Clinical Research Directory

A cardiopulmonary exercise test in a treadmill will be performed after an overnight fasting. Gas exchange, heart rate, and muscle oxygen saturation levels will be assessed continuously during the entire test. Blood pressure and rate of perceived exertion will be recorded prior the end of each stage whereas blood glucose concentration will be assessed before and after the test. All the hemodynamic parameters will be assessed at rest to standardize the cardio-metabolic condition of the participants prior to exercise testing. Maximal exertion will be requested from all participants except elders, in whom a submaximal test will be applied, following the guidelines provided by the American College of Sports Medicine. From this trial, maximal oxygen uptake, ventilatory thresholds/dynamics, chronotropic and inotropic response, and metabolic flexibility will be examined. A trained exercise physiologist will supervise all the tests and validate the obtained data.

Bioelectrical impedance analysis will be used to estimate body compartments through a mechanism of resistance and reactance (InBody 770, KOR) . The compartments measured include body cell mass, fat mass, extracellular tissue, lean mass, muscle mass, visceral adipose tissue area, phase angle, among others.

The frequency of micronuclei, nuclear buds, basal cells, binucleated cells, condensed chromatin cells, karyorrhexis, karyolysis, and pyknosis will be determined through microscopic examination of exfoliated oral mucosal cells from each participant.

Physical activity and sedentary time will be assessed through the Spanish version of the International Questionnaire of Physical activity. In half of the analyzed subjects a wearable device (Fitbit luxe, Fit bit Inc) will be also used to record daily steps, energy expenditure and heart rate patterns.

Insomnia severity index, sleep quality, somnolence and chronotype will be subjectively assessed in all participants, using validated scales such as the Pittsburgh, Epworth and ISI questionnaires. In half of the participants, sleep quality will be tracked by wearing a Fit band luxe device in the wrist.

The concentrations of glucose, glycated hemoglobin, and lipid profile will be determined through serum analysis using a blood chemistry analyzer (Spin120, Spinreact, ESP). Serum samples will be obtained by centrifuging peripheral venous blood samples (4-6 mL) collected in Vacutainer tubes at 2500 rpm for 10 minutes. From the same serum samples, circulating levels of insulin, ovarian hormones (estradiol and progesterone), insulin-like growth factor 1 (IGF-1), and vascular endothelial growth factor (VEGF) will be assessed using enzyme-linked immunosorbent assays (ELISA) on a microplate reader (iMark, BIORAD, USA), following the specifications provided by each kit manufacturer (Biotechne, USA; AccuBind, GUA). Glucose, insulin and triglyceride values obtained from the blood chemistry analyzer and ELISA assays will be used to calculate the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and the triglyceride-glucose index.

Perceived stress will be obtained from the Perceived Stress Scale adapted for Mexican population. Additionally, depression and anxiety scores will be obtained from the Becks Depression Inventory, validated in Mexican adults. Ruminative thinking will be assessed through the short version of the Ruminative Responses Scale and substance abuse will be examined through the 10-items Drug Abuse Screening Test. Social media disorder and screen time will be also investigated from the Social Media Disorder Test and a cell-phone screen capture.

A semi quantitative food frequency questionnaire will be applied to collect data about macronutrient intake and supplements consumption. Hierarchical consumption of each food groups will be also assessed. Last meal consumed prior to exercise testing will be also recorded in conjunction with fasting time.

The P10L polymorphism of the OPN4 gene, previously associated with chronic insomnia and severe daytime sleepiness in the Mexican population will be determined using RFLP-PCR assays. DNA will be extracted from previously collected blood samples (4 ml) using the Master Pure DNA purification kit from Epicentre (Illumina Inc., US).