Novel measures of inflammation and insulin resistance are related to obesity and fitness in a diverse sample of 11-14 year olds: The HEALTHY Study

Beyond Obesity and Overweight: The Clinical Assessment and Treatment of Excess Body Fat in Children : Part 1 - Insulin Resistance as the Root Cause of Pediatric Obesity

PURPOSE OF REVIEW

Pediatric obesity and comorbidities related to insulin resistance continue to be a growing public health crisis. If lifestyle measures are unsuccessful, pharmacological and surgical interventions are offered. In this paper, we describe the driving force of the obesity crisis: hyperinsulinemia and the development of insulin resistance. We give historical background of key policy issues which have contributed to this pandemic as well as the physiologic mechanisms of insulin resistance. The prevalence of obesity will continue to rise unless the root cause of hyperinsulinemia is addressed.

RECENT FINDINGS

Current research on insulin resistance demonstrates that a decreased consumption of carbohydrates is an effective first-line dietary intervention for the treatment of obesity and related metabolic diseases. Evidence shows it is safe and beneficial. A low-carbohydrate eating pattern can be helpful to address pediatric obesity. However, there must be policy guardrails in place to ensure that this is a sustainable and viable option for children and their families. There must be a change in the nutritional environment to help individuals battle the chronic disease of obesity.

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.

Title: Human Serum/Plasma Glycoprotein Analysis by 1H-NMR, an Emerging Method of Inflammatory Assessment

Several studies suggest that variations in the concentration of plasma glycoproteins can influence cellular changes in a large number of diseases. In recent years, proton nuclear magnetic resonance (1H-NMR) has played a major role as an analytical tool for serum and plasma samples. In recent years, there is an increasing interest in the characterization of glycoproteins through 1H-NMR in order to search for reliable and robust biomarkers of disease. The objective of this review was to examine the existing studies in the literature related to the study of glycoproteins from an analytical and clinical point of view. There are currently several techniques to characterize circulating glycoproteins in serum or plasma, but in this review, we focus on 1H-NMR due to its great robustness and recent interest in its translation to the clinical setting. In fact, there is already a marker in H-NMR representing the acetyl groups of the glycoproteins, GlycA, which has been increasingly studied in clinical studies. A broad search of the literature was performed showing a general consensus that GlycA is a robust marker of systemic inflammation. The results also suggested that GlycA better captures systemic inflammation even more than C-reactive protein (CRP), a widely used classical inflammatory marker. The applications reviewed here demonstrated that GlycA was potentially a key biomarker in a wide range of diseases such as cancer, metabolic diseases, cardiovascular risk, and chronic inflammatory diseases among others. The profiling of glycoproteins through 1H-NMR launches an encouraging new paradigm for its future incorporation in clinical diagnosis.

Cardiometabolic Risk Factors and Physical Activity Patterns Maximizing Fitness and Minimizing Fatness Variation in Malaysian Adolescents: A Novel Application of Reduced Rank Regression

Patterns of physical activity (PA) that optimize both fitness and fatness may better predict cardiometabolic health. Reduced rank regression (RRR) was applied to identify combinations of the type (e.g., football vs. skipping), location and timing of activity, explaining variation in cardiorespiratory fitness (CRF) and Body Mass Index (BMI). Multivariable regressions estimated longitudinal associations of PA pattern scores with cardiometabolic health in n = 579 adolescents aged 13–17 years from the Malaysian Health and Adolescent Longitudinal Research Team study. PA pattern scores in boys were associated with higher fitness (r = 0.3) and lower fatness (r = −0.3); however, in girls, pattern scores were only associated with higher fitness (r = 0.4) (fatness, r = −0.1). Pattern scores changed by β = −0.01 (95% confidence interval (CI) −0.04, 0.03) and β = −0.08 (95% CI −0.1, −0.06) per year from 13 to 17 years in boys and girls respectively. Higher CRF and lower BMI were associated with better cardiometabolic health at 17 years, but PA pattern scores were not in either cross-sectional or longitudinal models. RRR identified sex-specific PA patterns associated with fitness and fatness but the total variation they explained was small. PA pattern scores changed little through adolescence, which may explain the limited evidence on health associations. Objective PA measurement may improve RRR for identifying optimal PA patterns for cardiometabolic health.

