Interventions for improving metabolic risk in overweight Latino youth

Dietary Adequacy among Multi-Ethnic Urban Youth in Edmonton: Findings from the Wellness and Health in Youth - Aboriginal and All Communities in Transition NOW (WHY ACT NOW) Project

OBJECTIVE

The development of obesity and chronic diseases in adulthood often results from a childhood pattern of dietary excesses. This study aimed to identify dietary inadequacies and excesses of multiethnic youth in Edmonton.

METHODS

A cross-sectional survey of a convenience sample of 473 multiethnic youth between 11 and 18 years was conducted in 12 schools in Edmonton between October 2013 and March 2014. Data were analyzed to determine for each participant mean daily energy and nutrient intakes, dietary adequacy, and nutrient densities. Participants were divided by self-identified ethnicity (Indigenous, European, African and Middle Eastern, and Asian).

RESULTS

For all nutrients examined, the mean percentage of calories from fat was higher among European (31.7%) and Indigenous youth (31.8%) compared to African and Middle Eastern (28.3%) and Asian youth (29.0%), while Asian youth had the highest percentage of calories from protein (17.7%) compared to other ethnic groups (Indigenous = 15.5%; African & Middle Eastern = 16.5%; European = 16.2%). The majority of youth fell below the recommended values for dietary fiber (83.3-92.0%), vitamins D (84.4-90.2%), and E (89.5-92.0%). More than 50% fell below the dietary reference intakes (DRIs) for vitamin A, vitamin B5, calcium, and magnesium; >30% were below the DRI for folate, zinc, and vitamins B6, and C. The diet of girls contained a greater density of fiber compared to boys (9.3 vs. 8.0 g/1000 kcal; p-value = 0.002).

CONCLUSIONS

Inadequate dietary intake is evident among the majority of multiethnic youth in Edmonton. There is a need to develop strategies to reduce the burden of poor nutrition status for youth.

Sex as a moderator of body composition following a randomized controlled lifestyle intervention among Latino youth with obesity

BACKGROUND

Body composition differences between males and females emerge during adolescence and continue throughout adulthood; however, whether sex moderates body composition changes in adolescents with obesity after an intervention is unknown.

OBJECTIVE

To examine sex as a moderator of changes in adiposity following lifestyle intervention.

METHODS

A total of 136 Latino youth with obesity (BMI% 98.2 ± 1.3) aged 14 to 16 years old were randomized to either a 12-week lifestyle intervention (27 males/40 females) or control (35 males/34 females) group. The intervention included nutrition education (1 h/wk) and moderate-to-vigorous physical activity (3 h/wk). Anthropometric data (body mass index [BMI], BMI%, waist circumference, total body fat, and fat-free mass) were obtained pre- and post-intervention. Sex differences were examined by general linear models with significance determined at P < .05 for the F-statistic.

RESULTS

Sex did not moderate changes in BMI (F1,115 = 0.01, P = .9), BMI% (F1,115 = 0.14, P = .7), or waist circumference (F1,117 = 1.1, P = .3). Sex significantly moderated changes in body fat percent (F1,117 = 5.3, P = .02), fat mass (F1,116 = 4.5, P = .04), and fat-free mass (F1,116 = 4.3, P = .04). Intervention males compared with females had greater relative reductions in fat percent (-4.1 ± 0.8% vs -1.2 ± 0.7%, P = .02) and fat mass (-5.0 ± 1.1 kg vs -1.5 ± 0.9 kg, P = .02) and gained more fat free mass (3.6 ± 0.9 kg vs 0.5 ± 0.8 kg, P = .02) when compared with same sex controls.

CONCLUSION

Males and females exhibited a differential response to lifestyle intervention for percent fat, fat mass, and fat-free mass indicating that sex-specific improvements in body composition favours males over females.

