Ethnic differences in triglyceride levels and high-density lipoprotein lead to underdiagnosis of the metabolic syndrome in black children and adults

Characterizing genetic profiles for high triglyceride levels in U.S. patients of African ancestry

Hypertriglyceridemia (HTG) is a common cardiovascular risk factor characterized by elevated triglyceride (TG) levels. Researchers have assessed the genetic factors that influence HTG in studies focused predominantly on individuals of European ancestry. However, relatively little is known about the contribution of genetic variation of HTG in people of African ancestry (AA), potentially constraining research and treatment opportunities. Our objective was to characterize genetic profiles among individuals of AA with mild-to-moderate HTG and severe HTG versus those with normal TGs by leveraging whole-genome sequencing data and longitudinal electronic health records available in the All of Us program. We compared the enrichment of functional variants within five canonical TG metabolism genes, an AA-specific polygenic risk score for TGs, and frequencies of 145 known potentially causal TG variants between HTG patients and normal TG among a cohort of AA patients (N = 15,373). Those with mild-to-moderate HTG (N = 342) and severe HTG (N ≤ 20) were more likely to carry APOA5 p.S19W (odds ratio = 1.94, 95% confidence interval = [1.48-2.54], P = 1.63 × 10-6 and OR = 3.65, 95% confidence interval: [1.22-10.93], P = 0.02, respectively) than those with normal TG. They were also more likely to have an elevated (top 10%) polygenic risk score, elevated carriage of potentially causal variant alleles, and carry any genetic risk factor. Alternative definitions of HTG yielded comparable results. In conclusion, individuals of AA with HTG were enriched for genetic risk factors compared to individuals with normal TGs.

Prevalence of the metabolic syndrome and its components in secondary school student population in the city of Douala, Cameroon

While the burden of metabolic syndrome (MetS) is still increasing in sub-Saharan Africa, there is a lack of data among young Cameroonian population. The aim of this study was to evaluate the prevalence of MetS and its components among secondary school students in Douala. This was a cross-sectional prospective study carried out on 803 students recruited from February to May 2021 in public and private secondary schools in Douala city, Cameroon. MetS was assessed according to the IDF/AHA/NHLBI 2009 consensus definition. The data collection consisted of a questionnaire on sociodemographic characteristics, measurement of anthropometric parameters (height, weight, body mass index (BMI), waist circumference) and overnight fasting blood sample. Blood pressure (BP), fasting blood glucose, HDL cholesterol and triglycerides were measured using standard methods. The mean age was 18±3 years, 73.3% female. The prevalence of MetS was 27.4%, common among participants aged ≥16 years, and higher in females compare to males (33.7% vs. 11.1%, P#x003C;0.0001). The prevalence of MetS components i.e abdominal obesity, high BP, fasting hyperglycemia, low-level HDL cholesterol and hypertriglyceridemia were 14.1, 18.1, 42.8, 51.4 and 38.6% respectively. All MetS components were significantly higher in females compared to males except for high BP which was similar among the genders. In our study population, the prevalence of MetS is high and this calls for improved monitoring to limit the evolution of associated cardiometabolic complications among young Cameroonians.

Epidemiological Impact of Metabolic Syndrome in Overweight and Obese European Children and Adolescents: A Systematic Literature Review

The prevalence of overweight and obesity is continuously increasing, both in the adult and pediatric populations, posing a substantial challenge to public health. Understanding the epidemiological burden of metabolic syndrome (MetS) among children, particularly regarding its complications and long-term effects in adulthood, is crucial for identifying effective preventive measures and enhancing the clinical care of obese children. Therefore, by searching two databases, a systematic review was conducted in order to evaluate studies that specifically addressed the epidemiological MetS impact among overweight/obese European children and adolescents. Overall, 15 studies were considered. The epidemiological data concerning the MetS impact were contingent on the diagnostic criteria used and varied across countries, resulting in a prevalence range of 1.44% to 55.8%. Spanish studies were the most numerous (34%), revealing a country prevalence rate ranging from 2.5% to 19.6%. Males (prevalence range: 1.4-55.8%) and subjects with overweight/obesity (prevalence range: 12.9-55.8%) were mainly affected. Obesity emerged as the main risk factor in the MetS development and the consequent onset of cardiovascular complications and diabetes. Knowing the MetS burden and its risk factors could improve their prevention, detection, and treatment, and guide the development of targeted public health interventions to appropriately address the health needs of younger patients.

Can the triglyceride-glucose index predict insulin resistance in LGA newborns?

BACKGROUND

The aim of this study is to investigate the TyG index and TG/HDL-C ratio and their relationships with insulin resistance in LGA infants.

METHODS

A prospective controlled study was conducted including 65 LGA and gestational age, gender-matched appropriate for gestational age (AGA) neonates. Serum TG, total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), insulin and glucose levels were measured within two hours after birth, TyG index and HOMA-IR values were calculated.

RESULTS

TyG index and TG/HDL- C ratio were higher in LGA neonates compared to AGA ones (p = 0.03; p = 0.00, respectively). Compared with AGA newborns, LGA newborns had higher levels of insulin and HOMA-IR (p = 0.00; p = 0.00, respectively). TyG index and TG/HDL-C ratio showed moderate correlation with HOMA-IR (r = 0.59 R2 = 0.35 p < 0.001; r = 0.5 R2 = 0.25 p < 0.001, respectively). CONCLUSıON: The results of this study show that LGA newborns have increased levels of TyG index and TG/HDL-C associated with insulin resistance.

Development and validation of a continuous metabolic syndrome severity score in the Tehran Lipid and Glucose Study

Metabolic syndrome (MetS), defined as the coexistence of interrelated cardiometabolic risk factors, is limited by ignoring the severity of the disease and individuals with a pre-metabolic state. We aimed to develop the first age- and sex-specific continuous MetS severity score in the adult population using confirmatory factor analysis (CFA) based on the MetS components in the Middle East. Using data from the population-based Tehran Lipid and Glucose Study (TLGS) I and II datasets, we conducted CFA of the single factor MetS on 8933 adults (20-60 years old) totally, and in age and sex subgroups. We allowed for different factor loadings across the subgroups to formulate age- and sex-specific continuous MetS severity score equations. Thereafter, we validated these equations in the dataset of TLGS III participants. Triglyceride had the highest factor loading across age and sex subgroups, indicating the most correlation with MetS. Except for women aged 40-60 years, waist circumference was the second most significant factor contributing to MetS. Systolic blood pressure was more closely related to MetS in women than in men. Systolic blood pressure and fasting plasma glucose had the weakest correlation with MetS among the 40-60 age group. Moreover, as women age, the contribution of fasting plasma glucose to MetS tended to decline, while it remained relatively constant in men. The resulting MetS severity score was correlated with age and homeostasis model assessment of insulin resistance. Furthermore, the continuous MetS severity score well predicted the traditional MetS according to receiver operating characteristic analysis in the validation dataset. The age- and sex-specific continuous MetS severity score for the West Asian adult population provides a tangible quantitative measure of MetS enabling clinicians to screen and monitor the individuals at risk and assess their metabolic trends.

Metabolic syndrome severity score in the middle-aged and elderly Iranian population: A cross-sectional survey of Bandare-Kong Cohort Study (the findings of PERSIAN Cohort Study)

Background

Metabolic syndrome (MetS) is defined as the presence of several metabolic risk factors. The traditional MetS criteria have been considered insufficient for evaluating individuals at risk. MetS has always been categorized using binary criteria, which deny that the risk associated with MetS is likely to exist as a continuum. Also, MetS may present differently depending on age, sex, race, or ethnicity. We aimed to derive age-sex-specific equations for MetS severity scores within a southern Iranian population.

Methods

This study used first-phase data from the Bandare-Kong Non-Communicable Diseases (BKNCD) Cohort Study as part of the Prospective Epidemiological Research Studies in IrAN (PERSIAN). After exclusion of the pregnant women, diabetic patients, and individuals taking antihypertensive, antihyperlipidemic, and antidiabetic medications, 2,735 individuals aged 35 to 70 years were selected for analysis. The diagnosis of MetS was based on the National Cholesterol Education Program (NCEP) criteria for the Iranian population. Confirmatory factor analysis (CFA) was performed to formulate MetS severity scores. The receiver operating characteristic (ROC) analysis was performed to validate MetS severity score equations for age-sex-specific categories.

Results

Triglyceride had the highest factor loading range in all age-sex categories for determining the MetS severity score. Conversely, systolic blood pressure and fasting plasma glucose (FPG) exhibited the lowest factor loadings across all age-sex groups. In both sexes, when age was considered, systolic blood pressure and FPG factor loadings were less significant among subjects aged ≥45 and 35-44 years, respectively.

Conclusion

MetS severity scores might be more applicable than the current criteria of MetS. Prospective population-based studies should be conducted to assess the accuracy and validity of the MetS severity score for predicting cardiometabolic diseases.

