Insulin Resistance of Normal Weight Central Obese Adolescents in Korea Stratified by Waist to Height Ratio: Results from the Korea National Health and Nutrition Examination Surveys 2008-2010

Association of normal weight obesity phenotype with inflammatory markers: A systematic review and meta-analysis

Background

Individuals with normal weight could suffer from obesity based on their body fat percentage (also known as normal weight obesity (NWO)), thus being at risk of significant morbidity and mortality compared to the general population. It seems that inflammatory pathways and chronic inflammation are significant contributors to the pathogenicity of NWO. This study aimed to assess and pool the association of proinflammatory and anti-inflammatory cytokines with NWO.

Methods

In this systematic review and meta-analysis, online international databases (PubMed, Scopus, EMBASE, Web of Science, and Google Scholar) were searched until August 2022. All observational studies with an English full text comparing the mean levels of proinflammatory and anti-inflammatory cytokines (e.g., C-reactive protein (CRP), various types of interleukins (IL) s, tumor necrosis factor-alpha (TNF)) and white blood cell (WBC) count, in subjects with NWO and "normal weight non-obese (NWNO)" were included. Two researchers independently screened, reviewed and assessed the quality of included studies. The remaining articles' data were extracted post-screening. The heterogeneity between studies was assessed using the I² and Cochran's Q tests. A random effect model meta-analysis was used to pool the standardized mean difference (SMD) as an effect size.

Results

From the initial 559 studies, 21 and 19 were included in the qualitative and quantitative synthesis, respectively. In the systematic review, 8 studies reported a significant association between various proinflammatory cytokines (CRP, IL₆, IL_1β, and TNFα) and NWO. According to random-effect meta-analysis, the association between NWO with CRP (SMD: 0.60, 95% CI: 0.30, 0.91) and IL6 (SMD: 0.90, 95%CI: 0.14, 1.66) was statistically significant. Moreover, the mean level of TNF_α in subjects with NWO and NWNO did not differ significantly (SMD: 0.67, 95% CI: -0.36, 1.70).

Conclusion

The findings of this study show that NWO was associated with high levels of CRP and IL6. Therefore, inflammatory pathways may play a role in the pathogenicity of NWO.

Triglyceride: A mediator of the association between waist-to-height ratio and non-alcoholic fatty liver disease: A second analysis of a population-based study

OBJECTIVE

Increasing evidence suggests that an increased waist-to-height ratio (WHtR) may increase the risk of non-alcoholic fatty liver disease (NAFLD). Whether this association is due to WHtR itself or mediated by WHtR-associated increases in triglyceride (TG) is uncertain. On that account, our research aims to disentangle these relationships.

METHODS

In this cross-sectional study, 14251 participants who participated in the medical examination program were consecutively and non-selectively collected in Murakami Memorial Hospital in Japan from 2004 to 2015. The independent and dependent variables were WHtR and NAFLD, respectively. Triglyceride was the mediating factor. The correlation between WHtR, TG, and NAFLD risk factors was examined using spearman correlation analysis. The association between WHtR or TG and NAFLD was examined using multiple logistic regression. In order to determine whether TG mediated the association between WHtR and NAFLD, a mediation analysis was performed.

RESULTS

The mean age of the included individuals was 43.53 ± 8.89 years old, and 7411 (52.00%) were male. The mean WHtR and TG were 0.46 ± 0.05, 0.89 ± 0.63, respectively. The prevalence rate of NAFLD was 2507 (17.59%). Individuals with NAFLD had significantly higher levels of WHtR and TG than those without NAFLD (P<0.05). After adjusting covariates, the multivariate linear regression analysis showed that WHtR was positively associated with TG. That was, for every 0.1 increase in WHtR, TG increased by 0.226mmol/L (β=0.226, 95%CI: 0.206, 0.247). Multiple logistic regression analysis indicated that WHtR (OR=8.743, 95%CI: 7.528, 10.153) and TG (OR=1.897, 95%CI: 1.732, 2.078) were positively associated with NAFLD. The mediation analysis showed that WHtR had a direct, significant effect on NAFLD (β=0.139, 95%CI: 0.126, 0.148), and TG partially mediated the indirect effect of WHtR on NAFLD (β=0.016, 95% CI: 0.013-0.019). TG contributed to 10.41% of WHtR-related NAFLD development.

CONCLUSION

Findings suggest a mediation link between WHtR and TG and the risk of NAFLD. The significance of TG as a mediator deserves recognition and consideration.

