Fasting serum leptin levels in elderly women with major depressive disorder: a case-control study

OBJECTIVE: Leptin is produced in the adipose tissue. It controls energy homeostasis by reducing food intake and increasing energy expenditure. According to the "leptin hypothesis of depression", chronic stress leads to reduced leptin concentration and leptin insufficiency may underlie depressive symptoms. However, it is also hypothesized that observed in depressed patients differences in leptin levels may be secondary to differences in adiposity. The aim of this case-control study is to evaluate fasting serum leptin levels in elderly women with major depression disorder and to compare them with non-depressed elderly women. METHODS: We measured fasting serum leptins levels and body composition in 32 elderly (age >= 60 years) European Caucasian women with major depression disorder and in 49 non-depressed elderly (age >= 60 years) European Caucasian women. RESULTS: There was no statistically significant difference (p=0.14) in fasting serum leptin level between patients with depression (3.04 +/- 1.79 ng/mL) and control subjects (2.46 +/- 1.70 ng/mL). CONCLUSIONS: In two groups of subjects with comparable adiposity parameters we did not confirm that leptin level is changed in patients with depression. We assume that changes in leptin level in patients with depression may be mediated by adiposity.