The correlations among racial/ethnic groups, hypertriglyceridemia, thrombosis, and mortality in hospitalized patients with COVID-19

Reports of racial and ethnic disparities regarding both rates of infection of the SARS-CoV-2 virus and morbidity of the coronavirus disease-19 (COVID-19) contain profound differences depending on the population. Our previous study has shown that patients with COVID-19 who developed hypertriglyceridemia during hospitalization have a 2.3 times higher mortality rate. However, whether the correlation between hypertriglyceridemia and mortality has disparity among different racial and ethnic groups is unknown. In this study, we investigated the impact of race/ethnicity on the correlation between hypertriglyceridemia and mortality in hospitalized patients with COVID-19. De-identified information from 904 hospitalized patients diagnosed with COVID-19 between March 2020 and June 2021 were extracted from the Medical College of Wisconsin Clinical Data Warehouse. A multivariable regression analysis suggested that the Asians and non-White Hispanics had 4 or 3.9 times higher mortality rate, respectively, after adjusting for age, morbid obesity (BMI ≥40), and gender. The hypertriglyceridemia (≥150 mg/dL) was associated with higher mortality, after adjusting for age, gender, and morbid obesity. The baseline hypertriglyceridemia occurrence had relevantly more consistent percentages among all racial/ethnic groups. However, non-White Hispanic and Asian patients had the highest frequencies of peak hypertriglyceridemia occurrence during hospitalization. The peak hypertriglyceridemia developed during hospitalization correlates with the incidence of thrombosis after adjusting for morbid obesity, age, and sex. In summary, in this retrospective study of 904 hospitalized COVID-19 patients, Asians and non-White Hispanics had a greater likelihood of developing hypertriglyceridemia during hospitalization and mortality than White patients.

Second-Trimester Constituents of the Metabolic Syndrome and Pregnancy Outcome: An Observational Cohort Study

Background: Gestational diabetes mellitus (GDM) increases the risk of type 2 diabetes mellitus and cardiovascular disease (CVD) in women in later life. In the general population, metabolic syndrome (MetS) shows identical associations. The aim of this study was to evaluate the association between GDM, constituents of MetS and pregnancy outcomes. Methods: Of 2041 pregnant women undergoing an oral glucose tolerance test (OGTT) between 22 and 30 weeks of gestation, data were collected to evaluate the constituents of MetS. Odds ratios (ORs) were calculated to determine the associations between MetS and pregnancy outcomes. Results: GDM and obesity did not affect the risk of fetal growth abnormalities (SGA/LGA), preterm birth or preeclampsia (PE). Hypertension significantly increased the risk of SGA (OR—1.59), PE (OR—3.14), and preterm birth <37 weeks (OR—2.17) and <34 weeks (OR—2.96) and reduced the occurrence of LGA (OR—0.46). Dyslipidemia increased the risk of PE (OR—2.25), while proteinuria increased the risk of PE (OR—12.64) and preterm birth (OR—4.72). Having ≥2 constituents increased the risk of PE and preterm birth. Conclusions: Constituents of metabolic syndrome, rather than treating impaired glucose handling, increased the risk of preeclampsia, altered fetal growth and preterm birth. Obesity was not related to adverse outcomes.

Metabolic risk is associated with sociodemographic characteristics in adolescents from both rural and urban regions from southern Brazil

Background

The prevalence of several cardiovascular metabolic disorders are increasingly cause for concern in adolescents worldwide. Given the complex interrelations between metabolic risk (MR) and sociodemographic variables, the present study aims to examine the association between the presence of MR with sociodemographic characteristics (sex, skin color, residential area, and parental socioeconomic status) in adolescents from Southern Brazil.

Methods

Cross-sectional study conducted with 1,152 adolescents (507 males) aged between 12 and 17 years. MR was assessed using a continuous score (cMetS; sum of Z-scores of the following variables: waist circumference, systolic blood pressure (SBP), glucose, high-density lipoprotein cholesterol [HDL-C, inverse], triglycerides [TG], and estimated cardiorespiratory fitness [CRF, inverse]). Poisson regression was used to examine associations between sociodemographic variables with the dichotomized cMetS and separate metabolic variables. The results were expressed with prevalence ratios (PR) and 95% confidence intervals (CI).

Results

The presence of MR (evaluated by the cMetS) was observed in 8.7% of adolescents. Higher MR was less prevalent among non-white adolescents (PR: 0.96; 95% CI: 0.93; 0.99). Adolescents living in rural areas had a lower prevalence of the following metabolic variables; low HDL-C (PR: 0.95; 95% CI: 0.94; 0.97), elevated TG (PR: 0.95; 95% CI: 0.92; 0.99), elevated glucose (PR: 0.96; 95% CI: 0.95; 0.98), and low CRF levels (PR: 0.88; 95% CI: 0.85; 0.92). Whereas, SBP was higher in those living in rural areas (PR: 1.11; 95% CI: 1.05; 1.17). In girls, there was a higher prevalence of raised TG (PR: 1.06; 95% CI: 1.02; 1.10) and lower levels of CRF (PR: 1.20; 95% CI: 1.16; 1.24), but a lower prevalence of elevated glucose (PR: 0.97; 95% CI: 0.97; 0.99).

Conclusion

Higher MR prevalence was lower in those self-reporting non-white skin color and selected MR factors were less prevalent in those living in rural areas. The identification of groups at higher MR is important for early prevention and monitoring strategies for both Type 2 diabetes and later cardiovascular disease. Future studies should be conducted to assess the socio-cultural aspects of the relationships between MR and socio-cultural and lifestyle variables.

Waist circumference thresholds predicting incident dysglycaemia and type 2 diabetes in Black African men and women

AIMS

To determine the waist circumference (WC) thresholds for the prediction of incident dysglycaemia and type 2 diabetes (T2D) in Black South African (SA) men and women and to compare these to the advocated International Diabetes Federation (IDF) Europid thresholds.

MATERIALS AND METHODS

In this prospective study, Black SA men (n = 502) and women (n = 527) from the Middle-aged Sowetan Cohort study who had normal or impaired fasting glucose at baseline (2011-2015) were followed up until 2017 to 2018. Baseline measurements included anthropometry, blood pressure and fasting glucose, HDL cholesterol and triglyceride concentrations. At follow-up, glucose tolerance was assessed using an oral glucose tolerance test. The Youden index was used to determine the optimal threshold of WC to predict incident dysglycaemia and T2D.

RESULTS

In men, the optimal WC threshold was 96.8 cm for both dysglycaemia and T2D (sensitivity: 56% and 70%; specificity: 74% and 70%, respectively), and had higher specificity (P < 0.001) than the IDF threshold of 94 cm. In women, the optimal WC threshold for incident dysglycaemia was 91.8 cm (sensitivity 86%, specificity 37%) and for T2D it was 95.8 cm (sensitivity 85%, specificity 45%), which had lower sensitivity, but higher specificity to predict incident dysglycaemia and T2D than the IDF threshold of 80 cm (sensitivity: 97% and 100%; specificity: 12% and 11%, respectively)).

CONCLUSIONS

We show for the first time using prospective cohort data from Africa that the IDF Europid WC thresholds are not appropriate for an African population, and show that African-specific WC thresholds perform better than the IDF Europid thresholds to predict incident dysglycaemia and T2D.

Glycemic control is associated with dyslipidemia over time in youth with type 2 diabetes: The SEARCH for diabetes in youth study

BACKGROUND

Dyslipidemia has been documented in youth with type 2 diabetes. There is a paucity of studies examining dyslipidemia over time in youth with type 2 diabetes and associated risk factors.

OBJECTIVE

To evaluate lipids at baseline and follow-up and associated risk factors in youth with type 2 diabetes.

METHODS

We studied 212 youth with type 2 diabetes at baseline and after an average of 7 years of follow-up in the SEARCH for Diabetes in Youth Study. Abnormal lipids were defined as high-density lipoprotein cholesterol (HDL-C) < 35, low-density lipoprotein cholesterol (LDL-C) > 100, or triglycerides >150 (all mg/dl). We evaluated participants for progression to abnormal lipids (normal lipids at baseline and abnormal at follow-up), regression (abnormal lipids at baseline and normal at follow-up), stable normal, and stable abnormal lipids over time for HDL-C, LDL-C, and triglycerides. Associations between hemoglobin A1c (HbA1c) and adiposity over time (area under the curve [AUC]) with progression and stable abnormal lipids were evaluated.

RESULTS

HDL-C progressed, regressed, was stable normal, and stable abnormal in 12.3%, 11.3%, 62.3%, and 14.2% of participants, respectively. Corresponding LDL-C percentages were 15.6%, 12.7%, 42.9%, and 28.8% and triglycerides were 17.5%, 10.8%, 55.7%, and 16.0%. Each 1% increase in HbA1c AUC was associated with a 13% higher risk of progression and stable abnormal triglycerides and a 20% higher risk of progression and stable abnormal LDL-C. Higher adiposity AUC was marginally (p = 0.049) associated with abnormal HDL-C.

CONCLUSIONS

Progression and stable abnormal LDL-C and triglycerides occur in youth with type 2 diabetes and are associated with higher HbA1c.

Reference values for the triglyceride to high-density lipoprotein ratio and its association with cardiometabolic diseases in a mixed adult population: The ELSA-Brasil study

BACKGROUND

Among several lipid ratios available, the triglyceride/HDL-cholesterol (TG/HDL-C) may detect individuals at risk of cardiometabolic diseases. However, its reference values for different ethnicities are not well established.

OBJECTIVE

To define sex- and ethnicity-specific reference values for TG/HDL-C ratio in a large sample of healthy multiethnic adults and test its association with cardiometabolic conditions.