Novel Insights into the Pathogenesis and Management of the Metabolic Syndrome

The metabolic syndrome, by definition, is not a disease but is a clustering of individual metabolic risk factors including abdominal obesity, hyperglycemia, hypertriglyceridemia, hypertension, and low high-density lipoprotein cholesterol levels. These risk factors could dramatically increase the prevalence of type 2 diabetes and cardiovascular disease. The reported prevalence of the metabolic syndrome varies, greatly depending on the definition used, gender, age, socioeconomic status, and the ethnic background of study cohorts. Clinical and epidemiological studies have clearly demonstrated that the metabolic syndrome starts with central obesity. Because the prevalence of obesity has doubly increased worldwide over the past 30 years, the prevalence of the metabolic syndrome has markedly boosted in parallel. Therefore, obesity has been recognized as the leading cause for the metabolic syndrome since it is strongly associated with all metabolic risk factors. High prevalence of the metabolic syndrome is not unique to the USA and Europe and it is also increasing in most Asian countries. Insulin resistance has elucidated most, if not all, of the pathophysiology of the metabolic syndrome because it contributes to hyperglycemia. Furthermore, a major contributor to the development of insulin resistance is an overabundance of circulating fatty acids. Plasma fatty acids are derived mainly from the triglycerides stored in adipose tissues, which are released through the action of the cyclic AMP-dependent enzyme, hormone sensitive lipase. This review summarizes the latest concepts in the definition, pathogenesis, pathophysiology, and diagnosis of the metabolic syndrome, as well as its preventive measures and therapeutic strategies in children and adolescents.

Can metabolic function and physical fitness improve without weight loss for inactive, obese, Hispanic adolescents? A feasibility study

INTRODUCTION

A case series that examines the effects of a 12-week combined resistance and aerobic training program for four sedentary obese, Hispanic adolescents without weight loss.

SUBJECTS/METHODS

Baseline and post-intervention anthropometric, metabolic and physical fitness measures were obtained. Body composition, hepatic, visceral, and intramuscular fat contents were analyzed via imaging. Fasting levels of alanine transaminase (ALT), insulin, glucose, free fatty acids, triglycerides, high- and low-density lipoproteins (LDL), and C-reactive protein were obtained via blood samples.

RESULTS

Two subjects decreased their glucose levels by 1.86% and 4.06%. Subjects 1, 3, and 4 increased their lean body mass by 4.12%, 9.70%, and 5.48%. ALT was reduced 13.0%, 16.0%, and 35.7% for subjects 2, 3, and 4, respectively. LDLs were reduced by 37.7%, 4.5%, and 7.5% for subjects 1, 2, and 3. Triglycerides were reduced by 25.4%, 37.8%, and 4.6% for subjects 1, 2, and 3. Visceral fat reductions by 16.5%, 14.2%, and 13.0% occurred for subjects 1, 2, and 3. C-reactive protein was reduced for subjects 1, 2, and 3 by 19.4%, 16.3%, and 32.0%.

CONCLUSION

Expected directions of change were made for most indicators of metabolic function and body composition, but measures of physical fitness improved for all four subjects.

Culturally-grounded diabetes prevention program for obese Latino youth: Rationale, design, and methods

BACKGROUND

Type 2 diabetes (T2D) disproportionately impacts Latino youth yet few diabetes prevention programs address this important source of health disparities.

OBJECTIVES

To address this knowledge gap, we describe the rationale, design, and methodology underpinning a culturally-grounded T2D prevention program for obese Latino youth. The study aims to: 1) to test the efficacy of the intervention for reducing T2D risk, 2) explore potential mediators and moderators of changes in health behaviors and health outcomes and, 3) examine the incremental cost-effectiveness for reducing T2D risk. Latino adolescents (N=160, age 14-16) will be randomized to either a 3-month intensive lifestyle intervention or a control condition. The intervention consists of weekly health education delivered by bilingual/bicultural promotores and 3 moderate-to-vigorous physical activity (PA) sessions/week. Control youth receive health information and results from their laboratory testing. Insulin sensitivity, glucose tolerance, and weight-specific quality of life are assessed at baseline, 3-months, 6-months, and 12-months. We will explore whether enhanced self-efficacy and/or social support mediate improvements in nutrition/PA behaviors and T2D outcomes. We will also explore whether effects are moderated by sex and/or acculturation. Cost-effectiveness from the health system perspective will be estimated by the incremental cost-effectiveness ratio using changes in insulin sensitivity at 12-months.

