Prevalence of the hypertriglyceridemic waist phenotype in Iranian adolescents

CD36 polymorphism, sugary drinks, and sedentarism are associated with hypertriglyceridemic waist phenotype

Background: The hypertriglyceridemic waist (HTGW) phenotype is characterized by concomitant increases in waist circumference (WC) and blood triglyceride levels (TG), which have been identified as a predictor of metabolic disorders. This study aimed to analyze associations between food consumption, exercise, and the CD36 gene rs1761667 G>A polymorphism with the HTGW phenotype in adult Mexicans. Methods: This cross-sectional study included a total of 255 participants (both genders, between 18-64 years of age). The HTGW phenotype was defined as WC >88 cm in women, WC >102 cm in men, and TG >150 mg/dL. Body composition was analyzed by electrical bioimpedance. Dietary intakes (macro and micronutrients) were evaluated through a validated 64-item food frequency questionnaire and a 24-h recall. Physical exercise was subjectively recorded asking the participants if they regularly performed some systematic exercise or sport of moderate intensity at least 150-300 minutes a week. Biochemical tests were determined by an automated system. A Taqman real-time assay was used to detect the rs1761667 (G>A) polymorphism of the CD36 gene. A multivariate logistic regression model was performed to analyze the variables potentially associated with the HTGW phenotype (adjusted for age, energy intake, and total fat mass). Results: Overall, 21.6% of the population presented the HTGW phenotype; compared to the HTGW-, also, they were older, had more body fat, higher glucose, cholesterol and insulin levels, and high blood pressure. Female sex (OR=2.92, 95% CI: 1.12-7.60, p=0.028), body mass index (OR=1.19, 95% CI: 1.07-1.32, p=0.001), total cholesterol (OR=1.01, 95% CI:1.00-1.02, p=0.039), daily consumption of sugary drinks (OR=6.94, 95% CI: 1.80-26.8, p=0.005), and the CD36 AG genotype (OR=3.81, 95% CI: 1.08-13.4, p=0.037) were positively associated with the HTGW phenotype, while performing exercise played a protective role (OR=0.23, 95% CI: 0.08-0.62, p=0.004). Overall, the model predicted the HTGW phenotype in 47% (R2=0.47, p≤0.001). Conclusion: The CD36 AG genotype, daily consumption of sugary drinks and sedentarism are risk factors for the HTGW phenotype in Mexicans.

Hypertriglyceridemic Waist Phenotype and Its Association with Metabolic Syndrome Components, among Greek Children with Excess Body Weight

The hypertriglyceridemic waist (HTGW) phenotype is characterized by abdominal obesity and elevated serum triglycerides. We aimed to assess the prevalence of the HTGW phenotype among children with overweight or obesity and its association with indices of insulin resistance (IR) and dyslipidemia. A total of 145 children with mean age of 10.2 years (SD = 2.31 years), 97.2% of whom with obesity, were analyzed. The HTGW phenotype was defined as WC > 90th Centers for Disease Control and Prevention (CDC) percentile and triglyceride levels of ≥100 mg/dL and ≥130 mg/dL for children 0 to 9 or >10 years of age, respectively. In total, 77.9% of the children had a waist circumference above the 90th percentile and 22.8% had elevated triglycerides. The prevalence of the HTGW phenotype in this sample was 19.3%. Patients with the HTGW phenotype had significantly lower levels of High-Density Lipoprotein (p < 0.001) and were insulin-resistant, as evident by an increased mean Triglycerides Glucose Index 8.64 (SD = 0.24) vs. 7.92 (SD = 0.41) for those without the HTGW phenotype (p < 0.001), and increased prevalence (54.5%) of Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) in ≥2.5 in patients with HTGW (p = 0.045). Children with the HTGW phenotype were more likely to have increased HOMA-IR [OR 7.9 95% CI (1.94, 32.1)]. The HTGW phenotype is a low-cost and easily available index that might help to identify children with increased cardiometabolic risk.

Hypertriglyceridemia-waist and risk of developing type 2 diabetes: The Rural Chinese Cohort Study

Limited information is available on the effect of hypertriglyceridemia–waist (HTGW) combination and its dynamic status on the risk of type 2 diabetes mellitus (T2DM) in rural China. A cohort of 12,086 participants 18 to 92 years old was retained in this study. Kaplan-Meier analysis yielded the cumulative incidence of T2DM for each phenotype group (based on TG level and waist circumference [WC] at baseline). Cox regression yielded hazard ratios relating HTGW (based on TG level and WC at baseline and follow-up) to risk of developing T2DM. After a median follow-up of 6.0 years (71,432 person-years of follow-up), T2DM developed in 621 participants. For HTGW participants, the incidence of T2DM was 26.4/1000, 20.6/1000, and 21.9/1000 person-years for males, females, and overall, respectively. The adjusted HR for HTGW associated with T2DM was 7.63 (95% CI 4.32–13.49) for males and 7.75 (4.71–12.78) for females. Compared with consistent HTGW, with transformation from baseline HTGW to normal WC and normal triglycerides level at follow-up, the risk of developing T2DM was reduced by 75% and 78% for males and females. HTGW is a major risk factor for T2DM, but the risk could be reduced by improved triglycerides level and WC.