METHODS

An apparently healthy sample (n = 2,472), aged 35-74, free of major cardiovascular risk factors, was used to generate the reference values for the TG/HDL-C. Exclusion criteria were diabetes, elevated blood pressure, obesity, hypercholesterolemia, severe hypertriglyceridemia, and smoking history. Cut-offs based on the reference values were tested in the whole ELSA Brasil study (n = 13,245), stratified by sex and ethnicity, to identify cardiometabolic conditions.

RESULTS

TG/HDL-C ratio was higher in men than women, and did not change significantly with age, regardless of sex and ethnicity. Also, black individuals showed lower levels of TG/HDL-C as compared to other ethnic groups. ROC curve showed that the cut-off based on the 75th percentile displayed better sensitivities and specificities for men and women, regardless of ethnicity. Also, the sex- and ethnicity-specific cut-offs based on the 75th percentile were significantly associated with all tested cardiometabolic conditions (hypertension, diabetes, obesity, metabolic syndrome, and insulin resistance). Also, we observed that the use of a single sex-specific cut-off (men: 2.6; women: 1.7) could be used for the different ethnicities with good reliability.

CONCLUSION

The defined TG/HDL-C cut-offs (men: 2.6; women: 1.7) are reliable and showed good clinical applicability to detect cardiometabolic conditions in a multiethnic population.

The Peculiar Trialogue between Pediatric Obesity, Systemic Inflammatory Status, and Immunity

Pediatric obesity is not only an energetic imbalance, but also a chronic complex multisystem disorder that might impair both the life length and quality. Its pandemic status should increase worldwide awareness regarding the long-term life-threatening associated complications. Obesity related complications, such as cardiovascular, metabolic, or hepatic ones, affect both short and long-term wellbeing, and they do not spare pediatric subjects, defined as life-threatening consequences of the systemic inflammatory status triggered by the adipose tissue. The energetic imbalance of obesity clearly results in adipocytes hypertrophy and hyperplasia expressing different degrees of chronic inflammation. Adipose tissue might be considered an immune organ due to its rich content in a complex array of immune cells, among which the formerly mentioned macrophages, neutrophils, mast cells, but also eosinophils along with T and B cells, acting together to maintain the tissue homeostasis in normal weight individuals. Adipokines belong to the class of innate immunity humoral effectors, and they play a crucial role in amplifying the immune responses with a subsequent trigger effect on leukocyte activation. The usefulness of complete cellular blood count parameters, such as leukocytes, lymphocytes, neutrophils, erythrocytes, and platelets as predictors of obesity-triggered inflammation, was also proved in pediatric patients with overweight or obesity. The dogma that adipose tissue is a simple energy storage tissue is no longer accepted since it has been proved that it also has an incontestable multifunctional role acting like a true standalone organ resembling to endocrine or immune organs.

Urinary biomarkers of polycyclic aromatic hydrocarbons and their associations with liver function in adolescents

Associations between polycyclic aromatic hydrocarbons (PAHs) and respiratory diseases have been widely studied, but the effects of PAH on liver toxicity in adolescents are unclear. Here, 3194 adolescents with NHANES data from 2003 to 2016 were selected. PAH exposure was assessed by measuring PAH metabolites in urine. The outcome variables were the levels of alanine aminotransferase (ALT), aspartate amino transferase (AST) and gamma-glutamyl transpeptidase (GGT). The association between PAH exposure and liver function was evaluated by the weighted quantile sum (WQS) and logistic regression, and the associations between PAHs and inflammation and blood lipids were evaluated by linear regression. Covariates were adjusted for age, ethnicity, BMI, physical activity, family income, cotinine, and urinary creatinine. The results showed that for females, mixed PAH exposure was related to an increased ALT level (OR = 2.33, 95% CI 1.15, 4.72), and 2-fluorene contributed the most (38.6%). Urinary 2-fluorene was positively associated with an elevated ALT level (OR = 2.19 95% 1.12, 4.27, p for trend = 0.004). Mechanistically, 2-fluorene can cause a 3.56% increase in the white blood cell count, a 6.99% increase in the triglyceride level, and 1.70% increase in the total cholesterol level. PAHs may have toxic effects, possibly mediated by inflammation and blood lipids, on the adolescent female liver. Additional confirmatory studies are needed.

Impact of Cardiovascular Risk Factors in Adolescence, Young Adulthood, and Midlife on Late-Life Cognition: Study of Healthy Aging in African Americans

BACKGROUND

Midlife cardiovascular risk factors (CVRFs) increase risk of dementia. Black Americans experience an elevated prevalence of CVRFs and dementia. However, little is known of how CVRFs prior to midlife affect late-life cognition. We examined CVRFs in adolescence, young adulthood, and midlife with late-life cognition in the Study of Healthy Aging in African Americans (STAR).

METHOD

STAR assesses cognitive aging among 764 Black Americans aged ≥50 (mean age = 69; SD = 9; range = 53-95). Participants' body mass index, blood pressure, glucose, and total cholesterol were collected during Multiphasic Health Checkups (MHC; 1964-1985). At STAR baseline (2018-2019), executive function, verbal episodic memory, and semantic memory were measured using the Spanish and English Neuropsychological Assessment Scales. Linear regression models examined associations between CVRFs and cognition adjusting for demographics and years since MHC.

RESULTS

At MHC, 36% of participants had 1 CVRF and 26% had ≥2. Twenty-two percent of participants were adolescents (age 12-20), 62% young adults (age 21-34), and 16% midlife adults (age 35-56). Overweight/obesity was not associated with cognition. Hypertension was associated with worse executive function (β [95% CI]: -0.14 [-0.28, -0.0003]) and verbal episodic memory (β [95% CI]: -0.22 [-0.37, -0.07]) compared to normotension. Diabetes was associated with worse executive function (β [95% CI]: -0.43 [-0.83, -0.03]). Having ≥2 CVRFs (vs 0) was associated with worse executive function (β [95% CI]: -0.19 [-0.34, -0.03]) and verbal episodic memory (β [95% CI]: -0.25 [-0.41, -0.08]). Adolescents with hypertension had lower late-life executive function compared to normotensive adolescents (β [95% CI]: -0.39 [-0.67, -0.11]). Young adulthood hypertension (β [95% CI]: -0.29 [-0.49, -0.09]) and midlife hyperlipidemia (β [95% CI]: -0.386 [-0.70, -0.02]) were associated with lower verbal episodic memory.

CONCLUSIONS

Among Black Americans, life-course CVRFs were associated with poorer executive function and verbal episodic memory emphasizing the importance of cardiovascular health on the aging brain.

The gap between overweight and obesity status in children - (STROBE-compliant article)

Overweight might represent only the early stage of obesity or it might act as a trigger of self-awareness turning into an ideal chance for preventing further obesity development.The aim of this study was to assess the differences between overweight and obese children in terms of anthropometric, low-grade systemic inflammation, liver impairment and atherosclerotic risk.We performed a study on 132 children aged between 5 and 18 years, divided according to the BMI into 2 groups: group 1 to 76 obese children, and group 2 to 56 overweight children, assessing anthropometric, laboratory and elastography parameters.We obtained significantly higher values of anthropometric parameters in obese children versus overweight ones. We found higher levels of leukocytes, lymphocytes, AST, ALT, and E median (P = .0345, P = .0103, P < .0001, P = .0008 and P < .0001) in the obese group as compared to the overweight one. BMI was positively correlated with neutrophils, NLR, ESR, glycemia, anthropometric parameters, and E median (P = .0007/<.0001/.0018/.0044/<.0001/<.0001/<.0001/<.0001/<.0001/.0204); and negatively with lymphocytes and HDL-cholesterol (r = -0.2747/-0.2181, P = .0116/.0120).Our study underlined significant differences between overweight and obese children in terms of inflammatory status and liver impairment suggesting that the risk is directly related to the increase in BMI.

Social Determinants of Cardiovascular Health in African American Children With CKD: An Analysis of the Chronic Kidney Disease in Children (CKiD) Study

RATIONALE & OBJECTIVE

To identify differences in socioeconomic factors (SES) and subclinical cardiovascular disease (CVD) markers by race among Chronic Kidney Disease in Children (CKiD) participants and determine whether differences in CVD markers persist after adjusting for SES.

STUDY DESIGN

Analysis of 3,103 visits with repeated measures from 628 children (497 White participants; 131 African American participants) enrolled in the CKiD study.

SETTING & PARTICIPANTS

Children with mild-moderate CKD with at least 1 cardiovascular (CV) parameter (ambulatory blood pressure, left ventricular mass index [LVMI], or lipid profile) measured.

EXPOSURE

African American race.

OUTCOMES

Ambulatory hypertension, LVMI, triglycerides, high-density lipoprotein cholesterol.

ANALYTICAL APPROACH

Due to increased CV risks of glomerular disease, the analysis was stratified by CKD cause. Inverse probability weighting was used to adjust for SES (health insurance, household income, maternal education, food insecurity, abnormal birth history). Linear and logistic regression were used to evaluate association of race with CV markers.

RESULTS

African American children were disproportionately affected by adverse SES. African Americans with nonglomerular CKD had more instances of ambulatory hypertension and higher LVMI but more favorable lipid profiles. After adjustment for SES, age, and sex, the magnitude of differences in these CV markers was attenuated but remained statistically significant. Only LVMI differed by race in the glomerular CKD group, despite adjustment for SES.

LIMITATIONS

Study design limits causal inference.

