Adiposity is inversely related to insulin sensitivity in relatively lean Chinese adolescents: a population-based twin study

The Relationship between Fat Mass Percentage and Glucose Metabolism in Children and Adolescents: A Systematic Review and Meta-Analysis

To assess the relationship between fat mass percentage (FMP) and glucose metabolism in children aged 0−18 years we performed a systematic review of the literature on Medline/PubMed, SinoMed, Embase and Cochrane Library using the PRISMA 2020 guidelines up to 12 October 2021 for observational studies that assessed the relationship of FMP and glucose metabolism. Twenty studies with 18,576 individuals were included in the meta-analysis. The results showed that FMP was significantly associated with fasting plasma glucose (FPG) (r = 0.08, 95% confidence interval (CI): 0.04−0.13, p < 0.001), fasting plasma insulin (INS) (r = 0.48, 95% CI: 0.37−0.57, p < 0.001), and homeostasis model assessment (HOMA)- insulin resistance (IR) (r = 0.44, 95% CI: 0.33−0.53, p < 0.001). The subgroup analysis according to country or overweight and obesity indicated that these associations remained significant between FMP and INS or HOMA-IR. Our results demonstrated that there is a positive relationship between FMP and FPG. Moreover, subgroup analysis according to country or overweight and obesity indicated that FMP is significantly associated with INS and HOMA-IR. This is the first known systematic review and meta-analysis to determine the associations of FMP with glucose metabolism in children and adolescents.

Childhood BMI and Fasting Glucose and Insulin Predict Adult Type 2 Diabetes: The International Childhood Cardiovascular Cohort (i3C) Consortium

OBJECTIVE

To examine childhood BMI, fasting glucose, and insulin in relation to incident adult type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

We used data from the International Childhood Cardiovascular Cohort (i3C) Consortium. Data included childhood (age 3-19 years) measurements obtained during the 1970s-1990s; a health questionnaire, including self-report of adult T2DM (occurrence age, medication use) obtained at mean age 40 years; and a medical diagnosis registry (Finland).

RESULTS

The sample included 6,738 participants. Of these, 436 (6.5%) reported onset of T2DM between ages 20 and 59 (mean 40.8) years, and 86% of them reported use of a confirmed antidiabetic medication. BMI and glucose (age and sex standardized) were associated with incident T2DM after adjustment for cohort, country, sex, race, age, and calendar year of measurement. Increasing levels of childhood BMI and glucose were related to an incrementally increased risk of T2DM beginning at age 30 years, beginning at cut points <95th percentile for BMI and <100 mg/dL for glucose. Insulin was positively associated with adult T2DM after adjustment for BMI and glucose and added to T2DM discrimination.

CONCLUSIONS

Childhood BMI and glucose are predictors of adult T2DM at levels previously considered to be within the normal range. These easy-to-apply measurements are appealing from a clinical perspective. Fasting insulin has the potential to be an additional predictor.

Effects of rosuvastatin on metabolic profile: Versatility of dose-dependent effect

Obesity refers to an excess of body fat content causing metabolic and inflammatory disorders. Therefore, the aim of the present study was to investigate dose-dependent effect of rosuvastatin on the metabolic profile of diet-induced obesity in mice model study. A total number of 40 male Albino Swiss mice were used which divided into Group I: Control group, fed normal diet for 8 weeks (n = 10); Group II: High-fat diet (HFD) group, fed on HFD for 8 weeks (n = 10); Group III: HFD + 20 mg/kg rosuvastatin for 8 weeks (n = 10); and Group IV: HFD +40 mg/kg rosuvastatin for 8 weeks (n = 10). Anthropometric and biochemical parameters were estimated, including fasting blood glucose, lipid profile, fasting insulin, and glucose tolerance test (GTT). Mice on HFD fed showed a significant increase in the insulin resistance, body weight, deterioration of lipid profile and significant reduction in the β-cell function, and insulin sensitivity compared to the control P < 0.05. GTT and blood glucose level were significantly high in HFD fed group compared to the control group P < 0.05. Rosuvastatin in a dose of 40 mg/kg illustrated better effect than 20 mg/kg on the glucometabolic profile P < 0.05. Rosuvastatin may has a potential effect on reduction of glucometabolic changes induced by HFD with significant amelioration of pancreatic β-cell function in dose-dependent manner.

