Waist circumference vs body mass index in association with cardiorespiratory fitness in healthy men and women: a cross sectional analysis of 403 subjects

The association between the weight-adjusted-waist index and frailty in US older adults: a cross-sectional study of NHANES 2007-2018

Objective

This study aimed to evaluate the relationship between the weight-adjusted waist circumference index (WWI) and the frailty in American adults aged over 60 years.

Methods

We utilized data from the National Health and Nutrition Examination Surveys (NHANES) spanning from 2007 to 2018. WWI was calculated using the square root of waist circumference (cm) divided by body weight (kg). The frailty index ≥ 0.25 was employed to assess frailty. Weighted multivariate logistic regression was conducted to explore the association between WWI and frailty. Generalized Additive Modeling (GAM) was used to explore potential non-linear relationships. Receiver operating characteristic curve (ROC) analysis was used to assess the predictive ability of WWI for frailty.

Results

The study encompassed 7765 participants. Higher WWI was significantly associated with higher odds of frailty. In the fully adjusted model, each unit increase of WWI was associated with an 82% increased odds of frailty (OR: 1.82, 95% CI: 1.61 - 2.06; P < 0.001). GAM found significant nonlinear relationships and threshold effects.

Conclusion

The study presented a robust correlation between elevated WWI and increased odds of frailty among American older adults. However, these findings require further validation in large-scale, prospective studies.

Association of Weight Status and Waist Circumference with Physical Activity in people with Schizophrenia Spectrum Disorders and healthy controls

BACKGROUND

Individuals with Schizophrenia Spectrum Disorders (SSD) often suffer from obesity and do limited Physical Activity (PA). PA has many beneficial effects on a variety of somatic and mental variables and it should be strengthened among people with mental disorders. The relationship between Body Mass Index (BMI), Waist Circumference (WC), and PA in this population is poorly understood, with a lack of precise PA assessment. This study investigates the association between BMI, WC, weight, and PA in individuals with SSD and controls using accelerometers.

METHODS

One hundred twenty-six patients with SSD (residents and outpatients) and 110 sex- and age-matched controls were enrolled. Clinical, sociodemographic, and quality-of-life data were collected. PA was measured with a tri-axial ActiGraph GT9X and quantified by Vector Magnitude (VM). Relationships between PA and BMI, WC, and weight changes were analysed using linear regression models.

RESULTS

Patients were more likely to be unmarried, unemployed, and less educated compared to controls (p < 0.001). Residents had more medical comorbidities (p = 0.001), while outpatients had higher BMI, weight, and WC (p < 0.001). Residents reported more severe psychopathology, lower functioning, and greater use of psychopharmacological medications (p < 0.001). Higher PA levels were not significantly associated with lower BMI, WC, or weight. Although not statistically significant, increased PA showed a trend towards lower obesity risk.

CONCLUSIONS

Sociodemographic, medical, and clinical characteristics of individuals with SSD define vulnerability factors that can inform tailored interventions to improve PA.

Diagnostic Performance of the Measurement of Skinfold Thickness for Abdominal and Overall Obesity in the Peruvian Population: A 5-Year Cohort Analysis

The escalating prevalence of overall and abdominal obesity, particularly affecting Latin America, underscores the urgent need for accessible and cost-effective predictive methods to address the growing disease burden. This study assessed skinfold thicknesses' predictive capacity for overall and abdominal obesity in Peruvian adults aged 30 or older over 5 years. Data from the PERU MIGRANT 5-year cohort study were analyzed, defining obesity using BMI and waist circumference. Receiver operating characteristic curves and area under the curve (AUC) with 95% confidence intervals (CI) were calculated. Adults aged ≥ 30 (n = 988) completed the study at baseline, with 47% male. A total of 682 participants were included for overall and abdominal obesity analysis. The 5-year prevalence values for overall and abdominal obesity were 26.7% and 26.6%, respectively. Subscapular skinfold (SS) best predicted overall obesity in men (AUC = 0.81, 95% CI: 0.75-0.88) and women (AUC = 0.77, 95% CI: 0.67-0.88). Regarding abdominal obesity, SS exhibited the highest AUC in men (AUC = 0.83, 95% CI: 0.77-0.89), while SS and the sum of trunk skinfolds showed the highest AUC in women. In secondary analysis excluding participants with type-2 diabetes mellitus (DM2) at baseline, SS significantly predicted DM2 development in men (AUC = 0.70, 95% CI: 0.58-0.83) and bicipital skinfold (BS) did in women (AUC = 0.73, 95% CI: 0.62-0.84). The findings highlight SS significance as an indicator of overall and abdominal obesity in both sexes among Peruvian adults. Additionally, SS, and BS offer robust predictive indicators for DM2.

Association of Spinal Alignment and Abdominal Circumference with Sarcopenia Status and Fall Risk in Patients with Osteoporosis: A Retrospective Study

Since vertebral kyphosis and abdominal circumference are thought to influence sarcopenia and fall risk in osteoporosis, we evaluated sarcopenia and fall risk in patients with different measurements of abdominal circumference and sagittal longitudinal axis (SVA). In this post hoc study, 227 patients aged 65 years or more who visited an outpatient osteoporosis clinic were included in the analysis. Sarcopenia was determined from lean body mass, grip strength, and walking speed by dual energy X-ray absorptiometry; SVA (median 40 mm) and abdominal circumference (median 80 cm) were compared between the four groups, each divided into two groups. Nutritional management, falls, and fall anxiety scores were also examined. The incidence of sarcopenia was significantly increased in those with abdominal circumference < 80 cm in both the SVA < 40 mm and SVA ≥ 40 mm groups (p < 0.05). Nonetheless, the fall scores of those with SVA < 40 mm were lower than those of individuals with SVA ≥ 40 mm (p < 0.01). Based on the results of this study, SVA and abdominal circumference values may predict the risk of sarcopenia and falls. More research is needed before our results can be translated into clinical practice.

Factors Associated with Normal-Weight Abdominal Obesity Phenotype in a Representative Sample of the Peruvian Population: A 4-Year Pooled Cross-Sectional Study

To examine factors associated with abdominal obesity among normal-weight individuals from the Demographic and Health Survey of Peru (2018-2021). Cross-sectional analytical study. The outcome variable was abdominal obesity defined according to JIS criteria. Crude (cPR) and adjusted prevalence ratios (aPR) were estimated for the association between sociodemographic and health-related variables and abdominal obesity using the GLM Poisson distribution with robust variance estimates. A total of 32,109 subjects were included. The prevalence of abdominal obesity was 26.7%. The multivariate analysis showed a statistically significant association between abdominal obesity and female sex (aPR: 11.16; 95% CI 10.43-11.94); categorized age 35 to 59 (aPR: 1.71; 95% CI 1.65-1.78); 60 to 69 (aPR: 1.91; 95% CI 1.81-2.02); and 70 or older(aPR: 1.99; 95% CI 1.87-2.10); survey year 2019 (aPR: 1.22; 95% CI 1.15-1.28); 2020 (aPR: 1.17; 95% CI 1.11-1.24); and 2021 (aPR: 1.12; 95% CI 1.06-1.18); living in Andean region (aPR: 0.91; 95% CI 0.86-0.95); wealth index poor (aPR: 1.26; 95% CI 1.18-1.35); middle (aPR: 1.17; 95% CI 1.08-1.26); rich (aPR: 1.26; 95% CI 1.17-1.36); and richest (aPR: 1.25; 95% CI 1.16-1.36); depressive symptoms (aPR: 0.95; 95% CI 0.92-0.98); history of hypertension (aPR: 1.08; 95% CI 1.03-1.13), type 2 diabetes (aPR: 1.13; 95% CI 1.07-1.20); and fruit intake 3 or more servings/day (aPR: 0.92; 95% CI 0.89-0.96). Female sex, older ages, and low and high income levels increased the prevalence ratio for abdominal obesity, while depressive symptoms, living in the Andean region, and fruit intake of 3 or more servings/day decreased it.