CONCLUSION

African American children with CKD are disproportionately affected by socioeconomic disadvantages compared with White children. The degree to which CV markers differ by race is influenced by disease etiology. African Americans with nonglomerular CKD have increased LVMI, more ambulatory hypertension, and favorable lipid profile, but attenuation in magnitude after adjustment for SES was observed. African Americans with glomerular CKD had increased LVMI, which persisted after SES adjustment. As many social determinants of health were not captured, future research should examine effects of systemic racism on CV health in this population.

Nuclear Magnetic Resonance Derived Biomarkers for Evaluating Cardiometabolic Risk in Youth and Young Adults Across the Spectrum of Glucose Tolerance

Youth with obesity have an increased risk for cardiometabolic disease, but identifying those at highest risk remains a challenge. Four biomarkers that might serve this purpose are "by products" of clinical NMR LipoProfile^® lipid testing: LPIR (Lipoprotein Insulin Resistance Index), GlycA (inflammation marker), BCAA (total branched-chain amino acids), and glycine. All are strongly related to insulin resistance and type 2 diabetes (T2DM) in adults (glycine inversely) and are independent of biological and methodological variations in insulin assays. However, their clinical utility in youth is unclear. We compared fasting levels of these biomarkers in 186 youth (42 lean normal glucose tolerant (NGT), 88 obese NGT, 23 with prediabetes (PreDM), and 33 with T2DM. All four biomarkers were associated with obesity and glycemia in youth. LPIR and GlycA were highest in youth with PreDM and T2DM, whereas glycine was lowest in youth with T2DM. While all four were correlated with HOMA-IR (Homeostatic Model Assessment for Insulin Resistance), LPIR had the strongest correlation (LPIR: r = 0.6; GlycA: r = 0.4, glycine: r = -0.4, BCAA: r = 0.2, all P < 0.01). All four markers correlated with HbA1c (LPIR, GlycA, BCAA: r ≥ 0.3 and glycine: r = -0.3, all P < 0.001). In multi-variable regression models, LPIR, GlycA, and glycine were independently associated with HOMA-IR (Adjusted R² = 0.473, P < 0.001) and LPIR, glycine, and BCAA were independently associated with HbA1c (Adjusted R² = 0.33, P < 0.001). An LPIR index of >44 was associated with elevated blood pressure, BMI, and dyslipidemia. Plasma NMR-derived markers were related to adverse markers of cardiometabolic risk in youth. LPIR, either alone or in combination with GlycA, should be explored as a non-insulin dependent predictive tool for development of insulin resistance and diabetes in youth.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, identifier NCT:02960659.

Identifying Africans with undiagnosed diabetes: Fasting plasma glucose is similar to the hemoglobin A1C updated Atherosclerosis Risk in Communities diabetes prediction equation

AIMS

Seventy percent of Africans living with diabetes are undiagnosed. Identifying who should be referred for testing is critical. Therefore we evaluated the ability of the Atherosclerosis Risk in Communities (ARIC) diabetes prediction equation with A1C added (ARIC + A1C) to identify diabetes in 451 African-born blacks living in America (66% male; age 38 ± 10y (mean ± SD); BMI 27.5 ± 4.4 kg/m²).

METHODS

All participants denied a history of diabetes. OGTTs were performed. Diabetes diagnosis required 2-h glucose ≥200 mg/dL. The five non-invasive (Age, parent history of diabetes, waist circumference, height, systolic blood pressure) and four invasive variables (Fasting glucose (FPG), A1C, triglycerides (TG), HDL) were obtained. Four models were tested: Model-1: Full ARIC + A1C equation; Model-2: All five non-invasive variables with one invasive variable excluded at a time; Model-3: All five non-invasive variables with one invasive variable included at a time; Model-4: Each invasive variable singly. Area under the receiver operator characteristic curve (AROC) predicted diabetes. Youden Index identified optimal cut-points.

RESULTS

Diabetes occurred in 7% (30/451). Model-1, the full ARIC + A1C equation, AROC = 0.83. Model-2: With FPG excluded, AROC = 0.77 (P = 0.038), but when A1C, HDL or TG were excluded AROC remained unchanged. Model-3 with all non-invasive variables and FPG alone, AROC=0.87; but with A1C, TG or HDL included AROC declined to ≤0.76. Model-4: FPG as a single predictor, AROC = 0.87. A1C, TG, or HDL as single predictors all had AROC ≤ 0.74. Optimal cut-point for FPG was 100 mg/dL.

CONCLUSIONS

To detect diabetes, FPG performed as well as the nine-variable updated ARIC + A1C equation.

Metabolic Syndrome in Children and Adolescents: Is There a Universally Accepted Definition? Does it Matter?

The concept of metabolic syndrome (MetS) as a cluster of cardiovascular risk factors (obesity, altered glucose metabolism, dyslipidemia, and hypertension) has been around for more than 30 years. It is considered to be the result of complex interactions between centrally located fat, insulin resistance, subclinical inflammation, and other factors in genetically predisposed individuals. MetS diagnosis in adults has been linked to increased risk for cardiovascular disease (CVD) and type 2 diabetes mellitus (T2D). However, MetS in children and adolescents remains a controversial issue despite the extensive research in the field. It is still uncertain which definition should be used for its diagnosis in this age group, what is the clinical significance of such a diagnosis, and how reliably it can predict the future risk of developing CVD and T2D. Even if a child is diagnosed with MetS, management includes addressing each of the syndrome's components individually with weight loss and lifestyle modifications as the basic approach. Co-morbid conditions, such as nonalcoholic fatty liver disease, obstructive sleep apnea, and polycystic ovary syndrome should also be considered. It seems that MetS in children and adolescents should be used clinically as a conceptual framework for the identification of risk factors clustered around obesity and insulin resistance rather than a syndrome that needs to be diagnosed by measuring absolute "all-or-none" criteria.

Involvement of Lipids in Alzheimer's Disease Pathology and Potential Therapies

Lipids constitute the bulk of the dry mass of the brain and have been associated with healthy function as well as the most common pathological conditions of the brain. Demographic factors, genetics, and lifestyles are the major factors that influence lipid metabolism and are also the key components of lipid disruption in Alzheimer's disease (AD). Additionally, the most common genetic risk factor of AD, APOE ϵ4 genotype, is involved in lipid transport and metabolism. We propose that lipids are at the center of Alzheimer's disease pathology based on their involvement in the blood-brain barrier function, amyloid precursor protein (APP) processing, myelination, membrane remodeling, receptor signaling, inflammation, oxidation, and energy balance. Under healthy conditions, lipid homeostasis bestows a balanced cellular environment that enables the proper functioning of brain cells. However, under pathological conditions, dyshomeostasis of brain lipid composition can result in disturbed BBB, abnormal processing of APP, dysfunction in endocytosis/exocytosis/autophagocytosis, altered myelination, disturbed signaling, unbalanced energy metabolism, and enhanced inflammation. These lipid disturbances may contribute to abnormalities in brain function that are the hallmark of AD. The wide variance of lipid disturbances associated with brain function suggest that AD pathology may present as a complex interaction between several metabolic pathways that are augmented by risk factors such as age, genetics, and lifestyles. Herewith, we examine factors that influence brain lipid composition, review the association of lipids with all known facets of AD pathology, and offer pointers for potential therapies that target lipid pathways.

The association of Native American genetic ancestry and high-density lipoprotein cholesterol: A representative study of a highly admixed population

OBJECTIVE

Hispanic populations typically show a high prevalence of dyslipidemias, especially of low high-density lipoproteins (HDLs) or HDL cholesterol. Highly admixed populations are ideal groups to clarify the role of genetic ancestry on HDL concentrations, isolating it from that of other factors. The objective of this study was to estimate the association between Native American genetic ancestry and HDL-cholesterol levels independent of socioeconomic factors in a representative sample of the Mexican population.

METHODS

We used data from the Mexican National Health Survey 2000, analyzing 1647 subjects from whom stored DNA samples and HDL measurements were available. To estimate proportional genetic ancestry (Native American, African, and European), we used a 107 genetic ancestry informative marker panel with the software STRUCTURE. To estimate the association between genetic ancestry and low HDL levels, we fitted logistic regression models with the percentage of Native American genetic ancestry, in quartiles, as the main predictor.

RESULTS

Mean HDL levels were 38.9 mg/dL, with 62% of subjects having levels below 40 mg/dL. Participants had on average 53.6% Native American, 39% European, and 7.3% African genetic ancestry. Those in the fourth quartile of Native American genetic ancestry had 35% higher odds of having low HDL-cholesterol relative to those in the first quartile (odds ratio, 1.35; 95% confidence interval, 0.99-1.81) after adjustment for socioeconomic level and other covariates, although the association is clearly nonlinear.

CONCLUSION

Native American genetic ancestry seems to play a small but distinct role in the development of low HDL cholesterol levels.

Perceived stress, psychological resilience, hair cortisol concentration, and metabolic syndrome severity: A moderated mediation model

BACKGROUND

Psychological resilience is considered to protect against detrimental effects of perceived stress on cardiovascular and metabolic health, but few studies have tested biological mechanisms underlying these relationships.

PURPOSE

This study examined whether psychological resilience moderated the indirect association of perceived stress with Metabolic Syndrome (MetS) severity via hair cortisol concentration (HCC), a retrospective index of hypothalamic pituitary adrenal (HPA) axis activity.