CONCLUSIONS

The results of this study will provide much needed information on how T2D prevention interventions for obese Latino youth are developed, implemented and evaluated. This innovative approach is an essential step in the development of scalable, cost-effective, solution oriented programs to prevent T2D in this and other high-risk populations.

Perceived health status and cardiometabolic risk among a sample of youth in Mexico

PURPOSE

To examine differences in self-reported perceived mental and physical health status, as well as known cardiometabolic risk factors in a sample of normal weight, overweight, and obese Mexican youths.

METHODS

Cross-sectional analysis of 164 youths aged 11-18 years recruited in Cuernavaca, Mexico. Participants completed a self-administered questionnaire that included measures of generic and weight-specific quality of life, perceived health, physical function, depressive symptoms, and body shape satisfaction. Height, weight, and waist circumference were measured, and body mass index (BMI) was determined. Fasting blood samples from participants yielded levels of glucose, triglycerides, and cholesterol (total, HDL, and LDL).

RESULTS

Nearly 50 % of participants were female, 21 % had a normal BMI, 39 % were overweight, and 40 % were obese. Obese youths reported significantly lower measures of perceived health status (PHS) and showed an increase in cardiometabolic risk, compared with normal weight youths. Physical functioning, generic and weight-specific QoL were inversely associated with BMI, waist circumference, and glucose. Depressive symptoms were positively correlated with BMI, waist circumference, glucose levels, and HDL cholesterol. No correlation was found between PHS and cardiometabolic risk measures after controlling for BMI.

CONCLUSIONS

In this sample of Mexican youths, obesity was associated with a significantly lower PHS and increased cardiometabolic risk.

Vegetable consumption is linked to decreased visceral and liver fat and improved insulin resistance in overweight Latino youth

There are limited data on the influence of vegetable consumption on adiposity and metabolic health, specifically nonstarchy vegetables and vegetables that are dark green and deep orange/yellow (also known as nutrient-rich vegetables). Our study examines the relationship between vegetable intake and adiposity, liver fat, and insulin dynamics in overweight Latino youth. This cross-sectional study of 175 overweight (body mass index ≥85th percentile) Latino youth (aged 8 to 18 years), with data collected during 2006-2011, included the following: dietary intake via multiple 24-hour recalls, total body fat via dual-energy x-ray absorptiometry, adipose tissue distribution and liver fat via magnetic resonance imaging, and insulin dynamics via frequently sampled intravenous glucose tolerance test. Linear regression and analysis of covariance were used for analysis, with the following a priori covariates: age, sex, energy intake, and total body fat. Participants who consumed the most nonstarchy vegetables (mean intake=1.7±1.0 servings/day) compared with the least (mean intake=0.1±0.1 servings/day) had 44% less liver fat (10.0%±8.5% vs 5.6%±8.7%; P=0.01). Nutrient-rich vegetable intake was positively correlated with insulin sensitivity (r=0.19; P=0.03). Consumers of nutrient-rich vegetables (mean intake=0.3±0.4 servings/day [n=107]), compared with nonconsumers (n=68), had 31% increased insulin sensitivity (1.6±1.6 vs 2.1±1.3×10(⁻⁴)/min/μU/mL; P=0.03) and 17% less visceral adipose tissue (2.3±0.9 vs 1.9±0.7 L; P=0.01). Consumption of specific vegetable types by overweight Latino youth is associated with positive metabolic outcomes, including reduced visceral and liver fat and risk factors for type 2 diabetes, even when consumed in small quantities. These may be relevant targets for interventions.