Circulating Osteonectin and Adipokine Profiles in Relation to Metabolically Healthy Obesity in Chinese Children: Findings From BCAMS

Background The role of adipokine dysregulation in determining the metabolic fate of obesity is not well studied. We aimed to examine whether the matricellular protein osteonectin and the profiles of certain adipokines could differentiate metabolically healthy obese ( MHO ) versus metabolically unhealthy obese phenotypes in childhood. Methods and Results This study included 1137 obese children and 982 normal-weight healthy ( NWH ) controls recruited from the BCAMS (Beijing Child and Adolescent Metabolic Syndrome) study. MHO was defined by the absence of insulin resistance and/or any metabolic syndrome components. Six adipokines-osteonectin, leptin, adiponectin, resistin, FGF21 (fibroblast growth factor 21), and RBP-4 (retinol binding protein 4)-were assessed. Approximately 20% of obese children displayed the MHO phenotype. MHO children had a more favorable adipokine profile than metabolically unhealthy obese children, with lower osteonectin, leptin, and RBP -4 and higher adiponectin (all P<0.05). Compared with normal-weight healthy controls, MHO children displayed increased leptin, resistin, and RBP -4 levels and reduced adiponectin concentrations (all P<0.05) but similar osteonectin and FGF 21 levels. Among obese subjects, decreased osteonectin (odds ratio [OR]: 0.82; 95% confidence interval [CI] per standard deviation, 0.70-0.97), RBP -4 (OR: 0.77; 95% CI per standard deviation, 0.64-0.93), and leptin/adiponectin ratio (OR: 0.58; 95% CI per standard deviation, 0.43-0.77) were independent predictors of MHO . In addition, compared with children without abnormalities, those with any 3 adipokine abnormalities were 80% less likely to exhibit the MHO phenotype ( OR : 0.20; 95% CI , 0.10-0.43) and 3 times more likely to have metabolic syndrome ( OR : 2.77; 95% CI , 1.52-5.03). Conclusions These findings suggest that dysregulation of adipokines might govern the metabolic consequences of obesity in children. Low osteonectin levels, along with a healthy adipokine profile, might be used as an early marker of the MHO phenotype.

Glycoprotein A and B Height-to-Width Ratios as Obesity-Independent Novel Biomarkers of Low-Grade Chronic Inflammation in Women with Polycystic Ovary Syndrome (PCOS)

The polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting women in reproductive age. Obesity and low-grade chronic inflammation are frequently associated with PCOS. Recently, proton nuclear magnetic resonance (¹H-NMR)-derived glycoprotein profiles have emerged as potential biomarkers that reflect systemic inflammation in type 2 diabetes, obesity, and other pathological processes. The aim of this work is to study plasma glycoprotein profiles as metabolic/inflammatory biomarkers underlying PCOS and its association with inflammation and obesity. We used ¹H-NMR spectroscopy to study five glycoprotein variables, namely GlycA, GlycB, and GlycF and the height-to-width (H/W) ratio of GlycA and GlycB, in 17 women with PCOS (9 non-obese and 8 obese), 17 control women (9 non-obese and 8 obese), and 19 healthy men (10 non-obese and 9 obese). H/W ratios of GlycA and GlycB, but not glycoprotein areas, were specifically associated with PCOS independently of obesity. When considered as a whole, obese subjects presented higher GlycA, GlycB, and GlycF areas and higher H/W GlycA and GlycB ratios than their non-obese counterparts. All glycoprotein variables were associated with hsCRP, IL-6, and TNF-α, showing different correlations among PCOS, women, and men. Our present exploratory results suggest that ¹H-NMR-derived glycoprotein profiles might serve as novel diagnostic markers of low-grade chronic inflammation in women with PCOS.

Lipoprotein particles in patients with pediatric Cushing disease and possible cardiovascular risks

BACKGROUND

Cardiovascular (CV) complications are the most significant cause of mortality in adults with Cushing disease (CD); little is known about CV risk factors in children with CD. Measurement of lipoprotein particles by nuclear magnetic resonance (NMR) spectroscopy is a novel technology to assess CV risk. The objective of the current study is to analyze the NMR lipid profile in pediatric CD patients before and 1 year after remission.

