Is body mass index still a good tool for obesity evaluation?

Association between visceral adipose tissue area and infertility: a cross-sectional analysis

RESEARCH QUESTION

Is intra-abdominal fat obesity associated with infertility?

DESIGN

This study analysed data from the 2013-2018 National Health and Nutrition Examination Survey, with a total of 3013 women enrolled. The participants were divided into two groups: infertility and non-infertility. Differences between the two groups were analysed using a weighted Student's t-test or Mann-Whitney U-test for continuous variables, or a weighted chi-squared test for categorical data. Visceral adipose tissue area (VATA) was assessed by dual-energy X-ray absorptiometry. The independent association between infertility and log VATA was assessed by weighted multivariate logistic regression models. Subgroup analyses were performed to assess the strength of the results. Interaction tests were used to examine whether covariates interacted with log VATA to influence infertility.

RESULTS

Log VATA was significantly higher in the infertility group compared with the non-infertility group (P < 0.001). After adjustment for potential confounders, the results of multivariate logistic regression analysis revealed that an increase in log VATA was associated with increased prevalence of female infertility (OR = 2.453, 95% CI 1.278-4.792). Subgroup analyses showed this association in individuals aged <35 years (P = 0.002), Mexican-Americans (P = 0.033), non-hypertensive individuals (P = 0.013) and non-diabetic individuals (P = 0.003).

CONCLUSIONS

An enlarged VATA is associated with increased risk of infertility. The direct effect of VATA on female infertility needs to be clarified further to provide a basis for future prevention and treatment of female infertility.

Sleep Satisfaction May Modify the Association between Metabolic Syndrome and BMI, Respectively, and Occupational Stress in Japanese Office Workers

The association between obesity and psychological stress is ambiguous. The aim is to investigate the association between metabolic syndrome (MetS) and body mass index (BMI), respectively, with occupational stress among Japanese office workers. The study is a secondary analysis of the intervention group from a randomized controlled trial. There are 167 participants included in the analysis. Occupational stress is self-reported using the Brief Job Stress Questionnaire (BJSQ). BMI and the classification of MetS/pre-MetS was based on the participants’ annual health check-up data. The primary exposure is divided into three groups: no MetS, pre-MetS, and MetS in accordance with Japanese guidelines. The secondary exposure, BMI, remains as a continuous variable. Multiple linear regression is implemented. Sensitivity analyses are stratified by sleep satisfaction. Pre-MetS is significantly associated with occupational stress (7.84 points; 95% CI: 0.17, 15.51). Among participants with low sleep satisfaction, pre-MetS (14.09 points; 95% CI: 1.71, 26.48), MetS (14.72 points; 95% CI: 0.93, 28.51), and BMI (2.54 points; 95% CI: 0.05, 4.99) are all significantly associated with occupational stress. No significant associations are observed in participants with high sleep satisfaction. The findings of this study indicate that sleep satisfaction may modify the association between MetS and BMI, respectively, and occupational stress.

Waist-Height Ratio and the Risk of Severe Diabetic Eye Disease in Type 1 Diabetes: A 15-Year Cohort Study

CONTEXT

Obesity prevalence has increased in type 1 diabetes (T1D). However, the relationship between body composition and severe diabetic eye disease (SDED) is unknown.

OBJECTIVE

To investigate the associations between body composition and SDED in adults with T1D.

METHODS

From 5401 adults with T1D in the Finnish Diabetic Nephropathy Study, we assessed 3468, and 437 underwent dual-energy X-ray absorptiometry for body composition analysis. The composite outcome was SDED, defined as proliferative retinopathy, laser treatment, antivascular endothelial growth factor treatment, diabetic maculopathy, vitreous hemorrhage, and vitrectomy. Logistic regression analysis evaluated the associations between body composition and SDED. Multivariable Cox regression analysis assessed the associations between the anthropometric measures and SDED. Subgroup analysis was performed by stages of albuminuria. The relevance ranking of each variable was based on the z statistic.

