Clinical measures of obesity and cumulative cardiometabolic risk in adolescents

Appraisal of Clinical Care Practices for Child Obesity Treatment. Part II: Comorbidities

The objective of this technical report is to provide clinicians with actionable evidence-based information upon which to make treatment decisions. In addition, this report will provide an evidence base on which to inform clinical practice guidelines for the management and treatment of overweight and obesity in children and adolescents. To this end, the goal of this report was to identify all relevant studies to answer 2 overarching key questions: (KQ1) "What are effective clinically based treatments for obesity?" and (KQ2) "What is the risk of comorbidities among children with obesity?" See Appendix 1 for the conceptual framework and a priori Key Questions.

Cardiovascular Implications in Idiopathic and Syndromic Obesity in Childhood: An Update

Childhood obesity is a modern worldwide epidemic with significant burden for health. It is a chronic metabolic disorder associated with multiple cardiovascular risk factors such as dyslipidemia, hypertension, stroke, and insulin resistance. Many obese adolescents remain obese into adulthood, with increased morbidity and mortality. As childhood obesity is a risk factor for adult obesity, the childhood obesity-related disorders account for an increased risk of cardiovascular consequences in adults, in addition to the effects already exerted by the fat mass in adulthood. Several papers have already described the cardiovascular implications of idiopathic obesity, while few data are available about syndromic obesity, due to the small sample size, not homogeneous phenotypes, and younger age at death. The aim of this mini-review is to give a comprehensive overview on knowledge about cardiovascular implications of idiopathic and syndromic obesity to allow the reader a quick comparison between them. The similarities and differences will be highlighted.

Wrist circumference is a biomarker of adipose tissue dysfunction and cardiovascular risk in children with obesity

PURPOSE

To evaluate the relationship between wrist circumference, markers of adipose dysfunction, and cardiovascular risk in youths with obesity.

METHODS

In this cross-sectional study, we measured body mass composition by dual-energy X-ray absorptiometry, wrist circumference, waist-to-height ratio, fasting blood insulin, glucose, lipid profile, adiponectin, and leptin in 280 children with overweight/obesity and without diabetes (age: 7-18 years). Cardiovascular risk was estimated by "metabolic syndrome score" (MetS score).

RESULTS

Study participants had median [25th-75th percentile] wrist circumference of 17.5 [16.7-18.5] cm and waist-to-height ratio of 0.62 [0.59-0.67]. Lower adiponectin-leptin ratio was found among subjects in the upper 50th percentiles of wrist circumference [0.17 (0.09-0.36) vs. 0.38 (0.16-0.79); p < 0.001]. Wrist circumference was independently associated with MetS score (r = 0.5 p < 0.001). Among MetS score components, an independent association between wrist circumference HDLc, triglycerides, and systolic blood pressure was found (r = - 0.253 p < 0.001; r =+ 0.204 p < 0.001; r = + 0.403 p = < 0.001, respectively). The coefficient of determination for MetS score was nominally higher when considering wrist circumference as independent variable (Adj-R² = 0.30) then when considering body mass index SD (Adj-R² = 0.28), waist-to-height ratio (Adj-R² = 0.26) or truncal fat percentage (Adj-R² = 0.01). The addition of wrist circumference in age and gender adjusted models, accounting to any other anthropometric parameters, resulted in a significant improvement of the Adj-R² (p < 0.001 for all).

CONCLUSIONS

Our study shows that wrist circumference independently relates to adiponectin-leptin ratio and to the prediction of cardiovascular risk, suggesting it as an efficient and adjunctive anthropometric marker of cardiometabolic risk in children with obesity.

