Potential factors in the interaction of obesity and ageing include inflammation in adipose and other ageing tissues, suppressed adiponectin production, leptin production and leptin resistance, reduction in lean mass, upregulation of the p53 oncogene, reduction of growth hormone secretions, late-onset hypogonadism, changes in thyroid and adrenal function, brown adipocyte induction, and adipose tissue expansion. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.