Obesity is associated with general low grade inflammation and, consequently, of oxidative stress that affects properties and functionality of lipoproteins. Metabolic syndrome exacerbate low grade inflammation. The intentional weight loss of at least 5% of the initial weight can modulate the pro-inflammatory state and reduce the oxidative stress related to the metabolic syndrome, thus diminishing the cardiovascular risk.

Metabolic syndrome is a clustering of risk factors for the development of cardiovascular disease and type 2 diabetes mellitus. Patients with metabolic syndrome have an increased general low grade inflammation and, consequently, of oxidative stress that affects properties and functions of lipoproteins (Dandona et al 2005). Intentional weight loss can improve or prevent many of the metabolic syndrome-related risk factors and these benefits are often found after weight loss of at least 5% of initial weigh.

Aim: i) to investigate the structure and functionality of plasma lipoproteins, oxidative stress and the inflammatory condition in subjects with BMI between 25kg/mq and 35 kg/mq and with or without metabolic syndrome; and ii) to test the effects of weight loss of at least 5% of initial weigh promoted by an hypo-caloric balanced diet on these parameters.

Methods: Eighty overweight and moderately obese subjects (BMI: 25 - 35 kg/m2) with or without metabolic syndrome were recruited for the study. Fasting blood samples were taken and analyzed for routine laboratory analysis, lipoprotein isolation and analysis, and oxidative stress and inflammation markers measurements. The subjects received an hypo-caloric balanced diet. Fasting blood samples were taken from subjects who had lost at least 5% of their initial weight at the end of the intervention period and analyzed for same markers determined at baseline.

1. Inclusion Criteria.

1.a Group "Obese with MS":

• BMI between 25 e 35 Kg/m2

• presence at least three of the following:1) waist circumference >102 cm for males or > 88 cm for females; 2) triglycerides: ≥ 150 mg/dL;3) HDL-cholesterol < 40 mg/dL in males or < 50 mg/dL in females; 4) hypertension (systolic blood pressure ≥ 130 mm Hg or diastolic blood pressure ≥ 85 mm Hg or antihypertensive intake); 5) glycemia: ≥ 110 mg/dL

• Alcohol consumption < 25 g/die

• No smoking or smoking less that 5 cigarettes/die

• No use of antioxidant based supplements

• Absence of hormonal treatments

• Informed consent signature

  1.b Group "Obese without MS":

• BMI between 25 e 35 Kg/m2

• Alcohol consumption < 25 g/die

• No smoking or smoking less that 5 cigarettes/die

• No use of antioxidant based supplements

• Absence of hormonal treatments

• Informed consent signature

  2. Exclusion Criteria

• Presence of major disease

• Receiving hypoglycemic treatment

• Receiving treatments that alter lipoprotein metabolism

• Receiving hormonal treatments

• Use of antioxidant supplement

• Alcohol consumption > 25 g/die

• Smoking > 5 cigarettes/die.

• For women:pregnancy

Subjects were males and females overweight or moderately obese with or without metabolic syndrome on a calorie-controlled diet.

Those that lost at least 5% of the initial weight were analyzed.