Importance of android/gynoid fat ratio in predicting metabolic and cardiovascular disease risk in normal weight as well as overweight and obese children

Numerous studies have shown that android or truncal obesity is associated with a risk for metabolic and cardiovascular disease, yet there is evidence that gynoid fat distribution may be protective. However, these studies have focused on adults and obese children. The purpose of our study was to determine if the android/gynoid fat ratio is positively correlated with insulin resistance, HOMA2-IR, and dislipidemia in a child sample of varying body sizes. In 7-13-year-old children with BMI percentiles ranging from 0.1 to 99.6, the android/gynoid ratio was closely associated with insulin resistance and combined LDL + VLDL-cholesterol. When separated by sex, it became clear that these relationships were stronger in boys than in girls. Subjects were stratified into BMI percentile based tertiles. For boys, the android/gynoid ratio was significantly related to insulin resistance regardless of BMI tertile with and LDL + VLDL in tertiles 1 and 3. For girls, only LDL + VLDL showed any significance with android/gynoid ratio and only in tertile 2. We conclude that the android/gynoid fat ratio is closely associated with insulin resistance and LDL + VLDL-, "bad," cholesterol in normal weight boys and may provide a measurement of metabolic and cardiovascular disease risk in that population.

Effects of in utero conditions on adult feeding preferences

The fetal or early origins of adult disease hypothesis states that environmental factors, particularly nutrition, act in early life to program the risks for chronic diseases in adult life. As eating habits can be linked to the development of several diseases including obesity, diabetes and cardiovascular disease, it could be proposed that persistent food preferences across the life-span in people who were exposed to an adverse fetal environment may partially explain their increased risk to develop metabolic disease later in life. In this paper, we grouped the clinical and experimental evidence demonstrating that the fetal environment may impact the individual's food preferences. In addition, we review the feeding preferences development and regulation (homeostatic and hedonic pathways, the role of taste/olfaction and the reward/pleasure), as well as propose mechanisms linking early life conditions to food preferences later in life. We review the evidence suggesting that in utero conditions are associated with the development of specific food preferences, which may be involved in the risk for later disease. This may have implications in terms of public health and primary prevention during early ages.

Prevention of type 2 diabetes among youth: a systematic review, implications for the school nurse

Childhood obesity and the early development of type 2 diabetes (T2 DM) place students at risk for chronic health problems. The school nurse is uniquely situated to promote school health initiatives that influence health behavior. The purpose of this review was to determine effective nonpharmacological interventions for prevention of T2 DM in youth. Researchers from 35 reports modified T2 DM risk factors. These nonpharmacological interventions often include increasing daily activity, decreasing caloric intake, and increasing muscle mass. Some researchers also included psychological and social support interventions intended to strengthen initiating and/or maintaining health behavior. Characteristics of effective nonpharmacological T2 DM prevention interventions are discussed. Findings from this review are a useful guide for the implementation of T2 DM prevention strategies in the school setting. Few school-based studies included high school students; therefore, further research is needed among older adolescents on the efficacy of nonpharmacological interventions in the high school.

Examining the Use of Dietary Fiber in Reducing the Risk of Type 2 Diabetes Mellitus in Latino Youth

Type 2 diabetes mellitus (T2DM) is a steadily growing epidemic in the United States, especially for overweight Latino youth who are among the highest at-risk for T2DM development. Although dietary interventions are not often inferred to patients prior to T2DM diagnosis, they may be implicated in risk reduction. The purpose of this review is to examine the use of dietary fiber in reducing the risk of T2DM in Latino youth. The main results of this examination found that a wide variation in use of dietary fiber intake or supplementation resulted in an overall inverse relationship and association with visceral adipose tissue, metabolic syndrome, and insulin resistance. However, due to inconsistencies in fiber definition and/or implementation, dietary and supplemental fiber intake must be further explored in randomized controlled trials so that more agreement may be reached on fiber recommendations, especially in populations at high risk for T2DM such as Latino youth.

