Expression of Circulating MicroRNAs Associated with Obesity and their Relationships with Biochemical Parameters and Health-related Physical Fitness in Children 6 to 10 Years Old in Cali, Colombia.

BACKGROUND: Obesity is a public health problem worldwide; it has reached pandemic proportions in the last 40 years. Its prevalence in children and adolescents increased from 0.7% to 7.8% between 1975 and 2016. Recently, microRNAs (miRNAs) have been reported as regulatory factors related to molecular functions under different conditions. These can be used as biomarkers of a disease to estimate risks in the early stages. OBJECTIVE: This study aimed to determine the expression levels of miRNAs associated with childhood obesity and their relationships with biochemical parameters and Health-related Physical Fitness (HRPF). METHODS: This was a descriptive cross-sectional study in which a population of 40 children between 6 and 10 years of age of both sexes from Cali, Colombia, was evaluated; the children were classified as 20 normal-weight and 20 obese. Blood biochemistry, HRPF, and miRNA expression levels were determined (hsa-miR-122-5p, hsa-miR-15b-5p, hsa-miR-191-5p, hsa-miR-486-3p, hsa-miR-222-3p. Comparisons were made between the groups, miRNA associations between the studied variables, and linear regression analysis. RESULTS: Twenty normal-weight and 20 obese patients were evaluated. Both groups had an average age of eight years old. The miRNA hsa-miR-122-5p (p < 0.05) was overexpressed in the obese group. According to the linear regression analysis, the amount of adipose tissue may be associated with the production of miRNAs (hsa-miR-15b-5p, hsa-miR-222-3p, hsa-miR-122-5p, and hsamiR- 191-5p). CONCLUSION: Four miRNAs (hsa-miR-15b-5p, hsa-miR-222-3p, hsa-miR-122-5p, and hsa-miR- 191-5p) are associated with modifications in biochemical variables of HRPF in this group. Adipose tissue mass could be associated with the production of these miRNAs, thus making them biomarkers of childhood obesity risk.

Association between circulating microRNAs and the metabolic syndrome in adult populations: A systematic review.

BACKGROUND: Circulating microRNAs (miRNAs) are one of the most abundant classes of gene regulatory molecules, and had been associated to the metabolic syndrome, higher BMI, dyslipidemia and diabetes mellitus. In this sense, miRNAs could help to understand the mechanism behind the development of metabolic syndrome. OBJECTIVE: To determine the relationship between circulating microRNAs and the metabolic syndrome in adult population. METHODS: We performed a systematic review according to the recommendations of the Cochrane Collaboration and following the PRISMA Statement. The results were grouped for miRNAs levels in MetS and metabolic variables included in MetS and their statistic association with miRNAs levels. RESULTS: We finally included sixteen studies with a total of 7195 individuals. We found 47 miRNAs reported to be related to metabolic syndrome (p < 0,05) and 98 associated with the metabolic alterations included in its diagnostic (p < 0,05). Forty-nine miRNAs levels were described as relate to insulin resistance, 29 with high triglycerides, 35 with hypertension, 28 with obesity, and 16 miRNAs with cholesterol HDL(p < 0,05). Changes in levels of miR-505-5p, miR-148a-3p, miR-19b-3p, miR-320b, miR-342-3p, miR-197-3p, miR-192-5p, miR-122-5p, miR-103, miR-130a, miR-155-5p and miR-375, were reported as significant in more than one study. The results only included a descriptive synthesis, clinical heterogeneity did not allow a meta-analysis. CONCLUSION: The findings on the current systematic review suggests a possible relationship between miRNAs with metabolic syndrome and metabolic traits. This association could help to understand the mechanism behind the develop of the metabolic syndrome. However, more studies are necessary for further validation.