Leptin Plasma Concentrations Increase During Antidepressant Treatment With Amitriptyline and Mirtazapine, But Not Paroxetine and Venlafaxine: Leptin Resistance Mediated by Antihistaminergic Activity?
ABSTRACT Treatment with several psychopharmacological agents has been associated with increased leptin plasma concentrations. We measured leptin plasma concentrations in 76 adult depressed patients after a 6-day washout phase and again after 35 days of treatment with amitriptyline or paroxetine, as well as in 73 depressed patients after 28 days of treatment with either mirtazapine or venlafaxine. Leptin plasma concentrations increased during treatment with amitriptyline and mirtazapine, even after controlling for increased body mass index and irrespective of response to treatment [14.5 (13.8) vs 20.3 (18.7) ng/mL, and 12.2 (15.8) vs 14.4 (16.5) ng/mL in the 2 cohorts, respectively]. In contrast, paroxetine and venlafaxine treatment was not associated with changes in leptin plasma concentrations [14.8 (12.0) vs 13.6 (10.6); 15.9 (17.3) vs 13.5 (14.6) ng/mL] nor with weight gain. We conclude that treatment with amitriptyline or mirtazapine is associated with an increase in leptin secretion beyond change in weight. Thus, high leptin levels apparently are ineffective in the control of weight gain, indicating leptin resistance. Leptin resistance may be mediated by an antihistaminergic effect on hypothalamic nuclei integrating signals relevant for energy balance.
SourceAvailable from: Rodrigo Machado-Vieira[Show abstract] [Hide abstract]
ABSTRACT: Adiponectin, leptin and resistin may play a role in the pathophysiology of major depressive disorder (MDD). However, differences in peripheral levels of these hormones are inconsistent across diagnostic and intervention studies. Therefore, we performed meta-analyses of diagnostic studies (i.e., MDD subjects versus healthy controls) and intervention investigations (i.e., pre-vs. post-antidepressant treatment) in MDD. Adiponectin (N = 1278; Hedge's g = -0.35; P = 0.16) and leptin (N = 893; Hedge's g = -0.018; P = 0.93) did not differ across diagnostic studies. Meta-regression analyses revealed that gender and depression severity explained the heterogeneity observed in adiponectin diagnostic studies, while BMI and the difference in BMI between MDD individuals and controls explained the heterogeneity of leptin diagnostic studies. Subgroup analyses revealed that adiponectin peripheral levels were significantly lower in MDD participants compared to controls when assayed with RIA, but not ELISA. Leptin levels were significantly higher in individuals with mild/moderate depression versus controls. Resistin serum levels were lower in MDD individuals compared to healthy controls (N = 298; Hedge's g = -0.25; P = 0.03). Leptin serum levels did not change after antidepressant treatment. However, heterogeneity was significant and sample size was low (N = 108); consequently meta-regression analysis could not be performed. Intervention meta-analyses could not be performed for adiponectin and resistin (i.e., few studies met inclusion criteria). In conclusion, this systematic review and meta-analysis underscored that relevant moderators/confounders (e.g., BMI, depression severity and type of assay) should be controlled for when considering the role of leptin and adiponectin as putative MDD diagnostic biomarkers.Journal of Psychiatric Research 08/2014; 59. DOI:10.1016/j.jpsychires.2014.08.002 · 4.09 Impact Factor
Article: Mood, food, and obesity[Show abstract] [Hide abstract]
ABSTRACT: Food is a potent natural reward and food intake is a complex process. Reward and gratification associated with food consumption leads to dopamine (DA) production, which in turn activates reward and pleasure centers in the brain. An individual will repeatedly eat a particular food to experience this positive feeling of gratification. This type of repetitive behavior of food intake leads to the activation of brain reward pathways that eventually overrides other signals of satiety and hunger. Thus, a gratification habit through a favorable food leads to overeating and morbid obesity. Overeating and obesity stems from many biological factors engaging both central and peripheral systems in a bi-directional manner involving mood and emotions. Emotional eating and altered mood can also lead to altered food choice and intake leading to overeating and obesity. Research findings from human and animal studies support a two-way link between three concepts, mood, food, and obesity. The focus of this article is to provide an overview of complex nature of food intake where various biological factors link mood, food intake, and brain signaling that engages both peripheral and central nervous system signaling pathways in a bi-directional manner in obesity.Frontiers in Psychology 09/2014; 5:925. DOI:10.3389/fpsyg.2014.00925 · 2.80 Impact Factor
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ABSTRACT: Stress is defined as a state that can threaten homeostasis in an organism to initiate the adaptive process. Stress mediators, which include the classic neuroendocrine hormones and a number of neurotransmitters, cytokines, and growth factors, regulate both basal and threatened homeostasis to help control the stress. Severity of stress, as well as malfunctioning of stress pathways, may impair its controllability, leading to the pathogenesis of psychiatric illnesses including depression. Leptin was initially identified as an antiobesity hormone, acting as a negative feedback adiposity signal to control energy homeostasis by binding to its receptors in the hypothalamus. Accumulating evidence has expanded the function of leptin from the control of energy balance to the regulation of other physiological and psychological processes. The aim of this paper is to evaluate the potential role of leptin in stress controllability. To this end, studies on the role of leptin in stress-induced activation of the hypothalamus-pituitary-adrenocortical axis, feeding behavior, learned helplessness, and other depression models have been accumulated. The knowledge accumulated in this article may facilitate the development of alternative treatment strategies, beyond serotonin and noradrenaline reuptake inhibition, for psychiatric care and stress-related disorders.Behavioural Pharmacology 07/2014; 25(5-6). DOI:10.1097/FBP.0000000000000050 · 2.19 Impact Factor