CLARISSA BUENO
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/63, Hospital das Clínicas, Faculdade de Medicina
LIM/63, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
Agora exibindo 1 - 2 de 2
- Melatonin Therapy Improves Cardiac Autonomic Modulation in Pinealectomized Patients(2020) CAMPOS, Luciana Aparecida; BUENO, Clarissa; BARCELOS, Isabella P.; HALPERN, Bruno; BRITO, Leandro C.; AMARAL, Fernanda G.; BALTATU, Ovidiu Constantin; CIPOLLA-NETO, JoseThe purpose of this investigational study was to assess the effects of melatonin replacement therapy on cardiac autonomic modulation in pinealectomized patients. This was an open-label, single-arm, single-center, proof-of-concept study consisting of a screening period, a 3-month treatment period with melatonin (3 mg/day), and a 6-month washout period. The cardiac autonomic function was determined through heart rate variability (HRV) measures during polysomnography. Pinealectomized patients (n = 5) with confirmed absence of melatonin were included in this study. Melatonin treatment increased vagal-dominated HRV indices including root mean square of the successive R-R interval differences (RMSSD) (39.7 ms, 95% CI 2.0-77.4, p = 0.04), percentage of successive R-R intervals that differ by more than 50 ms (pNN50) (17.1%, 95% CI 9.1-25.1, p = 0.003), absolute power of the high-frequency band (HF power) (1,390 ms(2), 95% CI 511.9-2,267, p = 0.01), and sympathetic HRV indices like standard deviation of normal R-R wave interval (SDNN) (57.6 ms, 95% CI 15.2-100.0, p = 0.02), and absolute power of the low-frequency band (LF power) (4,592 ms(2), 95% CI 895.6-8,288, p = 0.03). These HRV indices returned to pretreatment values when melatonin treatment was discontinued. The HRV entropy-based regularity parameters were not altered in this study, suggesting that there were no significant alterations of the REM-NREM ratios between the time stages of the study. These data show that 3 months of melatonin treatment may induce an improvement in cardiac autonomic modulation in melatonin-non-proficient patients. ClinicalTrials.gov Identifier: NCT03885258.
- Melatonin Increases Brown Adipose Tissue Volume and Activity in Patients With Melatonin Deficiency: A Proof-of-Concept Study(2019) HALPERN, Bruno; MANCINI, Marcio C.; BUENO, Clarissa; BARCELOS, Isabella P.; MELO, Maria Edna de; LIMA, Marcos S.; CARNEIRO, Camila G.; SAPIENZA, Marcelo T.; BUCHPIGUEL, Carlos Alberto; AMARAL, Fernanda Gaspar do; CIPOLLA-NETO, JoseMelatonin, a pineal hormone synthesized at night, is critical for the synchronization of circadian and seasonal rhythms, being a key regulator of energy metabolism in many animal species. Although studies in humans are lacking, several reports, mainly on hibernating animals, demonstrated that melatonin supplementation and a short photoperiod increase brown adipose tissue (BAT) mass. The present proof-of-concept study is the first, to our knowledge, to evaluate BAT in patients with melatonin deficiency (radiotherapy or surgical removal of pineal gland) before and after daily melatonin (3 mg) replacement for 3 months. All four studied patients presented increased BAT volume and activity measured by positron emission tomography-MRI. We also found an improvement in total cholesterol and triglyceride blood levels without significant effects on body weight, liver fat, and HDL and LDL levels. Albeit not statistically significant, fasting insulin levels and HOMA of insulin resistance decreased in all four patients. The present results show that oral melatonin replacement increases BAT volume and activity and improves blood lipid levels in patients with melatonin deficiency, suggesting that melatonin is a possible BAT activator. Future studies are warranted because hypomelatoninemia is usually present in aging and appears as a result of light-at-night exposure and/or the use of beta-blocker drugs.