'At risk' waist-to-height ratio cut-off points recently adopted by NICE and US Department of Defense will unfairly penalize shorter adults. What is the solution?

OBJECTIVES

To a) demonstrate that adopting 'at risk' waist-to-height ratio (WHTR) cut-off points, recently approved by National Institute for Health and Care Excellence (NICE) and the United States Department of Defense (USDoD), will unfairly penalize shorter individuals and will be too lenient for taller individuals, b) to confirm that waist circumference (WC) of a sample of US service personnel, scales to approximately height^0.5, supporting the notion that WC, to be independent of height (HT), should be normalized using WC.HT^-0.5 (WHT•5R), and c) to identify the WHT•5R cut-off points that will reduce or eliminate this unwanted bias.

SUBJECTS/METHODS

We employed a three independent cross-sectional sample design. All n = 58,742 participants underwent anthropometric assessment of body mass, stature and waist circumference.

RESULTS

The allometric power-law model WC=a.HT^b for US service personnel identified the height exponent to be b= 0.418 (95 % CI 0.251-0.585), confirming that the simple body-shape index for WC to be independent of HT, should be WC.HT^-0.5. Chi-square tests of independence and for linear trend confirmed that by adopting WHTR cut-off point, shorter individuals (both service personnel and non-service participants) will be over penalized (classified as being 'at risk'). New WC independent-of-height ratio cut-off points were found to resolve this problem.

CONCLUSIONS

Adopting WHTR cut-off thresholds (either 0.5 or 0.55) will lead to shorter adults being unfairly classified as being 'at risk' in terms of their central adiposity and general health status. Adopting new WHT•5R cut-off point thresholds were found to greatly reduce or eliminate this bias.

Prediction of maximal oxygen uptake based on anthropometric indices in Iranian male adults

BACKGROUND

Assessment of maximal oxygen consumption is important in both general community and occupational settings. Validity and reliability tests are needed to indicate the functionality of the cardiopulmonary system.

OBJECTIVE

This study aimed to establish a maximal oxygen consumption (VO2max) prediction model using anthropometric and demographic variables for young adults in Iran.

METHODS

This cross-sectional study was conducted on 64 healthy young men aged 19-29 years. Oxygen consumption was measured directly and the prediction models to estimate VO2max were determined by multiple linear regression. The accuracy of the prediction models was considered using regression coefficient (R), coefficient of determination (R2), and standard error of estimate (SEE).

RESULTS

The average VO2max was 44.02±4.31 ml/kg/min. Significant correlations were found between the measured VO2max and the anthropometric and demographic variables (r = 0.16-0.86, P < 0.05). Three significant regression models with acceptable accuracy were developed (R2 = 0.67-0.71, SEE = 3.19-3.21).

CONCLUSION

The predictive models consisted of 3-5 variables as significant predictors of VO2max and had acceptable accuracy for Iranian young adults. The proposed models are a simple and valid tool that can be used to estimate the VO2max in the field and in laboratory settings.

Validity and reliability of the measurement instrument of the nursing outcome health-related Physical Fitness (2004), proposed and transculturally adapted to the Spanish context

BACKGROUND

Presently, physical inactivity is the main public health problem in many countries worldwide. Physical activity promotes the maintenance or improvement of one's physical condition. Physical fitness has been established as the main biological marker of the state of health of an individual, and therefore, there is a clear need to measure health-related physical fitness through the use of a reliable and valid instrument. This study is a continuation of the transcultural adaptation process and a new proposal of the nursing outcome Physical Fitness (2004), found in the 5^th Edition of the Nursing Outcomes Classification. The objective of this study was to examine the validity and reliability of the nursing outcome Health-Related Physical Fitness survey, proposed and transculturally adapted to the Spanish context.

METHODS

An instrumental study to validate the nursing outcome Physical Fitness (2004), from the 5^th Edition of the Nursing Outcome Classification was carried out. It took place between the months of May, 2016 to May, 2017. On the first stage, the instrument proposed Health-Related Physical Fitness survey was administered to 160 adults who used the Health Services of Murcia, Spain by three independent evaluators. After 4 weeks, it was administered again to 33 participants to calculate the intra-rater reliability. Lastly, the SF-12v2 Health Survey was administered to obtain external evidence of validity.

RESULTS

The inter-rater reliability of the nursing outcome proposed obtained high values (between 0.91-0.99) in the evaluations performed by the three evaluators. As for the intra-rater reliability, high values were obtained (0.94-1), except for the item "balance", which was moderate (0.56). Lastly, a positive and statistically significant correlation (p < 0.05) was obtained between the Physical Component Summary, and the dimensions Physical Functioning and General Health from the SF-12v2 Health Survey, and the global score of the Health-Related Physical Fitness proposed instrument.

CONCLUSIONS

The validity and reliability results of the nursing outcome Health-Related Physical Fitness survey, proposed and transculturally adapted to the Spanish context, were adequate for its use by nurses with adults who use the Health Services of Murcia. However, this instrument must be analyzed with more diverse samples of health services users.

Derivation and validation of sex-specific continuous metabolic syndrome scores for the Mexican adult population

Traditionally the diagnosis of Metabolic syndrome (MetS) is binary (present/absent). The goal of this work is to propose a sex-specific continuous score to measure the severity of MetS in Mexican adults using waist circumference and body mass index as adiposity measures. MetSx-WC and MetSx-BMI indexes by sex were derived by confirmatory factor analysis (CFA) using data for 6567 adult participants of the National Health and Nutrition Survey 2018. The overall fit of the two proposed CFA models was excellent. We then validated these scores using a community-based health study of 862 university participants and determined that the reliability and strength of agreement between the MetSx-WC and MetSx-BMI scores were excellent. The ROC analysis of the resulting indexes indicates that they have excellent ability to discriminate a MetS classification according to the different criteria. The correlations of MetSx scores and surrogate markers of insulin resistance and obesity ranged from weak to strong. Subsequently, a retrospective study of 310 hospitalized patients with COVID-19 was used to determined that MetSx-BMI score was associated with the mortality of patients with COVID-19. The proposed indices provide a continuous measure in the identification of MetS risk in Mexican adults.

Comparison Between Statistical Model and Machine Learning Methods for Predicting the Risk of Renal Function Decline Using Routine Clinical Data in Health Screening

Purpose

Using machine learning method to predict and judge unknown data offers opportunity to improve accuracy by exploring complex interactions between risk factors. Therefore, we evaluate the performance of machine learning (ML) algorithms and to compare them with logistic regression for predicting the risk of renal function decline (RFD) using routine clinical data.

Patients and Methods

This retrospective cohort study includes datasets from 2166 subjects, aged 35–74 years old, provided by an adult health screening follow-up program between 2010 and 2020. Seven different ML models were considered – random forest, gradient boosting, multilayer perceptron, support vector machine, K-nearest neighbors, adaptive boosting, and decision tree - and were compared with standard logistic regression. There were 24 independent variables, and the baseline estimate glomerular filtration rate (eGFR) was used as the predictive variable.

