The inter-operator variability in measuring waist circumference and its potential impact on the diagnosis of the metabolic syndrome

Obesity prediction: Novel machine learning insights into waist circumference accuracy

AIMS

This study aims to enhance the precision of obesity risk assessments by improving the accuracy of waist circumference predictions using machine learning techniques.

METHODS

We utilized data from the NHANES and Look AHEAD studies, applying machine learning algorithms augmented with uncertainty quantification. Our approach centered on conformal prediction techniques, which provide a methodological basis for generating prediction intervals that reflect uncertainty levels. This method allows for constructing intervals expected to contain the true waist circumference values with a high degree of probability.

RESULTS

The application of conformal predictions yielded high coverage rates, achieving 0.955 for men and 0.954 for women in the NHANES dataset. These rates surpassed the expected performance benchmarks and demonstrated robustness when applied to the Look AHEAD dataset, maintaining coverage rates of 0.951 for men and 0.952 for women. Traditional point prediction models did not show such high consistency or reliability.

CONCLUSIONS

The findings support the integration of waist circumference into standard clinical practice for obesity-related risk assessments using machine learning approaches.

Ultrasonographic Assessment of Body Fat Index for Prediction of Gestational Diabetes Mellitus and Neonatal Complications

OBJECTIVES

To assess maternal pre-peritoneal fat and subcutaneous fat at 16-20 weeks gestation by ultrasound. Thus, calculate body fat index (BFI) and determine its cut-off value for prediction of gestational diabetes mellitus (GDM) and neonatal subcutaneous adiposity.

METHODS

A cohort study was conducted in 200 pregnant women with singleton fetus during anomaly scan using BFI where they were screened for GDM at 24-28 weeks gestation by oral glucose tolerance test. Labour and neonatal outcomes were recorded. The receiver operating characteristic curve was used to determine the cut-offs for BFI, pre-peritoneal fat thickness, and subcutaneous fat thickness in order to predict GDM.

RESULTS

The area under receiver operating characteristic curve for BFI was 0.967 (95% CI 0.932-0.987) with a sensitivity of 97.3%, specificity of 89.57%, negative predictive value of 99.3%, and diagnostic accuracy of 91% at a BFI cut-off of 0.88. The study analysis demonstrated BFI to be statistically superior to BMI > 22.9 kg/m2 for prediction of GDM. BFI > 0.88 was a risk factor for developing neonatal subcutaneous adiposity.

CONCLUSIONS

BFI is a practical and convenient non-invasive screening tool to predict GDM and neonatal subcutaneous adiposity.

Comparison of bioelectrical impedance analysis, mass index, and waist circumference in assessing risk for non-alcoholic steatohepatitis

OBJECTIVE

Non-alcoholic fatty liver disease is a leading cause of liver disease worldwide and includes nonalcoholic steatohepatitis (NASH), which can progress to cirrhosis. Because NASH is associated with obesity severity, routine evaluation of obesity/body fat in clinical settings may help detect patients at risk. The aim of this study was to determine whether assessing body fat by bioelectrical impedance analysis (BIA) is superior to body mass index (BMI) and waist circumference (WC) in assessing the risk for NASH.

METHODS

In this cross-sectional study, patients were recruited and gave consent from a local hospital. All had a liver biopsy. Measurements before the biopsy included BMI, WC, and BIA. BIA was used to measure percentage body fat and fat mass (kg). Based on histology, patients were grouped into one of three categories: simple steatosis (SS), NASH, or normal liver (NL).

RESULTS

Of the 139 participants who participated, 39 were classified as SS, 53 as NASH, and 47 as NL. Regardless of sex, patients with NASH had significantly higher BMI, WC, percentage body fat and fat mass than those with NL or SS. These four parameters were significantly positively correlated with liver histology measurements. In all patients, when controlling for sex and age we found that BMI, WC, and BIA were equal at predicting the presence of NASH (P = 0.0571).

CONCLUSION

All three methods, BIA, BMI, and WC, were comparable in assessing the risk for NASH. For practical purpose in clinical settings, using BMI is acceptable.

Tri-Ponderal Mass Index as a Screening Tool for Identifying Body Fat and Cardiovascular Risk Factors in Children and Adolescents: A Systematic Review

Because of the limitation of body mass index (BMI) in distinguishing adipose mass from muscle, the tri-ponderal mass index (TMI) has been proposed as a new indicator for better assessing adiposity in children and adolescents. However, it remains unclear whether TMI performs better than BMI or other adiposity indices in predicting obesity status in childhood and obesity-related cardiovascular risk factors (CVRFs) in childhood or adulthood. We searched PubMed, Cochrane Library, and Web of Science for eligible publications until June 15, 2021. A total of 32 eligible studies were included in this systematic review. We found that TMI had a similar or better ability to predict body fat among children and adolescents than BMI. However, most of the included studies suggested that TMI was similar to BMI in identifying metabolic syndrome although TMI was suggested to be a useful tool when used in combination with other indicators (e.g., BMI and waist circumference). In addition, limited evidence showed that TMI did not perform better than BMI for identifying specific CVRFs, including insulin resistance, high blood pressure, dyslipidemia, and inflammation in children and adolescents, as well as CVRFs in adults.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero, CRD42021260356.

Magnitude of Central Obesity and its Associated Factors Among Adults in Urban Areas of Northwest Ethiopia

PURPOSE

Obesity is becoming one of the most common public health problems worldwide. In particular, central obesity which indicates abnormal fat accumulation in the abdominal regions is highly associated with the risk of getting cardiometabolic diseases and their progression to end stage diseases or death. However, in developing countries, including Ethiopia less attention has been given to analyze the magnitude and associated factors of it. Therefore, we aimed to determine the prevalence of central obesity and its associated factors among adults in urban areas of Northwest Ethiopia.

METHODS

A cross-sectional study was conducted among 773 adults who lived in urban areas of Northwest Ethiopia from April 1 to May 30, 2019. Central obesity was assessed using both waist to hip ratio and waist circumference of the participants. Data were analyzed using STATA 14.0. The factors associated with central obesity were identified by binary logistic regression analyses using 95% confidence interval and the degree of association of the factors was measured using adjusted odds ratio (AOR). P-value <0.05 was used to declare statistical significance.