Normal Weight Obesity and Cardiometabolic Risk Factors: A Systematic Review and Meta-Analysis

BACKGROUND

Obesity is one of the most significant causes of morbidity and mortality worldwide. Current studies suggest a new type of obesity, normal weight obesity (NWO), which is defined as having a normal body mass index (BMI), but a high-fat percentage increases the risk of cardiometabolic risk factors (CMRFs). This systematic review and meta-analysis aimed to pool the association between NWO with CMRFs.

METHODS

A systematic search of the literature in all available electronic databases, including Scopus, Web of Science, EMBASE, and PubMed, was performed until October 2021. All English studies that assessed the association of NWOs [compared to normal weight non-obese (NWNO)] and the CMRFs were included. Two investigators extracted data and performed a quality assessment. The heterogeneity between studies was assessed with I-squared and Cochran's Q tests. Odds ratio (OR) was used as an effect size to pool the association of NWO with CMRFs.

RESULTS

Twenty-five articles that met the inclusion criteria entered the study. The total number of participants was 177,792, with an age range of 13 to 75 years. Most studies were conducted on the general population (adults) and were from China. The result of fixed-effect model meta-analysis indicated an increased odds of hyperglycemia (OR:1.50, 95%:1.23, 1.76), high TG (OR:1.90, 95% CH:1.44, 2.35), low HDL (OR: 1.28, 95% CI:1.06, 1.49) and diabetes (OR:1.39, 95% CI:1.30, 1.49). Moreover, the random effect meta-analysis showed that NWO increased the odds of dyslipidemia (OR:1.83, 95% CI:1.61, 20.4), HTN (OR:1.40, 95% CI:1.28, 1.51) and metabolic syndrome (OR:1.92, 95% CI:1.58, 2.26). Moreover, the mean of all CMRFs except plasma glucose in NWO subjects was statistically higher than NWNO subjects (p-value<0.05).

CONCLUSION

The present study showed that NWO increased the odds of CMRFs. These findings indicate the inadequacy of the BMI measurement and the need for body fat assessment for a better obesity risk assessment.

Association between anthropometric measures and insulin resistance in Brazilian adolescents: data from the national study of cardiovascular risk factors in adolescents - ERICA

OBJECTIVES

To evaluate anthropometric measures (AM) and insulin resistance (IR) association in adolescents aged 12-17 years and investigates how body mass index (BMI) interrelates with specific indicators of fat distribution in this association.

METHODS

This analysis is from the Study of Cardiovascular Risks in Adolescents (ERICA) study, a national, cross-sectional study. AM was categorized by quartiles, and their means and 95% confidence intervals (95% CI) were estimated. The prevalence of IR was estimated for each AM according to the quartiles. The associations between AM and homeostatic model assessment of insulin resistance (HOMA-IR) levels were analyzed using Poisson models.

RESULTS

37,892 adolescents were included. IR prevalence tended to increase as quartiles increased for each AM. The association of BMI with IR persisted with the adjustment for others AM. The greatest reduction in the association's strength was achieved with the adjustment by the waist circumference (WC) and the waist-to-height ratio (WHtR). Most other AM were also associated with IR.

CONCLUSION

AM has a positive association with the prevalence of IR, and the joint effect of BMI and central adiposity measures should be considered in cardiometabolic risk evaluation in adolescents.

Waist-to-height ratio and non-alcoholic fatty liver disease in adults

Background

The waist-to-height ratio (WHtR) has been recognised as a powerful indicator to evaluate non-alcoholic fatty liver disease (NAFLD) in recent years, but few related studies are available. Thus, clarifying the association between the WHtR and NAFLD may be beneficial to the prevention and treatment of NAFLD.

Methods

The cross-sectional study population was from a large-scale health examination programme called ‘human dock’ in Japan. In this study, 14,125 participants in this health examination programme were included. To understand the association between the WHtR and NAFLD more intuitively, we grouped the WHtR values into quintiles and used a multivariable logistic regression model to assess WHtR and its quintile with NAFLD risk. Moreover, we used the generalised additive model to model the association between WHtR and NAFLD to explore their non-linear relationship.