Results

A total of 2166 participants (mean age 49.2±11.2 years old, 63.3% males) were enrolled and randomly divided into a training set (n=1732) and a test set (n=434). The area under receiver operating characteristic curve (AUROC) for detecting RFD corresponding to the different models were above 0.85 during the training phase. The gradient boosting algorithms exhibited the best average prediction accuracy (AUROC: 0.914) among all algorithms validated in this study. Based on AUROC, the ML algorithms improved the RFD prediction performance, compared to logistic regression model (AUROC:0.882), except the K-nearest neighbors and decision tree algorithms (AUROC:0.854 and 0.824, respectively). However, the improvement differences with logistic regression were small (less than 4%) and nonsignificant.

Conclusion

Our results indicate that the proposed health screening dataset-based RFD prediction model using ML algorithms is readily applicable, produces validated results. But logistic regression yields as good performance as ML models to predict the risk of RFD with simple clinical predictors.

SVM-Based Blood Exam Classification for Predicting Defining Factors in Metabolic Syndrome Diagnosis

Biomarkers have already been proposed as powerful classification features for use in the training of neural network-based and other machine learning and artificial intelligence-based prognostic models in the scientific field of personalized nutrition. In this paper, we construct and study cascaded SVM-based classifiers for automated metabolic syndrome diagnosis. Specifically, using blood exams, we achieve an average accuracy of about 84% in correctly classifying body mass index. Similarly, cascaded SVM-based classifiers achieve a 74% accuracy in correctly classifying systolic blood pressure. Next, we propose and implement a system that achieves an 84% accuracy in metabolic syndrome prediction. The proposed system relies not only on prediction of the body mass index but also on prediction from blood exams of total cholesterol, triglycerides and glucose. For the aim of self-completeness of the paper, the key concepts with regard to metabolic syndrome are summarized, and a review of previous related work is included. Finally, conclusions are drawn and indications for related future research are outlined.

Income-related health inequality in urban China (1991-2015): The role of homeownership and housing conditions

Unprecedented economic growth has been experienced over the several decades worldwide, but such rapid economic growth wasn't accompanied by equally-substantial improvement in health, especially health inequalities between the rich and poor. This study examines the role of housing in income-related health inequalities (income-health gradient) in urban China. We here analyze 1991-2015 China Health and Nutrition Survey data to ask how housing affects income-related health inequalities in urban China. We find pro-poor inequalities in self-reported bad health but pro-rich inequalities in objective bad health (general overweight/obesity, central obesity and high blood pressure). Housing conditions serve to reduce the health gradient, especially for objective health. On the contrary, homeownership exacerbates the health gradient. Improving housing conditions thus appears to be an effective way of reducing the income-health gradient in urban China.

Anthropometry as a readily accessible health assessment of older adults

Anthropometry (derived from the Greek Anthropos: human, and metron: measure) refers to the systematic collection, and measurement of the physical characteristics of the human body, primarily body weight, body size, and shape. Anthropometric values are closely related to genetic factors, environmental characteristics, social, and cultural conditions, lifestyle, functional status, and health. Anthropometric measurements can be used to assess risk of malnutrition, obesity, muscle wasting, increased fat mass, and maldistribution of adipose tissue. Potential modifiable factors include circumferences, skinfolds, and body weight. While are height, and the bone diameters are non-modifiable. Kinanthropometry is the study of size, shape, proportionality, composition, biological maturation, and body function, in order to understand the process of growth, exercise, sports performance, and nutrition. Aging of the population, which is associated with increased risk of chronic disease, and disability, is one of the most important demographic changes facing many countries. Anthropometric indicators are simple, portable, non-invasive, inexpensive, and easily applied measurements that can be readily applied in geriatric populations to guide preventative measures, and medical interventions in older adults.

Chinese Adults Are More Susceptible to Effects of Overall Obesity and Fat Distribution on Cardiometabolic Risk Factors

CONTEXT

The body mass index (BMI) and waist circumference (WC) as diagnostic tools of obesity do not reflect the same level of fat mass and whether obesity leads to various effects on cardiometabolic risk factors among different racial/ethnic population is unknown.

OBJECTIVE

The study aims to address the multicollinearity between BMI and WC by using the residual model approach and to assess and compare the effects of obesity metrics on cardiometabolic risk factors among different races/ethnicities.

DESIGN, SETTING, AND PARTICIPANTS

Data from a nationally representative sample of mainland Chinese adults collected in 2010 and data from the National Health and Nutrition Evaluation Survey 2005-2016 were used. By conducting a regression analysis between WC and BMI, the variation of BMI was removed from WC measures and residual of WC was obtained. The associations between obesity metrics and cardiometabolic risk factors were compared among different races/ethnicities by sex.

RESULTS

The residual WC was significantly associated with all the cardiometabolic risk factors in mainland Chinese, and most of the factors in non-Hispanic white and non-Hispanic black adults, but not in the other races/ethnicities. The standardized regression coefficients of the associations between obesity metrics and cardiometabolic factors showed that the obesity metrics had greater impact on systolic blood pressure, diastolic blood pressure, and triglyceride in Chinese adults than those of other racial/ethnic groups.

CONCLUSIONS

Chinese adults are more susceptible to the effects of overall obesity and fat distribution on cardiometabolic risk factors than the other racial/ethnic population.

Inequality of weight status in urban Cuba: 2001-2010

Background

Although understanding changes in the body weight distribution and trends in obesity inequality plays a key role in assessing the causes and persistence of obesity, limited research on this topic is available for Cuba. This study thus analyzed changes in body mass index (BMI) and waist circumference (WC) distributions and obesity inequality over a 9-year period among urban Cuban adults.

Methods

Kolmogorov-Smirnov tests were first applied to the data from the 2001 and 2010 National Survey on Risk Factors and Chronic Diseases to identify a rightward shift in both the BMI and WC distributions over the 2001–2010 period. A Shapley technique decomposed the increase in obesity prevalence into a mean-growth effect and a (re)distributional component. A univariate assessment of obesity inequality was then derived by calculating both the Gini and generalized entropy (GE) measures. Lastly, a GE-based decomposition partitioned overall obesity inequality into within-group and between-group values.

Results

Despite some relatively pronounced left-skewing, both the BMI and WC distributions exhibited a clear rightward shift to which the increases in general and central obesity can be mostly attributed. According to the Gini coefficients, both general and central obesity inequality increased over the 2001–2010 period, from 0.105 [95% confidence interval (CI) = 0.103–0.106] to 0.110 [95% CI = 0.107–0.112] and from 0.083 [95% CI = 0.082–0.084] to 0.085 [95% CI = 0.084–0.087], respectively. The GE-based decomposition further revealed that both types of inequality were accounted for primarily by within-group inequality (93.3%/89.6% and 87.5%/84.8% in 2001/2010 for general/central obesity, respectively).

Conclusions

Obesity inequality in urban Cuba worsened over the 2001–2010 time period, with within-group inequality in overall obesity dominant over between-group inequality. In general, the results also imply that the rise in obesity inequality is immune to health care system characteristics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12963-021-00251-6.

