Evidence of inappropriate cardiovascular risk assessment in middle-age women based on recommended cut-points for waist circumference

Body fat estimates from bioelectrical impedance equations in cardiovascular risk assessment: The PREVEND cohort study

Aims

To investigate prospectively the association of body fat percentage (BF%) estimates using various equations from bioelectrical impedance analysis (BIA) with cardiovascular events, compared with body mass index (BMI) and waist circumference.

Methods and results

We used data of 34 BIA-BF%-equations that were used for estimation of BF% in 6486 (men = 3194, women = 3294) subjects. During a median follow-up of 8.3 years, 510 (7.9%) cardiovascular events (363 in men; 147 in women) occurred. In men, the crude hazard ratio (95% confidence interval) for BF% from the best predicting BIA-BF%-equation was 3.97 (3.30–4.78) against 2.13 (1.85–2.45) for BF% from the BIA device's BIA-BF%-equation, 1.34 (1.20–1.49) for BMI and 1.49 (1.40–1.73) for waist circumference per log-1-SD increase of all. In women, the hazard ratios for best predicting BIA-BF%-equation, BIA device estimation, BMI and waist circumference were 3.80 (2.85–4.99), 1.89 (1.57–2.28), 1.35 (1.21–1.51) and 1.52 (1.31–1.75), respectively. After adjustments for age, Framingham cardiovascular disease risk score and creatinine excretion – a marker of muscle mass – BF%s and BMI remained independently associated with cardiovascular events in both men and women, while waist circumference was independently associated with cardiovascular events in men, but not in women. According to discrimination ability (C-index) and additive predictive value (net reclassification index and integrated discrimination index) on obesity measures to the Framingham cardiovascular disease risk score, BF% was superior to BMI and waist circumference in both men and women.

Conclusions

BF% was independently associated with future cardiovascular events. Body fat estimates from the best-predicting BIA-BF%-equations can be a more predictive measurement in cardiovascular risk assessment than BMI or waist circumference.

[High prevalence of abdominal obesity among the elderly and its association with diabetes, hypertension and respiratory diseases]

Rapid population aging and abdominal obesity (AO) are worldwide public health problems among the elderly and have been insufficiently investigated. This article sets out to identify the prevalence of AO among the elderly, its association with different morbidities, sociodemographic variables, and lifestyle according to sex. It is a cross-sectional study with a representative sample of elderly people resident in Goiânia, Brazil. Home visits were conducted to measure weight, height, waist circumference (WC), blood pressure, and to fill out a standardized form. The outcome variable, was calculated at WC> 102 cm for men and> 88 cm for women. Multiple Poisson regression was performed using a hierarchical model, adopting a significance level of 5%. The prevalence of AO was 55.1%, with 65.5% in women and 34.8% in men, with a significant difference (p <0.001). In men, AO was associated with age range between 70 and 74 years, the presence of respiratory diseases and high blood pressure. In women, AO continued to be associated with the presence of diabetes mellitus. The results contribute to the understanding of AO and developing preventive approaches in public health.

Should Waist Circumference Cutoffs in the Context of Cardiometabolic Risk Factor Assessment be Specific to Sex, Age, and BMI?

OBJECTIVE

A sex-specific standard waist circumference (WC) is widely used to determine cardiometabolic risk across ages even though aging impacts the link between fat distribution and cardiometabolic risk. The objective was to propose WC thresholds that better predict metabolic abnormalities according to sex, age, and body mass index (BMI) categories.

METHODS

First, receiver operating characteristic analyses were performed to identify optimal age (20-49, 50-64, and 65-80 years) and BMI (normal weight, overweight, obese I, and obese II+) specific WC thresholds to correctly identify at-risk individuals, that is, presenting ≥2 cardiometabolic risk factors of metabolic syndrome (n = 23,482; NHANES 2007-2014). Second, cross-validation analyses (n = 18,686; NHANES 1999-2006) were used to validate these WC optimal thresholds. Univariate logistic regression models with WC as an independent predictor were performed to quantify odds of being at-risk for each age and BMI subgroups.

RESULTS

When age and BMI categories were considered in the identification of optimal WC thresholds, sensitivity to correctly identify at-risk individuals significantly improved.

CONCLUSIONS

Our results indicate that the use of WC thresholds that are specific to age and BMI subcategories significantly increases the capacity to accurately identify at-risk individuals. They would thus be highly appropriate for clinicians in the context of efficient cardiometabolic risk assessment and intervention recommendations.

Optimal Cutoffs of Cardiometabolic Risk for Postmenopausal Korean Women

PURPOSE

The purpose of the study was to identify the optimal cutoff values of indices for cardiometabolic risk in postmenopausal Korean women. Specifically, we intended to determine the cutoffs of waist circumference, waist-to-hip ratio (WHR), serum lipid profile, and homeostatic model of assessment-insulin resistance (HOMA-IR) for detecting metabolic syndrome (MetS), and metabolic obesity (MO).

METHODS

The study participants were 397 postmenopausal women. We defined MetS and MO with the International Diabetes Federation criteria except for waist circumference. A receive operating characteristic curve analysis was used to assess the accuracy of diagnostic indices for identifying MetS and MO. Cutoff values were obtained both from the point on the receive operating characteristic curve which was closest to (0,1) and from the Youden's index.

