Lipodystrophy including familial, acquired and secondary forms displays the full spectrum of the metabolic syndrome including severe insulin resistance, hyperinsulinaemia; hypertension, hypertriglyceridaemia, low HDL cholesterol, and hyperglycaemia1. This group have an absolute or partial reduction in fat mass, yet often show more extreme metabolic features than obese individuals.
Partial lipodystrophy may be genetic or acquired. Genetic causes of familial partial lipodystrophy (FPLD), often an autosomal dominant condition; include mutations in LMNA, PPARG, AKT2, ZMPSTE24, CIDEC2 however the majority of subjects have no identified genetic aetiology.
Diagnosing FPLD has depended mainly on clinical observations of fatless limbs and phlebectasia (prominent leg veins). Using the Oxford Biobank (database of >1000 healthy individuals in Oxfordshire) and PLD subjects from the Oxford Lipodystrophy Clinic, we have been able to define a normal ratio of central to peripheral skin-fold measurements in healthy individuals. This ratio is markedly increased (>95%CI) in LMNA mutation positive FPLD subjects and subjects with clinical lipodystrophy but no known genetic aetiology.
Subjects with FPLD require individualised treatment in view of their adverse metabolic profile and increased cardiovascular risk. Specific treatments include leptin therapy, in leptin deficient subjects, which improves insulin resistance, hyperglycaemia and dyslipidaemia3. Isolated reports suggest that thiazolidinediones have been successful although prospective studies have been less rewarding. Bariatric surgery has been rewarding in patients with FPLD4.
Familial partial lipodystrophy is less rare than previously reported with a prevalence of ~0.3% in secondary care diabetes clinics, these subjects have a high cardiovascular risk and require identification and individualised management.
References: 1. Garg A. Acquired and inherited lipodystrophies. N Engl J Med 2004 350 12201234.
2. Huang-Doran I, Sleigh A, Rochford J, ORahilly S & Savage DB. Lipodystrophy: metabolic insights from a rare disorder. J Endocrinol 2010 207 245255.
3. Oral EA, Simha V, Ruiz E, Andewelt A, Premkumar A, Snell P, Wagner AJ, DePaoli AM, Reitman ML, Taylor SI, Gorden P & Garg A. Leptin-replacement therapy for lipodystrophy. N Engl J Med 2002 346 570578.
4. Utzschneider KM & Trence DL. Effectiveness of gastric bypass surgery in a patient with familial partial lipodystrophy. Diabetes Care 2006 29 13801382.