Results

The prevalence of NAFLD among participants in this study was 17.59%, with an average age of 43.53 ± 8.89 years. After adjusting for all non-collinear covariables, we observed a 66% increase in the NAFLD risk per SD increase in WHtR. Furthermore, in the quintile groups of WHtR, the participants in quintile 2, quintile 3, quintile 4, and quintile 5 had 3.62-fold, 5.98-fold, 9.55-fold, and 11.08-fold increased risks of NAFLD, respectively, compared with those in quintile 1 (P_trend < 0.0001). Non-linear relationship analysis revealed threshold and saturation effects between WHtR and NAFLD in which a WHtR of approximately 0.4 might be the threshold effect of NAFLD risk, 0.6 might be the saturation effect of NAFLD risk. Additionally, subgroup analysis showed that the interaction between WHtR and BMI was significant.

Conclusions

Our results suggest that in adults, the WHtR is associated with NAFLD, and the association is not purely linear but non-linear, with significant threshold and saturation effects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01824-3.

The Effect of Solution-Oriented Counseling on Coping Strategies in Mental Health Issues in Women with Gestational Diabetes

This study aimed to investigate the effectiveness of solution-oriented intervention in patients with gestational diabetes, stress and anxiety on using coping strategies. This study was a randomized clinical trial with a control group. The population consisted of 56 diabetic women under treatment with insulin, who obtained higher score in one of the psychological disorders using DASS-21 (Depression, anxiety, stress scale). The participants were randomly assigned in two interventional (n = 28) and control (n = 28) groups after signing the written informed consent forms. The solution-oriented interventional program was conducted in six 60-min sessions for 6 weeks. Immediately after the final session and 6-8 weeks after the first session of the intervention, both groups completed coping inventory for stressful situations. The analytical statistic of t-test, chi-square, and variance analysis with repeated measurements using SPSS were used to analyze the data. solution-oriented counseling increased the problem-solving coping strategy in the intervention group (P = 0.001); the scores obtained by the subjects in the interventional group after adjusting the score before the intervention increased 2.68 units immediately after the intervention, which was not statistically significant (p-value = 0.44). However, it increased 11.5 scores six weeks after the intervention, which was statistically significant (P = 0.00). But, emotional and avoidance coping strategies were not significantly different between the two groups. This technique can be easily trained to all clients, and since it is focused on finding various solutions for psychological problems by clients, it can be used to reduce stress and anxiety in other chronic diseases as well.IRCT code: The code of this clinical trial study is IRCT20200202046339N1.

A simple cut-off for waist-to-height ratio (0·5) can act as an indicator for cardiometabolic risk: recent data from adults in the Health Survey for England

The National Institute for Health and Care Excellence (NICE) has acknowledged the value of waist-to-height ratio (WHtR) as an indicator for ‘early health risk’. We used recent UK data to explore whether classification based on WHtR identifies more adults at cardiometabolic risk than the ‘matrix’ based on BMI and waist circumference, currently used for screening. Data from the Health Survey for England (4112 adults aged 18+ years) were used to identify cardiometabolic risk, indicated by raised glycated Hb, dyslipidaemia and hypertension. HbA1c, total/HDL-cholesterol and systolic blood pressure (BP) were more strongly associated with WHtR than the ‘matrix’. In logistic regression models for HbA1c ≥ 48 mmol/mol, total/HDL-cholesterol > 4 and hypertension (BP > 140/90 mmHg or on medication), WHtR had a higher predictive value than the ‘matrix’. AUC was significantly greater for WHtR than the ‘matrix’ for raised HbA1c and hypertension. Of adults with raised HbA1c, 15 % would be judged as ‘no increased risk’ using the ‘matrix’ in contrast to 3 % using WHtR < 0·5. For hypertension, comparative values were 23 and 9 %, and for total/HDL-cholesterol > 4, 26 and 13 %. Nearly one-third of the ‘no increased risk’ group in the ‘matrix’ had WHtR ≥ 0·5 and hence could be underdiagnosed for cardiometabolic risk. WHtR has the potential to be a better indicator of cardiometabolic risks associated with central obesity than the current NICE ‘matrix’. The cut-off WHtR 0·5 in early screening translates to a simple message, ‘your waist should be less than half your height’, that allows individuals to be aware of their health risks.

Secular change in waist circumference and waist-height ratio and optimal cutoff of waist-height ratio for abdominal obesity among Korean children and adolescents over 10 years

PURPOSE

This study aimed to evaluate the time trends of waist circumference (WC) and waist-height ratio (WHR), and to present WC and WHR distributions with optimal WHR cutoff for abdominal obesity in Korean children and adolescents.

METHODS

We performed a retrospective cross-sectional analysis of data from 13,257 children and adolescents (6,987 boys and 6,270 girls) aged 6-18 years who were included in the third to sixth Korea National Health and Nutrition Examination Survey (KNHANES, 2005-2015). Linear regression analyses were used to identify secular changes in WC and WHR by age, sex, and KNHANES waves. A receiver operating characteristic curve analysis was used to determine the optimal WHR cutoff values for abdominal obesity and cardiometabolic risk factors.