Multidisciplinary approach to the treatment of obese adolescents: effects on cardiovascular risk factors, inflammatory profile, and neuroendocrine regulation of energy balance

The prevention of obesity and health concerns related to body fat is a major challenge worldwide. The aim of this study was to investigate the role of a medically supervised, multidisciplinary approach, on reduction in the prevalence of obesity related comorbidities, inflammatory profile, and neuroendocrine regulation of energy balance in a sample of obese adolescents. A total of 97 postpuberty obese adolescents were enrolled in this study. Body composition, neuropeptides, and adipokines were analysed. The metabolic syndrome was defined by the International Diabetes Federation (IDF). The abdominal ultrasonography was performed to measure visceral, subcutaneous fat and hepatic steatosis. All measures were performed at baseline and after one year of therapy. The multidisciplinary management promoted the control of obesity reducing body fat mass. The prevalence of metabolic syndrome, asthma, nonalcoholic fatty liver disease (NAFLD), binge eating, and hyperleptinemia was reduced. An improvement in the inflammatory profile was demonstrated by an increase in anti-inflammatory adiponectin and reduction in proinflammatory adipokines, plasminogen activator inhibitor-1, interleukin-6 concentrations, and in the Lep/Adipo ratio. Moreover, a reduction in the AgRP and an increase in the alfa-MSH were noted. The multidisciplinary approach not only reduced obesity but also is efficacious in cardiovascular risk factors, inflammatory profile, and neuroendocrine regulation of energy balance.

Use of MRI and CT for fat imaging in children and youth: what have we learned about obesity, fat distribution and metabolic disease risk?

Childhood obesity is a matter of great concern for public health. Efforts have been made to understand its impact on health through advanced imaging techniques. An increasing number of studies focus on fat distribution and its associations with metabolic risk, in interaction with genetics, environment and ethnicity, in children. The present review is a qualitative synthesis of the existing literature on visceral and subcutaneous abdominal, intrahepatic and intramuscular fat. Our search revealed 80 original articles. Abdominal as well as ectopic fat depots are prevalent already in childhood and contribute to abnormal metabolic parameters, starting early in life. Visceral, hepatic and intramuscular fat seem to be interrelated but their patterns as well as their independent contribution on metabolic risk are not clear. Some ethnic-specific characteristics are also prevalent. These results encourage further research in childhood obesity by using imaging techniques such as magnetic resonance imaging and computed tomography. These imaging methods can provide a better understanding of fat distribution and its relationships with metabolic risk, compared to less detailed fat and obesity assessment. However, studies on bigger samples and with a prospective character are warranted.

Is adipose tissue metabolically different at different sites?

This review focuses on metabolic differences of adipose tissue at different sites of the body, with emphasis in pediatrics. Adipose tissue is composed of various cell types, which include adipocytes and other cells of the stromal vascular fraction such as preadipocytes, blood cells, endothelial cells and macrophages. Mammals have two main types of adipose tissue: white adipose tissue (WAT), and brown adipose tissue (BAT), each of which possesses unique cell autonomous properties. WAT and BAT differ at the functional, as well as the morphological and molecular levels. WAT accumulates surplus energy mainly in the form of triacylglycerols and BAT dissipates energy directly as heat. Recently, functional BAT in humans has been located in the neck, supraclavicular, mediastinal and interscapular areas. WAT is distributed throughout the body in the form of two major types: subcutaneous adipose tissue (SWAT) and the intra-abdominal visceral adipose tissue (VWAT). VWAT tissue is associated with insulin resistance, diabetes mellitus, dyslipidaemia, hypertension, atherosclerosis, hepatic steatosis, and overall mortality whereas SWAT and BAT have intrinsic beneficial metabolic properties. Subcutaneous and visceral adipocytes derive from different progenitor cells that exhibit a different gene expression pattern. SWAT responds better to the antilipolytic effects of insulin and other hormones, secrets more adiponectin and less inflammatory cytokines, and is differentially affected by molecules involved in signal transduction as well as drugs compared with VWAT. Current research is investigating various approaches of BAT and SWAT transplantation, including new sources of adipocyte progenitors. This may be important for the potential treatment of childhood obesity.