RESULTS

The prevalence of central obesity with waist circumference and waist to hip ratio definition criteria was 37.6% and 35.7%, respectively. According to body mass index, about 26.26% and 10.29% of the study participants were overweight and obese, respectively. A one-year increase in age (AOR=1.05; 95%CI: 1.03-1.07), being female (AOR=9.62; 95%CI: 4.84-19.12) and eating of liquid oils (AOR=2.58; 95%CI: 1.71-3.90) were found to have statistically significant variables with central obesity.

CONCLUSION

The prevalence of central obesity was relatively high in comparison with similar studies. Thus, governmental and nongovernmental organizations that work in the health system as well as health professionals should focus on the preventive measure of central obesity to control its associated disorders at an early stage.

Agreement and Reliability of Clinician-in-Clinic Versus Patient-at-Home Clinical and Functional Assessments: Implications for Telehealth Services

Objective

To compare agreement and reliability between clinician-measured and patient self-measured clinical and functional assessments for use in remote monitoring, in a home-based setting, using telehealth.

Design

Reliability study: repeated-measure, within-subject design.

Setting

Trained clinicians measured standard clinical and functional parameters at a face-to-face clinic appointment. Participants were instructed on how to perform the measures at home and to repeat self-assessments within 1 week.

Participants

Liver transplant recipients (LTRs) (N=18) (52±14y, 56% men, 5.4±4.3y posttransplant] completed the home self-assessments.

Interventions

Not applicable.

Main Outcome Measures

The outcomes assessed were body weight, systolic and diastolic blood pressure (SBP and DBP), waist circumference, repeated chair sit-to-stand (STST), maximal push-ups, and the 6-minute walk test (6MWT). Intertester reliability and agreement between face-to-face clinician and self-reported home-based participant measures were determined by intraclass-correlation coefficients (ICCs) and Bland-Altman plots, which were compared with minimal clinically important differences (MCID) (determined a priori).

Results

The mean difference (95% confidence interval) and [limits of agreement] for measures (where positive values indicate lower participant value) were weight, 0.7 (0.01-1.4) kg [−2.2 to 3.6kg]; waist 0.4 (−1.2 to 2.0) cm [−5.9 to 6.8cm]; SBP 7.7 (0.6-14.7 ) mmHg [−19.4 to 34.9mmHg]; DBP 2.4 (−1.4 to 6.2 ) mmHg [−12.2 to 17.0mmHg]; 6MWT, 7.5 (−29.1 to 44.1) m [−127.3 to 142.4m]; STST 0.5 (−0.8 to 1.7) seconds [−4.3 to 5.3s]; maximal push-ups −2.2 (−4.4 to −0.1) [−10.5 to 6.0]. ICCs were all >0.75 except for STST (ICC=0.73). Mean differences indicated good agreement than MCIDs; however, wide limits of agreement indicated large individual variability in agreement.

Conclusions

Overall, LTRs can reliably self-assess clinical and functional measures at home. However, there was wide individual variability in accuracy and agreement, with no functional assessment being performed within acceptable limits relative to MCIDs >80% of the time.

Relationship between Maternal Central Obesity and the Risk of Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis of Cohort Studies

OBJECTIVE

Nowadays, body mass index (BMI) is used to evaluate the risk stratification of obesity-related pregnancy complications in clinics. However, BMI cannot reflect fat distribution or the proportion of adipose to nonadipose tissue. The objective of this study is to evaluate the association of maternal first or second trimester central obesity with the risk of GDM. Research Design and Methods. We searched in PubMed, Embase, and Web of Science for English-language medical literature published up to 12 May 2019. Cohort studies were only included in the search. Abdominal subcutaneous fat thickness, waist circumference, waist-hip ratio or body fat distribution were elected as measures of maternal central obesity, and all diagnostic criteria for GDM were accepted. The random effect meta-analysis was performed to evaluate the relationship between central obesity and the risk of GDM.

RESULTS

A total of 11 cohort studies with an overall sample size of 27,675 women and 2,226 patients with GDM were included in the analysis. The summary estimate of GDM risk in the central obesity pregnant women was 2.76 (95% confidence interval [CI]: 2.35-3.26) using the adjusted odds ratio (OR). The degree of heterogeneity among the studies was low (I ² = 14.4, P = 0.307). The subgroup analyses showed that heterogeneity was affected by selected study characteristics (methods of exposure and trimesters). After adjusting for potential confounds, the OR of adjusted BMI was significant (OR = 3.07, 95% CI: 2.35-4.00).

CONCLUSIONS

Our findings indicate that the risk of GDM was positively associated with maternal central obesity.

Relative Fat Mass as an estimator of whole-body fat percentage among children and adolescents: A cross-sectional study using NHANES

We evaluated the ability of the Relative Fat Mass (RFM) to estimate whole-body fat percentage among children and adolescents who participated in the National Health and Nutrition Examination Survey from 1999 through 2006 (n = 10,390). The RFM equation for adults (64 − (20 × height/waist circumference) + (12 × sex)) may be used for adolescents 15 to 19 years of age. For children and adolescents 8 to 14 years of age, we suggest a modified RFM equation, named as the RFMp (RFM pediatric): 74 − (22 × height/waist circumference) + (5 × sex). In both equations, sex equals 0 for boys and 1 for girls. RFMp was more accurate than BMI to estimate whole-body fat percentage (measured by dual energy X-ray absorptiometry, DXA) among girls (percentage of estimates that were <20% of measured body fat percentage, 88.2% vs. 85.7%; P = 0.027) and boys 8 to 14 years of age (83.4% vs. 71.0%; P < 0.001). RFM was more accurate than BMI among boys 15 to 19 years of age (82.3% vs. 73.9%; P < 0.001) but slightly less accurate among girls (89.0% vs. 92.6%; P = 0.002). Compared with BMI-for-age percentiles, RFMp had lower misclassification error of overweight or obesity (defined as a DXA-measured body fat percentage at the 85^th percentile or higher) among boys 8 to 14 years of age (6.5% vs. 7.9%; P = 0.018) but not girls (RFMp: 8.2%; BMI-for-age: 7.9%; P = 0.681). Misclassification error of overweight or obesity was similar for RFM and BMI-for-age percentiles among girls (RFM: 8.0%; BMI-for-age: 6.6%; P = 0.076) and boys 15 to 19 years of age (RFM: 6.9%; BMI-for-age: 7.8%; P = 0.11). RFMp for children and adolescents 8 to 14 years of age and RFM for adolescents 15 to 19 years of age were useful to estimate whole-body fat percentage and diagnose body fat-defined overweight or obesity.

