Endocrine Abstracts

Introduction: Superior mesenteric artery (SMA) syndrome is a rare cause of abdominal pain due to proximal intestinal obstruction which is characterized by compression of the third portion of the duodenum secondary to the narrowing of the space between the superior mesenteric artery and aorta. The development of the SMA syndrome is primarily attributed to the loss of the intervening mesenteric fat. Lipodystrophy is a rare clinical syndrome characterized by the loss of adipose tissue that can affect the amount of visceral and mesenteric fat.

Method: We measured aortomesenteric distance (AOM) in patients with various forms of lipodystrophy. Sixty patients with lipodystrophy (11 males; 49 females; mean age 38 ± 13 years; 20 congenital generalized lipodystrophy, 30 familial partial lipodystrophy, and 10 acquired partial lipodystrophy) were included. An age-, gender- and BMI-matched control group (1:2) was generated from a cohort of subjects with hormone inactive adrenal incidentalomas. The AOM distance was measured on MR images.

Results: Median AOM distance was 10.8 mm (25-75 percentiles: 7.1-16.1 mm) in patients with lipodystrophy and 11.0 mm (25-75 percentiles: 8.0-15.5 mm) in the control group (P=0.311). Patients with congenital generalized lipodystrophy had lower AOM distance (8.2 mm [25-75 percentiles: 6.0-12.4 mm]; P=0.024) compared to controls and patients with familial partial lipodystrophy (vs. 12.4 mm [25-75 percentiles: 7.2-18.0 mm]; P=0.059). Twelve of 20 patients (60%) with congenital generalized lipodystrophy had an AOM distance of less than 10 mm, a risk factor that may predispose patients to develop SMA syndrome. Body mass index was positively correlated with AOM distance, both in the overall sample (r=0.397, P<0.001) and in patients with lipodystrophy (r=0.485, P<0.001). BMI was found to be a significant predictor of AOM distance in multivariate linear regression analysis including age, sex, and BMI (r²= 0.27, P<0.001).

Conclusion: Visceral fat loss in lipodystrophy syndromes may pose a risk to SMA syndrome that is likely to only affect patients with generalized lipodystrophy. Abdominal pain is a common symptom in lipodystrophy mostly attributed to episodes of acute pancreatitis secondary to severely elevated triglycerides. SMA syndrome should be kept in mind in patients with generalized lipodystrophy who presented with abdominal pain, nausea, and vomiting, especially when the initial workup does not support a diagnosis of acute pancreatitis.