Urban Exposome and Biological Age

DNA methylation patterns are evaluated in peripheral blood samples from participants exposed to different levels of urban air pollution. Genomic DNA is extracted and analyzed using bisulfite sequencing, quantitative polymerase chain reaction (qPCR), and pyrosequencing techniques to quantify DNA methylation in specific genomic regions. Methylation measures are evaluated in relation to participants' measured exposure to urban air pollutants.

Biological age is estimated using an epigenetic clock algorithm based on DNA methylation patterns measured in peripheral blood samples. Biological age estimates are compared between workers highly exposed to urban air pollution during outdoor occupational activities and workers with minimal occupational exposure to outdoor urban air pollution.

Blood glucose concentration measured from the peripheral blood sample to characterize glucose metabolism. Unit: mg/dL

Serum insulin concentration measured to characterize glucose and insulin metabolism.

Unit: mIU/L

HOMA-IR is calculated from fasting glucose and insulin concentrations as an estimate of insulin resistance.

Mean corpuscular volume (MCV) measured as part of the complete blood count. Unit: fL

Hemoglobin concentration measured in peripheral blood as part of the complete blood count.

Unit: g/L

Leukocyte count measured in peripheral blood as part of the complete blood count. Unit: 10^9/L

Telomere length is measured in peripheral blood leukocytes as a biomarker of biological aging and cellular senescence. Analyses evaluate associations between telomere length and exposure to urban air pollutants.

Serum Creatinine Concentration. Unit: mg/dL

Estimated glomerular filtration rate (eGFR) used to characterize renal function.

Unit: mL/min/1.73 m²

Unit: µg/L

Unit: ng/L

Unit: µmol/L

FIB-4 is a non-invasive index of liver fibrosis calculated from age, AST, ALT, and platelet count.

Unit: U/L

Unit: U/L

Unit: U/L

Unit: mg/dL

Unit: mg/dL

Unit: mg/dL

Unit: mg/dL

Unit: µg/L

Unit: mUI/L

Unit: ng/L

Unit: ng/dL

Unit: KUI/L

Unit: KUI/L

Body mass index (BMI) is calculated as body weight in kilograms divided by height in meters squared (kg/m²) and is used to assess overall body size.

Waist-to-hip ratio (WHR) is calculated from waist and hip circumference measurements as an indicator of body fat distribution.

Waist-to-height ratio (WHtR) is calculated from waist circumference and height measurements as an indicator of central adiposity.

Phase angle is measured by bioelectrical impedance analysis using the BIA 101 device (BIVA® PRO, Akern) as an indicator of cellular integrity and body composition status. Phase angle is reported in degrees.

Handgrip strength is measured using a digital handgrip dynamometer (GripwiseTech). 3 test on non dominant hand are repeated and the mean value is used as an indicator of handgrip strenght.

Liver stiffness is measured by transient elastography (FibroScan® Compact 530, Echosens SA) and reported in kilopascals (kPa).

The Controlled Attenuation Parameter (CAP) is measured by transient elastography (FibroScan® Compact 530, Echosens SA) to estimate hepatic steatosis.

Adherence to the Mediterranean diet is assessed using the validated MEDI-LITE questionnaire (doi: 10.1080/09637486.2017.1287884.).

The questionnaire evaluates the usual consumption of nine dietary components: fruit, vegetables, legumes, cereals, fish and fish products, meat and processed meat, milk and dairy products, alcoholic beverages, and olive oil. Each component is assigned a score ranging from 0 to 2. For food groups characteristic of the Mediterranean dietary pattern (i.e. fruit, vegetables, legumes, cereals, and fish), higher consumption is assigned a higher score, whereas lower consumption of meat and processed meat and milk and dairy products received a higher score. Olive-oil use is scored according to its reported frequency of consumption. The original MEDI-LITE score ranges from 0 to 18, with higher values indicating greater adherence to the Mediterranean dietary pattern.

The Dietary Inflammatory Index (DII) is calculated from dietary intake data obtained through a 24-hour dietary recall collected through the Handydiet® software to estimate the inflammatory potential of participants' diets.

