Obesity and impairment of pancreatic β-cell function in early adulthood, independent of obesity age of onset: The Santiago Longitudinal Study

Phenotyping obesity: A focus on metabolically healthy obesity and metabolically unhealthy normal weight

Over the past 4 decades, research has shown that having a normal body weight does not automatically imply preserved metabolic health and a considerable number of lean individuals harbour metabolic abnormalities typically associated with obesity. Conversely, excess adiposity does not always equate with an abnormal metabolic profile. In fact, evidence exists for the presence of a metabolically unhealthy normal weight (MUHNW) and a metabolically healthy obese (MHO) phenotype. It has become increasingly recognised that different fat depots exert different effects on the metabolic profile of each individual by virtue of their location, structure and function, giving rise to these different body composition phenotypes. Furthermore, other factors have been implicated in the aetiopathogenesis of the body composition phenotypes, including genetics, ethnicity, age and lifestyle/behavioural factors. Even though to date both MHO and MUHNW have been widely investigated and documented in the literature, studies report different outcomes on long-term cardiometabolic morbidity and mortality. Future large-scale, observational and population-based studies are required for better profiling of these phenotypes as well as to further elucidate the pathophysiological role of the adipocyte in the onset of metabolic disorders to allow for better risk stratification and a personalised treatment paradigm.

Waist to height ratio in nonalcoholic fatty liver disease - Systematic review and meta-analysis

BACKGROUND AND AIMS

Current nonalcoholic fatty liver disease (NAFLD) guidelines do not provide any recommendations regarding the waist-to-height ratio (WHtR), a simple obesity metric calculated by dividing waist circumference by height. Therefore, we performed a systematic review and meta-analysis aiming to evaluate WHtR in NAFLD.

METHODS

We performed a systematic electronic search on PubMed, Embase, and Scopus, identifying observational studies assessing WHtR in NAFLD. QUADAS-2 tool was used to evaluate the quality of included studies. The two main statistical outcomes were the area under the curve (AUC) and the mean difference (MD).

RESULTS

We included a total of 27 studies in our quantitative and qualitative synthesis, with a total population of 93,536 individuals. WHtR was significantly higher in NAFLD patients compared to controls with an MD of 0.073 (95% CI 0.058 - 0.088). This was also confirmed after conducting a subgroup analysis according to the hepatic steatosis diagnosis method, for ultrasound (MD 0.066 [96% CI 0.051 - 0.081]) and transient elastography (MD 0.074 [96% CI 0.053 - 0.094]). Moreover, NAFLD male patients presented significantly lower WHtR compared to female patients (MD -0.022 [95% CI -0.041 - -0.004]). The AUC of WHtR for predicting NAFLD was 0.815 (95% CI 0.780 - 0.849).

CONCLUSIONS

WHtR is considerably higher in NAFLD patients compared to controls. Female NAFLD patients present higher WHtR compared to NAFLD male patients. In comparison to other presently suggested scores and markers, the WHtR's accuracy in predicting NAFLD is considered acceptable.

Developmental trajectories at a high risk for childhood overweight/obesity

BACKGROUND

The associations between developmental patterns (trajectories) in children and maternal factors have been widely investigated, but paternal effects on these trajectories are unclear. This study aimed to determine child and parental factors involved in developmental trajectories at high risk for causing adverse cardiovascular (CV) profiles in children.

METHODS

We analyzed longitudinal anthropometric data from birth to the present and CV profiles of 1,832 healthy volunteers (51% girls) aged 3-15 years who participated in a nationwide study between July 2012 and January 2014. Six trajectory latent class growth models were developed using body mass index z- scores. Predictors for being in developmental trajectories at high risk for causing adverse CV profiles were determined by multivariate regression analysis.

RESULTS

The mean±standard deviation number of anthropometric data points was 12±3 for both boys and girls. Among the six trajectories, the infantile onset and continual increase groups had significantly worse levels of many CV profiles than those in the remaining groups. Paternal overweight/obesity was an independent predictor for boys being in the infantile onset group and for girls being in the continual increase group. Additionally, maternal pre-pregnancy overweight/obesity in boys and maternal excessive gestational weight gain in girls were independent predictors for being in the infantile onset group. Having no sibling in boys and an older maternal age were independent predictors for being in the continual increase group.

CONCLUSIONS

Interventions to prevent childhood obesity should include strategies that focus on fathers and mothers as well as those that focus on children with certain types of familial background.

Multiple events case-control study in a prospective cohort to identify systemic, cellular, and molecular biomarkers of obesity-induced accelerated aging in 30-years-olds: the ObAGE study protocol

Background

Aging is characterized by a progressive loss of capacities linked to fundamental alterations/damage in multiple cellular and molecular pathways. It is the most significant risk factor for all non-communicable diseases (NCDs). Another contributing factor to the rise in NCDs is obesity. It has been suggested that obesity not only accelerates the onset of metabolic imbalances but also decreases lifespan and impacts cellular and molecular processes in a manner similar to aging. Obesity might accelerate the pace of aging. Guided by a lifecourse approach, we will explore how exposure to obesity in critical developmental stages disrupt homeostatic resilience mechanisms that preserve physiological integrity, inducing an early expression of aging phenotypes. Also, we will determine whether exposure to early psychosocial adversity influences vulnerability to obesity as a risk factor for accelerated aging.