Hypertriglyceridemic Waist Phenotype and Changes in the Fasting Glycemia and Blood Pressure in Children and Adolescents Over One-Year Follow-Up Period

BACKGROUND:

The hypertriglyceridemic waist (HTW) phenotype is defined as the simultaneous presence of increased waist circumference (WC) and serum triglycerides (TG) levels and it has been associated with cardiometabolic risk in children and adolescents.

OBJECTIVE:

The objective was to evaluate the influence of HTW phenotype in the fasting glycemia and blood pressure in children and adolescents over one-year follow-up period.

METHODS:

It is a cohort study involving 492 children and adolescents from 7 to 15 years old, both genders, who were submitted to anthropometric, biochemical and clinical evaluation at the baseline, and also after 6 and 12 months of follow-up. Generalized Estimating Equation (GEE) models were calculated to evaluate the longitudinal influence of the HTW phenotype in the glycemia and blood pressure over one-year.

RESULTS:

It was observed a prevalence of 10.6% (n = 52) of HTW phenotype in the students. The GEE models identified that students with HTW phenotype had an increase of 3.87 mg/dl in the fasting glycemia mean (CI: 1.68-6.05) and of 3.67mmHg in the systolic blood pressure (SBP) mean (CI: 1.55-6.08) over one-year follow-up, after adjusting for confounding variables.

CONCLUSIONS:

The results of this study suggest that HTW phenotype is a risk factor for longitudinal changes in glycemia and SBP in children and adolescents over one-year follow-up period.

FUNDAMENTO:

O fenótipo de cintura hipertrigliceridêmica (CHT) é definido como a presença simultânea de circunferência de cintura (CC) e níveis séricos de triglicérides (TG) aumentados e tem sido associado com risco cardiometabólico em crianças e adolescentes.

OBJETIVO:

Avaliar a influência do fenótipo CHT na glicemia de jejum e na pressão arterial em crianças e adolescentes em um período de acompanhamento de um ano.

MÉTODOS:

Trata-se de um estudo de coorte envolvendo 492 crianças e adolescentes de 7 a 15 anos de ambos os sexos, que foram submetidos à avaliação antropométrica, bioquímica e clínica no início e também após 6 e 12 meses de seguimento. Os modelos de Equação de Estimulação Generalizada (GEE) foram calculados para avaliar a influência longitudinal do fenótipo CHT na glicemia e na pressão arterial ao longo de um ano.

RESULTADOS:

Foi observada uma prevalência de 10,6% (n = 52) do fenótipo CHT nos estudantes. Os modelos GEE identificaram que os estudantes com fenótipo CHT apresentaram aumento de 3,87 mg/dl na média de glicemia em jejum (IC: 1,68-6,05) e de 3,67 mmHg na pressão arterial sistólica media (PAS) (IC: 1,55-6,08) depois de um ano de acompanhamento, após ajuste para variáveis de confusão.

CONCLUSÕES:

Os resultados deste estudo sugerem que o fenótipo CHT é um fator de risco para alterações longitudinais da glicemia e da PAS em crianças e adolescentes em um período de um ano de seguimento.

Prevalence of cardio-metabolic risk factors in a nationally representative sample of Iranian adolescents: The CASPIAN-III Study

Introduction: The aim of the present study is to explore the prevalence and mean of cardiometabolic risk factors and liver enzymes of Iranian adolescents living in regions with different socioeconomic status (SES). To the best of our knowledge this is the first study reporting these data at sub-national level in Iran.

Methods: This multi-centric study was performed in 2009-2010 on a stratified multi-stage probability sample of 5940 students aged 10-18 years, living in urban and rural areas of 27 provinces of Iran. Trained healthcare professionals measured anthropometric indices, systolic and diastolic blood pressures (SBP, DBP) according to standard protocols. Fasting venous blood was examined for fasting blood sugar (FBS), lipid profile and liver enzymes including alanine aminotransferase (ALT) and aspartate aminotransferase (AST). We classified the country into four sub-national regions based on criteria of the combination of geography and SES. Mean and frequency of risk factors were compared across these regions.