Associations of Body Composition Measurements with Serum Lipid, Glucose and Insulin Profile: A Chinese Twin Study

OBJECTIVES

To quantitate and compare the associations of various body composition measurements with serum metabolites and to what degree genetic or environmental factors affect obesity-metabolite relation.

METHODS

Body mass index (BMI), waist circumference (WC), lean body mass (LBM), percent body fat (PBF), fasting serum high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), total cholesterol (TC), glucose, insulin and lifestyle factors were assessed in 903 twins from Chinese National Twin Registry (CNTR). Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from fasting serum glucose and insulin. Linear regression models and bivariate structural equation models were used to examine the relation of various body composition measurements with serum metabolite levels and genetic/environmental influences on these associations, respectively.

RESULTS

At individual level, adiposity measurements (BMI, WC and PBF) showed significant associations with serum metabolite concentrations in both sexes and the associations still existed in male twins when using within-MZ twin pair comparison analyses. Associations of BMI with TG, insulin and HOMA-IR were significantly stronger in male twins compared to female twins (BMI-by-sex interaction p = 0.043, 0.020 and 0.019, respectively). Comparison of various adiposity measurements with levels of serum metabolites revealed that WC explained the largest fraction of variance in serum LDL-C, TG, TC and glucose concentrations while BMI performed best in explaining variance in serum HDL-C, insulin and HOMA-IR levels. Of these phenotypic correlations, 64-81% were attributed to genetic factors, whereas 19-36% were attributed to unique environmental factors.

CONCLUSIONS

We observed different associations between adiposity and serum metabolite profile and demonstrated that WC and BMI explained the largest fraction of variance in serum lipid profile and insulin resistance, respectively. To a large degree, shared genetic factors contributed to these associations with the remaining explained by twin-specific environmental factors.

Distribution and determinants of plasma homocysteine levels in rural Chinese twins across the lifespan

Plasma homocysteine (Hcy) is a modifiable, independent risk factor for cardiovascular disease (CVD) and is affected by both environmental and genetic factors. This study aimed to describe the gender- and age-specific distribution of Hcy concentration for 1117 subjects aged 10–66 years, a subset of a community-based rural Chinese twin cohort. In addition, we examined environmental and genetic contributions to variances in Hcy concentration by gender and age groups. We found that the distribution pattern for Hcy varied by both age and gender. Males had higher Hcy than females across all ages. Elevated Hcy was found in 43% of male adults and 13% of female adults. Moreover, nearly one fifth of children had elevated Hcy. Genetic factors could explain 52%, 36% and 69% of the variation in Hcy concentration among children, male adults and female adults, respectively. The MTHFR C677T variant was significantly associated with Hcy concentrations. Smokers with the TT genotype had the highest Hcy levels. Overall, our results indicate that elevated Hcy is prevalent in the children and adults in this rural Chinese population. The early identification of elevated Hcy will offer a window of opportunity for the primary prevention of CVD and metabolic syndrome.

Variation in the heritability of body mass index based on diverse twin studies: a systematic review

OBJECTIVES

Over the past three decades, twin studies have shown variation in the heritability of obesity. This study examined the difference of body mass index (BMI) heritability (BMI-H) by population characteristics, such as sex, age, time period of observation and average BMI, as well as by broad social-environmental factors as indicated by country-level gross domestic product (GDP) per capita and GDP growth rate.

METHODS

Twin studies that reported BMI-H and were published in English from January 1990 to February 2011 after excluding those with disease, special occupations or combined heritability estimates for country/ethnic groups were searched in PubMed. 32 studies were identified from Finland (7), the United Kingdom (6), the United States (3), Denmark (3), China (3), Netherlands (2), South Korea (2), Sweden (2) and four from other countries. Meta-regression models with random effects were used to assess variation in BMI-H.

RESULTS

Heterogeneity of BMI-H is significantly attributable to variations in age (<20, 20-55 and ≥56 years), time period of observation (i.e. year of data collection), average BMI and GDP (≤$20,000, $20,001-26,000 and >$26,000). BMI-H was higher in adolescents (<20 years), in studies done in past years, and in populations with higher average BMIs or higher GDP per capita (≥$26,000) than their counterparts. Consistent lowering effects of high GDP growth rate (>median) on BMI-H were shown through stratified analyses by GDP. BMI-H was lower in countries of mid-level GDP, particularly those experiencing rapid economic growth.

