The study of Haap et al. (1) on two patients with multiple symmetric lipomatosis (MSL), also known as the Launois-Bensaude Syndrome, adds interesting new insights into a condition still poorly understood.

As for the conclusions drawn concerning insulin sensitivity in patient 1, we would like to suggest some caution. Our study group has also measured the insulin sensitivity index (ISI) in three subjects with MSL with the euglycemic-hyperinsulinemic clamp and found the ISI to be higher in one and lower in two male subjects in comparison with sex- and BMI-matched control subjects (2). The good insulin sensitivity in patient 1 in the study of Haap et al. may indeed be related to the low visceral fat mass in this very patient, but it is rather questionable whether this finding is typical in MSL. From five patients with MSL identified in our clinic, computed tomographies of the abdomen had been performed in two case subjects, and the degree of visceral fat was described as comparable with that of healthy subjects. In a systematic evaluation of the fat mass and deposition in 18 patients with MSL by computed tomography, Enzi et al. (3) also did not describe a distinct reduction of visceral fat in these patients. Given this and the considerable phenotypical and clinical variability in patients with MSL (4), the conclusion of a good insulin sensitivity in MSL patients should not be generalized. Studies in larger populations are mandatory, although not easily performed due to the rareness of the disease. In a literature search of our own, we identified about 400 cases published since the first description by Brodie in 1846 (5).

One further aspect on MSL seems worth mentioning: three of the five patients with MSL in our clinic had obstructive sleep apnea syndrome (OSAS). We recently identified (5) the presence of OSAS as an independent risk factor contributing to insulin resistance. Thus, the investigation for OSAS in MSL patients might also be useful in the discussion of insulin sensitivity and of other metabolic aspects of MSL.

Haap M, Siewecke C, Thamer C, Machann J, Schick F, Häring H-U, Szeimies RM, Stumvoll M: Multiple symmetric lipomatosis: a paradigm of metabolically innocent obesity? (Brief Report).
Diabetes Care
Harsch IA, Pour Schahin S, Fuchs FS, Hahn EG, Lohmann T, Konturek PC, Ficker JH: Insulin resistance, hyperleptinemia, and obstructive sleep apnea in Launois-Bensaude syndrome.
Obes Res
Enzi G, Biondetti PR, Fiore D, Mazzoleni F: Computed tomography of deep fat masses in multiple symmetrical lipomatosis.
Enzi G, Busetto I, Ceschin E, Coin A, Digito M, Pigozzo S: Multiple symmetrical lipomatosis: clinical aspects and outcome in a long-term longitudinal study.
Int J Obes
Brodie BC:
Lectures Illustrative of Various Subjects in Pathology and Surgery
. London, Longman, Brown, Green, and Longman,
, p.
Harsch IA, Pour Schahin S, Radespiel-Tröger M, Weintz O, Jahreiss H, Fuchs FS, Wiest GH, Hahn EG, Lohmann T, Konturek PC, Ficker JH: Continuous positive airway pressure treatment rapidly improves insulin sensitivity in patients with obstructive sleep apnea syndrome.
Am J Respir Crit Care Med