Association of adiposity with thyroid nodules: a cross-sectional study of a healthy population in Beijing, China

BACKGROUND

The relationship between thyroid nodules (TNs) and adiposity is controversial. This paper describes a cross-sectional investigation performed to determine the existence of any such relationship. To assess adiposity, body mass index (BMI) and visceral fat area (VFA) were utilized.

METHODS

Between January 1, 2017 and March 3, 2019. Three thousand five hundred thirty four healthy people were examined using thyroid ultrasonography, visceral fat and anthropometric measurements, laboratory tests and questionnaire interview. Binary logistic regression analyses were used.

RESULTS

Of the 3534 healthy subjects, 58.69% (2074/3534) of the subjects had TNs. A total of 55.91% (1976/3534) had BMI ≥ 25 kg/m² and 39.67% (1402/3534) had VFA ≥ 100 cm². After adjustment to address confounders, BMI-based overweight and obesity levels only correlated with higher risk TNs when used as a continuous variable (OR = 1.031, 95% CI: 1.008-1.055, P = 0.008), while VFA was both a continuous variable (OR = 1.003, 95% CI: 1.000-1.005, P = 0.034) and a categorical variable (OR = 1.198, 95% CI: 1.014-1.417, P = 0.034) associated with significantly elevated risk of TNs. Analyzing the subgroups, BMI ≥ 25 kg/m² (OR = 1.500, 95% CI: 1.110-2.026, P = 0.008) was significantly correlated with TN risk in individuals with TG ≥ 1.7 mmol/L. VFA ≥ 100 cm² correlated with the TN risk irrespective of age (< 50 years: OR = 1.374, 95% CI: 1.109-1.703, P = 0.004; ≥ 50 years: OR = 1.367, 95% CI: 1.063-1.759, P = 0.015) and in the following subgroups: women (OR = 4.575, 95% CI: 2.558-8.181, P = 0.000), FBG ≥ 6.1 mmol/L (OR = 1.522, 95% CI: 1.048-2.209, P = 0.027), and TG ≥ 1.7 mmol/L (OR = 1.414, 95% CI: 1.088-1.838, P = 0.010).

CONCLUSIONS

Adiposity correlates with TNs. To assess TN risk in Chinese individuals, VFA is better than BMI.

Additive interaction of snoring and body mass index on the prevalence of metabolic syndrome among Chinese coal mine employees: a cross-sectional study

BACKGROUND

Although snoring has been previously reported to be associated with metabolic syndrome (MetS), its interaction with body mass index(BMI) on MetS remains unclear. We aimed to examine the individual effects and possible interaction between snoring and BMI on MetS.

METHODS

From July 2013 to December 2013, 3794 employees of coal mining enterprises aged 18 to 65 were recruited from Shanxi province of China. The individual effects were assessed by multivariable logistic regression model. Additive interaction was evaluated by calculating the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index(S).

RESULTS

We found that, after adjusting for potential confounders, odds ratio (OR) and 95% CI for MetS was 1.30 (1.09, 1.56) in occasional snorers and 1.50 (1.24, 1.82) in habitual snorers compared with non-snorers. BMI ≥ 24 was related to high risk of MetS (OR, 3.27; 95% CI, 2.93-3.63). Significant additive interaction between snoring and BMI on MetS was detected. The estimates and 95% CI of the RERI, AP and S were 1.89 (0.67, 3.24), 0.23 (0.08, 0.38), and 1.37 (1.11, 1.75), respectively. However, stratified by workplace, the additive interaction was only significant among underground front-line and ground workers.

CONCLUSIONS

Both Snoring and BMI were related to high risk of Mets. Moreover, there are additive interaction between snoring and BMI. Snorers who worked underground front-line and ground are more susceptible to the negative impact of being overweight on MetS.

Body fat index: A novel alternative to body mass index for prediction of gestational diabetes and hypertensive disorders in pregnancy

OBJECTIVES

To evaluate the association of ultrasound measurement of maternal abdominal subcutaneous and pre-peritoneal fat thickness in relation to the subsequent diagnosis of gestational diabetes (GDM), and to assess the association of body fat index (BFI), compared to conventional body mass index (BMI), with respect to the development of some obstetric related complications.

STUDY DESIGN

A prospective study included non-diabetic pregnant women who were scheduled for fetal anatomic survey. Women underwent fat measurements and BFI (pre-peritoneal fat x subcutaneous fat/height) was calculated. They underwent routine glucose screening and diagnostic tests for GDM. Obstetric complications, mode of delivery, and delivery related events were reported. Multivariable logistic regression was used to test potential predictors for development of obesity-related complications. Primary outcome was development of GDM. Secondary outcomes included development of hypertensive disorders during pregnancy and need for cesarean delivery due to labor dystocia. The optimal cut-off points for continuous variables were obtained using a receiver operating characteristic (ROC) curve analyses.

RESULTS

389 women met study criteria. Median gestational age at time of ultrasound evaluation was 19.1 weeks. Positive family history of diabetes (adjusted odds ratio "OR" 2.30, 95% CI 1.35-3.92), history of GDM (adjusted OR 6.87, 95% CI 3.03-15.61), subcutaneous fat≥13 mm (adjusted OR 4.63, 95% CI 1.60-13.38) and pre-peritoneal fat≥12 mm (adjusted OR 3.32, 95% CI 1.06-10.42) were significant predictors for development of GDM. ROC analysis demonstrated that a BFI > 0.5 was statistically superior to a BMI > 25 or 30 as a predictor of gestational diabetes (adjusted OR 6.24, 95% CI 1.86-20.96). A Similar ROC analysis demonstrated that a BFI > 0.8 was associated with a higher risk for the development of hypertensive disorders of pregnancy (adjusted OR 2.70 [95% CI 1.60-4.55]), and need for cesarean delivery (adjusted OR 2.01[95% CI 1.23-3.28]) than a BMI > 25 or 30.