Profiling children longitudinally: A three-year follow-up study of perceived and actual motor competence and physical fitness

Longitudinal designs enhance our understanding of children's development and its influence on movement behaviors and health. This three-year follow-up study aimed to develop profiles according to perceived and actual motor competence (MC) (locomotion, object control, and overall) and physical fitness in boys and girls longitudinally including children's temporal migrations among clusters in terms of profiling trends. A secondary aim was to compare physical activity participation and weight status at each time point according to these profiles. One hundred and four typically developing Spanish children (45.8% girls) between 4 and 9 years old at baseline participated in this study. Data were collected at three time points one year apart, between January 2016 and May 2018. A self-organizing map and K-means cluster analysis were used to classify and visualize the values and temporal trajectories longitudinally. The study of the profiles in three consecutive years revealed five profiles, three for boys [ie, profile 1 (aligned-high), profile 2 (aligned-partially-low perception-medium actual MC and fitness), and profile 3 (non-aligned-medium perception-low actual MC and fitness)]; and two for girls [ie, profile 4 (aligned-high) and profile 5 (aligned-low)]. For highly perceived and capable children, boys (profile 1) and girls (profile 4), there was a tendency for higher physical activity participation and lower body mass index and waist circumference over time compared to their counterparts who had medium and/or low levels in perception and actual MC and fitness (P < .05). As children age, those with low values in perceived and actual MC and fitness in object control skills will present a higher probability of maintaining unhealthy lifestyles. So, prior intervention, children's profiles identification should be analyzed according to the type of MC.

Relationship between anthropometric characteristics and aerobic fitness among Malaysian men and women

This cross-sectional study evaluated the relationships between anthropometric and aerobic fitness (rate of perceived exertion [RPE] and predicted maximal oxygen uptake [VO_2max]) among 228 participants (age: 23.78±4.42 years). RPE and predicted VO_2max were determined during the cycle ergometer exercise test. Data were also obtained for height, weight, body mass index (BMI), hip and waist (WC) circumferences. Data analysis revealed VO_2max is correlated with WC (r=−0.571), weight (r=−0.521), waist-to-height ratio (WHtR) (r=−0.516), waist-to-hip ratio (WHR) (r=−0.487), and BMI (r=−0.47) in men, while, in women with WC (r=−0.581), weight (r=−0.571), WHtR (r=−0.545), BMI (r=−0.545), WHR (r=−0.473), and height (r=−0.287) (all P<0.05). Regression analysis showed WC was a significant predictor for VO_2max in men and women (r₂=32.6% vs. 33.7%). The receiver operating characteristic curve of WC showed 0.786 and 0.831 for men and women, respectively. WC or abdominal obesity is the strongest predictor for VO_2max, which is an indicator of aerobic fitness in Malaysian adults.

Sarcopenia, Diet, Physical Activity and Obesity in European Middle-Aged and Older Adults: The LifeAge Study

The revised European consensus defined sarcopenia as a progressive and generalized skeletal muscle disorder that is associated with an increased likelihood of adverse outcomes including falls, fractures, physical disability and mortality. The aim of this study was to determine the prevalence of sarcopenia and analyse the influence of diet, physical activity (PA) and obesity index as risk factors of each criteria of sarcopenia. A total of 629 European middle-aged and older adults were enrolled in this cross-sectional study. Anthropometrics were assessed. Self-reported PA and adherence to the Mediterranean diet were evaluated with the Global Physical Activity Questionnaire (GPAQ) and Prevention with Mediterranean Diet questionnaire (PREDIMED), respectively. The functional assessment included handgrip strength, lower body muscle strength, gait speed and agility/dynamic balance. Of the participants, 4.84% to 7.33% showed probable sarcopenia. Sarcopenia was confirmed in 1.16% to 2.93% of participants. Severe sarcopenia was shown by 0.86% to 1.49% of participants. Male; age group ≤65 years; lower body mass index (BMI); high levels of vigorous PA; and the consumption of more than one portion per day of red meat, hamburgers, sausages or cold cuts and/or preferential consumption of rabbit, chicken or turkey instead of beef, pork, hamburgers or sausages (OR = 0.126-0.454; all p < 0.013) resulted as protective factors, and more time of sedentary time (OR = 1.608-2.368; p = 0.032-0.041) resulted as a risk factor for some criteria of sarcopenia. In conclusion, age, diet, PA, and obesity can affect the risk of having low muscle strength, low muscle mass or low functional performance, factors connected with sarcopenia.

Comparative Analysis of Some Structural Equation Model Estimation Methods with Application to Coronary Heart Disease Risk

This study compared a ridge maximum likelihood estimator to Yuan and Chan (2008) ridge maximum likelihood, maximum likelihood, unweighted least squares, generalized least squares, and asymptotic distribution-free estimators in fitting six models that show relationships in some noncommunicable diseases. Uncontrolled hypertension has been shown to be a leading cause of coronary heart disease, kidney dysfunction, and other negative health outcomes. It poses equal danger when asymptomatic and undetected. Research has also shown that it tends to coexist with diabetes mellitus (DM), with the presence of DM doubling the risk of hypertension. The study assessed the effect of obesity, type II diabetes, and hypertension on coronary risk and also the existence of converse relationship with structural equation modelling (SEM). The results showed that the two ridge estimators did better than other estimators. Nonconvergence occurred for most of the models for asymptotic distribution-free estimator and unweighted least squares estimator whilst generalized least squares estimator had one nonconvergence of results. Other estimators provided competing outputs, but unweighted least squares estimator reported unreliable parameter estimates such as large chi-square test statistic and root mean square error of approximation for Model 3. The maximum likelihood family of estimators did better than others like asymptotic distribution-free estimator in terms of overall model fit and parameter estimation. Also, the study found that increase in obesity could result in a significant increase in both hypertension and coronary risk. Diastolic blood pressure and diabetes have significant converse effects on each other. This implies those who are hypertensive can develop diabetes and vice versa.

Cumulative exposure to premenopausal obesity and risk of postmenopausal cancer: A population-based study in Icelandic women

Obesity, often assessed at one point in time, is an established risk factor of several types of cancer, however, associations with cumulative exposure to obesity across the life course are not well understood. We investigated the relationship between combined measures of duration and intensity of premenopausal overweight and obesity and the incidence of postmenopausal breast, endometrial, and colorectal cancers in Icelandic women. Body mass index (BMI) trajectories between ages 20 and 50 of 88,809 women from the Cancer Detection Clinic Cohort were predicted using growth curve models. Indicators of overweight and obesity duration and intensity were computed and their association with risk of postmenopausal breast, endometrial, and colorectal cancers was examined using multivariate Cox models for subjects followed-up beyond the age of 50 (n = 67,488). During a mean follow-up of 17 years, incident events of 3,016 postmenopausal breast, 410 endometrial and 987 colorectal cancers were ascertained. Each 0.1 kg/m2 per year increase in BMI between ages 20 and 50 was positively associated with risks of postmenopausal breast, endometrium and colorectal cancers with hazard ratios equal to 1.09 (95% Confidence Interval (CI):1.04-1.13), 1.31 (95% CI: 1.18-1.44) and 1.10 (95% CI: 1.00-1.21), respectively. Compared to women who were never obese, cumulative BMI × years of obesity were linearly positively associated with risk of endometrial cancer, whereas the association with breast cancer was initially positive, but leveled off with increasing cumulative BMI × years. Cumulative exposure to obesity may provide additional insights into the etiology of cancer and should be considered in future studies that assess obesity-cancer relationships.