Results: The mean of body mass index had linear rise with increase in the regions’ SES (P for trend <0.001). The mean levels of DBP, total cholesterol (TC), high-density lipoproteincholesterol (HDL-C), triglycerides (TG), FBS, ALT, and AST had linear association with regions’ SES in the whole population and in both genders (P for trend < 0.05), whereas the corresponding figure was statistically significant for the mean SBP only in girls (P for trend: 0.03) and for the mean of LDL-C in the whole population and in boys (P for trend <0.001). In total and in both genders, there was an escalating trend in the prevalence of elevated FBS, TC and liver enzymes, low HDL-C, and metabolic syndrome by increase in the SES of the region(P for trend <0.01).

Conclusion: This study proposes that in addition to national health policies on preventing cardiometabolic risk factors, specific interventions should be considered according to the regional SES level.

Is high waist circumference and body weight associated with high blood pressure in Iranian primary school children?

INTRODUCTION AND OBJECTIVES

The prevalence of overweight, abdominal obesity and hypertension among children has increased worldwide including Iran over several decades. We carried out a study to provide current estimates of the prevalence and trends of hypertension, overweight and obesity along with the relationship between weight status and hypertension in Iranian school-children.

METHOD

This study was carried out among 1184 fifth-grade students, whose ages ranged from 11 to 14 years. Body weight, body mass index (BMI), height and waist circumference (WC), systolic (SBP) and diastolic blood pressure (DBP) were measured.

RESULTS

22.04 and 5.32 % of students were overweight and obese, respectively. The prevalence of overweight and obesity was significantly higher among girls than boys (all p = 0.02), whereas the prevalence of hypertension was significantly higher in boys than girls (p = 0.001). Although 27 % of boys and 24.32 % of girls had abdominal obesity, no significant associations were reported between abdominal obesity and sex (p = 0.12). The prevalence of hypertension in children with normal weight, overweight and obesity, was 3, 9.7 and 17.8 %, respectively (p < 0.01). We have obtained that the mean values of weight and WC were significantly higher in boys than girls. Based on linear regression, every 1 cm increase in abdominal circumference leads to an estimated DBP and SBP increase of 0.173 and 0.164 mmHg, respectively (p < 0.05).

CONCLUSIONS

This study showed a high prevalence of hypertension and obesity in a school-based population in Tehran, Iran, in which the prevalence of hypertension was significantly and positively correlated with weight and WC.

Hypertriglyceridemic Waist Phenotype Indicates Insulin Resistance in Adolescents According to the Clamp Technique in the BRAMS Study

OBJECTIVE

This study aimed to identify cutoff points for detecting hypertriglyceridemic waist phenotype (HTWP) in adolescents and to investigate the association of the HTWP with insulin resistance (IR) and metabolic syndrome components.

METHODS

A multicentric cross-sectional study of 861 adolescents (10-19 years of age, 504 girls) was conducted. Pubertal stage, anthropometric, and laboratory parameters were assessed. IR was assessed by Homeostasis Model Assessment for Insulin Resistance (HOMA1-IR) index and hyperglycemic clamp (n = 80). HTWP was defined by the presence of increased plasma triglycerides (TGs) and increased waist circumference (WC) according to cutoff points obtained in ROC curve analysis given the HOMA1-IR index as a reference method.

RESULTS

Cutoffs for WC and TGs, with a higher sum of sensitivity (S) and specificity (E), were, respectively: >84 cm (S:65.1%, E:71.9%) and >87 mg/dL (S:65.1%, E:73.4%) in pubertal girls; >88.5 cm (S:80.2%, E:60.2%) and >78 mg/dL (S:60.5%, E:53.2%) in postpubertal girls; >94 cm (S:73.1%, E:83.1%) and >79 mg/dL (S:61.5%, E:60.2%) in pubertal boys; and >99 cm (S:81.3%, E:78.7%) and >86 mg/dL in postpubertal boys (S:68.1%, E:60.7%). HTWP frequency was 27.5%. In the phenotype presence, after adjustment for age and pubertal stage, blood pressure and fasting glucose levels were elevated and high-density lipoprotein cholesterol was lower (p < 0.001). Adolescents with the HTWP showed more IR, evaluated both by the HOMA1-IR and by the clamp test (p < 0.003).

CONCLUSION

The findings suggest HTWP as an IR status in adolescents. Cutoff point standardization for gender and pubertal stage, combined with the ease of application of the method, may allow their use for screening adolescents who would most benefit from lifestyle changes.

Utility of the hypertriglyceridemic waist phenotype in the cardiometabolic risk assessment of youth stratified by body mass index

BACKGROUND

It is unclear whether the hypertriglyceridemic waist phenotype (HTWP) can be used to identify those at most risk of cardiometabolic disorders.

OBJECTIVES

The utility of the HTWP as a useful predictor of cardiometabolic risk in youth stratified by body mass index was assessed.