METHODS

NMR lipid profile was obtained via the Vantera NMR analyzer, using frozen serum samples from 33 CD patients (mean age 13.8 ± 4.0 years) evaluated between 1997 and 2017 at the National Institutes of Health (NIH) Clinical Center (CC).

RESULTS

GlycA (glycosylated acute-phase proteins), triglyceride-rich particles (TRLP medium and very small sizes), low-density lipoprotein (LDL) particles (LDLP total and large size), high-density lipoprotein (HDL) particles (HDLP total, medium and small sizes), total cholesterol, LDL-cholesterol, HDL-cholesterol, GlycA inflammatory biomarker, and apolipoprotein B and apolipoprotein A1 (ApoA1) concentrations showed statistically significant changes after remission of CD (p < 0.05).

CONCLUSION

In our study population, most of the lipid variables improved post-CD remission, with the exception of HDL and ApoA1, indicating that NMR lipoprotein profile may be a helpful tool in assessing the CV risk in pediatric patients with CD.

Elevated GlycA in severe obesity is normalized by bariatric surgery

Chronic inflammation drives many obesity-associated conditions including atherosclerosis. GlycA, a marker of systemic inflammation with lower intra-individual variability than high sensitivity C-reactive protein, is independently associated with incident cardiovascular events and mortality. Although GlycA is elevated in obesity, correlations with anthropometric measures are modest and the effect of body weight loss on GlycA is untested. Obese (body mass index [BMI] 44.6 ± 6.6 kg/m² ), non-diabetic women (33.7 ± 8.2 years) undergoing Roux-en-Y gastric bypass (n = 23) or sleeve gastrectomy (n = 31) were prospectively studied at baseline, 6 and 12 months postprocedure. Women with normal BMI (n = 14) served as controls. Bariatric surgery significantly reduced GlycA by 6 months (451 ± 47 μmol/L vs. 383 ± 50 μmol/L; P < 0.001) with further reduction at 12 months (348 ± 41 μmol/L; P < 0.001) and no difference between procedures. At 12 months, despite 41% of surgical subjects maintaining BMI >30 kg/m² , GlycA levels did not differ between surgical and control subjects (P = 0.13). Increased high density lipoprotein particle size was strongly associated with reduced GlycA (r = -0.49; P < 0.001) and was found to mediate up to 43% of its body weight-loss-associated fall. This is the first study to demonstrate that surgical body weight loss markedly reduces levels of GlycA.

Decreased GlycA after lifestyle intervention among obese, prediabetic adolescent Latinos

BACKGROUND

Obese youth with prediabetes are at increased risk for premature morbidity and mortality through multiple mechanisms, including increased systemic inflammation. GlycA is a novel measure of systemic inflammation that predicts type II diabetes, cardiovascular events, and all-cause mortality in adults.

OBJECTIVE

The purpose of the present study was to examine changes in GlycA after lifestyle intervention among obese, prediabetic Latino youth.

METHODS

Obese, prediabetic Latino youth (n = 27; 15.5 ± 1.1 years, 13 males/14 females) completed a 12-week lifestyle intervention that included weekly nutrition education and 3 d/wk of moderate to vigorous physical activity. Prediabetes was characterized by an expanded definition of impaired glucose tolerance, using 2-hour glucose ≥120 mg/dL after an oral glucose tolerance test. GlycA was assessed at baseline and 12 weeks using nuclear magnetic resonance spectroscopy.

RESULTS

After the lifestyle intervention, GlycA was significantly reduced (445.3 ± 51.3 μmol/L to 419.0 ± 50.0 μmol/L, P = .01) (mean ± standard deviation). Additional improvements were observed in multiple cardiovascular risk factors, including body mass index (BMI; 34.8 ± 5.0 kg/m² to 34.0 ± 5.1 kg/m², P < .001), total cholesterol (154.1 ± 30.3 mg/dL to 143.3 ± 29.1 mg/dL, P = .003), and 2-hour glucose (141.0 ± 13.2 mg/dL to 115.9 ± 31.4 mg/dL, P < .001). Decreases in GlycA were associated with decreases in 2-hour glucose (r = 0.49, P = .008) and BMI (r = 0.41, P = .03).