METHOD

Participants included 228 adults (73 White, 86 Hispanic, 69 African American; mean age 45.29 years; 68% females). Participants completed questionnaires assessing perceived stress (Perceived Stress Scale) and resilience (Brief Resilience Scale). The first 3 cm of scalp-near hair were analyzed for cortisol concentration using enzyme-linked immunoassay analysis. Cardiometabolic risk factors including blood glucose, lipids, blood pressure, and waist circumference were assessed, from which a sex- and race/ethnicity-specific continuous MetS severity score was calculated. A moderated mediation model was tested using path analysis.

RESULTS

Psychological resilience moderated the association of perceived stress with HCC (R² change for interaction = 0.014, p =  0.043), such that the association of perceived stress and HCC decreased as resilience scores increased. Resilience also moderated the indirect association of perceived stress with MetS severity via HCC (b = -0.039, 95% CI [-0.001; -0.100]), such that HCC mediated the association of greater perceived stress with greater MetS severity only for individuals reporting Brief Resilience Scale scores 3 or below (range: 1.17-5.00). Psychological resilience was also associated with lower MetS severity (β = -0.227, p =  0.014) independent of perceived stress and HCC.

CONCLUSION

Findings suggest that psychological resilience may serve as both a stress buffer and as a direct determinant of cardiometabolic health. These results extend literature on psychological resilience to measures of retrospective HPA axis function and MetS severity in a diverse sample.

Screening and socioeconomic associations of dyslipidemia in young adults

Background

The Southern region of the United States is home to substantial populations with obesity, dyslipidemia, and hypertriglyceridemia, while also housing a large percentage of America’s minority, rural, and low socioeconomic status (SES) peoples. Adult-onset cardiovascular disease (CVD) research may be informed by investigating associations(s) between late adolescent demographic variables and lipid values. Our objective was to investigate lipid parameter associations with college-age socioeconomic status, which may improve age-specific screening algorithms for management or prevention of adult-onset CVD.

Methods

Using an Analysis of Variance test and a general linear model, associations between gender, race/ethnicity, SES, and athletic participation on lipid parameters (VLDL-C, LDL-C, TG, TC, and HDL-C) were analyzed in 4423 private liberal arts college students enrolled in freshman-level wellness courses at Furman University in Greenville, SC. Comparative data were collected from an age-matched sample (National Health and Nutrition Examination Survey: NHANES 2003–2016). Our main outcomes were statistically significant relationships between any lipid values (TC, HDL-C, LDL-C, TG) and any demographic variables (gender, SES, ethnicity, athlete status).

Results

Males demonstrated lower TC and LDL-C, and higher HDL-C values. HDL-C was highest in athletes. African-American students demonstrated healthier VLDL-C, TG, and HDL-C values. With similar distributions, the age-matched NHANES comparison group showed unhealthier values in nearly all categories.

Conclusions

College students may have better lipid health than the general population. African-Americans may have seemingly healthier lipid values than age-matched individuals independent of athletic or college enrollment which has already been demonstrated in other studies. Future research should include SES relationships in lipid screening paradigms along with other appropriate risk factors for cardiovascular disease. Based on our comparative data, pediatric health providers and researchers may consider education as a potential protective factor against poor lipid health when considering lipid screening protocols for students.

The adipokines and inflammatory status in the era of pediatric obesity

INTRODUCTION

Obesity is associated with a chronic inflammation due to the deficiency in immune activity related to adipose tissue. A wide-spectrum of pro-inflammatory cytokines secreted by adipocytes play an important role in the assessment of obesity-associated inflammatory status. The aim of this study was to assess the relationship between IL and 1β, IL-6, TNF α, leptin, and inflammatory status in children with overweight/obesity.

MATERIAL AND METHODS

We performed a cross-sectional study on 193 children, admitted to a Pediatric Tertiary Hospital in Romania. The children were divided according to BMI into: the study group-91 children with overweight/obesity, and the control group-102 children with normal BMI. Demographic, anthropometric, and laboratory parameters including the serum levels of several adipokines (leptin, IL-1β, IL-6, and TNF α) were assessed in both groups.

RESULTS

Our findings revealed significantly higher values of leukocytes, lymphocytes, platelets, AST, and ALT, as well as for the lipid metabolism parameters including cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and CRP, in children with overweight/obesity. We found significantly higher levels of adipokines in the serum of children with overweight and obesity assessed for leptin, IL6, and TNF α (p = 0.0145/p < 0.0001/p = 0.004/), except for IL-1β serum levels.

CONCLUSIONS

Childhood overweight and/or obesity is associated with a systemic inflammatory status demonstrated by increased levels of CBC parameters. Pro-inflammatory adipokines are also an essential factor in obesity-related inflammatory status according to our findings that underlined the importance of increased serum levels of IL-6, TNF α, and leptin in pediatric patients with overweight/obesity. Clinically, CBC parameters along with adipokines might represent useful diagnostic tools for low-grade systemic inflammation in children with overweight or obesity.

Triglyceride Paradox Is Related to Lipoprotein Size, Visceral Adiposity and Stearoyl-CoA Desaturase Activity in Black Versus White Women

RATIONALE

In black women, triglycerides are paradoxically normal in the presence of insulin resistance. This relationship may be explained by race-related differences in central adiposity and SCD (stearoyl-CoA desaturase)-1 enzyme activity index.

OBJECTIVE

In a cross-sectional study, to compare fasting and postprandial triglyceride-rich lipoprotein particle (TRLP) concentrations and size in black compared with white pre- and postmenopausal women and determine the relationship between TRLP subfractions and whole-body insulin sensitivity, hepatic and visceral fat, and SCD-1 levels.

METHODS AND RESULTS

In 122 federally employed women without diabetes mellitus, 73 black (58 African American and 15 African immigrant) and 49 white; age, 44±10 (mean±SD) years; body mass index, 30.0±5.6 kg/m², we measured lipoprotein subfractions using nuclear magnetic resonance. Hepatic fat was measured by proton magnetic resonance spectroscopy, insulin sensitivity index calculated by minimal modeling from a frequently sampled intravenous glucose test, and red blood cell fatty acid profiles were measured by gas chromatography and were used to estimate SCD-1 indices. Hepatic fat, insulin sensitivity index, and SCD-1 were similar in black women and lower than in whites, regardless of menopausal status. Fasting and postprandial large, medium, and small TRLPs, but not very small TRLPs, were lower in black women. Fasting large, medium, and very small TRLPs negatively correlated with insulin sensitivity index and positively correlated with visceral and hepatic fat and SCD-1 activity in both groups. In multivariate models, visceral fat and SCD-1 were associated with total fasting TRLP concentrations (adjR2, 0.39; P=0.001). Black women had smaller postprandial changes in large (P=0.005) and medium TRLPs (P=0.007).

CONCLUSIONS

Lower visceral fat and SCD-1 activity may contribute to the paradoxical association of lower fasting and postprandial TRLP subfractions despite insulin resistance in black compared with white pre- and postmenopausal women. Similar concentrations of very small TRLPs are related to insulin resistance and could be important mediators of cardiometabolic disease risk in women.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01809288.

Long-Term Burden of Increased Body Mass Index from Childhood on Adult Dyslipidemia: The i3C Consortium Study

Background: Data are limited regarding the association of cumulative burden and trajectory of body mass index (BMI) from early life with adult lipid disorders. Methods: The study cohort consisted of 5195 adults who had BMI repeatedly measured 4 to 21 times from childhood and had blood lipid measurements of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) and information on lipid-lowering medications in the last adult survey. The area under the curve (AUC) was calculated as a measure of long-term burden (total AUC) and trends (incremental AUC) of BMI. Results: Participants with dyslipidemia, high LDL-C, low HDL-C and high TG had consistently and significantly higher BMI levels from childhood to adulthood compared to those with normal lipid levels. After adjusting for age, race, sex, and cohort, increased risk of adult dyslipidemia was significantly associated with higher values of childhood BMI, adulthood BMI, total AUC and incremental AUC, with odds ratio (95% confidence interval) = 1.22 (1.15–1.29), 1.85 (1.74–1.97), 1.61 (1.52–1.71), and 1.59 (1.50–1.69), respectively, and p < 0.001 for all. The association patterns were similar in most race–sex subgroups. Conclusions: Adults with dyslipidemia versus normal lipid levels have consistently higher levels and distinct life-course trajectories of BMI, suggesting that the impact of excessive body weight on dyslipidemia originates in early life.

Ethnic distinctions in the pathophysiology of type 2 diabetes: a focus on black African-Caribbean populations

Type 2 diabetes (T2D) is a global public health priority, particularly for populations of black African-Caribbean ethnicity, who suffer disproportionately high rates of the disease. While the mechanisms underlying the development of T2D are well documented, there is growing evidence describing distinctions among black African-Caribbean populations. In the present paper, we review the evidence describing the impact of black African-Caribbean ethnicity on T2D pathophysiology. Ethnic differences were first recognised through evidence that metabolic syndrome diagnostic criteria fail to detect T2D risk in black populations due to less central obesity and dyslipidaemia. Subsequently more detailed investigations have recognised other mechanistic differences, particularly lower visceral and hepatic fat accumulation and a distinctly hyperinsulinaemic response to glucose stimulation. While epidemiological studies have reported exaggerated insulin resistance in black populations, more detailed and direct measures of insulin sensitivity have provided evidence that insulin sensitivity is not markedly different to other ethnic groups and does not explain the hyperinsulinaemia that is exhibited. These findings lead us to hypothesise that ectopic fat does not play a pivotal role in driving insulin resistance in black populations. Furthermore, we hypothesise that hyperinsulinaemia is driven by lower rates of hepatic insulin clearance rather than heightened insulin resistance and is a primary defect rather than occurring in compensation for insulin resistance. These hypotheses are being investigated in our ongoing South London Diabetes and Ethnicity Phenotyping study, which will enable a more detailed understanding of ethnic distinctions in the pathophysiology of T2D between men of black African and white European ethnicity.