CONCLUSION

Values obtained by ultrasound measurement of subcutaneous and pre-peritoneal fat are associated with development of GDM and hypertensive disorders in pregnancy. Our data suggest that BFI was a better predictor than BMI for development of GDM and hypertensive disorders in pregnancy and should be studied further.

Reference centile curves for wrist circumference for Indian children aged 3-18 years

BACKGROUND

Childhood obesity and its consequences have reached alarming proportions worldwide and in India. Wrist circumference is emerging as an easily measurable reproducible parameter for screening children at risk of obesity-related morbidities such as hypertension and insulin resistance. The objectives of this study were: (1) to compute age and gender-specific wrist circumference percentiles for 3-18-year-old apparently healthy Indian children and adolescents; (2) to assess the relationship of wrist circumference with measures of obesity and adiposity such as body mass index (BMI), fat percentage and blood pressure (BP) and (3) to suggest age and gender-specific cut-offs for wrist circumference percentile for the risk of hypertension in Indian children and adolescents.

METHODS

This was a cross-sectional study on samples of 10,199 3-18-year-old children (5703 boys) from randomly selected schools from five major cities in India. Height, weight, waist and wrist circumference and BP were recorded. Body composition was measured using bioelectrical impedance analysis (BIA). Wrist circumference percentiles were computed using the LMS method.

RESULTS

The average wrist circumference of boys and girls was 10.4 cm and 10.0 cm at 3 years and increased to 15.1 cm and 13.9 cm, respectively, at 18 years. Compared to their Caucasian counterparts, Indian children's wrists were smaller. Receiver operating characteristic (ROC) curve analysis derived the 70th percentile of wrist circumference as the cut-off for identifying the risk of hypertension.

CONCLUSIONS

Contemporary cross-sectional reference percentile curves for wrist circumference for 3-18-year-old Indian children are presented. The 70th percentile of the current study is proposed as the cut-off to screen children for cardiometabolic risk factors such as hypertension.

Solving a weighty problem: systematic review and meta-analysis of nutrition interventions in severe mental illness

BACKGROUND

Nutrition interventions would appear fundamental for weight management and cardiometabolic risk reduction in people experiencing severe mental illness (SMI). Comprehensive evaluation of nutrition interventions is lacking.

AIMS

To subject randomised controlled trials of nutrition interventions in people with SMI to systematic review and meta-analysis, and to measure anthropometric and biochemical parameters and nutritional intake.

METHOD

An electronic database search identified trials with nutrition intervention components. Trials were pooled for meta-analysis. Meta-regression analyses were performed on anthropometric moderators.

RESULTS

Interventions led to significant weight loss (19 studies), reduced body mass index (17 studies), decreased waist circumference (10 studies) and lower blood glucose levels (5 studies). Dietitian-led interventions (6 studies) and studies delivered at antipsychotic initiation (4 studies) had larger effect sizes.

CONCLUSIONS

Evidence supports nutrition interventions as standard care in preventing and treating weight gain among people experiencing SMI.

Association between Serum Thyroid-Stimulating Hormone Levels and Visceral Adipose Tissue: A Population-Based Study in Northeast Germany

BACKGROUND

Abdominal obesity is a major driver for adverse medical conditions. While an interaction between adipose tissue and thyroid function is thought to exist, to our knowledge, no study has examined the effect of thyroid-stimulating hormone (TSH) on visceral adipose tissue (VAT) in a population-based context.

OBJECTIVE

We determined an association between serum TSH levels and VAT.

METHODS

A sample of 1,021 female and 956 male adults aged 20-79 years was drawn from registry offices in the cross-sectional, population-based Study of Health in Pomerania Trend (SHIP Trend) in Northeast Germany from 2008 to 2012. Our main exposure was serum TSH levels. Our main outcome was VAT measured using magnetic resonance imaging. The possibly mediating role of leptin on the TSH-VAT association was also assessed.

RESULTS

A total of 1,719 participants (87.9%) had serum TSH levels within the reference range. The mean volume of VAT was 5.33 liters for men and 2.83 liters for women. No association between TSH and VAT (β = 0.06, 95% CI: -0.02, 0.14) was observed, and there were no differences detected between sexes. VAT was strongly associated with leptin with a greater effect in women than in men. Leptin was strongly associated with TSH.

CONCLUSIONS

No association between TSH and VAT was observed. Other biomarkers such as leptin may play a role in the relationship between thyroid function and metabolic risk.

Inter- and intra-operator variability in the analysis of packed cell volume

OBJECTIVES

To identify whether inter- and intra-operator variability occurs in the measurement of canine packed cell volume and, if so, at which stage these errors occur.

MATERIALS AND METHODS

Undergraduate veterinary students and veterinary surgeons were recruited to measure the packed cell volumes of three samples in duplicate. Measurements from each sample were confirmed by one author, and it was then ascertained whether the error was made in the capillary preparation or reading.

RESULTS

Data were obtained from 44 students and 11 vets. A total of 25% of students made errors associated with inadequate mixing; 23% students and 9% of vets made errors consistent with incorrect reading. There was also less intra-operator variation in values within the vet group (0·027 from the mean) in comparison to the student group (-0·21 from the mean). A total of 68·2% of students and 91% of vets filled the capillary tubes outwith World Health Organisation standards of two-thirds to three-quarters full.

CLINICAL SIGNIFICANCE

Packed cell volume measurement is extremely useful when measuring erythroid mass, but it is crucial that the results upon which decisions are made are accurate and precise in order to manage these cases appropriately. Operator variation is a significant factor and must be addressed by proper training and following standard operating procedures.

Association of Serum Thyrotropin with Anthropometric Markers of Obesity in the General Population

BACKGROUND

Except from associations study with body weight, there are few longitudinal data regarding the association between thyroid function and anthropometric measurements such as waist circumference, waist-to-hip ratio, or waist-to height ratio.

