Insulin sensitivity and associated risk factors in Mexican children and adolescents

Fat-free/lean body mass in children with insulin resistance or metabolic syndrome: a systematic review and meta-analysis

BACKGROUND

Lean / Fat Free Body Mass (LBM) is metabolically involved in active processes such as resting energy expenditure, glucose uptake, and myokine secretion. Nonetheless, its association with insulin sensitivity / resistance / glucose tolerance and metabolic syndrome remains unclear in childhood.

METHODS

The current investigation aimed to examine the differences in fat-free mass /lean body mass according to the presence of insulin sensitivity/insulin resistance/glucose tolerance/metabolic syndrome in children. A systematic search was carried out in Medline/PubMed, Embase, Scopus, Web of Science, and SciELO, covering the period from each database's respective start to 21 June 2021. Two researchers evaluated 7111 studies according to the inclusion criteria: original human studies, written in English or Spanish, evaluating fat-free mass/lean body mass in children and adolescents including both with and without insulin sensitivity/insulin resistance /glucose tolerance and metabolic syndrome and reported the differences between them in terms of fat free mass/lean body mass. The results of the studies were combined with insulin sensitivity, insulin, resistance, glucose tolerance and metabolic syndrome. The standardized mean difference (SMD) in each study was calculated and combined using the random-effects model. Heterogeneity between studies was tested using the index of heterogeneity (I2), leave-one-out sensitivity analyses were performed, and publication bias was assessed using the Egger and Begg tests.

RESULTS

Finally, 15 studies which compared groups defined according to different glucose homeostasis criteria or metabolic syndrome out of 103 eligible studies were included in this systematic review and 12 studies in the meta-analysis. Meta-analysis showed lower fat-free mass/lean body mass percentage in participants with insulin resistance/glucose tolerance/metabolic syndrome (SMD -0.47; 95% CI, - 0.62 to - 0.32) while in mass units (kg), higher values were found in the same group (SMD, 1.01; 95% CI, 0.43 to 1.60).

CONCLUSIONS

Our results identified lower values of fat-free mass/lean body mass (%) in children and adolescents with insulin resistance/glucose tolerance/metabolic syndrome and higher values of fat-free mass/lean body mass when these are expressed in kg. The evidence of the impact of lean mass on children's glucose homeostasis or metabolic syndrome is limited, so future studies research should focus on explaining the effect of fat-free mass/lean body mass on different metabolic outcomes. Moreover, it may be interesting to evaluate the quality (muscle density) or functional (muscle strength) outcomes in addition to both absolute (kg) and relative (%) values in future studies. The systematic review was prospectively registered at PROSPERO (registration number CRD42019124734; available at: http://www.crd.york.ac.uk/prospero [accessed: 05 April 2019]).

Caloric beverage consumption patterns in Mexican children

BACKGROUND

Mexico has seen a very steep increase in child obesity level. Little is known about caloric beverage intake in this country as well as all other countries outside a few high income countries. This study examines overall patterns and trends in all caloric beverages from two nationally representative surveys from Mexico.

METHODS

The two nationally representative dietary intake surveys (1999 and 2006) from Mexico are used to study caloric beverage intake in 17, 215 children. The volume (ml) and caloric energy (kcal) contributed by all beverages consumed by the sample subjects were measured. Results are weighted to be nationally representative.

RESULTS

The trends from the dietary intake surveys showed very large increases in caloric beverages among pre-school and school children. The contribution of whole milk and sugar-sweetened juices was an important finding. Mexican pre-school children consumed 27.8% of their energy from caloric beverages in 2006 and school children consumed 20.7% of their energy from caloric beverages during the same time. The three major categories of beverage intake are whole milk, fruit juice with various sugar and water combinations and carbonated and noncarbonated sugared-beverages.

CONCLUSION

The Mexican government, greatly concerned about obesity, has identified the large increase in caloric beverages from whole milk, juices and soft drinks as a key target and is initiating major changes to address this problem. They have already used the data to shift 20 million persons in their welfare and feeding programs from whole to 1.5% fat milk and in a year will shift to nonfat milk. They are using these data to revise school beverage policies and national regulations and taxation policies related to an array of less healthful caloric beverages.

Distribution of fasting plasma glucose and prevalence of impaired fasting glucose, impaired glucose tolerance and type 2 diabetes in the Mexican paediatric population

Published data on the distribution of fasting plasma glucose (FPG) in children are scarce. We therefore set out to examine the distribution of FPG and determine the prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes (T2-DM) in Mexican children aged 6-18 years in a community-based cross-sectional study. A total of 1534 apparently healthy children were randomly enrolled and underwent an oral glucose tolerance test. IFG was defined by an FPG value between >or=100 and <126 mg/dL, IGT by glucose concentration 2-h post-load between >or=140 and <200 mg/dL, and T2-DM by glucose concentration 2-h post-load >or=200 mg/dL. The FPG level at the 75(th) percentile of distribution was 98.0, 100.0 and 99.0 mg/dL for children aged 6-9, 10-14 and 15-18 years, respectively; the 95(th) percentile of FPG was greater than 100 mg/dL for all the age strata. In the population overall, the prevalences of IFG, IGT, and T2-DM were 18.3%, 5.2% and 0.6%, respectively. Among obese children and adolescents, the prevalences of IFG, IGT, IFG + IGT and T2-DM were 19.1%, 5.7%, 2.5% and 1.3%. Our study shows a high prevalence of prediabetes and is the first that reports the distribution of FPG in Mexican children and adolescents.

Hyperinsulinemia in healthy children and adolescents with a positive family history for type 2 diabetes

OBJECTIVE

Our goal was to determine the relationship between family history of type 2 diabetes and fasting hyperinsulinemia in healthy children and adolescents.

METHODS

A total of 317 children and adolescents, 10 to 14 years of age with Tanner stage 1 or 2, were randomly selected from elementary and middle schools in Durango, northern Mexico, to participate in a cross-sectional, community-based study. Family history was ascertained by a direct, detailed medical examination that included anthropometric and laboratory measurements from both parents. We determined the prevalence of family history of type 2 diabetes, high blood pressure, obesity, hyperinsulinemia, and the adjusted odds ratio that computes the relationship between hyperinsulinemia and family history of type 2 diabetes.

RESULTS

Family history of type 2 diabetes, high blood pressure, and obesity was recognized in 30 (9.2%), 61 (18.7%), and 74 (22.7%) children and adolescents, respectively. Children and adolescents with positive family history showed higher systolic and diastolic blood pressure, were more obese, and exhibited significantly higher fasting insulin and triglycerides levels, as well as a higher homeostasis model analysis insulin resistance index, than children with negative family history. A total of 48 (15.1%) children and adolescents exhibited hyperinsulinemia, 35 (72.9%) with and 13 (27.1%) without family history. The odds ratio adjusted by gender, fat mass (kilograms and percent), waist circumference, BMI, and Tanner stage showed that family history of diabetes, but not high blood pressure and obesity, was independently related with hyperinsulinemia.

CONCLUSIONS

Among children and adolescents, family history of diabetes, but not high blood pressure and obesity, is independently associated with hyperinsulinemia.