Prevalence and determinants of hypertension among students of the University of Kinshasa, Democratic Republic of Congo: a cross-sectional study

Background

The 2017 ACC/AHA Guideline categorized blood pressure into 4 levels:normal (SBP<120 and DBP <80mm Hg), elevated (SBP of 120–129 or DBP< 80 mmHg) and stage 1 (SBP of 130–139 or DBP of 80–89 mm Hg) or 2 (SBP≥140 orDBP≥90mmHg). Compared with the JNC7 guideline, the 2017 ACC/AHA guideline recommends using lower SBP and DBP levels to define hypertension.

Objective

To determine the prevalence of hypertension as well as associated factors among students of the University of Kinshasa.

Methods

This was a cross-sectional study conducted at the University of Kinshasa and including 1 281 students aged between 18 and 30. Blood pressure was assessed according to the WHO STEPwise approach, which is a standardized method of data collection, analysis and dissemination for the surveillance of non-communicable diseases in WHO member countries. The Chi-square and Student's t-tests and a multivariate logistic regression analysis have been used to evaluate the results. Statistical analyses were done using IBM SPSS version 21.

Results

The prevalence of hypertension according to the guidelines from the 2017 ACC/AHA and the JNC 7 was 26.4 % (CI 95%; 23.9 – 28.9) and 7.3 % (CI 95%; 5.8 – 8.8), respectively. The results of multivariate logistic regression analysis showed that smoking, alcohol abuse, overweight, male sex, age ≥ 24 years old and low physical activity were associated with hypertension (p < 0.0001).

Conclusion

At least one out of four students had hypertension. These data should encourage public health authorities to develop strategies for screening of BP and topromote the adoption of healthy lifestyle in young adults.

Obesity and insulin sensitivity effects on cardiovascular risk factors: Comparisons of obese dysglycemic youth and adults

BACKGROUND

Obesity and pubertal insulin resistance worsen cardiovascular (CV) risk factors in youth. It is unclear how the relationships of obesity and insulin resistance with CV risk compare to adults.

SUBJECTS AND METHODS

We evaluated 66 pubertal youth (mean ± SD: age 14.2 ± 2.0 years, body mass index [BMI] 36.6 ± 6.0 kg/m² , hemoglobin A1c [HbA1c] 38.5 ± 6.1 mmol/mol) and 355 adults with comparable BMI (age 52.7 ± 9.4 years, BMI 35.1 ± 5.1 kg/m² , HbA1c 39.8 ± 4.2 mmol/mol) participating in a multicenter study. Insulin sensitivity was quantified using hyperglycemic clamps. Assessment of CV risk factors was standardized across sites. Regression analyses compared the impact of insulin sensitivity and CV risk factors between youth and adults.

RESULTS

Obese pubertal youth were more insulin resistant than comparably obese adults (P < .001), but with similar slopes for the inverse relationship between insulin sensitivity and obesity. The impact of obesity on CV risk factors was explained by insulin sensitivity (P = NS after adjustment for sensitivity). The two age groups did not differ in relationships between insulin sensitivity and diastolic blood pressure, total cholesterol, and low-density lipoprotein (LDL) cholesterol, after adjusting for obesity. However, while systolic blood pressure (SBP) and high-density lipoprotein (HDL) cholesterol exhibited the expected direct and inverse relationships, respectively with insulin sensitivity in adults, these slopes were flat in youth across the range of insulin sensitivity (P ≤ .05 for group differences).

CONCLUSIONS

Effects of obesity on CV risk factors were attributable to insulin sensitivity in both groups. The relationships between insulin sensitivity and CV risk factors were similar in obese youth and adult groups except for SBP and HDL cholesterol.

CLINICAL TRIAL REGISTRATION

The RISE consortium studies are registered through Clinicaltrials.gov as NCT01779362 (Adult Medication Study); NCT01763346 (Adult Surgery Study); and NCT01779375 (Pediatric Medication Study). Clinical trial registration numbers: NCT01779362, NCT01779375 and NCT01763346 at clinicaltrials.gov.

Ethnic differences in progression of islet autoimmunity and type 1 diabetes in relatives at risk

AIMS/HYPOTHESIS

We hypothesised that progression of islet autoimmunity and type 1 diabetes mellitus differs among races/ethnicities in at-risk individuals.