OBJECTIVE

This study aimed to investigate the association of thyrotropin (TSH) at baseline with changes in different anthropometric markers between baseline and follow-up in the general population.

METHOD

Data were used from four population-based longitudinal cohort studies and one population-based cross-sectional study. A total of 16,902 (8204 males) subjects aged 20-95 years from the general population were studied. Body mass index, waist circumference, waist-to-hip ratio, and waist-to-height ratio were measured. Multivariable median regression models were calculated adjusting for the following covariates: age, sex, baseline value of the respective anthropometric marker, smoking status, follow-up-time period, and study site.

RESULTS

In cross-sectional analyses, serum TSH within the reference range was positively associated with waist circumference (β = 0.94 cm [confidence interval (CI) 0.56-1.32]) and waist-to-height-ratio (β = 0.029 [CI 0.017-0.042]). These associations were also present for the full range of TSH. In the longitudinal analyses, serum TSH at baseline was inversely associated with a five-year change of all considered anthropometric measures within the prior defined study-specific reference range, as well as in the full range of serum TSH.

CONCLUSION

High TSH serum levels were positively associated with current anthropometric markers, even in the study-specific reference ranges. In contrast, high TSH serum levels were associated with decreased anthropometric markers over a time span of approximately five years. Further research is needed to determine possible clinical implications as well as public health consequences of these findings.

Association of anthropometric measures with kidney disease progression and mortality: a retrospective cohort study of pre-dialysis chronic kidney disease patients referred to a specialist renal service

BACKGROUND

Although elevated body mass index (BMI) is a predictor of better clinical outcomes in dialysis patients, the evidence in pre-dialysis chronic kidney disease (CKD) is conflicting. Clinical measures of central obesity may be better prognostic indicators, although investigation has been limited. The aim of this study was to assess the predictive value of anthropometric measures for kidney failure progression and mortality in stage 3-4 CKD.

METHODS

The study included newly referred stage 3-4 CKD patients at a single centre between 1/1/2008 and 31/12/2010. The associations between clinical measures of obesity (BMI, waist circumference [WC] and conicity index [ConI]) and time to a composite primary outcome of doubling of serum creatinine, commencement of renal replacement therapy or mortality were evaluated using the Kaplan-Meier method and multivariable Cox regression models.

RESULTS

Over a median follow-up period of 3.3 years, 229 (25.4 %) patients of a total population of 903 experienced the composite primary renal outcome. When compared to normal BMI (18.5-24.9 kg/m(2), n = 174), the risk of the composite primary outcome was significantly lower in both the overweight (BMI 25-29.9 kg/m(2), n = 293; adjusted hazard ratio [HR] 0.50, 95 % CI 0.33-0.75) and obese class I/II groups (BMI 30-39.9 kg/m(2), n = 288; HR 0.62, 95 % CI 0.41-0.93), but not in the obese class III group (BMI ≥40 kg/m(2), n = 72; HR 0.94, 95 % CI 0.52-1.69). All-cause mortality was also lower in the overweight group (HR 0.50, 95 % CI 0.30-0.83). WC and ConI were not associated with either the composite primary outcome or mortality.

CONCLUSION

BMI in the overweight range is associated with reduced risks of kidney disease progression and all-cause mortality in stage 3-4 CKD. WC and ConI were not independent predictors of these outcomes in this population.

Excellent Intra and Inter-Observer Reproducibility of Wrist Circumference Measurements in Obese Children and Adolescents

In a previous study, we found that wrist circumference, in particular its bone component, was associated with insulin resistance in a population of overweight/obese children. The aim of the present study was to evaluate the intra- and inter-operator variability in wrist circumference measurement in a population of obese children and adolescents. One hundred and two (54 male and 48 female) obese children and adolescents were consecutively enrolled. In all subjects wrist circumferences were measured by two different operators two times to assess intra- and inter-operator variability. Statistical analysis was performed using SAS v.9.4 and JMP v.12. Measurements of wrist circumference showed excellent inter-operator reliability with Intra class Correlation Coefficients (ICC) of 0.96 and ICC of 0.97 for the first and the second measurement, respectively. The intra-operator reliability was, also, very strong with a Concordance Correlation Coefficient (CCC) of 0.98 for both operators. The high reproducibility demonstrated in our results suggests that wrist circumference measurement, being safe, non-invasive and repeatable can be easily used in out-patient settings to identify youths with increased risk of insulin-resistance. This can avoid testing the entire population of overweight/obese children for insulin resistance parameters.

Ability of body mass index and waist circumference to identify risk factors for non-communicable disease in the Pacific Islands

Body mass index and waist circumference are widely used tools to identify risk of non-communicable diseases. Research has indicated that the risk relationships differ by ethnicity. In this study, data from chronic disease surveys in Fiji, Nauru, Solomon Islands and Wallis and Futuna were merged and analysed using receiver operator curves. The action points for body mass index and waist circumference with the highest specificity and sensitivity for identifying the risk of NCDs were identified. The analysis showed considerable differences between Melanesians and other Pacific Islanders, and also gender differences. Action points for non-Melanesians were higher than for Melanesians, and region-wide values are therefore inappropriate.:

Prevalance of obesity in children with cerebral palsy

INTRODUCTION

Obesity are epidemic among children and adolescents. There is worldwide tendency of increasing prevalence of obesity in children. Cerebral palsy (CP) is leading cause of childhood disability.studies have proposed mechanism of children with disability leading towards obesity and related health risks. So this study is aimed at determining whether such trend of obesity exists in children with CP in terms of BMI and WHR.

STUDY DESIGN

Cross -sectional study.

MATERIALS AND METHODS

PARTICIPANTS

40 children diagnosed as CP age 2-18 years, GMFCS I-IV.

PROCEDURE

BMI; kg/m(2) was calculated from height and weight. WHR was calculated by measuring waist circumference and hip circumference. BMI percentiles were reported according to sex-specific age group standards for growth set by the WHO growth charts.

