Recommendations for the prevention and diagnosis of asthma in children: Evidence from international guidelines adapted for Mexico

BACKGROUND

With the availability of high-quality asthma guidelines worldwide, one possible approach of developing a valid guideline, without re-working the evidence, already analysed by major guidelines, is the ADAPTE approach, as was used for the development of National Guidelines on asthma.

METHODS

The guidelines development group (GDG) covered a broad range of experts from medical specialities, primary care physicians and methodologists. The core group of the GDG searched the literature for asthma guidelines 2005 onward, and analysed the 11 best guidelines with AGREE-II to select three mother guidelines. Key clinical questions were formulated covering each step of the asthma management.

RESULTS

The selected mother guidelines are British Thoracic Society (BTS), GINA and GEMA 2015. Responses to the questions were formulated according to the evidence in the mother guidelines. Recommendations or suggestions were made for asthma treatment in Mexico by the core group, and adjusted during several rounds of a Delphi process, taking into account: 1. Evidence; 2. Safety; 3. Cost; 4. Patient preference - all these set against the background of the local reality. Here the detailed analysis of the evidence present in BTS/GINA/GEMA sections on prevention and diagnosis in paediatric asthma are presented for three age-groups: children with asthma ≤5 years, 6-11 years and ≥12 years.

CONCLUSIONS

For the prevention and diagnosis sections, applying the AGREE-II method is useful to develop a scientifically-sustained document, adjusted to the local reality per country, as is the Mexican Guideline on Asthma.

DNA methylation of leptin and adiponectin promoters in children is reduced by the combined presence of obesity and insulin resistance

OBJECTIVE

Epigenetic alterations have been suggested to be associated with obesity and related metabolic disorders. Here we examined the correlation between obesity and insulin resistance with the methylation frequency of the leptin (LEP) and adiponectin (ADIPOQ) promoters in obese adolescents with the aim to identify epigenetic markers that might be used as tools to predict and follow up the physiological alterations associated with the development of the metabolic syndrome.

SUBJECTS

One hundred and six adolescents were recruited and classified according to body mass index and homeostasis model of assessment-insulin resistance index. The circulating concentrations of leptin, adiponectin and of several metabolic markers of obesity and insulin resistance were determined by standard methods. The methylation frequency of the LEP and ADIPOQ promoters was determined by methylation-specific PCR (MS-PCR) in DNA obtained from peripheral blood samples.

RESULTS

Obese adolescents without insulin resistance showed higher and lower circulating levels of, respectively, leptin and adiponectin along with increased plasmatic concentrations of insulin and triglycerides. They also exhibited the same methylation frequency than lean subjects of the CpG sites located at -51 and -31 nt relative to the transcription start site of the LEP gene. However, the methylation frequency of these nucleotides dropped markedly in obese adolescents with insulin resistance. We found the same inverse relationship between the combined presence of obesity and insulin resistance and the methylation frequency of the CpG site located at -283 nt relative to the start site of the ADIPOQ promoter.

CONCLUSIONS

These observations sustain the hypothesis that epigenetic modifications might underpin the development of obesity and related metabolic disorders. They also validate the use of blood leukocytes and MS-PCR as a reliable and affordable methodology for the identification of epigenetic modifications that could be used as molecular markers to predict and follow up the physiological changes associated with obesity and insulin resistance.