Individual and interpersonal correlates of cardiorespiratory fitness in adults - Findings from the German Health Interview and Examination Survey

Cardiorespiratory fitness (CRF) is an established predictor of adverse health outcomes. The aim of this study is to investigate potential behavioral, interpersonal and socioeconomic correlates of CRF among men and women living in Germany using data from a population-based nationwide cross-sectional study. 1,439 men and 1,486 women aged 18-64 participated in the German Health Interview and Examination Survey (2008-2011) and completed a standardized sub-maximal cycle ergometer test. Maximal oxygen consumption ([Formula: see text]) in ml·min-1·kg-1 was estimated. Mean values of VO2max for various anthropometric, behavioral, interpersonal, and sociodemographic variables were estimated. Linear regression analyses using multiple imputations technique for missing values was performed to analyze the influence of potential correlates on CRF. Women with high alcohol consumption had higher [Formula: see text], (β = 2.20; 95% CI 0.98 to 3.42) than women with low alcohol consumption and women with high occupational status had higher [Formula: see text] (β = 1.83; 95% CI 0.21 to 3.44) in comparison to women with low occupational status. Among men, high fruit intake (β = 1.52; 95% CI 0.63 to 2.40), compared to low or medium fruit intake and performing at least 2.5 hours of total PA per week (β = 2.19; 95% CI 1.11 to 3.28), compared to less than 2.5 hours was associated with higher [Formula: see text]. Among both men and women, lower body mass index, lower waist circumference and higher levels of physical exercise were considerably associated with higher [Formula: see text]. Among women, those in higher age groups showed a considerably lower level of [Formula: see text] compared with those aged 18-24. Furthermore, mean estimated [Formula: see text] was higher among men (36.5; 95% CI 36.0 to 37.0) than among women (30.3; 95% CI 29.8 to 30.7). Despite the cross-sectional nature of the current study, we conclude that several behavioral, anthropometric, and sociodemographic factors are associated with CRF in the general adult population in Germany. These results can provide evidence to tailor prevention measures according to the needs of specific subgroups.

Type 2 Diabetes Mellitus, Glycated Hemoglobin Levels, and Cardiopulmonary Exercise Capacity in Patients With Ischemic Heart Disease

PURPOSE

Diabetes mellitus (DM) is associated with long-term cardiovascular complications, including ischemic heart disease (IHD). Nonetheless, DM may directly impair myocardial and lung structure and function. The aim of this study was to assess the impact of type 2 DM (T2DM) and glycemic control on cardiopulmonary exercise capacity in patients with IHD.

METHODS

The study involved a cross-sectional analysis of 91 consecutive patients (57 ± 10 yr, 90% men) who underwent a cardiopulmonary exercise test at the beginning of an exercise-based standard phase-II cardiac rehabilitation program, 2 to 3 mo after an acute coronary syndrome. Association of T2DM with cardiopulmonary exercise test parameters was assessed using multiple linear regression analysis controlling for prespecified potential confounders.

RESULTS

There were 26 (29%) diabetic subjects among IHD patients included in the study. After adjustment, T2DM was an independent predictor of a reduced peak oxygen uptake ((Equation is included in full-text article.)O2peak) (P = .005), a reduced pulse O2 trajectory (P = .001), a steeper minute ventilation to carbon dioxide output (VE/(Equation is included in full-text article.)CO2) slope (P = .046), and an increased dead space-to-tidal volume ratio (VD/VT) at peak exercise (P = .049). Glycated hemoglobin (HbA1c) levels were significantly associated with a reduced forced expiratory volume in the first second of expiration (FEV1) (P = .013), VE (P = .001), and VT (P = .007). (Equation is included in full-text article.)O2peak (P trend < .001), (Equation is included in full-text article.)O2 at anaerobic threshold (P trend < .001), and pulse O2 trajectory (P trend < .001) decreased among HbA1c tertiles.

CONCLUSIONS

Patients with IHD and a previous diagnosis of T2DM had a reduced aerobic capacity and a ventilation- perfusion mismatch compared with nondiabetic patients. Poor glycemic control in men further deteriorates aerobic capacity probably due to ventilatory inefficiency.

Correlates and Determinants of Cardiorespiratory Fitness in Adults: a Systematic Review

Background

Enhanced cardiorespiratory fitness (CRF) is now a well-established predictor of numerous adverse health outcomes. Knowledge about the pathways leading to enhanced CRF is essential for developing appropriate interventions. Hence, the aim of this review was to provide a detailed overview of the current state of research regarding individual factors associated with or influencing CRF among the general adult population.

Methods

We searched the PubMed, EMBASE, and Cochrane Library databases and also conducted a search for grey literature (Google Scholar). Eligible indicators of CRF were objectively assessed measures of CRF by submaximal or maximal exercise testing measured using treadmill or cycle ergometer tests. We included quantitative observational studies of the general adult population. Using a semi-quantitative approach, we compiled summary tables aggregating the study results for each potential correlate or determinant of CRF.

Results

We identified 3005 studies, 78 of which met the inclusion criteria. Almost all of these studies were conducted in high-income countries. Study quality scores assessing the risk of bias in the individual studies ranged from 40 to 100%. Male sex, age (inverse), education, socioeconomic status, ethnicity, body mass index (inverse), body weight (inverse), waist circumference, body fat (inverse), resting heart rate (inverse), C-reactive protein (inverse), smoking (inverse), alcohol consumption, and multiple measures of leisure-time physical activity were independently and consistently associated with CRF.

Conclusions

In synthesizing the current research on the correlates and determinants of CRF among adults, this systematic review identified gaps in the current understanding of factors influencing CRF. Beyond the scope of this review, environmental and interpersonal determinants should be further investigated.

Systematic Review Registration

PROSPERO, CRD42017055456.

Electronic supplementary material

The online version of this article (10.1186/s40798-019-0211-2) contains supplementary material, which is available to authorized users.

Factors Associated with Cardiorespiratory Fitness in a Swiss Working Population

Background

Good cardiorespiratory fitness (high VO_2max) has beneficial effects on morbidity and mortality. Therefore, a tool to estimate VO_2max in daily clinical practice is of great value for preventing chronic diseases in healthy adults. This study aimed at exploring the cardiometabolic profile in a representative Swiss working population. Based on these insights, a regression model was derived revealing factors associated with VO_2max.

Methods

Cross-sectional data of 337 healthy and full-time employed adults recruited in the Basel region, Switzerland, were collected. Anthropometric measurements to compute body mass index (BMI) and waist circumference (WC) were performed. A 20-meter shuttle run test was conducted to determine individual VO_2max. Heart rate (HR) was measured at rest, during maximal exertion, and two minutes after exercise. Systolic (SBP) and diastolic blood pressure (DBP) were assessed at rest and after exercise. A multiple linear regression model was built to identify a set of nonexercise predictor variables of VO_2max.

Results

Complete data of 303 individuals (63% male) aged 18 to 61 years (mean 33 ± 12 years) were considered for analysis. The regression model (adjusted R² = 0.647, SE = 5.3) identified sex (β = -0.699, p < 0.001), WC (β = -0.403, p < 0.001), difference of maximal to resting HR (β = 0.234, p < 0.001), smoking (β = -0.171, p < 0.001), and age (β = -0.131, p < 0.01) as the most important factors associated with VO_2max, while BMI, SBP, and DBP did not contribute to the regression model.

Conclusions

This study introduced a simple model to evaluate VO_2max based on nonexercise parameters as part of daily clinical routine without needing a time-consuming, cost-intense, and physically demanding direct assessment of VO_2max. Knowledge about VO_2max may help identifying individuals at increased cardiovascular risk and may provide the basis for health counselling and tailoring preventive measures.

