changes in all phenotypes. At baseline, moderate heritabilities were observed [body mass: heritability coefficient (h²) = 56%; BMI, h² = 39%; SF5, h² = 41%; and WC, h² = 39%], whereas values were attenuated for each change score except for WC (Δbody mass, h² = 23%; ΔBMI, h² = 14%; ΔSF5, h² = 12%; and ΔWC, h² = 45%). Discussion: Changes in body mass and adiposity significantly aggregate within families over 7 years. However, baseline values are characterized by higher heritability levels except WC. The significant heritabilities observed for change scores suggest that lifestyle, transient environmental factors, and possibly age‐related gene effects are important determinants of changes in body mass and adiposity.     

Influence of Excess Fat on Cardiac Morphology and Function: Study in Uncomplicated Obesity

Objective: To evaluate whether or not “uncomplicated” obesity (without associated comorbidities) is really associated with cardiac abnormalities. Research Methods and Procedures: We evaluated cardiac parameters in obese subjects with long‐term obesity, normal glucose tolerance, normal blood pressure, and regular plasma lipids. We selected 75 obese patients [body mass index (BMI) >30 kg/m²], who included 58 women and 17 men (mean age, 33.7 ± 11.9 years; BMI, 37.8 ± 5.5 kg/m²) with a ≥10‐year history of excess fat, and 60 age‐matched normal‐weight controls, who included 47 women and 13 men (mean age, 32.7 ± 10.4 years; BMI, 23.1 ± 1.4 kg/m²). Each subject underwent an oral glucose tolerance test to exclude impaired glucose tolerance or diabetes mellitus, bioelectrical impedance analysis to calculate fat mass and fat‐free mass, and echocardiography. Results: Obese patients presented diastolic function impairment, hyperkinetic systole, and greater aortic root and left atrium compared with normal subjects. No statistically significant differences between obese subjects and normal subjects were found in indexed left ventricular mass (LVM/body surface area, LVM/height^2.7, and LVM/fat‐free mass_kg), and no changes in left ventricular geometry were observed. No statistically significant differences in cardiac parameters between extreme (BMI > 40 kg/m²) and mild obesity (BMI < 35 kg/m²) were observed. Discussion: In conclusion, our data showed that obesity, in the absence of glucose intolerance, hypertension, and dyslipidemia, seems to be associated only with an impairment of diastolic function and hyperkinetic systole, and not with left ventricular hypertrophy.     

Obesity and Quality of Life: Mediating Effects of Pain and Comorbidities

Objective: To estimate the association between body mass index (BMI) and health‐related quality of life (HRQL) and examine whether joint pain and obesity‐related comorbidities mediate the BMI‐HRQL association. Research Methods and Procedures: Population‐based survey data from the 1999 Behavioral Risk Factor Surveillance Survey. Adults (N = 155, 989) were classified according to BMI as underweight (<18.5 kg/m²), desirable weight (18.5 to 24.9 kg/m²), overweight (25 to 29.9 kg/m²), obese class I (30 to 34.9 kg/m²), obese class II (35 to 39.9 kg/m²), and obese class III (≥40 kg/m²). Data including general health status, unhealthy days in the past 30 caused by physical problems and mental problems, and total unhealthy days in the past 30 were collected. Results: After adjusting for age, sex, race, smoking, education, and income, we observed J‐shaped associations between BMI and HRQL. Compared with desirable weight adults, underweight, overweight, and obesity classes I, II, and III adults [odds ratio (OR) = 1.57, 1.19, 1.95, 2.72, and 4.36, respectively] were significantly (p < 0.001) more likely to report fair/poor general health status. For unhealthy days caused by physical problems, the corresponding ORs were 1.51, 1.15, 1.66, 2.27, and 3.61 (p < 0.001). For unhealthy days caused by mental problems, the ORs were 1.35, 1.14 1.43, 1.57, and 2.25 (p < 0.001). For total unhealthy days, the corresponding ORs were 1.27, 1.09, 1.37, 1.73, and 2.46 (p < 0.01). Adding joint pain and obesity‐related comorbidities into models attenuated BMI‐HRQL associations. Discussion: Associations between BMI and HRQL indices were J‐shaped. Joint pain and comorbidities may mediate BMI‐HRQL associations.     

Differential Effects of Abdominal Adipose Tissue Distribution on Insulin Sensitivity in Black and White South African Women

