The effects of age and reproductive status on carbohydrate and lipid metabolism of Iberian sows reared in an intensive management system were examined. These animals, with age, are predisposed to hyperglycaemia and dyslipidemia which may develop in response to nutritional challenges during lactation. At weaning, high levels of glucose, triglycerides and low-density lipoproteins cholesterol (LDL-c) with low high-density lipoproteins cholesterol (HDL-c) are indicative of insulin resistance.