Glycemic control and lipid outcomes in children and adolescents with type 2 diabetes

BACKGROUND

The incidence of type 2 diabetes (T2DM) in children has increased dramatically. However, limited published information is known about the glycemic control and lipid outcomes in pediatric T2DM outside of clinical trials.

OBJECTIVES

To determine the glycemic control and lipid measure outcomes at one and three- year follow-up in children with T2DM.

METHODS

A retrospective electronic medical record review of children with T2DM at the Children's Hospital of Alabama over a 12-year period.

RESULTS

There were 301 patients with a diagnosis of T2DM who had a 1-year follow-up visit, of which 184 also had a 3-year follow-up. Most patients (78%) received either insulin with metformin or insulin alone at diagnosis. At one year, 37% of the cohort achieved 'optimal glycemic control' (HbA1C ≤6.5%) and 58% of patients achieved durable glycemic control (HbA1C ≤8%). Optimal glycemic control was seen in 48 patients at 3 years. The patients treated with insulin (alone or in combination with metformin) tended to have higher HbA1C at diagnosis, but had improved lipid and glycemic outcomes at follow-up. The group treated with insulin along with metformin had significant improvements in non-HDL, HDL and TC/HDL ratios. The effects of insulin treatment on glycemic control at 3 years were not statistically significant.

CONCLUSION

With the current modality of treatment, only a minority of patients achieve optimal glycemic control at 1 and 3 years of follow-up. Studies are warranted to further elucidate the optimal therapies in the management of pediatric T2DM.

Geographical variation in the prevalence of obesity and metabolic syndrome among US adolescents

BACKGROUND

Among adolescents, obesity and the metabolic syndrome (MetS) contribute to adult cardiovascular disease risk. By parent report, obesity prevalence in the USA was highest in the South.

OBJECTIVES

The aim of this study was to determine the prevalence of obesity and MetS by US division and region.

METHODS

We used in-person assessment of 4600 US adolescents age 12-19 years participating in the National Health and Nutrition Examination Survey, 1999-2014.

RESULTS

Prevalence of obesity was highest in the East North Central division (21.3%) and the three census divisions in the South (all >20%), compared with lower prevalence in the Mountain and New England divisions (both <15%). MetS was most prevalent in the two divisions in the Midwest (both >10%) and lowest in the Mountain and New England divisions (both <6%). For the amount of obesity in each division, there was a higher prevalence of MetS in the West North Central division (obesity 17.1%, MetS 13.6%) and lower prevalence in the East South Central (obesity 23.5%, MetS 6.6%) and South Atlantic divisions (obesity 20.4%, MetS 6.7%).

CONCLUSIONS

The degree of obesity-related and MetS-related risk among adolescents in the Midwest is higher than suggested from previous parent-reported weight data. The Midwest and South may warrant particularly strong cardiovascular disease prevention efforts.

The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio as a predictor of insulin resistance, β-cell function, and diabetes in Hispanics and African Americans

OBJECTIVE

The TG/HDL-C ratio is used as a marker of insulin resistance (IR) in Caucasians; however, there is limited data in other ethnic groups. We hypothesized that the TG/HDL-C ratio is associated with IR in Hispanics and African Americans (AA).

RESEARCH DESIGN AND METHODS

Data from the Insulin Resistance Atherosclerosis Family Study was examined for associations between TG/HDL-C ratio and IR, β-cell function and incident diabetes in non-diabetic Hispanics (n = 872, 63% female) and AA (n = 371, 61% female). Insulin sensitivity index (S_I) and disposition index (DI) from frequently-sampled intravenous glucose tolerance tests were used as markers of IR and β-cell function respectively. Incident type 2 diabetes was determined by fasting glucose ≥ 126 mg/dl or initiation of anti-hyperglycemia agents over 5 year follow-up.

RESULTS

Higher TG/HDL-C ratio was associated with IR in Hispanic and AA men and women (P < 0.0002), as well as β-cell function in Hispanic women and AA men and women (P < 0.02). TG/HDL-C predicted incident type 2 diabetes in women (area under the curves 0.703 and 0.795 for Hispanics and AA respectively).

CONCLUSIONS

Similar to Caucasians, the TG/HDL-C ratio can be used to identify IR in Hispanics and AA, and may predict type 2 diabetes in women.

Risk prediction model of dyslipidaemia over a 5-year period based on the Taiwan MJ health check-up longitudinal database

OBJECTIVE

This study aimed to provide an epidemiological model to evaluate the risk of developing dyslipidaemia within 5 years in the Taiwanese population.

METHODS

A cohort of 11,345 subjects aged 35-74 years and was non-dyslipidaemia in the initial year 1996 and followed in 1997-2006 to derive a risk score that could predict the occurrence of dyslipidaemia. Multivariate logistic regression was used to derive the risk functions using the check-up centre of the overall cohort. Rules based on these risk functions were evaluated in the remaining three centres as the testing cohort. We evaluated the predictability of the model using the area under the receiver operating characteristic (ROC) curve (AUC) to confirm its diagnostic property on the testing sample. We also established the degrees of risk based on the cut-off points of these probabilities after transforming them into a normal distribution by log transformation.

RESULTS

The incidence of dyslipidaemia over the 5-year period was 19.1%. The final multivariable logistic regression model includes the following six risk factors: gender, history of diabetes, triglyceride level, HDL-C (high-density lipoprotein cholesterol), LDL-C (low-density lipoprotein cholesterol) and BMI (body mass index). The ROC AUC was 0.709 (95% CI: 0.693-0.725), which could predict the development of dyslipidaemia within 5 years.

CONCLUSION

This model can help individuals assess the risk of dyslipidaemia and guide group surveillance in the community.

Cardiometabolic Dysfunction Among U.S. Adolescents and Area-Level Poverty: Race/Ethnicity-Specific Associations

PURPOSE

To examine race/ethnicity-specific associations between area-level poverty and cardiometabolic dysfunction among U.S. adolescents.

METHODS

Data were from 10,415 adolescents aged 12-19 in the National Health and Nutrition Examination Survey (1999-2012), linked with census tract data on area-level poverty (the percent population living in poverty, grouped into race/ethnicity-specific quartiles). Cardiometabolic dysfunction was parameterized by summing z-scores of six cardiometabolic biomarkers, grouped into quintiles. Hierarchical ordinal models estimated overall and race/ethnicity specific associations. Posthoc analysis explored associations between area-level poverty and family poverty-to-income ratio.

RESULTS

Overall, compared to adolescents residing in areas with the lowest area-level poverty (i.e., first quartile), residents in third (OR 1.32, 95% CI 1.13, 1.53) and fourth (OR 1.27, 95% CI 1.08, 1.50) quartiles of area-level poverty experienced elevated odds of cardiometabolic dysfunction. Area-level poverty predicted cardiometabolic dysfunction between non-Hispanic white and Mexican American adolescents, but not between non-Hispanic black adolescents.

CONCLUSIONS

We found race/ethnicity-specific associations between area-level poverty and cardiometabolic dysfunction among U.S. adolescents, highlighting the moderating effect of race-ethnicity. Among non-Hispanic black adolescents, neither higher area-level nor family-level socioeconomic status is associated with cardiometabolic health, in contrast to non-Hispanic white adolescents. Similar associations among non-Hispanic white and Mexican American groups aligns with evidence of the Hispanic Paradox. Future studies of effect of area-level determinants of cardiometabolic dysfunction may consider race/ethnicity-specific associations.

Biomarker Differences between Controlled and Uncontrolled Hypertension among US Adults: National Health and Nutrition Examination Survey 2005-2010

This study aims to determine biomarker differences between controlled and uncontrolled hypertension using nationally representative samples. Those in the uncontrolled hypertension group were more likely to have CVD (p=0.0258) and diabetes (p=0.0004), less likely to meet the recommended waist circumference (p=0.0039) and BMI (p=0.0209), and less likely to drink alcohol (p=0.0002) than those in the controlled hypertension group, after controlling for demographic variables. Upon controlling for demographic variables, risk factors and diseases related to hypertension, those in the uncontrolled hypertension group had higher total cholesterol (p<.0001), HDL (p=0.0702, marginally significant), LDL (p<.0001), triglycerides (p=0.0702, marginally significant), apolipoprotein B (p<.0001), transferrin receptor (p=0.0692, marginally significant), and ACR (p<.0001) than those in the controlled hypertension group.

CONCLUSION

Our study found that ACR, total cholesterol, HDL, LDL, triglycerides, apolipoprotein B, and transferrin receptor are biomarkers associated with the risk of uncontrolled hypertension compared to controlled hypertension. Since uncontrolled hypertension is linked to very high risks of cardiovascular disease and chronic kidney disease, our findings may provide a partial answer to why antihypertensive treatment is ineffective for certain groups of patients. Further studies are warranted to examine the cause of uncontrolled hypertension.

Dyslipidemia is associated with pediatric nonalcoholic fatty liver disease

BACKGROUND

With the increasing prevalence of childhood obesity, nonalcoholic fatty liver disease (NAFLD) has emerged as the most common cause of pediatric chronic liver disorder. Factors underlying the pathophysiology of NAFLD remain poorly defined.

