Endocrine Abstracts

Background

In lipodystrophy (LD) adipose tissue function is impaired, leading to a severe metabolic syndrome. Familiar Partial LD (FPLD) type I (Kobberling Syndrome) overlaps with Cushing’s syndrome phenotype. The latter and the metabolic impairment observed in FPLD1 may suggest a crosstalk between the HPA axis, assuming that leptin sensitivity is preserved in this context. We aimed to evaluate if leptin levels are associated with glucocorticoid activity in FPLD1.

Methods

12 adult patients (2 males, 10 females) with PLD were recruited. Physical parameters, plasma lipid profile, renal function, liver enzymes, glucose, HbA1c, and leptin levels were determined. 24-h urine cortisol (F) and cortisone (E) through LC–MS/MS analysis were also measured.

Results

Twelve adult subjects were classified as Köbberling syndrome after the genetic and immune exclusion of other LD forms. All of them presented increased waist circumferences, decreased hip circumference and peripheral skinfold thickness. All patients had type 2 diabetes under treatment (insulin with or without other antidiabetic drugs), with high HbA1c levels (8.2±0.3%). The patients were treated for high lipid levels (statin, ezetimibe, fibrates, omega 3, PCSK9 inhibitors alone or combined), with LDL in the target range in 33%, and triglycerides lower than 150 mg/dl in 26.6%. Leptin levels were in the lower range according to sex and BMI (29.5±5.5 µg/l). All subjects had correct serum cortisol suppression after an overnight 1-mg dexamethasone test. Leptin levels correlated in all the subjects and females alone with BMI (r: 0.623), HDL-cholesterol (r: 0.485), estimated glomerular filtration rate (eGFR, r: -0.687), and 24 h urine F/E ratio (r: 0.750), but not with urine F and E alone. F/E ratio was also correlated with eGFR (r: -0.457). Urine F/E ratio, in a stepwise model composed of significant variables, was positively predicted by leptin levels and BMI (R: 0.756, R2: 0.562, P <0.032).

Conclusion

In FPLD 1 (Kobberling), leptin levels are directly associated with the 24 h urine F/E ratio suggesting complex crosstalk among leptin, 11β-hydroxysteroid dehydrogenase 1 and 2 activity. Glucocorticoid sensitivity and renal impairment could contribute to the severity of the phenotype.