RESULTS

Among the participants, 34.5% and 73% were classified as having MetS and MO. The optimal cutoff of waist circumference and WHR were 81.9 cm [area under curve (AUC): 0.687, sensitivity: 61.7%, specificity: 68.9%], 0.87 (AUC: 0.660, sensitivity: 64.7%, Specificity: 60.2%) for MetS and 77.4 cm (AUC: 0.655, sensitivity: 65.6%, specificity: 57.8%), 0.86 (AUC: 0.680, sensitivity: 67.0%, specificity: 62.7%) for MO. Triglyceride to high-density lipoprotein ratio for MetS and MO were 2.11 (AUC: 0.838, sensitivity: 71.5%, specificity: 79.6%) and 1.59 (AUC: 0.725, sensitivity: 65.9%, specificity: 68.2%) respectively. The HOMA-IR for MetS was 1.36 (AUC: 0.773, sensitivity: 73%, specificity: 71.9%) and for MO was 1.17 (AUC: 0.713, sensitivity: 64.5%, specificity: 69.2%).

CONCLUSIONS

For postmenopausal women, we suggest waist circumference of 81.9 cm and WHR of 0.87 as criteria of MetS. However, women with waist circumference over 77.4 cm and WHR over 0.86 should be monitored for the future development of MetS.

Sex, BMI and age differences in metabolic syndrome: the Dutch Lifelines Cohort Study

INTRODUCTION

To evaluate the prevalence of metabolic syndrome (MetS) and its individual components within sex-, body mass index (BMI)- and age combined clusters. In addition, we used the age-adjusted blood pressure thresholds to demonstrate the effect on the prevalence of MetS and elevated blood pressure.

SUBJECTS AND METHODS

Cross-sectional data from 74,531 Western European participants, aged 18-79 years, were used from the Dutch Lifelines Cohort Study. MetS was defined according to the revised NCEP-ATPIII. Age-adjusted blood pressure thresholds were defined as recommended by the eight reports of the Joint National Committee (≥140/90 mmHg for those aged <60 years, and ≥150/90 mmHg for those aged ≥60 years).

RESULTS

19.2% men and 12.1% women had MetS. MetS prevalence increased with BMI and age. Independent of BMI, abdominal obesity dominated MetS prevalence especially in women, while elevated blood pressure was already highly prevalent among young men. Applying age-adjusted blood pressure thresholds resulted in a 0.2-11.9% prevalence drop in MetS and 6.0-36.3% prevalence drop in elevated blood pressure, within the combined sex, BMI and age clusters.

CONCLUSIONS

We observed a gender disparity with age and BMI for the prevalence of MetS and, especially, abdominal obesity and elevated blood pressure. The strict threshold level for elevated blood pressure in the revised NCEP-ATPIII, results in an overestimation of MetS prevalence.

Agreement in cardiovascular risk rating based on anthropometric parameters

OBJECTIVE

To investigate the agreement in evaluation of risk of developing cardiovascular diseases based on anthropometric parameters in young adults.

METHODS

The study included 406 students, measuring weight, height, and waist and neck circumferences. Waist-to-height ratio and the conicity index. The kappa coefficient was used to assess agreement in risk classification for cardiovascular diseases. The positive and negative specific agreement values were calculated as well. The Pearson chi-square (χ2) test was used to assess associations between categorical variables (p<0.05).

RESULTS

The majority of the parameters assessed (44%) showed slight (k=0.21 to 0.40) and/or poor agreement (k<0.20), with low values of negative specific agreement. The best agreement was observed between waist circumference and waist-to-height ratio both for the general population (k=0.88) and between sexes (k=0.93 to 0.86). There was a significant association (p<0.001) between the risk of cardiovascular diseases and females when using waist circumference and conicity index, and with males when using neck circumference. This resulted in a wide variation in the prevalence of cardiovascular disease risk (5.5%-36.5%), depending on the parameter and the sex that was assessed.

CONCLUSION

The results indicate variability in agreement in assessing risk for cardiovascular diseases, based on anthropometric parameters, and which also seems to be influenced by sex. Further studies in the Brazilian population are required to better understand this issue.

Cardiometabolic risk in young adults from northern Mexico: Revisiting body mass index and waist-circumference as predictors

BACKGROUND

A body mass index (BMI) ≥30 kg/m(2) and a waist circumference (WC) ≥80 cm in women (WCF) or ≥90 cm in men (WCM) are reference cardiometabolic risk markers (CMM) for Mexicans adults. However, their reliability to predict other CMM (index tests) in young Mexicans has not been studied in depth.

METHODS

A cross-sectional descriptive study evaluating several anthropometric, physiological and biochemical CMM from 295 young Mexicans was performed. Sensitivity (Se), specificity (Sp) and Youden's index (J) of reference BMI/WC cutoffs toward other CMM (n = 14) were obtained and their most reliable cutoffs were further calculated at Jmax.

RESULTS

Prevalence, incidence and magnitude of most CMM increased along the BMI range (p < 0.01). BMI explained 81 % of WC's variance [Se (97 %), Sp (71 %), J (68 %), Jmax (86 %), BMI = 30 kg/m(2)] and 4-50 % of other CMM. The five most prevalent (≥71 %) CMM in obese subjects were high WC, low HDL-C, and three insulin-related CMM [Fasting insulin, HOMA-IR, and QUICKI]. For a BMI = 30 kg/m(2), J ranged from 16 % (HDL-C/LDL-C) to 68 % (WC), being moderately reliable (Jmax = 61-67) to predict high uric acid (UA), metabolic syndrome (MetS) and the hypertriglyceridemic-waist phenotype (HTGW). Corrected WCM/WCF were moderate-highly reliable (Jmax = 66-90) to predict HTGW, MetS, fasting glucose and UA. Most CMM were moderate-highly predicted at 27 ± 3 kg/m(2) (CI 95 %, 25-28), 85 ± 5 cm (CI 95 %, 82-88) and 81 ± 6cm (CI 95 %, 75-87), for BMI, WCM and WCF, respectively.

CONCLUSION

BMI and WC are good predictors of several CMM in the studied population, although at different cutoffs than current reference values.