RESULTS

The mean WC and WHR distributions from 2005 to 2015 showed no significant secular changes between the KNHANES 4 waves (P for trend ≥0.05 in all ages and both sexes). The mean WCs in the present study were lower than those in the 2007 Korean National Growth Charts. The mean WHR at ages <13 years was statistically higher in the boys than in the girls, but did not significantly differ between the sexes among those aged 13 to 18 years. The optimal WHR cutoff for abdominal obesity was 0.48 (area under the curve, 0.985; 95% confidence interval, 0.985-0.985) in the 13- to 18-yearold adolescents.

CONCLUSION

WC and WHR showed no secular changes over 10 years. The optimal WHR cutoff for abdominal obesity of 0.48 is useful for diagnosing and managing obesity and thus preventing obesityrelated cardiometabolic complications in 13- to 18-year-old Korean adolescents.

Metabolic risk factors in Korean adolescents with severe obesity: Results from the Korea National Health and Nutrition Examination Surveys (K-NHANES) 2007-2014

AIMS

To investigate the metabolic risk factors according to the degree of obesity in Korean adolescents.

METHODS

Among 7197 subjects aged 10-18 years who participated in the 2007-2014 K-NHANES, 1326 adolescents (M = 744, F = 582) with age and sex specific body mass index (BMI) ≥85th percentile were included. These adolescents with obesity were classified as: overweight, obesity, severe obesity, and extreme severe obesity. For assessing central obesity, the subjects were further-classified as: normal waist obese, abdominal obesity I, abdominal obesity II and abdominal obesity III.

RESULTS

The prevalence of overweight, obesity, severe obesity and extreme severe obesity were 5.6%, 6.2%, 5.9% and 0.9% in Korean adolescents. With increasing levels of obese category, the incidence of metabolic risk factors such as HDL-C < 40 mg/dL or <50 mg/dL in girls older than 16 years-old (20.2%, 18.5%, 34.4%, 43.6%, P < .0001), TG ≥ 150 mg/dL (15.3%, 16.7%, 26.5%, 30.9%, P < .003), HbA1C ≥ 5.8% (12.8%, 13.5%, 21.9%, 42.2%, P < .006), SBP ≥ 130 mg/dL (3.5%, 6.4%, 8.1%, 19.5%, P < .003) significantly increased. With increasing levels of central obese category, the incidence of metabolic risk factors such as HDL-C < 40 mg/dL or <50 mg/dL in girls older than 16 years-old (20.2%, 26.2%, 37.9%, 35.7%, P < .0007), TG ≥ 150 mg/dL (16.1%, 21.2%, 25.8%, 29.8%, P < .004), glucose ≥ 100 mg/dL (7.7%, 7.3%, 11.7%, 17.4%, P < .009) and SBP ≥ 130 mg/dL (5.1%, 7.1%, 3.0%, 13.9%, P < .002) significantly increased.

CONCLUSION

Adolescents with severe obesity have more metabolic risk factors compared to adolescents with less severe degree of obesity.

Normal-weight obesity and cardiometabolic risk: A 7-year longitudinal study in girls from prepuberty to early adulthood

OBJECTIVE

To study whether normal-weight obesity in childhood is associated with increased cardiometabolic risk in early adulthood.

METHODS

This study assessed data for 236 girls followed from prepuberty to early adulthood. Growth chart data were obtained from birth to 18 years. Body composition was assessed by dual-energy x-ray absorptiometry and cardiometabolic risk by calculating continuous clustered risk score (at ages 11, 14, and 18). The association of body weight status with cardiometabolic risk from childhood to early adulthood was examined.

RESULTS

Subjects with normal-weight obesity were virtually indistinguishable from their normal-weight lean peers in terms of relative body weight and BMI but had significantly higher fat mass (7.1-7.3 kg) and cardiometabolic risk already in childhood, and this difference persisted into early adulthood (P <  0.001 for all).

CONCLUSIONS

Children and adolescents with normal body weight and high body fat percentage may be at increased risk for cardiometabolic morbidity in adulthood. Body fatness may be of utility in clinical practice to effectively identify children and adolescents at risk and to permit recommendation of lifestyle changes that could translate to lower risks of cardiovascular diseases in the future.

