Study Population
The SPHERE study is a cross-sectional study investigating the effects of particulate air pollution on a population of susceptible overweight/obese subjects, residing in Lombardy Region, Italy. Lombardy is situated in the Northern part of Italy and is physically divided into three parts from north to south: Alpine and pre-Alpine mountains, foothills, and a zone of alluvial plains sloping to the Po river. The region covers an area of 23.864 km2 with a population of about 10 million people and consists of 12 provinces, among which Milan is the regional capital. The Milan metropolitan area counts 7 million inhabitants with 1.3 million residing in the core municipality.
The overall study enrollment target is to recruit 2,000 participants presenting at the Center for Obesity and Work, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy. The recruitment period started in September 2010 and will continue until the end of 2015.
The eligibility criteria for participants are: 1) older than 18 years at enrollment; 2) obese/overweight according to the following definition: overweight is defined as a BMI between 25 and 30 kg/cm², obesity is defined as a BMI of 30 kg/cm² or more; 3) resident in Lombardy at the time of the recruitment; 4) agreement to sign an informed consent and donate blood and urine samples.
Exclusion criteria include: previous diagnosis of cancer, heart disease or stroke in the last year or other chronic diseases such as multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, depression, bipolar disorder, schizophrenia and epilepsy.
he participation rate in the years 2010-2013 was 90%. Most participants are females (73.6%). The mean BMI is 33.5 Kg/cm2 (±5.5): 27.8% are overweight, 38.6% obese, and 33.6% severe obese (BMI ≥ 35 Kg/cm2). The mean age is 51.9 years (±13.6).
At recruitment, each study subject is asked to: -fill in a lifestyle and a diet questionnaire, -donate a 15 ml blood sample (for molecular tests), -provide a 50 ml urine sample (for metal internal dose assessment), -provide a lock of hair cut next to the root in the occipital area of the head (for metal internal dose assessment).
As part of the routine protocol, for each subject presenting at the Center, physical examination (including weight and height measured by a nurse following standardized procedures), spirometry, and electrocardiogram (ECG) are performed and biochemical parameters are also collected, including Emocrome, Fibrinogen, C-reactive protein, Total cholesterol, HDL, LDL, Triglyceride, Serum creatinine, AST, ALT, Gamma-Glutamyltransferase, fasting blood glucose, Homocysteine, TSH, Glycated haemoglobin, Postprandial glycaemia, Insulin level, 2-hour post glucose insulin level, Urinary pH, Uric acid.