OBJECTIVE

This study aimed to describe the metabolic characteristics of children with NAFLD differing in race/ethnicity and to test associations between dyslipidemia and NAFLD.

METHODS

A retrospective chart review was conducted at a tertiary referral university hospital among 309 children with a diagnosis of NAFLD.

RESULTS

Participants (mean age 12.5 ± 3.4 years) were 64% male, 63% white, 23% Hispanic, and 14% black. Hispanic children were diagnosed with NAFLD at a significantly younger age (10.6 ± 3.1 years, P < .0001) and lower body mass index (31.5 ± 6.8 kg/m², P < .0001) than their white and black counterparts. For the entire cohort, prevalence of systolic hypertension was 41%, diabetes 14%, elevated cholesterol 42%, elevated non-high-density lipoprotein cholesterol (non-HDL-C) 58%, elevated low-density lipoprotein cholesterol 36%, elevated triglycerides (TG) 88%, and low high-density lipoprotein cholesterol 77%. Whites had elevated non-HDL-C, low-density lipoprotein cholesterol, and TG compared to blacks or Hispanics. Serum TG and non-HDL-C were significantly correlated to alanine aminotransferase (r = 0.18, P = .01; r = 0.16, P = .02), respectively, and persisted after adjusting for age and body mass index.

CONCLUSION

Cardiometabolic derangements, especially dyslipidemia, are highly prevalent in children with NAFLD and differ based on race/ethnicity. Serum TG and non-HDL-C may play an important role in the pathophysiology of pediatric NAFLD.

Hypertension in Obese Black Women is Not Caused by Increased Sympathetic Vascular Tone

Background

Black women have one of the highest prevalence rates of hypertension and obesity in the United States. We previously reported that sympathetic activation induced by obesity is a significant contributor to hypertension in white patients. It is unknown whether sympathetic activity similarly contributes to hypertension in obese black women.

Methods and Results

We studied 42 obese women (16 white, body mass index 36±4 kg/m², 44% with hypertension; 26 black, body mass index 35±4 kg/m², 46% with hypertension). Antihypertensive medications were discontinued for 2 weeks before the day of the study. All patients underwent complete autonomic blockade with trimethaphan at a dosage of 4 mg/min. Resting sympathetic activity determined from muscle sympathetic nerve recordings was similar between obese black women with hypertension and those with normotension. In whites, sympathetic activity was elevated in obese patients with hypertension compared with normotension; the decrease in mean arterial blood pressure produced by trimethaphan was greater in obese white patients with hypertension compared with those with normotension (−26.8±9.7 mm Hg versus −14.8±7.9 mm Hg, P=0.02). In contrast, there was no difference in the depressor responses induced by trimethaphan between obese black women with hypertension and those with normotension (−15.5±10.5 mm Hg versus −12.3±10.2 mm Hg, P=0.45). Mean arterial blood pressure remained elevated in obese blacks with hypertension compared with those with normotension during trimethaphan infusion (83.7±15.0 mm Hg versus 71.7±9.8 mm Hg, P=0.02). Heart rate increased similarly with trimethaphan between white (P=0.11) and black (P=0.76) women with hypertension and normotension.

Conclusions

These findings suggest that sympathetic activity does not contribute to hypertension in obese black women and provide further evidence for racial differences in hypertension mechanisms.

The association between insulin resistance and atrial fibrillation: A cross-sectional analysis from SPRINT (Systolic Blood Pressure Intervention Trial)

It is unclear whether metabolic syndrome (MetS) is associated with atrial fibrillation (AF) in an older population with greater cardiovascular risk, including those with chronic kidney disease. The authors investigated the association between MetS and AF in participants in SPRINT (Systolic Blood Pressure Intervention Trial). MetS was defined based on the Modified Third National Cholesterol Education Program. The baseline prevalence rate for MetS was 55%, while 8.2% of the participants had AF. In multivariate regression analyses, AF was not associated with presence of MetS in either chronic kidney disease or non-chronic kidney disease subgroups. Age, race, history of cardiovascular diseases, decreased triglycerides, decreased pulse pressure, and albuminuria remained significantly associated with AF risk. In contrast to the general population, MetS was not associated with AF in the older population with increased cardiovascular risk studied in SPRINT.

Independent associations between a metabolic syndrome severity score and future diabetes by sex and race: the Atherosclerosis Risk In Communities Study and Jackson Heart Study

AIMS/HYPOTHESIS

The study aimed to assess for an association between the degree of severity of the metabolic syndrome and risk of type 2 diabetes beyond that conferred by the individual components of the metabolic syndrome.

METHODS

We assessed HRs for an Adult Treatment Panel III (ATP-III) metabolic syndrome score (ATP-III MetS) and a sex- and race-specific continuous metabolic syndrome severity z score related to incident diabetes over a median of 7.8 years of follow-up among participants of two observational cohorts, the Atherosclerosis Risk in Communities study (n = 10,957) and the Jackson Heart Study (n = 2137).

RESULTS

The ATP-III MetS had an HR for incident diabetes of 4.36 (95% CI 3.83, 4.97), which was attenuated in models that included the individual metabolic syndrome components. By contrast, participants in the fourth quartile of metabolic syndrome severity (compared with the first quartile) had an HR of 17.4 (95% CI 12.6, 24.1) for future diabetes; in models that also included the individual metabolic syndrome components, this remained significant, with an HR of 3.69 (95% CI 2.42, 5.64). There was a race × metabolic syndrome interaction in these models such that HR was greater for black participants (5.30) than white participants (2.24). When the change in metabolic syndrome severity score was included in the hazard models, this conferred a further association, with changes in metabolic syndrome severity score of ≥0.5 having a HR of 2.66 compared with changes in metabolic syndrome severity score of ≤0.

CONCLUSIONS/INTERPRETATION

Use of a continuous sex- and race-specific metabolic syndrome severity z score provided an additional prediction of risk of diabetes beyond that of the individual metabolic syndrome components, suggesting an added risk conferred by the processes underlying the metabolic syndrome. Increases in this score over time were associated with further risk, supporting the potential clinical utility of following metabolic syndrome severity over time.

Ethnic Differences in Lipid Profiles of Overweight, Obese, and Severely Obese Children and Adolescents 6-19 Years of Age

BACKGROUND

Ethnic differences in lipid profiles exist in children and adolescents. This study assessed whether variations in lipid profiles present in overweight and obese youth were also observed in severely obese youth. Variations could explain the lower prevalence of the metabolic syndrome in certain ethnic groups at even severe levels of obesity.

METHODS

Data were obtained from the National Health and Nutrition Examination Survey for the years of 2001 through 2012. Subjects were divided into groups according to BMI classification. Normal weight was defined as a BMI less than the 85th percentile. Overweight was defined as a BMI between the 85th and 95th percentile. Class 1 obesity was defined as a BMI greater than the 95th percentile up to 120% of the 95th percentile. A BMI between 120% and 140% of the 95th percentile was defined as Class 2 obesity. Class 3 was defined as a BMI above 140% of the 95th percentile. Primary outcomes were mean total cholesterol, triglyceride, low-density lipoprotein, and high-density lipoprotein levels (HDL).

RESULTS

The sample included 14,481 non-Hispanic black (NHB) (N = 4710), non-Hispanic white (N = 4910), and Mexican American (N = 4861) subjects. Across all BMI categories, the NHB group had significantly lower mean TG and higher mean HDL levels (p < 0.0001).

CONCLUSIONS

Ethnic variations in lipid profiles were found in severely obese youth. These findings could explain the lower prevalence of the metabolic syndrome in NHB youth. Ethnic-specific guidelines are necessary for improved identification of those at risk at all levels of obesity.

Interethnic Differences in Serum Lipids and Implications for Cardiometabolic Disease Risk in African Ancestry Populations

African Americans generally have a healthier lipid profile (lower triglycerides and higher high-density lipoprotein cholesterol concentration) compared with those of other ethnicities. Paradoxically, African Americans do not experience a decreased risk of the cardiometabolic diseases that serum lipids are expected to predict. This review explores this mismatch between biomarker and disease among African ancestry individuals by investigating the presence of interethnic differences in the biological relationships underlying the serum lipids-disease association. This review also discusses the physiologic and genomic factors underlying these interethnic differences. Additionally, because of the importance of serum lipids in assessing disease risk, interethnic differences in serum lipids have implications for identifying African ancestry individuals at risk of cardiometabolic disease. Where possible, data from Africa is included, to further elucidate these ancestral differences in the context of a different environmental background.

Racial and ethnic differences in the polycystic ovary syndrome metabolic phenotype

BACKGROUND

Women with polycystic ovarian syndrome have a high prevalence of metabolic syndrome and type 2 diabetes mellitus. Blacks and Hispanics have a high morbidity and mortality due to cardiovascular disease and diabetes mellitus in the general population. Since metabolic syndrome is a risk factor for development of type 2 diabetes and cardiovascular disease, understanding any racial and ethnic differences in metabolic syndrome among women with polycystic ovarian syndrome is important for prevention strategies. However, data regarding racial/ethnic differences in metabolic phenotype among women with polycystic ovary syndrome are inconsistent.

OBJECTIVE

We sought to determine if there are racial/ethnic differences in insulin resistance, metabolic syndrome, and hyperandrogenemia in women with polycystic ovarian syndrome.