RESULTS

During a median follow-up of 14.5 (interquartile range 7.8-17.5) years, 886 SDED events occurred. Visceral/android fat ratio was associated with SDED [odds ratio (OR) 1.40, z = 3.13], as well as the percentages of visceral (OR 1.80, z = 2.45) and android fat (OR 1.28, z = 2.08) but not the total body fat percentage. Waist-height ratio (WHtR) showed the strongest association with the SDED risk [hazard ratio (HR) = 1.28, z = 3.73], followed by the waist (HR 1.01, z = 3.03), body mass index (HR 1.03, z = 2.33), and waist-hip ratio (HR 1.15, z = 2.22). The results were similar in normo- and microalbuminuria but not significant in macroalbuminuria. A WHtR ≥ 0.5 increased the SDED risk by 28% at the normo- and microalbuminuria stages.

CONCLUSIONS

WHtR, a hallmark of central obesity, is associated with SDED in individuals with T1D.

Evaluation of Cardiovascular Risk by Waist-to-Height Ratio in School-Age Children

Background: Childhood overweight and obesity are among the major public health problems worldwide. In Mexico, it has been reported in 2018 that 35.6% of children between 5 and 11 years old were overweight or obese. Central obesity is associated with the development of different complications, such as cardiovascular diseases (CVDs). An important tool used to evaluate obesity is the waist-to-height ratio (WHtR), and values higher than 0.5 suggest the existence of cardiovascular risk (CVR). The aim of this study was to evaluate CVR by the WHtR in school-age children from Yucatan, Mexico. Methods: This study included a sample of school-age children between the ages of 10 and 13 years from public schools in Yucatan, Mexico. Anthropometric parameters such as body weight, height, body mass index z-score (zBMI), waist circumference, WHtR, and CVR were evaluated. Results: A total of 2559 children with a median age of 12.1 ± 0.57 years old were evaluated. The classification by height z score showed that 26.8% were of short height, 73.1% were of normal height, and 0.1% were of tall height. The prevalence of body weight excess determined by zBMI was 48%. The prevalence of normal weight was 44%, and the prevalence of body weight deficiencies was 8%. The CVR determined by WHtR was 47.5%. In the population with obesity, 63.3% had an increased risk of CVDs and 30.7% had a very high risk. Moreover, it was observed that 13.2% of the population with normal weight had an increased risk of CVDs. Conclusion: One out of two child 10 to 13 years of age is overweight or obese as defined with zBMI in Mexico. According to WHtR, almost half of this population is at increased CVR, while near two-third of child with obesity are at high or very high CVR.

The impact of central obesity on the risk of hospitalization or death due to heart failure in type 1 diabetes: a 16-year cohort study

BACKGROUND

Obesity and type 2 diabetes are well-known risk factors for heart failure (HF). Although obesity has increased in type 1 diabetes, studies regarding HF in this population are scarce. Therefore, we investigated the impact of body fat distribution on the risk of HF hospitalization or death in adults with type 1 diabetes at different stages of diabetic nephropathy (DN).

METHODS

From 5401 adults with type 1 diabetes in the Finnish Diabetic Nephropathy Study, 4668 were included in this analysis. The outcome was HF hospitalization or death identified from the Finnish Care Register for Health Care or the Causes of Death Register until the end of 2017. DN was based on urinary albumin excretion rate. A body mass index (BMI)  ≥  30 kg/m² defined general obesity, whilst WHtR  ≥  0.5 central obesity. Multivariable Cox regression was used to explore the associations between central obesity, general obesity and the outcome. Then, subgroup analyses were performed by DN stages. Z statistic was used for ranking the association.

RESULTS

During a median follow-up of 16.4 (IQR 12.4-18.5) years, 323 incident cases occurred. From 308 hospitalizations due to HF, 35 resulted in death. Further 15 deaths occurred without previous hospitalization. The WHtR showed a stronger association with the outcome [HR  1.51, 95% CI (1.26-1.81), z  =  4.40] than BMI [HR 1.05, 95% CI (1.01-1.08), z = 2.71]. HbA_1c [HR 1.35, 95% CI (1.24-1.46), z = 7.19] was the most relevant modifiable risk factor for the outcome whereas WHtR was the third. Individuals with microalbuminuria but no central obesity had a similar risk of the outcome as those with normoalbuminuria. General obesity was associated with the outcome only at the macroalbuminuria stage.