METHODS

In this study, we analysed the data from the Type 1 Diabetes TrialNet Pathway to Prevention Study. We studied 4873 non-diabetic, autoantibody-positive relatives of individuals with type 1 diabetes followed prospectively (11% Hispanic, 80.9% non-Hispanic white [NHW], 2.9% non-Hispanic black [NHB] and 5.2% non-Hispanic other [NHO]). Primary outcomes were time from single autoantibody positivity confirmation to multiple autoantibody positivity, and time from multiple autoantibody positivity to type 1 diabetes mellitus diagnosis.

RESULTS

Conversion from single to multiple autoantibody positivity was less common in Hispanic individuals than in NHW individuals (HR 0.66 [95% CI 0.46, 0.96], p = 0.028) adjusting for autoantibody type, age, sex, Diabetes Prevention Trial Type 1 Risk Score and HLA-DR3-DQ2/DR4-DQ8 genotype. In participants who screened positive for multiple autoantibodies (n = 2834), time to type 1 diabetes did not differ by race/ethnicity overall (p = 0.91). In children who were <12 years old when multiple autoantibody positivity was determined, being overweight/obese had differential effects by ethnicity: type 1 diabetes risk was increased by 36% in NHW children (HR 1.36 [95% CI 1.04, 1.77], p = 0.024) and was nearly quadrupled in Hispanic children (HR 3.8 [95% CI 1.6, 9.1], p = 0.0026). We did not observe this interaction in participants who were ≥12 years old at determination of autoantibody positivity, although this group size was limited. No significant differential risks were observed between individuals of NHB and NHW ethnicity.

CONCLUSIONS/INTERPRETATION

The risk and rate of progression of islet autoimmunity were lower in Hispanic compared with NHW at-risk individuals, while significant differences in the development of type 1 diabetes were limited to children <12 years old and were modified by BMI.

Arm Circumference-to-Height Ratio as a Situational Alternative to BMI Percentile in Assessing Obesity and Cardiometabolic Risk in Adolescents

OBJECTIVE

To determine whether arm circumference-to-height ratio (AHtR) predicts adolescents' cardiometabolic risk and how its predictive statistics compare to those of body mass index (BMI) percentile.

METHODS

Pooled data for adolescents (N = 12,269, 12-18 years) from the National Health and Nutrition Examination Survey, U.S., 1999-2014, were analyzed. For each of the eight cardiometabolic variables, borderline-risk and high-risk were considered unhealthy, and being unhealthy on any variable was considered "unhealthy overall" in terms of cardiometabolic risk. Area under the curve and R ² were used to compare BMI percentile and AHtR for accuracy in predicting risk.

RESULTS

Female AHtR ≥ 0.19 and BMI percentile ≥ 94 and male AHtR ≥ 0.16 and BMI percentile ≥ 64 predicted a probability of >0.7 being unhealthy overall. AHtR predicted overall risk and unhealthy levels of six variables more accurately than BMI percentile. Significant differences were overall risk (χ ² = 4.18; p=0.041), total cholesterol (χ ² = 8.68; p=0.003), glycated hemoglobin (χ ² = 5.24; p=0.022), and systolic pressure (χ ² = 5.10; p=0.024). AHtR had higher accuracy in predicting high-density cholesterol, fasting glucose, glycated hemoglobin, and systolic/diastolic pressures plus higher specificity in predicting all variables except triglycerides. BMI percentile had higher sensitivity for all variables. Sensitivity and accuracy were higher for males. No significant race/ethnicity differences were observed.

CONCLUSIONS

Without needing adjustment for age and weight, AHtR can predict some cardiometabolic risk factors of adolescents, especially of males, more accurately than BMI percentile, thus facilitating population risk estimation and early interventions. Further research is required to validate these findings in younger children.