METHODS

Three hundred and eighty-seven children (12-17.5 years) were used within this cross-sectional study. Participants were classified as normal weight or overweight/obese according to the International Obesity Task Force criteria. The HTWP phenotype was defined as having a waist circumference ≥90th percentile for age and gender with concomitant triglyceride concentrations ≥1.24 mmol L(-1) . Cardiometabolic risk profiles were compared using MANCOVA.

RESULTS

Normal weight participants with the HTWP had significantly higher levels of C-reactive protein 2.6 ± 0.4 vs. 1.6 ± 0.3 mg L(-1) (P < 0.05) and cardiometabolic risk scores (1.3 ± 0.3 vs. -0.7 ± 0.2 and 2.1 ± 0.4 vs. -0.5 ± 0.2; both P < 0.05) compared with those of a normal weight without the HTWP. Overweight/obese participants with the HTWP had significantly higher C-reactive protein levels (3.5 ± 0.6 vs. 2.6 ± 0.5; P < 0.05) as well as both cardiometabolic risk scores (1.6 ± 0.6 vs. 0.9 ± 0.2 and 2.2 ± 0.6 vs. 0.8 ± 0.2; both P < 0.001) when compared with overweight/obese participants without the HTWP.

CONCLUSIONS

The HTWP may serve as a simple and clinically useful approach to identify youth at increased cardiometabolic risk.

Prevalence of hypertriglyceridemic waist and association with risk of type 2 diabetes mellitus: a meta-analysis

INTRODUCTION

A meta-analysis of studies assessing the prevalence of hypertriglyceridemic waist and an association with risk of type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

PubMed, EMBASE, Web of Science, CNKI, CQVIP and Wanfang databases were searched for studies of the prevalence of hypertriglyceridemic waist or association with risk of T2DM. Reference lists of each original article were also searched. A random-effects model was used to synthesize the combined prevalence and odds ratios. Publication bias and substantial heterogeneity were examined.

RESULTS

Twenty-five eligible studies involving 93 194 participants (93 194 for prevalence and 34 199 for odds ratios): 17 articles of prevalence, and 8 of both prevalence and risk of T2DM. Prevalence of hypertriglyceridemic waist ranged from 4% to 47%, with pooled prevalence of 18% (95% CI 13-23%), overall: 18% (95% CI 13-23%) for men and 19% (95% CI 13-24%) for women. Odds ratios ranged from 2.8 to 9.6 for T2MD in overall, with pooled odds ratios of 4.18 (95% CI 3.55-4.92), overall: 3.55 (95% CI 2.93-4.31) for men and 4.18 (95% CI 3.43-5.09) for women.

DISCUSSION/CONCLUSION

The prevalence of hypertriglyceridemic waist has reached an alarming level and is closely associated with increased risk of T2DM in the general population, particularly among women and among brown-skinned men and women.

Predictors of metabolic abnormalities in phenotypes that combined anthropometric indices and triglycerides

BACKGROUND

The hypertriglyceridemic waist (HW) phenotype has been shown to be strongly associated with metabolic abnormalities; however, to date, no study has reported the prediction of metabolic abnormalities using the HW phenotype along with waist circumference (WC) and the triglyceride (TG) level or various phenotypes consisting of an individual anthropometric index combined with the TG level. The objectives of this study were to assess the association of the HW phenotype with metabolic abnormalities in Korean women and to evaluate the predictive powers of various phenotypes with regard to metabolic abnormalities.

METHODS

Total cholesterol (TC), high- and low-density lipoprotein (HDL and LDL) cholesterol, and TG levels, systolic and diastolic blood pressures (SBP and DBP), and anthropometric indices were measured in 7661 women. The Naive Bayes algorithm and logistic regression were used to determine the predictive powers of the models using different phenotypes.

RESULTS

The HW phenotype demonstrated the strongest association with all metabolic components. The best phenotypic predictors were the forehead-to-rib circumference ratio + TG for the HDL level, age + TG for the LDL level, age + TG for SBP, and rib circumference + TG and neck circumference + TG for DBP. The associations between TG and TC or HDL were higher compared with those between WC and TC or HDL, whereas the associations between WC and SBP or DBP were higher compared with those between TG and SBP or DBP. Age was strongly associated with hypercholesterolemia, the HDL and LDL cholesterol levels, and SBP and had good predictive power, but not with respect to DBP.

CONCLUSIONS

We have determined that the HW phenotype is a useful indicator of metabolic abnormalities in Korean women; although HW had the strongest association with metabolic abnormalities, the best phenotype combination consisting of a single anthropometric index and the TG level may differ depending on the metabolic factors in question. Our findings provide insights into the detection of metabolic abnormalities in complementary and alternative medicine.