RESULTS

Out of total CP subjects 40% were found to be underweight, 45%, 7.5% and 7.5% were found to be normal, overweight and obese respectively according to BMI. Whereas 20%, 20% 60% were found to be at high risk, moderate risk and high risk of obesity respectively according to WHR.

CONCLUSION

In our patient population, analysis of BMI and WHR suggests that children with CP have a high rate of overweight and are at risk of overweight, particularly of central obesity.

Regional anthropometric measures associated with the severity of liver injury in patients with non-alcoholic fatty liver disease

BACKGROUND

Not all NAFLD patients are obese and many obese patients do not have NAFLD. Impaired peripheral fat storage may increase the delivery of lipids to the liver and facilitate NAFLD progression.

AIM

To assess the association of anthropometric measures of regional adiposity including arm fat index (AFI) (upper body fat), waist circumference (visceral fat) and body mass index (total body fat) on liver injury and fibrosis in NAFLD.

METHODS

One hundred and forty-one patients with histological evidence of NAFLD were included in this study. Multivariate logistic regression models examined the contribution of age, sex, body mass index, AFI, triceps fold thickness (TST), waist and hip circumference to the odds of liver injury (NAS scores ≥3) and fibrosis (fibrosis scores ≥2) by liver biopsy.

RESULTS

Arm fat index (OR: 0.82, 95% CI: 0.59-0.91) and TST (OR: 0.13, 95% CI: 0.04-0.42) were negatively correlated with NAFLD histological severity. In women, waist circumference was positively correlated with NAFLD severity (OR: 1.21(1.02-1.44). Age (OR: 1.05, 95% CI: 1.01-1.0) and waist circumference (OR: 1.07, 95% CI: 1.00-1.15) were significantly associated with fibrosis risk. In women, AFI (OR: 0.87, 95% CI: 0.76-0.99) and TST (OR: 0.22, 95% CI: 0.05-0.95) were negatively associated with fibrosis risk.

CONCLUSIONS

Regional anthropometric measures are associated with severity of NAFLD in a sex-specific manner. Men and women with lower arm fat depots and women with bigger waist circumference have a greater likelihood of liver injury. Age and waist circumference seem to be associated with liver fibrosis. Simple anthropometric measurements of peripheral fat deposits may help stratify significant liver injury risk.

Determinants of (sustained) overweight and complaints in children and adolescents in primary care: the DOERAK cohort study design

BACKGROUND

Almost half of the adult Dutch population is currently overweight and the prevalence of overweight children is rising at alarming rates as well. Obese children consult their general practitioner (GP) more often than normal weight children. The Dutch government has assigned a key role to the GP in the prevention of overweight.The DOERAK cohort study aims to clarify differences between overweight and non-overweight children that consult the GP; are there differences in number of consultations and type and course of complaints? Is overweight associated with lower quality of life or might this be influenced by the type of complaint? What is the activity level of overweight children compared to non-overweight children? And is (sustained) overweight of children associated with parameters related to the energy balance equation?

METHODS/DESIGN

A total of 2000 overweight (n = 500) and non-overweight children (n = 1500) aged 2 to 18 years who consult their GP, for any type of complaint in the South-West of the Netherlands are included.At baseline, height, weight and waist circumference are measured during consultation. The number of GP consultations over the last twelve months and accompanying diagnoses are acquired from the medical file. Complaints, quality of life and parameters related to the energy balance equation are assessed with an online questionnaire children or parents fill out at home. Additionally, children or parents keep a physical activity diary during the baseline week, which is validated in a subsample (n = 100) with an activity monitor. Parents fill out a questionnaire about demographics, their own activity behaviour and perceptions on dietary habits and activity behaviour, health and weight status of their child. The physical and lifestyle behaviour questions are repeated at 6, 12 and 24 months follow-up. The present study is a prospective observational cohort in a primary care setting.

DISCUSSION

The DOERAK cohort study is the first prospective study that investigates a large cohort of overweight and non-overweight children in primary care. The total study population is expected to be recruited by 2013, results will be available in 2015.

Pulse pressure amplification in relation to body fatness

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Aortic-brachial pulse pressure amplification (PPA) is a measure of arterial elasticity and it is also an independent cardiovascular risk factor. The PPA is mainly determined by age, height, central and peripheral pressure waveforms characteristics, including measures of arterial stiffness and wave reflection.

WHAT THIS STUDY ADDS

In this study, however, we demonstrate that PPA is also significantly associated with indirect indices of body fatness. As the body fatness is treatable, our findings might be used as a reference for future studies on the effects of body fat reduction on PPA and the PPA-related cardiovascular risk. AIMS Arterial pressure transfer to the periphery is accompanied by pulse pressure amplification (PPA). Pulse pressure is influence by body fat. The purpose of the present study was to evaluate any possible inter-relation between body fatness and PPA in healthy subjects.

METHODS

Haemodynamic and wave reflection indices were estimated by pulse wave analysis. Body fat was measured by bio-impedance.

RESULTS

A total of 367 healthy volunteers (136 men and 231 women) was studied. Pulse pressure amplification correlated significantly with percentage of body fat (r=-0.53, P < 0.0001), age (r=-0.62, P < 0.0001), height (r= 0.43, P < 0.0001), heart rate (r= 0.28, P < 0.0001) and mean blood pressure (r=-0.29, P < 0.0001). The association of PPA with body fat was also significant in a multiple linear regression model. Age was an independent predictor of PPA and analysis of study subjects subdivided into two groups, those <50 years and those >50 years showed that body fatness correlated inversely and significantly with PPA in individuals both younger and older than 50 years (r=-0.44, P < 0.0001, r=-0.37, P < 0.0001 respectively). Augmentation pressure was also associated significantly with percentage of body fat in both subgroups (r= 0.48, P < 0.0001 and r= 0.49, P < 0.0001 respectively).

CONCLUSIONS

This study performed on healthy subjects showed that pulse pressure amplification is related to body fatness over a wide age range. Percentage body fat is significantly associated with augmentation pressure, a component of central pulse pressure.