Physical Fitness and Body Composition in Women with Systemic Lupus Erythematosus

Background and objectives: Higher physical fitness is associated with a more favorable weight and body composition in the general population, although this association has not been studied in patients with systemic lupus erythematosus (SLE). The aim of the present study was to examine the association of different components of physical fitness with body composition in women with SLE with mild disease activity. Materials and Methods: This cross-sectional study included 77 women with SLE (43.2 ± 13.8 years old) and clinical stability during the previous 6 months. Body composition (including body mass index (BMI), fat mass index (FMI), waist circumference, waist-to-height ratio and waist-to-hip ratio) was assessed using a stadiometer, an anthropometric tape, and a bioimpedance device. Physical fitness included cardiorespiratory fitness (Siconolfi step test and 6 min walk test), muscular strength (handgrip strength test as upper body measure and 30 s chair stand as lower body measure), and flexibility (back-scratch test). Participants with a fitness level equal or above the median of the study sample were categorized as "fit" and those below the median were categorized as "unfit". Linear regression assessed the association of physical fitness with body composition parameters. Results: Cardiorespiratory fitness and upper body muscular strength were negatively associated with BMI, FMI, waist circumference, and waist-to-height ratio (all, p < 0.05). Lower body muscular strength and flexibility were negatively related to FMI, waist circumference, waist-to-height ratio, and waist-to-hip ratio (all, p < 0.05). These relationships were still significant after controlling for age, disease duration, accrual damage, and SLE activity. Overall, fit patients presented significantly lower values in all body composition parameters compared to unfit patients (all, p < 0.05). Conclusions: The main findings of the present study suggest that physical fitness is inversely associated with body composition in women with SLE. Given the cross-sectional nature of this study, future clinical trials should study the causal pathways underlying these relationships.

Waist circumference thresholds and cardiorespiratory fitness

PURPOSE

This study's purpose was to examine whether established risk categories of waist circumference (WC)-normal, high risk, and very high health risk-reflected significant differences in cardiorespiratory fitness (CRF) and physical activity (PA) level.

METHODS

CRF was directly measured as maximal oxygen uptake during a progressive graded treadmill test to exhaustion in 722 individuals (349 women) aged 20-85 years. WC was measured between the lower rib and the iliac crest. Objectively measured PA was assessed using an accelerometer.

RESULTS

Men in the normal risk group (WC < 94 cm) had a 31% higher CRF and 43% higher level of moderate-to-vigorous PA than men in the very high risk group (with a WC > 102 cm). Corresponding numbers for women within normal (WC < 80 cm) and very high risk group (WC > 88 cm) were 25% and 18% (p < 0.05). There was a high negative correlation between CRF and WC in men (r = -0.68), and a moderate correlation for women (r = -0.49; p < 0.001). For each cm increase in WC, CRF was reduced by 0.48 and 0.27 mL/kg/min in men and women, respectively (p < 0.001).

CONCLUSION

The recommended WC thresholds for abdominal obesity reflected significant differences in CRF for both men and women, and could serve as a useful instrument for estimating health-related differences in CRF.

Association between Physical Condition and Body Composition, Nutrient Intake, Sociodemographic Characteristics, and Lifestyle Habits in Older Spanish Adults

In this study, we assessed physical condition and its association with body composition, nutrient intake, sociodemographic characteristics, and lifestyle habits in older Spanish adults. In this cross-sectional study, we investigated 380 individuals (54% women; men aged 55⁻80 years and women aged 60⁻80 years) with no previously documented cardiovascular disease. A general questionnaire was used, and body weight, height, fat, appendicular skeletal muscle mass, and waist circumference were assessed. Physical condition measurements included handgrip strength (HGS) and agility/dynamic balance by eight-foot time up-and-go (8-f TUG) test. The lowest maximum HGS score (kg) was found in older participants, inactive men, and men with abdominal obesity. The highest maximum 8-f TUG score (s) was found in older and inactive, low education, low income, and abdominal obesity and overfat participants; 24.5% of participants had low maximum HGS and 36.8% had a high 8-f TUG score. Sex- and/or age-adjusted odds ratio (OR) for low maximum HGS in women, older participants, overweight and overfat participants were 4.6, 2.9, 0.6 and 0.6 respectively. Sex and/or age adjusted OR for high maximum 8-f TUG in women, overweight, overfat, and abdominally obese participants were 2.4, 1.6, 1.7, and 3.4, respectively; in participants with higher education, those who earned €900 or more per month, and slightly active and active participants had OR values of 0.4, 0.4, and 0.3, respectively. Sarcopenia incidence was 0.3%; however, 4.5% of men and 19.1% of women registered low physical condition (high and low scores in 8-f TUG and HGS tests, respectively). Overall, 36.8%, 24.5%, and 0.3% of participants had high maximum 8-f TUG score, low maximum HGS, and sarcopenia, respectively. Prevalence of these low values varies according to sociodemographic and body composition variables.

The rise in obesity in Cuba from 2001 to 2010: An analysis of National Survey on Risk Factors and Chronic Diseases data

Using two waves of the National Survey on Risk Factors and Chronic Diseases in Cuba, we identify demographic and socioeconomic characteristics associated with obesity among urban adults aged 18+ and decompose the change in obesity within this 9-year period using both the mean-based Blinder-Oaxaca decomposition and a nonlinear approach. Our results reveal significant increases in overweight and obesity (2.3, 3.1, and 7.6 percentage points for BMI-based overweight, BMI-based obesity, and abdominal obesity, respectively). Depending on the decompositional approach and obesity measure, our analysis explains between 13% and 51% of the rise in overweight and obesity, with most part attributable to changes in risky behavior, age, and education. Of particular importance are the large decline in smoking and the population's changing age structure.

Short Telomere Length is Associated with Aging, Central Obesity, Poor Sleep and Hypertension in Lebanese Individuals

In Lebanon, data stemming from national cross-sectional surveys indicated significant increasing trends in the prevalence of cardiovascular diseases and associated behavioral and age-related risk factors. To our knowledge, no data are available on relative telomere length (RTL) as a potential biomarker for age-related diseases in a Lebanese population. The aim of this study was to evaluate whether there is an association between RTL and demographic characteristics, lifestyle habits and diseases in the Lebanese. This was a cross-sectional study of 497 Lebanese subjects. Peripheral blood RTL was measured by amplifying telomere and single copy gene using real-time PCR. Mean ± SD RTL was 1.42 ± 0.83, and it was categorized into 3 tertiles. Older age (P=0.002) and wider waist circumference (WC) (P=0.001) were statistically significantly associated with shorter RTL. Multinomial logistic regression showed that subjects who had some level of sleeping difficulty had a statistically significantly shorter RTL when compared to those with no sleeping difficulties at all [OR (95% CI): 2.01 (1.11-3.62) in the first RTL tertile]. Importantly, statistically significantly shorter RTL was found with every additional 10 cm of WC [OR (95% CI): 1.30 (1.11-1.52) for first RTL tertile]. In addition, and after performing the multivariate logistic regression and adjusting for “predictors” of RTL, the odds of having hypertension or being treated for hypertension were higher in patients who had shorter RTL: OR (95% CI): 2.45 (1.36-4.44) and 2.28 (1.22-4.26) in the first RTL tertiles respectively with a similar trend, though not statistically significant, in the second RTL tertiles. This is the first study in Lebanon to show an association between age, central obesity, poor sleep and hypertension and RTL. It is hoped that telomere length measurement be potentially used as a biomarker for biological age and age-related diseases and progression in the Lebanese.

Cardiorespiratory fitness and its association with adiposity indices in young adults

Objective:

This study investigated the relationship between cardiorespiratory fitness (CRF) and adiposity in young adults.

Methods:

Data was collected from 133 students of a medical college of Pakistan. The study was conducted on young adults, aged 17-24 years, recruited from Jinnah Medical & Dental College, Karachi, between Aug-Dec, 2015. Queen’s College Step Test was conducted to measure CRF and maximal oxygen uptake (VO_2max) evaluated. Anthropometric measurements (body mass index, body fat, visceral fat, waist circumference) were taken to assess adiposity. Associations of VO_2max and adiposity were analyzed.