Black South African women are more insulin resistant than BMI‐matched white women. The objective of the study was to characterize the determinants of insulin sensitivity in black and white South African women matched for BMI. A total of 57 normal‐weight (BMI 18–25 kg/m²) and obese (BMI > 30 kg/m²) black and white premenopausal South African women underwent the following measurements: body composition (dual‐energy X‐ray absorptiometry), body fat distribution (computerized tomography (CT)), insulin sensitivity (S_I, frequently sampled intravenous glucose tolerance test), dietary intake (food frequency questionnaire), physical activity (Global Physical Activity Questionnaire), and socioeconomic status (SES, demographic questionnaire). Black women were less insulin sensitive (4.4 ± 0.8 vs. 9.5 ± 0.8 and 3.0 ± 0.8 vs. 6.0 ± 0.8 × 10^?5/min/(pmol/l), for normal‐weight and obese women, respectively, P < 0.001), but had less visceral adipose tissue (VAT) (P = 0.051), more abdominal superficial subcutaneous adipose tissue (SAT) (P = 0.003), lower SES (P < 0.001), and higher dietary fat intake (P = 0.001) than white women matched for BMI. S_I correlated with deep and superficial SAT in both black (R = ?0.594, P = 0.002 and R = 0.495, P = 0.012) and white women (R = ?0.554, P = 0.005 and R = ?0.546, P = 0.004), but with VAT in white women only (R = ?0.534, P = 0.005). In conclusion, body fat distribution is differentially associated with insulin sensitivity in black and white women. Therefore, the different abdominal fat depots may have varying metabolic consequences in women of different ethnic origins.     

Adapted Changes in Left Ventricular Structure and Function in Severe Uncomplicated Obesity

Objective: A massive amount of fat tissue, as that observed in obese subjects with BMI over 50 kg/m², could affect cardiac morphology and performance, but few data on this issue are available. We sought to evaluate cardiac structure and function in uncomplicated severely obese subjects. Research Methods and Procedures: We studied 55 uncomplicated severely obese patients, 40 women, 15 men, mean age 35.5 ± 10.2 years, BMI 51.2 ± 8.8 kg/m², range 43 to 81 kg/m², with a history of fat excess of at least 10 years, and 55 age‐matched normal‐weight subjects (40 women, 15 men, mean BMI 23.8 ± 1.2 kg/m²) as a control group. Each subject underwent an echocardiogram to evaluate left ventricular (LV) mass and geometry and systolic and diastolic function. Results: Severely obese subjects showed greater LV mass and indexed LV mass than normal‐weight subjects (p < 0.01 for all parameters). Nevertheless, LV mass was appropriate for sex, height^2.7, and stroke work in most (77%) uncomplicated severely obese subjects. In addition, no significant difference in LV mass indices and LV mass appropriateness between obese subjects with BMI ≥ 50 kg/m² and those with BMI ≤ 50 kg/m² was found. Obese subjects also showed higher ejection fraction and midwall shortening than normal‐weight subjects (p = 0.05 and p < 0.01, respectively), suggesting a hyperdynamic systolic function. No significant difference in systolic performance between obese subjects with BMI ≥ 50 kg/m² and those with BMI ≤ 50 kg/m² was seen. Discussion: Our data show that uncomplicated severe obesity, despite the massive fat tissue amount, is associated largely with adapted and appropriate changes in cardiac structure and function.     

Self‐Reported Body Mass Index and Health‐Related Quality of Life: Findings from the Behavioral Risk Factor Surveillance System

Objective: To examine the relationship between self‐reported body mass index (BMI) and health‐related quality of life in the general adult population in the United States. Research Methods and Procedures: Using data from 109,076 respondents in the 1996 Behavioral Risk Factor Surveillance System, we examined how self‐reported BMI is associated with five health‐related quality of life measures developed by the Centers for Disease Control and Prevention for population health surveillance. Results: After adjusting for age, gender, race or ethnicity, educational attainment, employment status, smoking status, and physical activity status, participants with a self‐reported BMI of <18.5 kg/m² and participants with a self‐reported BMI of ≥30 kg/m² reported impaired quality of life. Compared with persons with a self‐reported BMI of 18.5 to <25 kg/m², odds ratios (ORs) of poor or fair self‐rated health increased among persons with self‐reported BMIs of <18.5 (1.57, 95% confidence interval [CI]: 1.31 to 1.89), 25 to <30 kg/m² (1.12, 95% CI: 1.04 to 1.20), 30 to <35 kg/m² (1.65, 95% CI: 1.50 to 1.81), 35 to <40 kg/m² (2.58, 95% CI: 2.21 to 3.00), and ≥40 kg/m² (3.23, 95% CI: 2.63 to 3.95); ORs for reporting ≥14 days of poor physical health during the previous 30 days were 1.44 (95% CI: 1.21 to 1.72), 1.04 (95% CI: 0.96 to 1.14), 1.32 (95% CI: 1.19 to 1.47), 1.80 (95% CI: 1.52 to 2.13), and 2.37 (95% CI: 1.90 to 2.94), respectively; ORs for having ≥14 days of poor mental health during the previous 30 days were 1.18 (95% CI: 0.97 to 1.42), 1.02 (95% CI: 0.95 to 1.11), 1.22 (95% CI: 1.10 to 1.36), 1.68 (95% CI: 1.42 to 1.98), and 1.66 (95% CI: 1.32 to 2.09), respectively. Discussion: In the largest study to date, low and increased self‐reported BMI significantly impaired health‐related quality of life. Particularly, deviations from normal BMI affected physical functioning more strongly than mental functioning.     