Measurement error of waist circumference: gaps in knowledge

Objective

It is not clear whether measuring waist circumference in clinical practice is problematic because the measurement error is unclear, as well as what constitutes a clinically relevant change. The present study aimed to summarize what is known from state-of-the-art research.

Design

To identify the magnitude of the measurement error of waist circumference measurements from the literature, a search was conducted in PubMed from 1975 to February 2011.

Results

The measurement error may vary between 0·7 cm and 15 cm. Taking a realistic range of measurable waist circumference into account (60–135 cm), we argue that a short-term clinically relevant change in waist circumference of 5 % may lie between 3·0 and 6·8 cm and a maintained clinically relevant change of 3 % between 1·8 and 4·1 cm.

Conclusions

Based on these results, we conclude it may be difficult to distinguish clinically relevant change from measurement error in individual subjects, due to the large measurement error and unclear definition of clinically relevant change. More research is needed to address these gaps in knowledge. To minimize measurement error, we recommend using a uniform measurement protocol, training and repeated measurements.

Validity of self-reported abdominal obesity in Thai adults: a comparison of waist circumference, waist-to-hip ratio and waist-to-stature ratio

BACKGROUND AND AIMS

Waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-stature ratio (WSR), being common proxy measures of abdominal obesity, are useful tools in epidemiologic studies, but little is known about their validity when the indices are derived from self-reported measurements. We determine and compare the validity of self-reported WC, WHR and WSR in order to identify the optimal index for use in epidemiologic surveys.

METHODS AND RESULTS

Technician- and self-reported measurements of height, waist and hip circumference were obtained from 613 Thai adults (mean age 35 years). Regarding technician-reported measurements as reference, diagnostic test properties were derived and performances of the indices compared using receiver-operator-characteristic curves and the area-under-the-curve (AUC) analyses. There was good agreement between technician- and self-reported measurements for WC and WSR (concordance correlation coefficients ranged from 0.84 to 0.90) but not for WHR (0.50 in men, 0.45 in women). The sensitivity and specificity of self-reported WC and self-reported WSR as measures of abdominal obesity were superior to those of self-reported WHR in both sexes. AUCs for WC and WSR were comparable (0.93 and 0.92, respectively, in men; 0.88 and 0.87 in women) and significantly higher than for WHR (0.80 in men; 0.76 in women; p<0.0001).

CONCLUSION

WC and WSR derived from self-reported waist and height measurements are valid methods for determining abdominal obesity. Self-reported measurements should not be used to derive the WHR. In Asian populations, WSR may be the optimal index of abdominal obesity when measurements are derived from self-reports in epidemiologic surveys.

Relation of dietary and lifestyle traits to difference in serum leptin of Japanese in Japan and Hawaii: the INTERLIPID study

BACKGROUND AND AIMS

Previously, we found significantly higher serum leptin in Japanese-Americans in Hawaii than Japanese in Japan. We investigated whether differences in dietary and other lifestyle factors explain higher serum leptin concentrations in Japanese living a Western lifestyle in Hawaii compared with Japanese in Japan.

METHODS AND RESULTS

Serum leptin and nutrient intakes were examined by standardized methods in men and women ages 40-59 years from two population samples, one Japanese-American in Hawaii (88 men, 94 women), the other Japanese in central Japan (123 men, 111 women). Multiple linear regression models were used to assess role of dietary and other lifestyle traits in accounting for serum leptin difference between Hawaii and Japan. Mean leptin was significantly higher in Hawaii than Japan (7.2 ± 6.8 vs 3.7 ± 2.3 ng/ml in men, P < 0.0001; 12.8 ± 6.6 vs 8.5 ± 5.0 in women <0.0001). In men, higher BMI in Hawaii explained over 90% of the difference in serum leptin; in women, only 47%. In multiple linear regression analyses in women, further adjustment for physical activity and dietary factors--alcohol, dietary fiber, iron--produced a further reduction in the coefficient for the difference, total reduction 70.7%; P-value for the Hawaii-Japan difference became 0.126.

CONCLUSION

The significantly higher mean leptin concentration in Hawaii than Japan may be attributable largely to differences in BMI. Differences in nutrient intake in the two samples were associated with only modest relationship to the leptin difference.

Relationship between Dietary and Other Lifestyle Habits and Cardiometabolic Risk Factors in Men

BACKGROUND

Prevalence of men with cardiometabolic risk factors (CMRF) is increasing in Japan. Few studies have comprehensively examined the relation between lifestyles and CMRF.

METHODS

We examined the baseline data from 3,498 male workers ages 19 to 69 years who participated in the high-risk and population strategy for occupational health promotion (HIPOP-OHP) study at 12 large-scale companies throughout Japan. The physical activity of each participant was classified according to the International Physical Activity Questionnaire (IPAQ). Dietary intake was surveyed by a semi-quantitative Food Frequency Questionnaire. We defined four CMRF in this study as follows: 1) high blood pressure (BP): systolic BP ≥ 130 mmHg, or diastolic BP ≥ 85 mmHg, or the use of antihypertensive drugs; 2) dyslipidemia: high-density lipoprotein-cholesterol concentration < 40 mg/dl, or triglycerides concentration ≥ 150 mg/dl, or on medication for dyslipidemia; 3) impaired glucose tolerance: fasting blood sugar concentration ≥110 mg/dl; 4) obese: a body mass index ≥ 25 kg/m2.

RESULTS

Those who had 0 to 4 CMRF accounted for 1,597 (45.7%), 1,032 (29.5%), 587 (16.8%), 236 (6.7%), and 44 (1.3%) participants, respectively, in the Poisson distribution. Poisson regression analysis revealed that independent factors that contributed to the number of CMRF were age (b = 0.020, P < 0.01), IPAQ (b = -0.091, P < 0.01), alcohol intake (ml/day) (b = 0.001, P = 0.03), percentage of protein intake (b = 0.059, P = 0.01), and total energy intake (kcal)(b = 0.0001, P < 0.01). Furthermore, alcohol intake and its frequency had differential effects.

CONCLUSIONS

Alcohol intake, percent protein and total energy intake were positively associated, whereas drinking frequency and IPAQ were inversely associated, with the number of CMRF.

Non-contact assessment of waist circumference: will tape measurements become progressively obsolete?