Genome- and epigenome-wide association study of hypertriglyceridemic waist in Mexican American families

BACKGROUND

There is growing interest in the hypertriglyceridemic waist (HTGW) phenotype, defined as high waist circumference (≥95 cm in males and ≥80 cm in females) combined with high serum triglyceride concentration (≥2.0 mmol/L in males and ≥1.5 mmol/L in females) as a marker of type 2 diabetes (T2D) and cardiovascular disease. However, the prevalence of this phenotype in high-risk populations, its association with T2D, and the genetic or epigenetic influences on HTGW are not well explored. Using data from large, extended families of Mexican Americans (a high-risk minority population in the USA) we aimed to: (1) estimate the prevalence of this phenotype, (2) test its association with T2D and related traits, and (3) dissect out the genetic and epigenetic associations with this phenotype using genome-wide and epigenome-wide studies, respectively.

RESULTS

Data for this study was from 850 Mexican American participants (representing 39 families) recruited under the ongoing San Antonio Family Heart Study, 26 % of these individuals had HTGW. This phenotype was significantly heritable (h (2) r = 0.52, p = 1.1 × 10(-5)) and independently associated with T2D as well as fasting glucose levels and insulin resistance. We conducted genome-wide association analyses using 759,809 single nucleotide polymorphisms (SNPs) and epigenome-wide association analyses using 457,331 CpG sites. There was no evidence of any SNP associated with HTGW at the genome-wide level but two CpG sites (cg00574958 and cg17058475) in CPT1A and one CpG site (cg06500161) in ABCG1 were significantly associated with HTGW and remained significant after adjusting for the closely related components of metabolic syndrome. CPT1A holds a cardinal position in the metabolism of long-chain fatty acids while ABCG1 plays a role in triglyceride metabolism.

CONCLUSIONS

Our results reemphasize the value of HTGW as a marker of T2D. This phenotype shows association with DNA methylation within CPT1A and ABCG1, genes involved in fatty acid and triglyceride metabolism. Our results underscore the importance of epigenetics in a clinically informative phenotype.

[Anthropometric indices to identify metabolic syndrome and hypertriglyceridemic waist phenotype: a comparison between the three stages of adolescence]

OBJECTIVE:

To determine the prevalence of metabolic syndrome (MS) and the hypertriglyceridemic waist phenotype (HW) in a representative adolescent sample; as well as to establish which anthropometric indicator better identifies MS and HW, according to gender and adolescent age.

METHODS:

This cross sectional study had the participation of 800 adolescents (414 girls) from 10-19 years old. Anthropometric indicators (body mass index, waist perimeter, waist/stature ratio, waist/hip ratio, and central/peripheral skinfolds) were determined by standard protocols. For diagnosis of MS, the criteria proposed by de Ferranti et al. (2004) were used. HW was defined by the simultaneous presence of increased waist perimeter (>75th percentile for age and sex) and high triglycerides (>100 mg/dL). The ability of anthropometric indicators was evaluated by Receiver Operating Characteristic curve.

RESULTS:

The prevalence of MS was identical to HW (6.4%), without differences between genders and the adolescence phases. The waist perimeter showed higher area under the curve for the diagnosis of MS, except for boys with 17-19 years old, for whom the waist/stature ratio exhibited better performance. For diagnosing HW, waist perimeter also showed higher area under the curve, except for boys in initial and final phases, in which the waist/stature ratio obtained larger area under the curve. The central/peripheral skinfolds had the lowest area under the curve for the presence of both MS and HW phenotype.

CONCLUSIONS:

The waist perimeter and the waist/stature showed a better performance to identify MS and HW in both genders and in all three phases of adolescence.

Identification of Type 2 Diabetes Risk Factors Using Phenotypes Consisting of Anthropometry and Triglycerides based on Machine Learning

The hypertriglyceridemic waist (HW) phenotype is strongly associated with type 2 diabetes; however, to date, no study has assessed the predictive power of phenotypes based on individual anthropometric measurements and triglyceride (TG) levels. The aims of the present study were to assess the association between the HW phenotype and type 2 diabetes in Korean adults and to evaluate the predictive power of various phenotypes consisting of combinations of individual anthropometric measurements and TG levels. Between November 2006 and August 2013, 11,937 subjects participated in this retrospective cross-sectional study. We measured fasting plasma glucose and TG levels and performed anthropometric measurements. We employed binary logistic regression (LR) to examine statistically significant differences between normal subjects and those with type 2 diabetes using HW and individual anthropometric measurements. For more reliable prediction results, two machine learning algorithms, naive Bayes (NB) and LR, were used to evaluate the predictive power of various phenotypes. All prediction experiments were performed using a tenfold cross validation method. Among all of the variables, the presence of HW was most strongly associated with type 2 diabetes (p < 0.001, adjusted odds ratio (OR) = 2.07 [95% CI, 1.72-2.49] in men; p < 0.001, adjusted OR = 2.09 [1.79-2.45] in women). When comparing waist circumference (WC) and TG levels as components of the HW phenotype, the association between WC and type 2 diabetes was greater than the association between TG and type 2 diabetes. The phenotypes tended to have higher predictive power in women than in men. Among the phenotypes, the best predictors of type 2 diabetes were waist-to-hip ratio + TG in men (AUC by NB = 0.653, AUC by LR = 0.661) and rib-to-hip ratio + TG in women (AUC by NB = 0.73, AUC by LR = 0.735). Although the presence of HW demonstrated the strongest association with type 2 diabetes, the predictive power of the combined measurements of the actual WC and TG values may not be the best manner of predicting type 2 diabetes. Our findings may provide clinical information concerning the development of clinical decision support systems for the initial screening of type 2 diabetes.