CONCLUSION

These data are consistent with the hypothesis that lifestyle intervention might improve GlycA levels in obese, prediabetic adolescent Latinos, but randomized trial evidence is needed. Healthy lifestyle modifications among high-risk youth may decrease future risk of cardiometabolic disease through reducing systemic inflammation, in addition to improving traditional cardiovascular risk factors.

Low fitness is associated with metabolic risk independently of central adiposity in a cohort of 18-year-olds

It is unclear whether cardiorespiratory fitness (CRF) remains associated with metabolic risk if controlled for central adiposity and other confounders; thus, the aim of this study was to investigate the independent effect of CRF on metabolic syndrome risk factors in relatively homogeneous age group of young adults. In this cross-sectional study, 828 participants performed CRF test on a cycle ergometer (W_{max kg} ) and were categorized into sex-specific tertiles. Continuous metabolic syndrome risk score (MetS-score) was calculated as the sum of standardized scores of five metabolic syndrome risk factors: glucose, mean arterial pressure, low-density lipoprotein cholesterol, triglycerides, and total cholesterol/high-density lipoprotein cholesterol ratio. Low fitness group had higher values in all measured metabolic syndrome parameters, except for cholesterol parameters, compared to high fitness group. The unadjusted model indicated that CRF was negatively associated with clustered metabolic risk (β = -0.116, P = .001). After the adjustment of smoking habits, sports training participation, and waist circumference, the association between CRF and MetS-score slightly increased (β = -0.126; P < .001). Low CRF was associated with increased risk (OR = 2.58 (95% CI 1.50-4.41)) for higher MetS-score after adjustment for potential confounders and waist circumference. The results of our study indicate that being highly fit increases the likelihood of having lower MetS-score for approximately 2 and 2.5 times independently of central adiposity compared to average and low fitness, respectively. In conclusion, it is highly important to improve CRF through regular exercise, not focusing just on body composition in young adulthood in every weight status group.

GlycA Is a Novel Biomarker of Inflammation and Subclinical Cardiovascular Disease in Psoriasis

RATIONALE

GlycA, an emerging inflammatory biomarker, predicted cardiovascular events in population-based studies. Psoriasis, an inflammatory disease associated with increased cardiovascular risk, provides a model to study inflammatory biomarkers in cardiovascular disease (CVD). Whether GlycA associates with psoriasis and how it predicts subclinical CVD beyond high-sensitivity C-reactive protein in psoriasis is unknown.

OBJECTIVE

To investigate the relationships between GlycA and psoriasis and between GlycA and subclinical CVD.

METHODS AND RESULTS

Patients with psoriasis and controls (n=412) participated in a 2-stage study. We measured GlycA by nuclear magnetic resonance spectroscopy. National Institutes of Health (NIH) participants underwent 18-F Fluorodeoxyglucose Positron Emission Tomography Computed Tomography (18-FDG PET/CT) scans to assess vascular inflammation (VI) and coronary computed tomographic angiography to quantify coronary artery disease burden. Psoriasis cohorts were young (mean age=47.9), with low cardiovascular risk and moderate skin disease. high-sensitivity C-reactive protein and GlycA were increased in psoriasis compared with controls (GlycA: [PENN: 408.8±75.4 versus 289.4±60.2, P<0.0001; NIH: 415.8±63.2 versus 346.2±46, P<0.0001]) and demonstrated a dose-response with psoriasis severity. In stage 2, VI (β=0.36, P<0.001) and coronary artery disease (β=0.29, P=0.004) associated with GlycA beyond CV risk factors in psoriasis. In receiver operating characteristic analysis, GlycA added value in predicting VI (P=0.01) and coronary artery disease (P<0.01). Finally, initiating anti-tumor necrosis factor therapy (n=16) reduced psoriasis severity (P<0.001), GlycA (463.7±92.5 versus 370.1±78.5, P<0.001) and VI (1.93±0.36 versus 1.76±0.19, P<0.001), whereas GlycA remained associated with VI (β=0.56, P<0.001) post treatment.

CONCLUSIONS

GlycA associated with psoriasis severity and subclinical CVD beyond traditional CV risk and high-sensitivity C-reactive protein. Moreover, psoriasis treatment reduced GlycA and VI. These findings support the potential use of GlycA in subclinical CVD risk assessment in psoriasis and potentially other inflammatory diseases.