Changes in plasma levels of endocrine hormones in lepromatous leprosy patients

Leprosy affects various endocrine glands and causes disorders in internal organs in addition to the skin and peripheral nerves. These disorders are often silent and remain undiagnosed or underreported. In particular, patterns of hormone changes during leprosy, especially in lepromatous leprosy (LL) patients, are often associated with dysregulation of different endocrine and sex hormones. The aim of this study was to assess changes in four endocrine hormones - namely cortisol, dehydroepiandrosterone (DHEA), growth hormone (GH), and leptin - among LL patients compared with apparently healthy controls.

In total, 80 plasma samples were systematically retrieved from a biorepository at the Armauer Hansen Research Institute (AHRI), based on quality, adequacy of sample volume, and appropriateness of linked clinical and sociodemographic data. Forty of the samples were obtained from LL patients (cases) and the remaining 40 from apparently healthy controls. Enzyme-linked immunosorbant assay (ELISA) was used to quantify levels of DHEA, cortisol, GH, and leptin hormones in the plasma samples. Data were analyzed using non-parametric statistics and the Mann-Whitney U-test (GraphPad Prism version 7.01). A p-value < 0.05 was considered statistically significant.

Plasma levels of cortisol concentration were significantly higher in LL cases (median = 111.4 ng/ml, range = 20.54-525.7) compared with healthy controls (median = 51.98 ng/ml, range = 3.805-328.4) (p = 0.003). Levels of GH and leptin were significantly lower in LL cases compared with healthy controls (median values for GH = 1.01 µIU/ml, range = 0.4625-86.82 and 2 µIU/ml, range = 0.5838-63.36, respectively (p = 0.022); median values for leptin = 891 pg/ml, range = 728.4-21816 and 5147 pg/ml, range = 730.4-52747, respectively (p < 0.0001)). There was an apparent reduction in the plasma levels of DHEA among LL cases compared with healthy controls (p = 0.297), although this difference was not statistically significant.

Alterations in levels of endocrine hormones seen in LL patients reflect clinical and immunological conditions during lepromatous leprosy. However, large-scale studies are warranted to determine how leprosy causes such alterations in hormones and the interplay between endocrine hormones and the immune system during leprosy disease.