CONCLUSIONS

BMI-H is sensitive to age, time period of observation, average BMI, GDP and rapid economic growth.

Association of adiposity trajectories with insulin sensitivity and glycemic deterioration: a longitudinal study of rural Chinese twin adults

OBJECTIVE

To evaluate associations between adiposity trajectories over time and insulin sensitivity and glucose deterioration in a Chinese twin cohort.

RESEARCH DESIGN AND METHODS

This study focused on 341 males and 292 females aged 20-50 years at baseline who had physical clinical examinations and oral glucose tolerance test at two time points with an average of 6 years apart. BMI, waist circumference, percent body fat (PBF), and percent trunk fat (PTF) trajectories were classified into five track groups based on age- and sex-specific tertiles at each visit. We calculated the odds of the insulin sensitivity index((0,120)) [ISI((0,120))] or glycemic deterioration at follow-up among five defined trajectories (tertile(baseline) → tertile(follow-up)) using generalized estimate equation models. Additionally, we applied structural equation models to examine genetic and environmental influences on adiposity, adiposity change over time (ACO), ISI((0,120)), and the interrelationships among them.

RESULTS

Participants with stable adiposity (BMI, waist circumference, PBF, and PTF) in the highest tertile or shifting to the highest tertile tended to have the lowest ISI((0,120)) at follow-up or experience glycemic deterioration. Genetic factors exerted the major influence on adiposity, but environmental factors unique to each twin contributed more strongly to ISI and ACO. Correlations between adiposity/ACO and insulin sensitivity were mainly due to environmental influences.

CONCLUSIONS

When adiposity stays or becomes high, insulin sensitivity falls and risk of glycemic deterioration rises. Additionally, we found that genetic factors exerted the major influence on adiposity, while environmental factors played the principal role for ACO and insulin sensitivity.

A population-based twin study on sleep duration and body composition

The aim of this study is to investigate the relationship between sleep duration and body composition and to estimate the genetic contribution of sleep duration and body composition in a Chinese twin population. This cross-sectional analysis included 738 men and 511 women aged 21-72 year. Anthropometric and dual-energy X-ray absorptiometry (DXA) measures of body composition were used. Sleep duration was obtained from a standard sleep questionnaire. Multiple regression models were used to examine the association between sleep duration and body composition measures. Structural equation modeling was used to assess the heritability of sleep duration and body composition. Compared with individuals in the 2nd and 3rd age-specific quartiles of sleep duration (reference group), shorter (1st quartile) sleep duration among women but not men was associated with higher z-scores (0.248-0.317) for all adiposity measures--BMI, fat mass index (FMI), percent body fat mass (%BF), and percent trunk fat mass (%TF), P < 0.05 for each--and with 0.306 lower z-scores for percent body lean mass (%LM) and 0.353 lower lean/fat mass ratio (LFR), P < 0.01 for each. The heritability of sleep duration was 0.27 in men and 0.29 in women, while the heritability of body composition was as high as 0.56-0.73 after adjustment for age in both genders. Short sleep duration was associated with increased body fat and decreased lean body mass in women but not in men. Sleep duration was largely influenced by environmental factors while adiposity measures were mainly influenced by genetic factors.

Body mass index, waist circumference, body fat, fasting blood glucose in a sample of moroccan adolescents aged 11-17 years