Does low birth weight predict hypertension and obesity in schoolchildren?

BACKGROUND

Birth weight appears to play a role in determining high blood pressure (BP) and obesity during childhood. The purpose of this study is to investigate the association between birth weight and later obesity and hypertension among 10- to 13-year-old schoolchildren.

METHODS

A total of 1,184 primary school students were selected from 20 randomized schools between 2011 and 2012 in Iran. Height, weight, waist circumference and BP were measured using standard instruments. Data were analyzed using stepwise regression and logistic regression models.

RESULTS

13.5% of children had a history of low birth weight. First-degree family history of obesity, excessive gestational weight gain and birth weight were significantly correlated with overweight/obesity and abdominal obesity (p = 0.001), whereas only birth weight was associated with high BP (p = 0.001). An inverse correlation was found between waist circumference and systolic/diastolic BP. The duration of breastfeeding in children with low birth weight was inversely correlated with obesity/overweight, abdominal obesity and hypertension.

CONCLUSION

The results suggests that birth weight is inversely associated with BP and more so with obesity and abdominal obesity. The duration of having been breastfed could have an influence on later hypertension, obesity and abdominal obesity. Further results are needed to test these correlations as well as diagnosing early life factors to prevent young adult overweight/obesity or hypertension.

The hypertriglyceridemic waist phenotype in young adults from the Southern Region of Brazil

The present study aimed to assess the prevalence of the hypertriglyceridemic waist phenotype and its associated factors among subjects that have been followed up from birth. In 1982, all maternity hospitals in the city of Pelotas, in the Southern Region of Brazil, were visited and all births were recorded. Babies whose parents lived in the urban area of Pelotas were subsequently followed up on several occasions. A 22 to 23-year follow-up of this birth cohort was carried out in 2004 and 2005. The presence of the hypertriglyceridemic waist phenotype was defined as waist circumference ≥ 90cm and triglyceride levels ≥ 177mg/dL for males, and waist circumference ≥ 85cm and triglyceride levels ≥ 133mg/dL for females. The prevalence of the hypertriglyceridemic waist phenotype was 5.9% and 4.5% among men and women, respectively. Among males, a sedentary lifestyle during leisure time, smoking and obesity were associated with the presence of the hypertriglyceridemic waist phenotype, whereas among females the condition was positively associated with skin color, family income, obesity and dietary fat intake.

The hypertriglyceridemic waist, waist-to-height ratio, and cardiometabolic risk

OBJECTIVE

To investigate whether the hypertriglyceridemic waist (HW) phenotype and waist-to-height ratio (WHTR) are associated with cardiometabolic disorders in children and adolescents.

STUDY DESIGN

This was a cross-sectional design study. Anthropometry, biochemical variables, and cardiorespiratory fitness were assessed in 234 participants (122 girls) aged 10-19 years from Bedfordshire, United Kingdom. The HW phenotype was defined as a waist circumference ≥90(th) percentile for age and sex, and triglyceride concentrations ≥1.24 mmol/L, and a high WHTR defined as >0.5. ANCOVA and logistic regression were used in the analysis.

RESULT

In participants with the HW phenotype, the odds of having high cardiorespiratory fitness (mL/kg/min) were lower (0.045; 95% CI 0.01, 0.42), and the odds of having low high-density lipoprotein cholesterol (4.41; 1.50, 12.91), impaired fasting glucose (3.37; 1.06, 10.72), and ≥1 (4.78; 1.32, 17.29) and ≥2 risk factors (7.16; 2.38, 21.54) were higher than those without the phenotype. Those with a high WHTR had higher odds of having low high-density lipoprotein cholesterol (2.57; 1.11, 5.95), high diastolic blood pressure (3.21; 1.25, 8.25), and ≥2 risk factors (5.57; 2.05, 15.17) than those with normal WHTR.

CONCLUSION

The HW phenotype may be a better simple marker than WHTR for identifying children and adolescents at risk for cardiometabolic disorders.