CONCLUSIONS

Central obesity associates with an increased risk of heart failure hospitalization or death in adults with type 1 diabetes, and WHtR may be a clinically useful screening tool.

Is body mass index (BMI) or body adiposity index (BAI) a better indicator to estimate body fat and selected cardiometabolic risk factors in adults with intellectual disabilities?

Background

The BMI index cannot always be used in people with intellectual disabilities due to neuromuscular coordination disorders and psychological barriers that may hinder conventional body weight measurement. The study aimed to assess the usefulness of BMI and BAI in estimating obesity and body fat in people with intellectual disabilities.

Methods

The first stage of the research involved 161 people with profound intellectual disabilities. Somatic parameters (BM, BH, WC, HC) were measured and BMI, BAI, WHR were calculated. Fifty seven persons with above-normal BMI and BAI were included in the second stage of the study and biochemical parameters were determined (TC, LDL-cholesterol, HDL-cholesterol, TG, GL).

Results

According to both BMI and BAI classifications, most people were overweight or obese. A high correlation of %BF with BMI and BAI indices was observed (r = 0.78). The sensitivity of both indices was 95.65%. In groups with above-normal BMI and BAI, an upward trend was found for mean values of TC, LDL, TG, and GL, with a simultaneous downward trend for HDL. Statistically significant intergroup differences were recorded for TG and GL (p < 0.05) for both indices (BMI and BAI).

Conclusions

Our research demonstrated that BAI is complementary to BMI and can be recommended for the estimation of body fat and cardiometabolic risks in people with intellectual disabilities. Due to the ease of measurement, BAI has high utility value.

Does Proteomic Mirror Reflect Clinical Characteristics of Obesity?

Obesity is a frightening chronic disease, which has tripled since 1975. It is not expected to slow down staying one of the leading cases of preventable death and resulting in an increased clinical and economic burden. Poor lifestyle choices and excessive intake of “cheap calories” are major contributors to obesity, triggering type 2 diabetes, cardiovascular diseases, and other comorbidities. Understanding the molecular mechanisms responsible for development of obesity is essential as it might result in the introducing of anti-obesity targets and early-stage obesity biomarkers, allowing the distinction between metabolic syndromes. The complex nature of this disease, coupled with the phenomenon of metabolically healthy obesity, inspired us to perform data-centric, hypothesis-generating pilot research, aimed to find correlations between parameters of classic clinical blood tests and proteomic profiles of 104 lean and obese subjects. As the result, we assembled patterns of proteins, which presence or absence allows predicting the weight of the patient fairly well. We believe that such proteomic patterns with high prediction power should facilitate the translation of potential candidates into biomarkers of clinical use for early-stage stratification of obesity therapy.

Waist-height ratio and waist are the best estimators of visceral fat in type 1 diabetes

Visceral fat is associated with cardiovascular and kidney disease. However, the relationship between body composition and anthropometric measures in type 1 diabetes is unknown. Using z-statistics, we ranked the ability of body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), waist-height ratio (WHtR) and a body shape index (ABSI) to capture measures of body composition from 603 Dual-energy-X-Ray-Absorptiometry scans of adults with type 1 diabetes. Albuminuria was defined as urinary albumin excretion rate of at least 30 mg/24 h. Women with albuminuria had higher visceral fat mass % (VFM%) (0.9 vs. 0.5%, p = 0.0017) and lower appendicular lean mass % (AppLM%) (25.4 vs 26.4%, p = 0.03) than those without. Men with albuminuria had higher VFM% (1.5 vs. 1.0%, p = 0.0013) and lower AppLM% (30.0 vs 32.3, p < 0.0001) than those without. In men, WHtR estimated VFM% best (z-statistics = 21.1), followed by WC (z = 19.6), BMI (z = 15.1), WHR (z = 14.6) and ABSI (z = 10.1). In women, the ranking was WC (z = 28.9), WHtR (z = 27.3), BMI (z = 20.5), WHR (z = 12.7) and ABSI (z = 10.5). Overall, the ranking was independent of albuminuria. Adults with type 1 diabetes and albuminuria have greater VFM% and lower AppLM% than those without. WHtR and WC best estimate the VFM% in this population, independently of albuminuria and sex.

