LEP and type 1 diabetes mellitus: Metreleptin, a synthetic analogue of human leptin, is an effective treatment for generalized lipodystrophies, but the evidence for efficacy in patients with FPLD3 is scarce.<h4>Case presentation</h4>We present a 61-year-old woman, initially misdiagnosed as type 1 diabetes since the age of 29, with severe insulin resistance, who gradually displayed a more generalized form of lipoatrophy and extreme hypertriglyceridemia, hypertension and multiple manifestations of cardiovascular disease.