Trends in risk factors for cardiovascular disease among Iranian adolescents: the Tehran Lipid and Glucose Study, 1999-2008

OBJECTIVES

Data on secular trends in adolescent obesity and dyslipidemia are limited. Data on obesity status collected during 3 surveys were used to evaluate these trends in obesity and dyslipidemia among Tehranian adolescents and to assess the likelihood of risk factors for cardiovascular disease.

METHODS

We analyzed data for adolescents (age 10 to 19 years) from 3 cross-sectional surveys of the Tehran Lipid and Glucose Study: 1999-2001 (n = 3010, 47.2% males), 2002-2005 (n = 1107, 48.4% males), and 2006-2008 (n = 1090, 46.6% males). Overweight and abdominal obesity were defined using Iranian body mass index (BMI) percentiles, International Obesity Task Force (IOTF) criteria, and Iranian waist circumference (WC) charts. Hypertension was defined by using the National Heart, Lung, and Blood Institute's recommended cut points, and dyslipidemia was defined according to the recent recommendations of the American Heart Association.

RESULTS

The overall adjusted prevalences of "at risk for overweight" and overweight changed from 13% and 8% (using Iranian cutoffs), respectively, and 14.8% and 4.7% (using IOTF criteria) in 1999-2001 to 19% and 15% (Iranian cutoffs) and 23.0% and 9.2% (IOTF criteria) in 2006-2008 (P < 0.01 for all comparisons). The prevalence of abdominal obesity increased in males from 14.5% in 1999-2001 to 33.3% in 2006-2008 (P < 0.001). Almost half the adolescents had low high-density lipoprotein cholesterol (HDL-C) in the 3 surveys. In all surveys, as BMI and WC increased, multivariate age- and sex-adjusted odds ratios of low HDL-C and high triglyceride levels significantly increased. Overweight was associated with a greater likelihood of these risk factors, as compared with increased WC.

CONCLUSIONS

Overweight and abdominal obesity are increasing in Tehranian adolescents, and these increases are accompanied by abnormalities in levels of serum triglyceride and HDL-C.

Association between angiotensin II type 1 receptor gene polymorphism and metabolic syndrome in a young female Iranian population

BACKGROUND AND AIMS

The overall prevalence of obesity and metabolic syndrome (MetS) is increasing among children and adolescents and can predispose to type II diabetes mellitus and cardiovascular disease. There are reported associations between an angiotensin II type I receptor gene polymorphism (AT(1)R/A1166C) with hypertension, myocardial infarction, insulin resistance and cardiovascular disease risk. In the present study, we aimed to investigate whether the AT(1)R/A1166C polymorphism was associated with MetS among adolescent Iranian girls.

METHODS

A total of 350 adolescent girls aged 15-17 years from high schools and different educational zones of Mashhad city participated in this population-based, genetic association study. Of these individuals, 101 patients had MetS (defined by the NCEP-ATP III criteria); the remaining 249 age-matched girls were considered as the control group. All subjects were genotyped for the AT(1)R/A1166C polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique.

RESULTS

Frequencies of the AA, AC and CC genotypes were 164 (65.9%), 80 (32.1%) and 5 (2.0%) in the control group and 79 (78.2%), 20 (19.8%) and 2 (2.0%) in patients, which were not consistent with the Hardy-Weinberg equilibrium (p <0.05 and p <0.001, respectively). Frequency of the AT(1)R C allele was found to be significantly lower in patients compared with controls (p <0.05).

CONCLUSIONS

Our findings suggested that the 1166C allele of AT(1)R gene may be associated with a decreased risk of MetS in adolescent Iranian females.

Low-grade inflammation in individuals with the hypertriglyceridemic waist phenotype: another feature of the atherogenic dysmetabolism

The purpose of this study was to explore the possibility that the recently described "hypertriglyceridemic waist" (HTGW) phenotype, a risk for future coronary artery disease, is associated with the presence of low-grade inflammation. This is a cross-sectional study in a cohort of apparently healthy nondiabetic employed individuals in whom the presence of low-grade inflammation was determined by using the Dade Behring high-sensitivity C-reactive protein (hs-CRP) assay. We have presently analyzed the results obtained in 9842 apparently healthy individuals, at a mean (SD) age of 44 (11) years. We identified 1249 individuals (70.0% men) with HTGW phenotype according to the cutoff points of waist girth of at least 90 cm for men and at least 85 cm for women and triglycerides levels of at least 177 mg/dL for men and at least 133 mg/dL for women. In addition, we identified 1164 individuals (69.3% men) with the metabolic syndrome (MetS) according to the updated Adult Treatment Panel III criteria. The mean (SD) of hs-CRP was 1.3 (2.9) mg/L for the 8055 individuals who had neither the HTGW phenotype nor the MetS, 2.1 (2.7) mg/L for those who had the HTGW phenotype and no MetS, and 2.5 (2.7) for 538 individuals with the MetS and no HTGW phenotype, whereas those who had both atherogenic disorders presented an hs-CRP concentration of 2.9 (2.3) mg/L. In this cohort of apparently healthy nondiabetic employed individuals, the HTGW phenotype had a similar prevalence as the MetS and was associated with the presence of low-grade inflammation. This inflammation could be a pathophysiologic link between this dysmetabolism and atherothrombosis. In addition, the HTGW phenotype is relatively prevalent and could be a simple and inexpensive way to single out individuals at risk for future coronary artery disease.