STUDY DESIGN

We conducted secondary data analysis of a prospective multicenter, double-blind controlled clinical trial, the Pregnancy in Polycystic Ovary Syndrome II study, conducted in 11 academic health centers. Data on 702 women with polycystic ovarian syndrome aged 18-40 years who met modified Rotterdam criteria for the syndrome and wished to conceive were included in the study. Women were grouped into racial/ethnic categories: non-Hispanic whites, non-Hispanic blacks, and Hispanic. The main outcomes were the prevalence of insulin resistance, metabolic syndrome, and hyperandrogenemia in the different racial/ethnic groups.

RESULTS

Body mass index (35.1 ± 9.8 vs 35.7 ± 7.9 vs 36.4 ± 7.9 kg/m2) and waist circumference (106.5 ± 21.6 vs 104.9 ± 16.4 vs 108.7 ± 7.3 cm) did not differ significantly between non-Hispanic white, non-Hispanic black, and Hispanic women. Hispanic women with polycystic ovarian syndrome had a significantly higher prevalence of hirsutism (93.8% vs 86.8%), abnormal free androgen index (75.8% vs 56.5%), abnormal homeostasis model assessment (52.3% vs 38.4%), and hyperglycemia (14.8% vs 6.5%), as well as lower sex hormone binding globulin compared to non-Hispanic whites. Non-Hispanic black women had a significantly lower prevalence of metabolic syndrome (24.5% vs 42.2%) compared with Hispanic women, and lower serum triglyceride levels compared to both Hispanics and non-Hispanic whites (85.7 ± 37.3 vs 130.2 ± 57.0 vs 120.1 ± 60.5 mg/dL, P < .01), with a markedly lower prevalence of hypertriglyceridemia (5.1% vs 28.3% vs 30.5%, P < .01) compared to the other 2 groups.

CONCLUSION

Hispanic women with polycystic ovarian syndrome have the most severe phenotype, both in terms of hyperandrogenism and metabolic criteria. Non-Hispanic black women have an overall milder polycystic ovarian syndrome phenotype than Hispanics and in some respects, than non-Hispanic white women.

Review: Metabolic Syndrome in Black South African Women

The prevalence of metabolic syndrome is increasing in African populations, and is particularly high in Black South African women (42%) vs women in the United Kingdom (23%) and the United States of America (36%). This population group is also known to have the highest prevalence of obesity in the sub-Saharan African region (42%), and consequently, a high risk of non-communicable diseases. In this article, we discuss factors (abdominal subcutaneous fat, visceral fat, lean mass, adiponectin, leptin, vitamin D, smoking and menopausal status) that have been investigated for their possible association with metabolic syndrome in African women, and discuss some recommendations for management of the syndrome. In particular, the infrastructural development of HIV/AIDS clinics in South Africa provides an ideal integrated platform to cater to the treatment needs of patients with multiple chronic morbidities.

Examining trends in prediabetes and its relationship with the metabolic syndrome in US adolescents, 1999-2014

AIMS

We sought to investigate temporal trends in prediabetes prevalence among US adolescents using two definitions and evaluate relationships with obesity and a MetS-severity score.

METHODS

We evaluated data from 5418 non-Hispanic white, non-Hispanic black, and Hispanic adolescents aged 12-19 participating in the National Health and Nutrition Examination Survey 1999-2014 with complete data regarding MetS and hemoglobin A1c (HbA1c). Prediabetes status was defined by American Diabetes Association (ADA) criteria: fasting glucose 100-125 mg/dL or HbA1c 5.7%-6.4%. MetS severity was assessed with a MetS-severity Z-score.

RESULTS

Prevalence of prediabetes as defined by HbA1c abnormalities significantly increased from 1999-2014, while prevalence of prediabetes as defined by fasting glucose abnormalities showed no significant temporal trend. There were variations in these trends across different racial/ethnic groups. MetS Z-score was overall more strongly correlated with HbA1c, fasting insulin, and the homeostasis model of insulin resistance than was BMI Z-score. These correlations were true in each racial/ethnic group with the exception that in non-Hispanic white adolescents, in whom the MetS Z-score was not significantly correlated with HbA1c measurements.

CONCLUSION

We found conflicting findings of temporal trends of US adolescent prediabetes prevalence based on the ADA's prediabetes criteria. The increasing prevalence of prediabetes by HbA1c assessment is concerning and raises the urgency for increased awareness and appropriate measures of prediabetes status among physicians and patients.

Heritability of the Severity of the Metabolic Syndrome in Whites and Blacks in 3 Large Cohorts

BACKGROUND

Although dichotomous criteria for the metabolic syndrome (MetS) appear heritable, it is not known whether MetS severity as assessed by a continuous MetS score is heritable and whether this varies by race.

METHODS AND RESULTS

We used SOLAR (Sequential Oligogenic Linkage Analysis Routines) to evaluate heritability of Adult Treatment Panel-III MetS and a sex- and race-specific MetS severity Z score among 3 large familial cohorts: the JHS (Jackson Heart Study, 1404 black participants), TOPS (Take Off Pounds Sensibly, 1947 white participants), and PLRS (Princeton Lipid Research Study, 229 black and 527 white participants). Heritability estimates were larger for Adult Treatment Panel-III MetS among black compared with white cohort members (JHS 0.48; 95% confidence interval [CI], 0.28-0.68 and PLRS blacks 0.93 [95% CI, 0.73-1.13] versus TOPS 0.21 [95% CI, -0.18 to 0.60] and PLRS whites 0.27 [95% CI, -0.04 to 0.58]). The difference by race narrowed when assessing heritability of the MetS severity score (JHS 0.52 [95% CI, 0.38, 0.66] and PLRS blacks 0.64 [95% CI, 0.13-1.15] versus TOPS 0.23 [95% CI, 0.15-0.31] and PLRS whites 0.60 [95% CI, 0.33-0.87]). There was a high degree of genetic and phenotypic correlation between MetS severity and the individual components of MetS among all groups, although the genetic correlations failed to reach statistical significance among PLRS blacks. Meta-analyses revealed a combined heritability estimate for Adult Treatment Panel-III MetS of 0.24 (95% CI, 0.11-0.36) and for the MetS severity score of 0.50 (95% CI, -0.05 to 0.99).

CONCLUSIONS

MetS severity seems highly heritable among whites and blacks. This continuous MetS severity Z score may provide a more useful means of characterizing phenotypic MetS in genetic studies by minimizing racial differences.

Correlation of metabolic syndrome severity with cardiovascular health markers in adolescents

BACKGROUND AND OBJECTIVES

The presence of metabolic syndrome (MetS) in childhood is a significant risk factor for later cardiovascular disease (CVD). Recent data showed temporal decreases in a sex- and race/ethnicity-specific MetS severity z-score among U.S. adolescents. Our goal was to characterize the relationship of this MetS z-score with other CVD risk indicators and assess their temporal trends and lifestyle influences.

METHODS

We analyzed 4837 participants aged 12-20years from the National Health and Nutrition Examination Survey by 2-year waves from 1999 to 2012. We used linear regression to compare MetS z-score and dietary factors with serum levels of low-density lipoprotein (LDL), apolipoprotein-B (ApoB), high-sensitivity C-reactive protein (hsCRP) and uric acid.

RESULTS

MetS severity z-score was positively correlated with LDL, ApoB, hsCRP, and uric acid measurements (p<0.0001 for all). These correlations held true among individual racial/ethnic groups. LDL, ApoB, and hsCRP measurements decreased over time among U.S. adolescents (p=0.002, p<0.0001, and p=0.024, respectively). Saturated fat consumption was positively correlated with LDL (p=0.005) and ApoB (p=0.012) and inversely related to serum uric acid (p=0.001). Total caloric intake was inversely related to LDL (p=0.003) and serum uric acid (p=0.003). Unsaturated fat, carbohydrate, and protein consumption were not related to LDL, ApoB, hsCRP, or serum uric acid.

CONCLUSIONS

There is a positive correlation between MetS severity and all four CVD risk indicators studied. LDL, ApoB, and hsCRP showed favorable temporal trends, which could be related to similar trends in MetS z-score. These data support the importance of considering multiple inter-related factors in clinical CVD risk assessment.

The Cut-off Values of Triglycerides and Glucose Index for Metabolic Syndrome in American and Korean Adolescents

The aim of this study was to establish ethnic- and gender-specific cut-off values of triglycerides and glucose index (TyG index) for clinical usefulness in a representative sample of Mexican American, Non-Hispanic White, Non-Hispanic Black, and Korean adolescents. The data were collected from datasets of the National Health and Nutrition Examination Survey between 1999 and 2012, and the Korean National Health and Nutrition Examination Survey between 2005 and 2013. Receiver operating characteristic curve analysis was used to find valid cut-off values of the TyG index for metabolic syndrome. The total number of eligible participants was 3,164 in the US and 4,873 in Korea. The optimal cut-off value with the Cook et al. definition revealed 8.55 in Mexican American, 8.55 in Non-Hispanic White, 8.35 in Non-Hispanic Black, and 8.45 in Korean, respectively. The cut-off value with the de Ferranti et al. definition was 8.45, 8.45, 8.15, and 8.35, and the cut-off value with the International Diabetes Federation definition was 8.65, 8.65, 8.15, and 8.55, respectively. These findings may be clinically useful for evaluating insulin resistance for determining metabolic abnormalities in adolescents.