Clinical characteristics and efficacy of pioglitazone in a Japanese diabetic patient with an unusual type of familial partial lipodystrophy.

This report describes a 46-year-old Japanese diabetic woman with an unusual type of familial partial lipodystrophy. She has marked loss of subcutaneous fat in her lower limbs and buttocks, with sparing of the face, neck, upper limbs, and trunk. This distribution of fat atrophy appears to be rare in comparison with previous reports. Sequencing of candidate genes LMNA, PPARG, AKT2, caveolin-1, as well as the PPARG4 promoter gene, which are known to be associated with familial partial lipodystrophy, revealed no genetic abnormalities, suggesting that this case may involve a novel gene. Pioglitazone was markedly effective in glycemic control in this case. Her diabetes remained uncontrolled despite a total daily dose of insulin of 30 U and combined treatment with 10 mg of glibenclamide and 0.6 mg of voglibose. We therefore attempted combined treatment with 30 mg of pioglitazone and 30 U/d insulin injection. The hemoglobin A(1c) level was reduced from 11.2% to 6.1% after 6 months of treatment and has since remained stable. Her body weight increased from 62.0 to 71.0 kg after 12 months of treatment, suggesting that weight gain may result from synergism between thiazolidinediones and insulin-promoting adipogenesis. Pioglitazone increased the fat mass in the upper limbs and trunk, while inducing less increase in the lower limbs, where fat atrophy exists in this patient. Pioglitazone may thus have improved the glycemic control in this case through adipocyte differentiation from progenitor cells mainly in the upper limbs and trunk.