Results:

The prevalence of overweight/obesity was 44% overall. The VO_2max (ml/kg/min) of males and females was 55.41±9.45 and 39.91±3.14, respectively, the gender difference being highly significant (p<0.001). Quartiles of VO_2max showed strong inverse relationship between adiposity and VO_2max, obese individuals having low VO_2max (1^st quartile) and normal weight individuals having high VO_2max (4^th quartile). VO2max correlated greatest with body fat in males (r = –0.600; p<0.001), and waist circumference in females (r = –0.319; p=0.004).

Conclusion:

The results indicate low CRF in young females and a strong inverse relationship between fitness levels and adiposity in young adults of both genders. Improving these parameters in our young population may prevent development of chronic non-communicable disease in later life.

Association between type 2 diabetes mellitus and anthropometric measurements - a case control study in South India

INTRODUCTION

Obesity is a major risk factor for type 2 diabetes mellitus (T2DM). Clinical evidence indicates a stronger association of diabetes with central obesity than general obesity. The present study aimed to compare the association between type 2 diabetes mellitus and different anthropometric measurements and evaluate the usefulness of these measurements in clinical practice.

METHODS

A case-control study was done among 102 individuals; of whom 51 cases included diagnosed T2DM (≥ 20 years age) patients attending the Medicine out-patient consultation of a tertiary care hospital and 51 controls who were screen negative for T2DM and recruited from the local community. Various anthropometric measurements were used according to standard World Health Organization (WHO) protocols. Data was entered and analyzed using Statistical Package for Social Sciences (SPSS) version 15.

RESULTS

The proportion of cases with Body Mass Index (BMI) ≥ 25 kg/m² was 55% as compared to 22% of controls and this association was statistically significant (p < 0.05). The proportion of cases with high waist circumference cut-offs (WC) was 74.5% as compared to 45.1% healthy individuals and this association was also statistically significant (p < 0.05, OR = 3.56). A Receiver Operating Characteristic (ROC) curve for both gender revealed highest area under the curve for body mass index (area = 0.787). Body mass index had the best discriminatory power. Waist to hip ratio was not a sensitive marker especially for females.

CONCLUSIONS

A strong association between obesity indices and diabetes was identified. BMI and WC could be used in clinical practice for suggesting life style modifications.

Mediterranean meal versus Western meal effects on postprandial ox-LDL, oxidative and inflammatory gene expression in healthy subjects: a randomized controlled trial for nutrigenomic approach in cardiometabolic risk

AIMS

Inflammation and oxidative damage contribute significantly to the development of cardiovascular diseases (CVD). Postprandial oxidative stress and inflammation are characterized by an increased susceptibility of the organism toward oxidative damage after consumption of a meal rich in lipids and/or carbohydrates. Micronutrients modulate immune system and exert a protective action by reducing oxidized low-density lipoprotein (ox-LDL) level. The aim of the present study was to evaluate the postprandial plasma ox-LDL level and the gene expression of 13 genes related to oxidative stress (HOSp) and human inflammasome pathways (HIp), after a tocopherol-enriched Mediterranean meal (TEM), and a Western high-fat meal (HFM). Moreover, Mediterranean Adequacy Index was calculated to define the quality of both meals.

METHODS

We set up a randomized and crossover trial in healthy human volunteers. Ox-LDL level was measured by enzyme-linked immunosorbent assay and the gene expression of 13 genes related to HOSp and HIp by qRT-PCR.

RESULTS

Ox-LDL levels significantly decreased comparing HFM versus TEM (p < 0.05). Percentages of significantly overexpressed genes after each dietary treatment are as follows: (A) baseline versus HFM: 7.69 % HIp and 23.08 % HOSp; (B) baseline versus TEM: 7.69 % HIp and 7.69 % HOSp; (C) HFM versus TEM: 15.38 % HIp and 15.38 % HOSp.

CONCLUSIONS

TEM reduced postprandial risk factors of CVD, such as ox-LDL, and the expression of inflammation and oxidative stress-related genes. Chronic studies on larger population are necessary before definitive conclusions.

TRIAL REGISTRATION

ClinicalTrials.gov Id: NCT01890070.

Overfat and Underfat: New Terms and Definitions Long Overdue

For the first time in human history, the number of obese people worldwide now exceeds those who are underweight. However, it is possible that there is an even more serious problem-an overfat pandemic comprised of people who exhibit metabolic health impairments associated with excess fat mass relative to lean body mass. Many overfat individuals, however, are not necessarily classified clinically as overweight or obese, despite the common use of body mass index as the clinical classifier of obesity and overweight. The well-documented obesity epidemic may merely be the tip of the overfat iceberg. The counterpart to the overfat condition is the underfat state, also a common and dangerous health circumstance associated with chronic illness and starvation. Currently (and paradoxically), high rates of obesity and overweight development coexist with undernutrition in developing countries. Studies in cognitive linguistics suggest that accurate, useful, and unintimidating terminology regarding abnormal body fat conditions could help increase a person's awareness of their situation, helping the process of implementing prevention and simple remedies. Our contention is that promoting the terms "overfat" and "underfat" to describe body composition states to the point where they enter into common usage may help in creating substantive improvements in world health.

Increased Gustatory Response Score in Obesity and Association Levels with IL-6 and Leptin

Background. The aim of this study was to investigate the relationship between the circulating IL-6 and leptin levels with taste alteration in young obese patients. Methods. A retrospective case-control study was conducted in thirty obese patients and thirty age- and sex-matched healthy controls. Results. Circulating levels of IL-6 and leptin were significantly increased in obese patients than in controls. However, catalase and ORAC levels were significantly decreased in obese patients compared to controls. Additionally, obese participants had high scores for the detection of fats (gustatory response scores [GRS]; p < 0.001). Moreover, IL-6 and leptin were strongly associated with GRS alteration among patients with GRS 4 (resp., OR =17.5 [95% CI, 1.56–193.32; p = 0.007]; OR = 16 [95% CI, 1.69–151.11; p = 0.006]). For the Mantel-Haenszel common odds ratio estimate (MH OR), IL-6 and leptin were strongly associated with obesity, in patients with either GRS 4 or GRS > 4 (resp., MH OR = 8.77 [95% CI, 2.06–37.44; p = 0.003]; MH OR = 5.76 [95% CI, 1.64–20.24; p = 0.006]). Conclusions. In a low grade inflammation linked to obesity, taste alteration is associated with high levels of IL-6 and leptin.

Multicollinearity in Regression Analyses Conducted in Epidemiologic Studies

The adverse impact of ignoring multicollinearity on findings and data interpretation in regression analysis is very well documented in the statistical literature. The failure to identify and report multicollinearity could result in misleading interpretations of the results. A review of epidemiological literature in PubMed from January 2004 to December 2013, illustrated the need for a greater attention to identifying and minimizing the effect of multicollinearity in analysis of data from epidemiologic studies. We used simulated datasets and real life data from the Cameron County Hispanic Cohort to demonstrate the adverse effects of multicollinearity in the regression analysis and encourage researchers to consider the diagnostic for multicollinearity as one of the steps in regression analysis.