Visceral and Subcutaneous Adiposity and Brachial Artery Vasodilator Function

Endothelial dysfunction may link obesity to cardiovascular disease (CVD). We tested the hypothesis that visceral abdominal tissue (VAT) as compared with subcutaneous adipose tissue (SAT) is more related to endothelium‐dependent vasodilation. Among Framingham Offspring and Third Generation cohorts (n = 3,020, mean age 50 years, 47% women), we used multivariable linear regression adjusted for CVD and its risk factors to relate computed tomography (CT)‐assessed VAT and SAT, BMI, and waist circumference (WC), with brachial artery measures. In multivariable‐adjusted models, BMI, WC, VAT, and SAT were positively related to baseline artery diameter and baseline mean flow velocity (all P < 0.001), but not hyperemic mean flow velocity. In multivariable‐adjusted models, BMI (P = 0.002), WC (P = 0.001), and VAT (P = 0.01), but not SAT (P = 0.24) were inversely associated with percentage of flow‐mediated dilation (FMD%). However, there was little incremental increase in the proportion of variability explained by VAT (R² = 0.266) as compared to SAT (R² = 0.265), above and beyond traditional risk factors. VAT, but not SAT was associated with FMD% after adjusting for clinical covariates. Nevertheless, the differential association with VAT as compared to SAT was minimal.     

Effect of soil water stress on soil respiration and its temperature sensitivity in an 18-year-old temperate Douglas-fir stand

We analyzed 17 months (August 2005 to December 2006) of continuous measurements of soil CO₂ efflux or soil respiration (R_S) in an 18‐year‐old west‐coast temperate Douglas‐fir stand that experienced somewhat greater than normal summertime water deficit. For soil water content at the 4 cm depth (θ) > 0.11 m³ m^?3 (corresponding to a soil water matric potential of ?2 MPa), R_S was positively correlated to soil temperature at the 2 cm depth (T_S). Below this value of θ, however, R_S was largely decoupled from T_S, and evapotranspiration, ecosystem respiration and gross primary productivity (GPP) began to decrease, dropping to about half of their maximum values when θ reached 0.07 m³ m^?3. Soil water deficit substantially reduced R_S sensitivity to temperature resulting in a Q₁₀ significantly < 2. The absolute temperature sensitivity of R_S (i.e. dR_S/dT_S) increased with θ up to 0.15 m³ m^?3, above which it slowly declined. The value of dR_S/dT_S was nearly 0 for θ < 0.08 m³ m^?3, thereby confirming that R_S was largely unaffected by temperature under soil water stress conditions. Despite the possible effects of seasonality of photosynthesis, root activity and litterfall on R_S, the observed decrease in its temperature sensitivity at low θ was consistent with the reduction in substrate availability due to a decrease in (a) microbial mobility, and diffusion of substrates and extracellular enzymes, and (b) the fraction of substrate that can react at high T_S, which is associated with low θ. We found that an exponential (van't Hoff type) model with Q₁₀ and R₁₀ dependent on only θ explained 92% of the variance in half‐hourly values of R_S, including the period with soil water stress conditions. We hypothesize that relating Q₁₀ and R₁₀ to θ not only accounted for the effects of T_S on R_S and its temperature sensitivity but also accounted for the seasonality of biotic (photosynthesis, root activity, and litterfall) and abiotic (soil moisture and temperature) controls and their interactions.     

Evaluation of Left Ventricular Synchronicity in Hypertensive Patients With Overweight or Obesity

The left ventricular synchronicity in hypertensive patients with overweight or obesity has not been well elucidated. This study was designed to evaluate the left ventricular synchronicity in these patients. Tissue Doppler imaging was performed in 126 hypertensive patients and 25 control subjects. The hypertensive patients were divided into three groups according to BMI: normal weight group (BMI <25 kg/m², n = 32, H‐NW group), overweight group (BMI 25–29.9 kg/m², n = 64, H‐OW group), and obese group (BMI ≥30 kg/m², n = 30, H‐OB group). Left ventricular systolic and diastolic synchronicity were determined by measuring the maximal differences in time to peak myocardial systolic contraction (T_s‐diff) and early diastolic relaxation (T_e‐diff) between any two of the left ventricular segments and the standard deviation of time to peak myocardial systolic contraction (T_s‐SD) and early diastolic relaxation (T_e‐SD) of all 12 segments. Compared with the control group, the indexes of synchronicity including T_s‐diff, T_s‐SD, T_e‐diff, and T_e‐SD were significantly prolonged in the hypertensive patients. Furthermore, although the indexes of blood pressure had no difference among the hypertensive groups, the impaired systolic and diastolic synchronicity including T_s‐diff, T_s‐SD, and T_e‐SD was obviously aggravated with the increasing BMI. Stepwise multivariate analysis revealed BMI as an independent predictor of T_s‐SD and T_e‐SD. Therefore, the impairment of left ventricular synchronicity was aggravated with increasing BMI in hypertensive patients. Overweight and obesity may be important factors to impact the left ventricular synchronicity.