Objectives. The study aimed to assess the relationship between body fat and each of body mass index (BMI) and waist circumference (WC), and to test the effectiveness of fat mass (FM), percent of body fat (PBF), BMI, and WC in predicting high levels of fasting blood glucose (FBG). Methods. A total of 167 adolescents aged 11–17 years were recruited from Rabat region. BMI and WC were determined using standard equipments. FM and PBF were derived from isotope dilution technique. FBG was determined by the hexokinase method. Results. Regardless of the weight status, BMI showed a strong positive correlation with FM and PBF in both genders. WC was significantly correlated with FM in boys and girls, and with PBF in different groups of girls and boys of the study sample. However, there was no significant relationship between WC and PBF in normal weight and overweight-obese groups of boys. FBG was highly correlated with FM and PBF in girls of the study sample and in overweight-obese girls. Similar significant relationship between FBG and both BMI and WC was observed in overweight-obese girls, while there was no significant association between FBG and other variables in boys and normal-weight girls. Conclusion. BMI and WC were closely associated with FM and PBF, respectively. However, the degree of these associations depends on gender and weight status. BMI may provide a better proxy estimate of overall adiposity than WC; nevertheless, both of them would appear to be a reasonable surrogate for FM and PBF as screening tools to identify adolescents at risk of developing excess body fat and high level of FBG.

C-reactive protein in adolescent twins: patterns and relationship to adiposity

CONTEXT

Elevated C-reactive protein (CRP) is a marker of cardiovascular risk in adults. Patterns and determinants of CRP in adolescents have not been well described.

OBJECTIVE

This study aimed to determine how CRP varies by age, gender, Tanner stage, and body fat composition in rural Chinese adolescents and to what degree adiposity-CRP associations are attributable to shared genetic and environmental factors.

DESIGN AND SETTING

Data were derived from an ongoing study of metabolic syndrome in a large community-based twin cohort enrolled in Anqing, China.

PARTICIPANTS

The study sample included 1180 adolescent twins aged 13-21 yr.

MAIN OUTCOME MEASURES

Plasma CRP concentrations were measured by sandwich immunoassay using flow metric xMAP technology. Body fat composition was assessed by dual-energy x-ray absorptiometry.

RESULTS

CRP levels linearly increased across age and Tanner stage in males (P ≤ 0.0001), but in females, CRP exhibited no trend after adjusting for fat mass (P > 0.05). For males, the most explanatory measure was body mass index (partial r(2) = 5.2%), whereas percent body fat (partial r(2) = 8.8%) was more explanatory in females. Of the phenotypic correlations between adiposity measures and CRP (0.25-0.28), 86-89% were attributed to shared genetic factors and 11-14% to common unique environmental factors in both sexes.

CONCLUSIONS

Adiposity is a strong determinant of CRP even in this relatively lean Chinese population. There is notable gender difference for the CRP pattern and the relationship of CRP with adiposity during adolescence. To a large degree, common genetic factors may underlie the observed adiposity-CRP-phenotypic correlations.

Clinical diagnosis of metabolic and cardiovascular risks in overweight children: early development of chronic diseases in the obese child

Childhood overweight (body mass index (BMI)>90th centile) poses a major public health problem in so far as adult diseases manifest themselves already during childhood. In this review, after examining the prevalence of metabolic and cardiovascular diseases, the issue of whether BMI or other clinical parameters are valid tools to predict co-morbidities in children is discussed. Data of 2001-2008 are reviewed, including several studies conducted on more than 260,000 overweight and obese children in Germany and Switzerland. Apart from non-metabolic co-morbidities, namely musculoskeletal complications and attention deficit/hyperactivity disorders in up to 74% and up to 58% of overweight children, respectively, at least one cardiovascular and metabolic risk factor was seen in 52% of the overweight children, mostly high blood pressure (35%) with increased left ventricular mass or arterial stiffness. Signs of fatty liver disease or dyslipidemia were found in up to 29 and 32% of the children, respectively. Type 2 diabetes was found in less than 0.7% of the children, and an elevated fasting glucose or glucose intolerance in 3%. Irrespective of BMI, the quality of fat and protein intake predicted hypertension or insulin resistance, and fructose predicted lower (and more atherogenic) particle size of low-density lipoprotein-cholesterol. Out of the adiposity markers, waist circumference was closely correlated with insulin resistance and the components of the metabolic syndrome. In conclusion, risk factors are found in more than half of the overweight children, most frequently high blood pressure or dyslipidemia, and were mainly related to waist circumference, but also to BMI and fat mass. Even in the presence of normal BMI, screening for cardiovascular risk factors is advocated in each child with elevated waist circumference, but its cut-off points still remain to be validated. The increased occurrence of orthopedic and psychiatric complaints may detrimentally influence health-related lifestyle and obesity therapy.