Cardiorespiratory Fitness and Metabolic Syndrome in Postmenopausal African-American Women

We examined the association of cardiorespiratory fitness with metabolic syndrome in overweight/obese postmenopausal African-American women. Pooled baseline data on 170 African-American women from 2 exercise trials were examined. Metabolic syndrome was defined as at least 3 of the following: abdominal obesity, glucose intolerance, hypertension, low high-density lipoprotein cholesterol (HDL-C), and high triglycerides. Cardiorespiratory fitness (VO2peak) was determined using the Bruce treadmill protocol and categorized as: Very Low (VLCRF<18 mL·kg(-1) min(-1)), Low (LCRF=18.0-220-22-22.0 mL·kg(-1) min(-1)), and Moderate (MCRF>22.0 mL·kg(-1) min(-1)). Associations of metabolic syndrome with cardiorespiratory fitness were analyzed using one-way ANOVA and linear regression. VO2peak was significantly lower in the VLCRF compared to the MCRF group. Lower cardiorespiratory fitness was associated with higher prevalence of metabolic syndrome, abdominal obesity, hypertriglyceridemia, and low HDL among overweight/obese postmenopausal African-American women. In fully adjusted models, higher waist circumference and triglycerides were associated with lower VO2peak levels (P<0.01) and higher HDL-C was associated with higher VO2peak levels (P=0.03). Overweight/obese postmenopausal African-American women with very low cardiorespiratory fitness are more likely to have metabolic syndrome, higher body mass index, and unhealthier levels of certain metabolic syndrome components than women with moderate cardiorespiratory fitness.

Risk Factors and Disability Associated with Low Back Pain in Older Adults in Low- and Middle-Income Countries. Results from the WHO Study on Global AGEing and Adult Health (SAGE)

BACKGROUND

Back pain is a common disabling chronic condition that burdens individuals, families and societies. Epidemiological evidence, mainly from high-income countries, shows positive association between back pain prevalence and older age. There is an urgent need for accurate epidemiological data on back pain in adult populations in low- and middle-income countries (LMICs) where populations are ageing rapidly. The objectives of this study are to: measure the prevalence of back pain; identify risk factors and determinants associated with back pain, and describe association between back pain and disability in adults aged 50 years and older, in six LMICs from different regions of the world. The findings provide insights into country-level differences in self-reported back pain and disability in a group of socially, culturally, economically and geographically diverse LMICs.

METHODS

Standardized national survey data collected from adults (50 years and older) participating in the World Health Organization (WHO) Study on global AGEing and adult health (SAGE) were analysed. The weighted sample (n = 30, 146) comprised respondents in China, Ghana, India, Mexico, South Africa and the Russian Federation. Multivariable regressions describe factors associated with back pain prevalence and intensity, and back pain as a determinant of disability.

RESULTS

Prevalence was highest in the Russian Federation (56%) and lowest in China (22%). In the pooled multi-country analyses, female sex, lower education, lower wealth and multiple chronic morbidities were significant in association with past-month back pain (p<0.01). About 8% of respondents reported that they experienced intense back pain in the previous month.

CONCLUSIONS

Evidence on back pain and its impact on disability is needed in developing countries so that governments can invest in cost-effective education and rehabilitation to reduce the growing social and economic burden imposed by this disabling condition.

Does selection bias explain the obesity paradox among individuals with cardiovascular disease?

OBJECTIVES

The objectives of this article are to demonstrate that the obesity paradox may be explained by collider stratification bias and to estimate the biasing effects of unmeasured common causes of cardiovascular disease (CVD) and mortality on the observed obesity-mortality relationship.

METHODS

We use directed acyclic graphs, regression modeling, and sensitivity analyses to explore whether the observed protective effect of obesity among individuals with CVD can be plausibly attributed to selection bias. Data from the third National Health and Examination Survey was used for the analyses.

RESULTS

The adjusted total effect of obesity on mortality was a risk difference (RD) of 0.03 (95% confidence interval [CI]: 0.02, 0.05). However, the controlled direct effect of obesity on mortality among individuals without CVD was RD = 0.03 (95% CI: 0.01, 0.05) and RD = -0.12 (95% CI: -0.20, -0.04) among individuals with CVD. The adjusted total effect estimate demonstrates an increased number of deaths among obese individuals relative to nonobese counterparts, whereas the controlled direct effect shows a paradoxical decrease in morality among obese individuals with CVD.

CONCLUSIONS

Sensitivity analysis demonstrates unmeasured confounding of the mediator-outcome relationship provides a sufficient explanation for the observed protective effect of obesity on mortality among individuals with CVD.

Impact of obesity and Down syndrome on peak heart rate and aerobic capacity in youth and adults

Individuals with Down syndrome (DS) exhibit reduced aerobic capacity with reduced peak heart rate (HR_peak). This condition is often coexistent with higher level of obesity compared to individuals without DS. The purpose of this study is to investigate the effects of obesity and Down syndrome (DS) on peak heart rate (HR_peak) and peak oxygen consumption (VO_2peak) in children and adults both with and without intellectual disabilities (ID)s. VO_2peak and HR_peak from individualized treadmill tests on 654 individuals were analyzed. Body mass index was used to categorize individuals' weight status using standard cut-offs. DS groups had the lowest HR_peak (167bpm±14, p<0.05) compared to individuals with (183bpm±12) without ID (187bpm±12). Obesity did not affect HR_peak among adults and children with DS. VO_2peak was lower among individuals with DS (25.2mL/kg/min±6.3, p<0.05) when compared individuals with (37.0mL/kg/min±10.5) and without ID (36.1mL/kg/min±10.4). Obese adults with DS had lower VO_2peak (24.3mL/kg/min±6.9, p=0.001) compared to the normal weight (26.7±7.1mL/kg/min) and overweight groups (27.0mL/kg/min±6.1) with DS. Conversely, in children, obesity level did not impact VO_2peak in individuals with DS. Our results suggest that DS attenuates both VO_2peak and HR_peak, regardless of obesity status and age group. However, obesity was associated with lower VO_2peak in all adults, but not in children with DS.

Genetic association of ADIPOQ gene variants with type 2 diabetes, obesity and serum adiponectin levels in south Indian population

OBJECTIVE

To investigate the genetic association of eight variants of the adiponectin gene with type 2 diabetes mellitus (T2DM), obesity and serum adiponectin level in the south Indian population.

METHODS

The study comprised of 1100 normal glucose tolerant (NGT) and 1100 type 2 diabetic, unrelated subjects randomly selected from the Chennai Urban Rural Epidemiology Study (CURES), in southern India. Fasting serum adiponectin levels were measured by radioimmunoassay. The variants were screened by polymerase chain reaction-restriction fragment length polymorphism. Linkage disequilibrium was estimated from the estimates of haplotype frequencies.

RESULTS

Of the 8 variants, four SNPs namely, +276 G/T (rs1501299), -4522 C/T (rs822393), -11365 C/G (rs266729), and +712 G/A (rs3774261) were significantly associated with T2DM in our study population. The -3971 A/G (rs822396) and -11391 G/A (rs17300539) SNPs' association with T2DM diabetes was mediated through obesity (where the association with type 2 diabetes was lost after adjusting for BMI). There was an independent association of +276 G/T (rs1501299) and -3971 A/G (rs822396) SNPs with generalized obesity and +349 A/G (rs2241767) with central obesity. Four SNPs, -3971 A/G (rs822396), +276 G/T (rs1501299), -4522 C/T (rs822393) and Y111H T/C (rs17366743) were significantly associated with hypoadiponectinemia. The haplotypes GCCATGAAT and AGCGTGGGT conferred lower risk of T2DM in this south Indian population.

CONCLUSION

The adiponectin gene variants and haplotype contribute to the genetic risk towards the development of type 2 diabetes, obesity and hypoadiponectinemia in the south Indian population.