Physical activity is assessed using the validated International Physical Activity Questionnaire Short Form (IPAQ-SF). The seven-item questionnaire investigates the frequency and duration of walking and moderate- and vigorous-intensity physical activity performed during the previous seven days, together with time spent sitting. Weekly physical activity was expressed as metabolic equivalent of task minutes per week (MET-min/week), calculated by multiplying the MET coefficient assigned to each activity intensity by the reported duration and weekly frequency of the activity. Participants were classified as having low, moderate, or high physical activity levels according to the IPAQ scoring protocol (doi: 10.1249/01.MSS.0000078924.61453.FB.).

Sleep quality during the previous month is assessed using the Pittsburgh Sleep Quality Index (PSQI) (doi: 10.1016/0165-1781(89)90047-4. PMID: 2748771.). The PSQI comprises 19 self-rated items grouped into seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. Each component is scored from 0 to 3, and the seven component scores are summed to generate a global score ranging from 0 to 21. Higher scores, and in particular a cut-off of 5, indicate poorer subjective sleep quality.

Quality of life is assessed using the abbreviated version of the World Health Organization Quality of Life questionnaire (doi: 10.1017/s0033291798006667.). The WHOQOL-BREF comprises 26 items, including two general questions on overall quality of life and perceived health and 24 items covering four domains: physical health, psychological health, social relationships, and environment. Items are rated using five-point response scales. Domain scores are calculated according to the instrument scoring guidelines and transformed to a 4-20 or 0-100 scale, with higher scores indicating better perceived quality of life.

Alcohol consumption is assessed through a structured interview investigating drinking frequency and the usual number of Alcohol Units consumed per each drinking occasion. Participants are classified as reporting no current alcohol consumption, alcohol consumption without a binge pattern, or binge-pattern alcohol consumption. Binge-pattern drinking is defined as the consumption of at least four Alcohol Units for women or at least five Alcohol Units for men on a single drinking occasion. One alcohol Unit equals to 12g of ethanol and is approximately equivalent to the quantity of alcohol in a bottle (330 ml) of beer, in a glass (125 ml) of wine, in a shot (40 ml) of spirit.

Smoking habits are assessed through a structured interview. Participants are classified as current, former, or never smokers. Additional information collected includes the average number of cigarettes smoked per day and the duration of smoking for current and former smokers.

Personal exposure to ozone (O₃) is assessed in warm season using passive diffusion samplers worn by participants during their usual daily activities over a five consecutive day monitoring period.

Unit of measure: µg/m3

Personal exposure to nitrogen dioxide (NO₂) is assessed using passive diffusion samplers worn by participants during their usual daily activities over a five consecutive day monitoring period.

Unit of measure: µg/m3

Personal exposure to sulfur dioxide (SO₂) is assessed using passive diffusion samplers worn by participants during their usual daily activities over a five consecutive day monitoring period.

Unit of measure: µg/m3

Personal exposure to Benzene (C₆H₆) is assessed using passive diffusion samplers worn by participants during their usual daily activities over a five consecutive day monitoring period.

Unit of measure: µg/m3

Personal exposure to toluene is assessed using passive diffusion samplers worn by participants during their usual daily activities over a five consecutive day monitoring period.

Unit of measure: µg/m3

Personal exposure to ethylbenzene is assessed using passive diffusion samplers worn by participants during their usual daily activities over a five consecutive day monitoring period.

Unit of measure: µg/m3

Personal exposure to xylenes is assessed using passive diffusion samplers worn by participants during their usual daily activities over a five consecutive day monitoring period.

Unit of measure: µg/m3

Personal exposure to naphthalene is assessed using passive diffusion samplers worn by participants during their usual daily activities over a five consecutive day monitoring period.

Unit of measure: µg/m3

Personal exposure to C9 aromatic hydrocarbons is assessed using passive diffusion samplers worn by participants during their usual daily activities over a five consecutive day monitoring period.

Unit of measure: µg/m3

Serum CCL2 concentration is measured to assess systemic inflammatory responses associated with urban air pollution exposure. CCL2 concentrations are analyzed in relation to participants' measured exposure to urban air pollutants.

Unit of measure: pg/mL

Serum CXCL8 concentration is measured to assess systemic inflammatory responses associated with urban air pollution exposure. CXCL8 concentrations are analyzed in relation to participants' measured exposure to urban air pollutants.

Unit of measure: pg/mL

Serum CXCL10 concentration is measured to assess systemic inflammatory responses associated with urban air pollution exposure. CXCL10 concentrations are analyzed in relation to participants' measured exposure to urban air pollutants.

Unit of measure: pg/mL