Melatonin and Inflammatory Cytokines as Modulators of the Interaction Between Gestational Diabetes Mellitus and Pregnancy-Specific Urinary Incontinence

BACKGROUND: The pathogenesis of developing gestational diabetes mellitus (GDM) integrated with pregnancy-specific urinary incontinence (PSUI) may be related to immunological and hormonal factors. Inflammatory cytokines influence the function and regulation of the urinary tract, and changes in melatonin concentration are a predisposing factor for smooth muscle dysfunction and cystometric changes. OBJECTIVE: This study examines the influence of melatonin, MT1 and MT2 receptors, and inflammatory cytokines in the blood and urine of pregnant women with GDM and PSUI. METHODS: Two hundred sixty-nine pregnant women were approached during the diagnostic investigation of GDM and answered a specifically structured questionnaire about the involuntary loss of urine. According to these criteria, mothers were divided into four groups: continent normoglycemic (NG-C), incontinent normoglycemic (NG-I), continent GDM (GDM-C), and incontinent GDM (GDM-UI). Blood and urine samples were collected to determine the levels of melatonin, melatonin sulfate, melatonin receptors (MT1 and MT2), and inflammatory cytokines. RESULTS: Blood level of melatonin and IL-10 was lower, but MT1, MT2, IL-1β, IL-8, and TNF-α were higher in GDM-UI compared with the NG-C group. The melatonin sulfate level was lower in the urine of the GDM-UI group compared with the NG-C group. CONCLUSIONS: Maternal hyperglycemia associated with urinary incontinence generates an inflammatory environment characterized by reduced melatonin and IL-10 and increased IL-1β, IL-8, and TNF-α in the blood of mothers with GDM with UI. This environmental condition may be involved in the pathogenesis of these pathologies.