Special considerations on the management of Latino patients with type 2 diabetes mellitus

BACKGROUND

Latinos are the largest minority population in the United States, and are characterized by higher rates of obesity and diabetes compared to Whites. The prevalence of diagnosed diabetes in Latinos is two-fold higher than in Caucasians, and Latinos suffer from higher rates of diabetic complications and mortality. As the diabetes epidemic continues to expand and exert greater socioeconomic strain on national healthcare systems, the success of global and national healthcare initiatives for diabetes prevention and improvement of care will depend upon strategies targeted specifically toward this population. Essential to such strategies is an understanding of success factors unique to the Latino population for diabetes prevention and achievement of optimal treatment outcomes.

METHODS

A PubMed search was conducted for literature describing type 2 diabetes and its complications in Latinos. Specifically, we sought data describing epidemiology, disparities, management considerations, and success factors in this population.

RESULTS

The title search yielded more than 2000 articles, 80 of which were deemed directly relevant to this review. The inherent limitations of this subjective selection process are acknowledged.

CONCLUSIONS

A number of studies have highlighted various ethnic disparities in Latinos with diabetes including higher HbA1c levels, greater rates of obesity and metabolic syndrome, and a larger proportion of individuals with inadequate access to care. While relatively fewer studies describe success factors for redressing cultural disparities in diabetes, the current body of literature supports primary care strategies aimed at effective provider-patient relationships and culturally tailored education and lifestyle modification regimens. Further research demonstrating effective, culturally tailored practices that are suitable to the primary care setting would be of value to providers treating Latinos with diabetes.

Increased hepatic fat in overweight Hispanic youth influenced by interaction between genetic variation in PNPLA3 and high dietary carbohydrate and sugar consumption

BACKGROUND

Recently, a genetic variant (rs738409; C→G) of the PNPLA3 gene was identified to be associated with increased hepatic fat deposition, and the effect was more pronounced in Hispanics. Animal models have also shown that PNPLA3 expression can be regulated by dietary carbohydrate.

OBJECTIVE

The aim of this study was to examine whether the influence of PNPLA3 genotype on hepatic fat is modulated by dietary factors in Hispanic children.

DESIGN

PNPLA3 was genotyped in 153 Hispanic children (75% female, ages 8-18 y) by using the TaqMan method. Dietary intake was assessed by using three 24-h dietary recalls or diet records. Visceral adipose tissue (VAT), subcutaneous abdominal adipose tissue (SAAT), and hepatic fat fraction (HFF) were assessed in multiple abdominal slices by magnetic resonance imaging. Analysis of covariance was used to assess the diet × genotype interaction in liver fat, with the following a priori covariates: sex, age, energy, VAT, and SAAT.

RESULTS

HFF was influenced by a significant interaction between genotype and diet (genotype × carbohydrate, P = 0.04; genotype × total sugar, P = 0.01). HFF was positively related to carbohydrate (r = 0.31, P = 0.04) and total sugar (r = 0.34, P = 0.02) intakes but only in the GG group, independent of covariates. Dietary variables were not related to HFF in the CC or CG group or to other fat depots in all genotype groups.

CONCLUSIONS

These findings suggest that Hispanic children carrying the GG genotype are susceptible to increased hepatic fat when dietary carbohydrate intake, specifically sugar, is high. Specific dietary interventions based on genetic predisposition in this population may lead to more effective therapeutic outcomes for fatty liver. This trial was registered at clinicaltrials.gov as NCT00697580, 195-1642394A1, and NCT00693511.