Hypertriglyceridemic waist: a useful screening phenotype in preventive cardiology?

The worldwide increase in the prevalence and incidence of type 2 diabetes represents a tremendous challenge for the Canadian health care system, especially if we consider that this phenomenon may largely be explained by the epidemic of obesity. However, despite the well-recognized increased morbidity and mortality associated with an elevated body weight, there is now more and more evidence highlighting the importance of intra-abdominal adipose tissue (visceral adipose tissue) as the fat depot conveying the greatest risk of metabolic complications. In this regard, body fat distribution, especially visceral adipose tissue accumulation, has been found to be a key correlate of a cluster of diabetogenic, atherogenic, prothrombotic and inflammatory metabolic abnormalities now often referred to as the metabolic syndrome. This dysmetabolic profile is predictive of a substantially increased risk of coronary artery disease (CAD) even in the absence of hyperglycemia, elevated low-density lipoprotein cholesterol or hypertension. For instance, some features of the metabolic syndrome (hyperinsulinemia, elevated apolipoprotein B and small low-density lipoprotein particles--the so-called atherogenic metabolic triad) have been associated with a more than 20-fold increase in the risk of ischemic heart disease in middle-aged men enrolled in the Quebec Cardiovascular Study. This cluster of metabolic complications has also been found to be predictive of a substantially increased risk of CAD beyond the presence of traditional risk factors. These results emphasize the importance of taking into account in daily clinical practice the presence of metabolic complications associated with abdominal obesity together with traditional risk factors to properly evaluate the cardiovascular risk profile of patients. From a risk assessment standpoint, on the basis of additional work conducted by several groups, there is now evidence that the simultaneous presence of an elevated waist circumference and fasting triglyceride levels (a condition that has been described as hypertriglyceridemic waist) may represent a relevant first-step approach to identify a subgroup of individuals at higher risk of being carriers of the features of the metabolic syndrome. Moreover, a moderate weight loss in initially abdominally obese patients is associated with a selective mobilization of visceral adipose tissue, leading to improvements in the metabolic risk profile predictive of a reduced risk of CAD and type 2 diabetes. In conclusion, hypertriglyceridemic waist as a marker of visceral obesity and related metabolic abnormalities is a useful and practical clinical phenotype to screen persons at risk for CAD and type 2 diabetes.

Clustering of metabolic abnormalities in adolescents with the hypertriglyceridemic waist phenotype

BACKGROUND

It remains unknown whether the hypertriglyceridemic waist (HW) phenotype, an appropriate screening tool in adults, can also be used to screen for metabolic abnormalities in adolescents.

OBJECTIVE

We aimed to evaluate metabolic risk factors identified by the HW phenotype in adolescents.

DESIGN

Anthropometric and biochemical measurements were assessed in a population-based cross-sectional study of 1413 male and 1623 female Iranian adolescents aged 10-19 y. The HW phenotype was defined as serum triacylglycerol concentrations > or = 110 mg/dL and concurrent waist circumference > or = 90th percentile for age and sex. Elevated fasting glucose (> or = 110 mg/dL), high LDL (> or = 130 mg/dL) and low HDL (< or = 40 mg/dL) cholesterol, hypercholesterolemia (total cholesterol > or = 200 mg/dL), and hypertension (systolic or diastolic blood pressure > or = 95th percentile for age, sex, and height) were considered as risk factors.

RESULTS

Adolescents with the HW phenotype had significantly higher prevalences of all metabolic risk factors except elevated fasting glucose than did those without the HW phenotype. After control for potential confounding variables, adolescents with the HW phenotype were significantly more likely to have high LDL cholesterol (odds ratio: 1.8; 95% CI: 1.3, 2.7), low HDL cholesterol (1.6; 1.3, 2.0), hypercholesterolemia (2.9; 2.0, 4.2), and > or = 1 (1.4; 1.1, 1.7) and > or = 2 (2.2; 1.6, 3.0) risk factors than were those without the HW phenotype. The HW phenotype had a significantly higher percentage of correct prediction of metabolic abnormalities than did overweight, elevated triacylglycerol concentration, or enlarged waist circumference.

CONCLUSION

This study shows a clustering of metabolic abnormalities in adolescents with the HW phenotype and suggests this phenotype as a simple marker for identifying adolescents at risk of metabolic syndrome and other metabolic abnormalities.