Waist circumference (WC) is a key variable to assess in health management as it is a proxy of abdominal fat mass and a surrogate marker of cardiometabolic disease risk, including the metabolic syndrome. Recently, a portable non-contact device calculating WC (ViScan) has been developed, which hence allows the tracking of WC independently of the inter-investigators error. We compared WC values obtained with this device with WC measured by simple non-stretchable tape in 74 adults of varying body mass indices (range 17-39 kg/m(2)). The correlation between the two methods was very high (r=0.97, P<0.0001) and the reproducibility (precision) assessed with a rigid phantom was excellent (<1 cm, coefficient of variability<1%). The instrument constitutes a potentially valuable tool for longitudinal surveys and comparative international studies, which require simple but precise measurements of WC in order to track the effect of subtle changes on various health outcomes.

Serum TSH related to measures of body mass: longitudinal data from the HUNT Study, Norway

OBJECTIVE

Thyroid function and body mass are related, but the causal relationship remains unclear. Our objective was to investigate the longitudinal relationship between thyroid stimulating hormone (TSH) and body mass measures [body weight, body mass index (BMI), waist circumference (WC) and waist-hip-ratio (WHR)].

DESIGN

We used data from two waves of a population-based study: HUNT 2 (1995-1997) and 3 (2006-2008). Average follow-up time was 10·5 years. Multivariable general linear and logistic regression models were used to assess the relation between TSH and the body mass measures.

PARTICIPANTS

In total 9954 women and 5066 men without self-reported thyroid disease and TSH within the reference range (0·5-3·5 mU/l) at baseline and <10 mU/l at follow-up.

RESULTS

For each mU/l increase in TSH among women, weight increased 0·9 kg (95% CI 0·8, 1·1), BMI 0·3 kg/m(2) (95% CI 0·3, 0·4) and WC 0·6 cm (95% CI 0·3, 0·8). In men, the corresponding figures were 0·8 kg (95% CI 0·5, 1·0), 0·2 kg/m(2) (95% CI 0·2, 0·3) and 0·5 cm (95% CI 0·2, 0·8). In line with this, a weight gain of more than 5 kg was associated with a TSH increase of 0·08 mU/l (95% CI 0·06, 0·11) in women and 0·15 mU/l (95% CI 0·12, 0·18) in men. Women who lost more than 5 kg decreased their TSH by 0·12 mU/l (95% CI 0·09, 0·16) and men by 0·03 mU/l (95% CI -0.02, 0·09).

CONCLUSION

Weight gain is accompanied by increasing TSH, and weight loss in women is related to decreasing TSH.

Wrist circumference is a clinical marker of insulin resistance in overweight and obese children and adolescents

BACKGROUND

Excess fat is one of the main determinants of insulin resistance, representing the metabolic basis for developing future cardiovascular disease. The aim of the current study was to find an easy-to-detect clinical marker of insulin resistance which can be used to identify young subjects at increased risk of cardiovascular disease.

METHODS AND RESULTS

Four-hundred and seventy-seven overweight/obese children and adolescents (mean age 10.31±2.80 years) were consecutively enrolled. Standard deviation score body mass index, fasting biochemical parameters, and homeostasis model assessment of insulin resistance were evaluated. Statistical differences were investigated using multiple linear regression analysis. Manual measure of wrist circumference was evaluated in all children and adolescents. Fifty-one subjects, randomly selected, underwent nuclear magnetic resonance imaging of the wrist to evaluate transversal wrist area at the Lister tubercle level. A statistically significant association was found between manual measure of wrist circumference and insulin levels or homeostasis model assessment of insulin resistance (β=0.34 and 0.35, respectively; P<10(-5) for both comparisons). These associations were more significant than those between SD score body mass index and insulin levels or homeostasis model assessment of insulin resistance (β=0.12 and 0.10, respectively; P≤0.02 for both comparisons). Nuclear magnetic resonance imaging acquisition clarified that the association between wrist circumference and insulin levels or homeostasis model assessment of insulin resistance reflected the association with bone tissue-related areas (P≤0.01 for both) but not with the adipose tissue ones (P>0.05), explaining 20% and 17% of the variances of the 2 parameters.

CONCLUSIONS

Our findings suggest a close relationship among wrist circumference, its bone component, and insulin resistance in overweight/obese children and adolescents, opening new perspectives in the prediction of cardiovascular disease.

Relationship among physical activity, smoking, drinking and clustering of the metabolic syndrome diagnostic components

AIM

To examine the relation between lifestyle and the number of metabolic syndrome (MetS) diagnostic components in a general population, and to find a means of preventing the development of MetS components.

METHODS

We examined baseline data from 3,365 participants (2,714 men and 651 women) aged 19 to 69 years who underwent a physical examination, lifestyle survey, and blood chemical examination. The physical activity of each participant was classified according to the International Physical Activity Questionnaire (IPAQ). We defined four components for MetS in this study as follows: 1) high BP: systolic BP > or = 130 mmHg or diastolic BP > or = 85 mmHg, or the use of antihypertensive drugs; 2) dyslipidemia: high-density lipoprotein-cholesterol concentration < 40 mg/dL, triglycerides concentration > or = 150 mg/dL, or on medication for dyslipidemia; 3) Impaired glucose tolerance: fasting blood sugar level > or = 110 mg/d, or if less than 8 hours after meals > or = 140 mg/dL), or on medication for diabetes mellitus; 4) obesity: body mass index > or = 25 kg/m(2).

RESULTS

Those who had 0 to 4 MetS diagnostic components accounted for 1,726, 949, 484, 190, and 16 participants, respectively, in the Poisson distribution. Poisson regression analysis revealed that independent factors contributing to the number of MetS diagnostic components were being male (regression coefficient b=0.600, p < 0.01), age (b=0.027, p < 0.01), IPAQ class (b=-0.272, p= 0.03), and alcohol consumption (b=0.020, p=0.01). The contribution of current smoking was not statistically significant (b=-0.067, p=0.76).

CONCLUSION

Moderate physical activity was inversely associated with the number of MetS diagnostic components, whereas smoking was not associated.