Insulin resistance is associated with elevated transaminases and low aspartate aminotransferase/alanine aminotransferase ratio in young adults with normal weight

OBJECTIVE

The aim of this study is to determine whether insulin resistance is associated with elevation of transaminases levels and aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio in normal-weight healthy young adults.

PARTICIPANTS AND METHODS

Apparently healthy nonpregnant women and men, aged 18-23 years, were enrolled in a cross-sectional study. According to the homeostasis model assessment of insulin resistance, the participants were allocated into groups of patients with (>2.5) and without (≤2.5) insulin resistance. Normal weight was defined by BMI of at least 18.5 and less than 25.0 kg/m. A multiple logistic regression analysis was carried out to determine the association between insulin resistance and elevated transaminases and AST/ALT ratio of 1 or less.

RESULTS

A total of 1732 young adults were enrolled and allocated into groups with (n=287) and without (n=1445) insulin resistance. The prevalence of insulin resistance was 16.6% in the overall population. The multivariate logistic regression analysis adjusted by age, sex, waist circumference, and BMI indicated that the odds ratio (OR) between insulin resistance and elevated ALT concentrations is 1.65 [95% confidence interval (CI): 1.04-2.62, P=0.03], for AST/ALT ratio lower than 1 OR is 1.69 (95% CI: 1.27-2.26, P<0.001), and for elevated AST levels OR is 1.31 (95% CI: 0.71-2.43, P=0.377).

CONCLUSION

The results of the present study suggest that insulin resistance is significantly associated with elevated ALT levels and AST/ALT ratio of lower than 1, but not with elevated AST levels.

Waist-to-height ratio as an indicator of 'early health risk': simpler and more predictive than using a 'matrix' based on BMI and waist circumference

OBJECTIVES

There is now good evidence that central obesity carries more health risks compared with total obesity assessed by body mass index (BMI). It has therefore been suggested that waist circumference (WC), a proxy for central obesity, should be included with BMI in a 'matrix' to categorise health risk. We wanted to compare how the adult UK population is classified using such a 'matrix' with that using another proxy for central obesity, waist-to-height ratio (WHtR), using a boundary value of 0.5. Further, we wished to compare cardiometabolic risk factors in adults with 'healthy' BMI divided according to whether they have WHtR below or above 0.5.

SETTING, PARTICIPANTS AND OUTCOME MEASURES

Recent data from 4 years (2008-2012) of the UK National Diet and Nutrition Survey (NDNS) (n=1453 adults) were used to cross-classify respondents on anthropometric indices. Regression was used to examine differences in levels of risk factors (triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), TC: HDL, glycated haemoglobin (HbA1c), fasting glucose, systolic (SBP) and diastolic blood pressure (DBP)) according to WHtR below and above 0.5, with adjustment for confounders (age, sex and BMI).

RESULTS

35% of the group who were judged to be at 'no increased risk' using the 'matrix' had WHtR ≥ 0.5. The 'matrix' did not assign 'increased risk' to those with a 'healthy' BMI and 'high' waist circumference. However, our analysis showed that the group with 'healthy' BMI, and WHtR ≥ 0.5, had some significantly higher cardiometabolic risk factors compared to the group with 'healthy' BMI but WHtR below 0.5.

CONCLUSIONS

Use of a simple boundary value for WHtR (0.5) identifies more people at 'early health risk' than does a more complex 'matrix' using traditional boundary values for BMI and WC. WHtR may be a simpler and more predictive indicator of the 'early heath risks' associated with central obesity.

The Prevalence of Metabolic Syndrome and Cardiovascular Risk Factors in Obese Children and Adolescents in Dalmatia: A Hospital Based Study

Obesity and metabolic syndrome (MS) are one of the biggest public health issues in child and adolescent population. To the best of the authors' knowledge, this hospital based study is the first report on the prevalence of MS in obese children and adolescents in Dalmatia, the Mediterranean part of Croatia. The objectives of this study were to determine the prevalence of individual cardiovascular risk factors and MS. Between January 2009 and June 2014, 201 obese subjects aged 6 to 18 were analyzed retrospectively from our Pediatric Endocrine Unit database. The subjects were then classified in two groups of obesity; subjects with BMI z score 2.0-3.0 were classified as moderately obese and subjects with BMI z score > 3.0 were classified as severely obese. The overall prevalence of MS using the modified IDF criteria was 30.3%. The most common component of MS in both groups was arterial hypertension, while impaired fasting glucose was the least common component of MS. Our finding of high prevalence of MS underlines the importance of early childhood obesity treatment.