Methods

Multiple events case–control study embedded in a prospective cohort of Chileans at 30-31y, 50% females, of low- to-middle socioeconomic status, who participated in nutrition research since birth. At 23y, 25% had obesity and cardiometabolic risk was high. We will use a multi-layer approach including: anthropometric assessment; DXA scan for body composition; abdominal ultrasound of the liver; stool samples collection and sequencing of the ribosomal RNA 16S gene to characterize the gut microbiome; determination of age-related pro-inflammatory cytokynes and anti-inflammatory miokynes. For the first time in Chile, we will address age-related epigenetic changes using the Horvath´s epigenetic clock. In a subset we will conduct a controlled physical challenge to characterize physical resilience (autophagy).

Discussion

ObAGE is in an excellent position to: approach aging as a process whose expression involves multiple factors from the early stages of a person's life; understand how longitudinal changes in health trajectories impact the biological mechanisms of aging; identify potential resilience mechanisms that help prevent unhealthy aging. Because SLS participants are still young, our research setting combined with advanced scientific techniques may identify individuals or groups at risk of early onset health issues. Results from ObAGE may pave the way to address the contribution of obesity to aging through lifespan from cells to systems and might be instrumental to developing interventions to improve health span in the Chilean population.

Trial registration

The proposed study does not consider any health care intervention on human participants.

Aerobic training reduces pancreatic fat content and improves β-cell function: A randomized controlled trial using IDEAL-IQ magnetic resonance imaging

AIMS

To explore the effects of six months of moderate-intensity aerobic exercise on pancreatic fat content and its impact on β-cell function.

MATERIALS AND METHODS

A total of 106 patients with type 2 diabetes mellitus were randomized to either a moderate-intensity aerobic training group (three times a week, including 5 min warm-up, 50 min aerobic dancing, and 5 min relaxation, n = 53) or control group (n = 53) with 6-month intervention. The primary endpoint was change in pancreatic fat content. An intention-to-treat analysis was conducted.

RESULTS

Eighty-six patients completed the study with 43 patients in the aerobic training group. The average age, HbA1c, and pancreatic fat content for all participants (106 patients) were 66.39 ± 5.59 years, 7.05 ± 1.24%, and 10.35 ± 9.20%, respectively. Nearly half (49.06%) of patients were males. Subjects in the aerobic training group saw a significant reduction in pancreatic fat content when compared to controls (p = 0.001). In logistic regression models containing age, diabetes duration, change in BMI, smoking/drinking status, changes in lipid indices, and other abdominal fat content, only reduction in pancreatic fat content (p < 0.05) was an independent protective factor for β-cell function and HbA1c.

CONCLUSIONS

Six months of moderate-intensity aerobic training significantly reduced the pancreatic fat content. The reduction of pancreatic fat content was an independent protective factor for β-cell function and HbA1c.

Resolving early obesity leads to a cardiometabolic profile within normal ranges at 23 years old in a two-decade prospective follow-up study

Obesity is the most important predisposing factor for cardiovascular disease and type-2 diabetes. We explored the relationship between the age at onset of obesity and selected cardiometabolic parameters in young adults. Longitudinal study of n = 1,039 participants (48% males) in their early twenties. BMI was measured at birth, 1–5–10–12–14–16–23 years. BMI trajectories were interpolated. Five groups were identified: never obese (never-OB); early childhood obesity transitioning to non-obesity before adolescence (former-OB); obesity starting in preadolescence transitioning to non-obesity as adolescents (transient-OB); obesity from adolescence into early adulthood (recent-onset-OB); participants who were obese in early childhood and remained obese into adulthood (persistent-OB). Waist circumference (WC), blood pressure, lipids, glucose, and insulin were measured at 23 years. HOMA-IR and the Metabolic Syndrome Risk Z-Score were estimated. In the sample, 47% were obese during at least one time-point. Mean obesity duration was 20.7 years, 8.5 years, 6.2 years, and 3.3 years in persistent-OBs, recent-onset-OBs, former-OBs, and transient-OBs, respectively. The cardiometabolic profile was more adverse in recent-onset-OBs (12%) and persistent-OBs (15%) compared to never-OB participants (53%). Although former-OBs (15%) and transient-OBs (4%) had higher WC values than never-OBs, no differences were seen in other biomarkers. Both persistent and recent-onset obesity led to a cardiometabolic profile of risk in early adulthood, as suggested by values of WC, HOMA-IR, and hs-CRP above normal limits and HDL-chol values below normal limits. Participants who had obesity in early childhood or preadolescence but transitioned to a non-obesity status had a cardiometabolic profile similar to participants who were never obese and within normal limits. Obesity leads to risky values in a number of cardiometabolic biomarkers in young adulthood independent of age at obesity onset. Likewise, overcoming obesity during the pediatric age leads to a cardiometabolic profile within normal ranges at 23 years of age.