Overweight and aging increase the risk of atrial fibrillation after cardiac surgery independently of left atrial size and left ventricular ejection fraction

BACKGROUND

Body mass index (BMI), age, left atrium (LA) dimension and left ventricular ejection fraction (LVEF) have been linked to post-operative atrial fibrillation (POAF) after cardiac surgery. The aim of this study was to better define the role of these risk factors.

METHODS

This retrospective cohort study evaluated 249 patients (without prior atrial dysrhythmia) undergoing cardiac or aortic surgery. Prior to surgery, the following data were collected: age, BMI, LA diameter, LA area, LVEF, thyroid stimulating hormone (TSH), creatinine and the presence of arterial hypertension (AH) and diabetes. Intraoperative data such as operation time, total clamp time, cardiopulmonary bypass time, and presence of pericardial/pleural effusion were also collected. Only patients without pre- and post-surgery prophylactic anti-arrhythmic therapy were included.

RESULTS

Patients with (N = 127, 51%) and without POAF (N = 122, 49%) were compared. No difference was observed for sex, LA diameter, LA area, LVEF, TSH, diabetes and use of ACE inhibitors or statins prior to intervention. Moreover, no difference was observed in terms of operation time, total clamp time, cardiopulmonary bypass time, and presence of pericardial/pleural effusion. However, patients with POAF were older (70.6 ± 10.7 vs. 60.4 ± 16.4 years, p = 0.001), had higher BMI (26.8 ± 4.5 vs. 24.9 ± 3.6 kg/m2, p = 0.001), higher baseline creatinine (1.06 ± 0.91 vs. 0.88 ± 0.32 mg/dL, p = 0.038) and a higher frequency of arterial hypertension (73.2% vs. 50%, p = 0.001) and Bentall procedure (24.4% vs. 9.8%, p = 0.023). Multivariate analysis showed that the only independent predictors of POAF were age (OR = 1.05, 95%CI 1.02-1.07, p = 0.001) and BMI (OR = 1.11 95%CI 1.03-1.2,p = 0.006).

CONCLUSIONS

These findings suggest that advanced age and a higher BMI are strong risk factors for POAF in patients without previous AF even in the presence of comparable LA dimensions and LVEF.

Association between dietary flavonoid intake and obesity among adults in Korea

This study aimed to investigate the association between dietary flavonoid intake and the prevalence of obesity using body mass index (BMI), waist circumference, and percent body fat (%BF) according to sex among Korean adults. Based on the Korean Health and Nutrition Examination Survey 2008-2011, 23 118 adults in Korea were included. Dietary intakes were obtained using 24-h dietary recall data. A higher total intake of flavonoid was associated with a lower prevalence of obesity in women, based on %BF (odds ratio [95% confidence interval] = 0.82 [0.71-0.94]), and abdominal obesity (0.81 [0.71-0.92]). The intake of flavonols (0.88 [0.78-0.99]), flavanones (0.81 [0.72-0.92]), flavanols (0.85 [0.74-0.97]), isoflavones (0.85 [0.75-0.96]), and proanthocyanidins (0.81 [0.71-0.92]) was inversely associated with abdominal obesity, and a higher intake of flavanones (0.87 [0.76-0.99]) and proanthocyanidins (0.85 [0.75-0.98]) was associated with a lower prevalence of obesity, with respect to %BF in women. In contrast, the intake of flavonols (1.16 [1.02-1.33]), flavanones (1.18 [1.04-1.35]), and anthocyanidins (1.27 [1.11-1.46]) was positively associated with obesity based on BMI in men. In conclusion, high intake of dietary flavonoids may be associated with a decreased prevalence of abdominal obesity and obesity, based on %BF, among women. Novelty Higher flavonoid intake was associated with decreased prevalence of abdominal obesity and obesity based on %BF in Korean women. However, in men, the intake of flavonols, flavanones, and anthocyanidins was positively associated with obesity as given by BMI.