Decreased nocturnal melatonin levels during acute myocardial infarction

Abstract

Acute myocardial infarction is accompanied by an increase in cellular oxidative stress in the pericardial coverings of the heart. Melatonin is a highly potent and efficient radical scavenger. Little research has been carried out concerning the relationship between this antioxidant and acute myocardial infarction in humans. In this work, serum levels of melatonin and parameters of oxidative stress, such as glutathione peroxidase and lipid peroxidation levels were examined in light/dark periods in patients with acute myocardial infarction. Twenty-five patients diagnosed with acute myocardial infarction were studied and 25 patients with no evidence of coronary artery disease served as controls. Venous blood samples were obtained from the patients and control subjects to determine melatonin, glutathione peroxidase and lipid peroxidation; the samples were collected at 10:00 hr (light period) and 03:00 hr (dark period) in the first 24 hr after admission to the coronary care unit. Our results demonstrate the existence of differences between changes in melatonin levels in control subjects and acute myocardial infarction patients, revealing a reduced nocturnal elevation in the acute myocardial infarction group. Glutathione peroxidase levels were lower after acute myocardial infarction and did not show diurnal variations. In the control group, lipid peroxidation levels presented a light/dark pattern but in the acute myocardial infarction group diurnal variations of this parameter were lost. Our data show that acute myocardial infarction is associated with a nocturnal serum melatonin deficit as well as increased oxidative stress, suggesting that melatonin is, at least in part, depleted during the dark phase to reduce the free radicals formed in acute myocardial infarction.

Melatonin secretion is impaired in women with preeclampsia and an abnormal circadian blood pressure rhythm

“…26,49 Furthermore, previous studies have showed a decreased nocturnal serum melatonin in coronary heart disease and during acute myocardial infarction. 50,51 This approach raises new questions regarding the mechanism of endothelial dysfunction in preeclampsia and suggests that melatonin might be somehow involved.…”

Levels of Interleukins and Melatonin in Patients With Acute Coronary Syndrome

“…По данным литературы продукция МТ снижена у пожилых [6,9]; у больных с артери-альной гипертензией (М. Jonas, 2003) [4,9,14]; ИБС, в большей степени у больных стенокар-дией покоя (Р. Brugger, 1995) [4,7,9], ИМ [15]; с декомпенсацией хронической сердечной не-достаточности (ХСН) (L. Girotti, 2003) и др. [9].…”

“…3), что не совсем согласуется с данными, полученными ранее в ра-ботах L. Girotti и соавт., А. Dominguez-Rodriguez и соавт. [15], Н.К. Малиновской и соавт.…”

Chronic Supplementation of Melatonin restores Impaired Circadian Rhythm in Patients with Coronary Artery Disease

“…In humans, melatonin production not only diminishes with age, but also lowers in many age-related diseases, including cardiovascular disease. 16,17 Coronary artery disease patients show a markedly decreased nighttime melatonin synthesis, 17 which may be assumed reason for absence of nocturnal dip in BP and high chances of myocardial infarction. 5 In addition, light/dark variations in the production of endogenous inflammatory markers in patients with CAD to some extent may be related to day/night fluctuations in circulating melatonin levels.…”

“…20 However, the mechanisms underlying this abnormal nighttime BP dipping pattern are not fully understood. 16 There is some evidence suggesting that a nondipping BP pattern may be related to advanced age, 21 sodium sensitivity, 22 postmenopausal status, 20 sleep apnea, and poor sleep quality. 21 Some studies state that melatonin supplementation at certain times during the night may function to increase endogenous melatonin level, potentially protecting against the melatonin downregulation associated with cardiovascular diseases.…”