Hot Flashes, Sleep, Menopause, Cardiovascular Diseases, Epigenetics, DNA Methylation
Conditions
Keywords
DNA methylation, Hot Flashes, Sleep, Vasomotor symptoms, Menopause, Cardiovascular Diseases, epigenetics
Brief summary
Vasomotor symptoms are the most common symptoms seen during climacterium. The hypoestrogenic state causes dysfunction of hypothalamic preoptic area, a thermoregulatory center. The sympathetic overactivation during the hot flashes is associated with awakening during sleep and have a negative impact on cardiac indexes and vascular reactivity. Therefore, hot flashes are accepted as subclinical cardiovascular risk factor. The association between the severity of the hot flashes and cardiovascular risk may have an epigenetic background. Recently, methylation changes of DNA was found to be associated with clinical and subclinical cardiovascular disease risk (atherosclerosis and hypertension etc.). A transposable element in the DNA, Long interspersed nuclear elements (LINE-1), was found to be hypomethylated in cases with ischemic heart disease and stroke. Therefore, the expression of repeating elements in the DNA (LINE-1 and ALU) may be considered as a mediator in the ischemic heart disease. Until now, menopausal age, vasomotor symptoms and epigenetic and biological aging have been evaluated. However, the epigenetic impact of severe vasomotor symptoms in postmenopausal women with low cardiovascular disease risk profile has not been evaluated. In this study, we aimed to evaluate the epigenetic basis of cardiovascular disease risk for women with vasomotor symptoms which disturb sleep by assessing the methylation levels of ALU and LINE-1.
Detailed description
Vasomotor symptoms are the most common symptoms seen during climacterium. The hypoestrogenic state causes dysfunction of hypothalamic preoptic area, a thermoregulatory center. The variations in the range of thermoneutral zone determine the severity of the vasomotor symptoms. Sympathetic overactivation during the hot flash and decreased rate of parasympathetic control on the heart rate are the main factors contributing to the cardiovascular disease risk. The hot flashes which occur and cause awakening during sleep have negative impact on cardiac indexes and vascular reactivity. Therefore, vasomotor symptoms are accepted as subclinical cardiovascular risk factor. Hot flashes associated with nighttime awakenings were shown to increase systolic and diastolic blood pressure and decrease pre-ejection period. Objectively recorded hot flashes and nighttime awakenings were found to be correlated white matter hyperintensities in the brain which show poor brain health. In addition, white matter hyperintensities may be considered as a cerebral small vascular disease and is associated with greater odds of having stroke and dementia. Among postmenopausal women, cardiovascular disease is the most prevalent cause for mortality and morbidity. It results from the interaction of environmental and genetic factors. The association between the severity of hot flashes and cardiovascular risk may have an epigenetic background. The global DNA methylations were found to be decreased in postmenopausal women with high cardiovascular disease risk. Recently, methylation changes of DNA was found to be associated with clinical and subclinical cardiovascular disease risk (atherosclerosis and hypertension etc.). A transposable element in the DNA, Long interspersed nuclear elements (LINE-1), was found to be hypomethylated in cases with ischemic heart disease and stroke. Therefore, the expression of repeating elements in the DNA (LINE-1 and ALU) may be considered a mediator in the ischemic heart disease. Until now, menopausal age, vasomotor symptoms and epigenetic and biological aging have been evaluated. However, the epigenetic impact of severe vasomotor symptoms in postmenopausal women with low cardiovascular disease risk profile has not been evaluated. In this study, we aimed to evaluate the epigenetic basis of cardiovascular disease risk for women who have low cardiovascular disease risk profile at baseline and have vasomotor symptoms which disturb sleep by assessing the methylation levels of ALU and LINE-1.
Interventions
DIAGNOSTIC_TESTPolysomnography
Polysomnography is performed by 3-channel electroencephalography ((EEG; F4-M1, C4-M1, O2-M1), 2-channel electrooculography (EOG), chin electromyography (EMG), surface EMG recording from tibialis anterior muscles of the right and left leg, body position, oronasal thermal airflow sensor, nasal pressure sensor, thoracic and abdominal respiratory belts for assesing the respiratory effort, electrocardiography (ECG), pulse, recording of respiratory sounds, oxygen saturation and synchronous video recording. The sleep stages are scored by the current criteria of American Academy of Sleep Medicine.
DIAGNOSTIC_TESTSkin conductance
The sympathetic skin response recordings are performed with a four-channel electromyography apparatus (Nihon-Kohden). They are recorded from both sides of the sternum with the active and reference electrodes placed 2 cm apart from the midline.
GENETICALU and LINE-1 DNA methylation analysis
2 cc peripheric venous blood is drawn from the participants to the test tubes with EDTA. DNA isolation is done by Nucleospin Blood Kit (REF:740951.250, Macherey-Nagel). Epitect Fast DNA Bisulfite Kit (REF:59824, Qiagen) is used to do DNA bisulfite modification. ALU and LINE-1 site specific methylation primer is designed and the methylation patterns are compared between the groups by Epitect Methylight PCR Kit (Cat. No:59496, Qiagen).
DIAGNOSTIC_TESTThe Menopause-Specific Quality of Life Questionnaire (MENQOL)
The Menopause-Specific Quality of Life Questionnaire (MENQOL) is filled by each participant to assess the health related quality of life before the polysomnography test.
DIAGNOSTIC_TESTPittsburgh Sleep Quality Index (PSQI)
Pittsburgh Sleep Quality Index (PSQI) is done by each participant to assess the sleep quality and disturbances before thepolysomnography test.
Sponsors
Scientific Research Project Coordination Unit of Istanbul University-Cerrahpasa
Istanbul University - Cerrahpasa
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
FEMALE
Age
45 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
* 45-55 years of age * Women with serum FSH levels \>35 IU/L, serum estradiol levels \<20 pg/mL * Women with low cardiovascular disease risk profile (Framingham score for coronary heart disease \<10%), * Low high sensitive CRP levels (\<5 mg/L), * Fasting glucose \<90 mg/dL, * Fasting levels of insulin \<37.06 µIU/mL, * Blood pressure \<140/90 mmHg (measured 2 times with 10 minutes interval), * TSH \<4.2 mIU/L and fT4 \<1.7 ng/dL, * Hemoglobin levels 12-16 g/dL, leucocyte count \<10.3\*10\^3/µL and neutrophil count \<4.9\*10\^3/µL; eosinophil count \<0.5\*10\^3/µL, basophil count \<0.2\*10\^3/µL
Exclusion criteria
* Women with high cardiovascular disease risk profile (Framingham score for coronary heart disease \>10%), * Women who were diagnosed with a cardiovascular disease (coronary heart disease, stroke), * Women with hypertension, * Smokers, * BMI \>30 kg/m2, * Women with diabetes * Women who were surgically postmenopausal, * Women who used hormone therapy in the last three months, * Women with obstructive sleep apnea * Women who are using medicine which may cause sleep disturbances.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Methylation levels of ALU and LINE-1 | 1 day | Methylation levels of ALU and LINE-1 in women with vasomotor symptoms |
| Polysomnographic findings | 1 night | Total sleep time in women with vasomotor symptoms |
| Number of objective hot flashes per night | 1 night | Number of objective hot flashes per night measured by sternal skin conductance in women with vasomotor symptoms |
| Number of nighttime awakenings per night | 1 night | Number of nighttime awakenings per night associated with hot flash episodes |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Subjective sleep findings (Pittsburgh Sleep Quality Index (PSQI)) | 1 night | Scores of PSQI questionnaire in women with vasomotor symptoms (\>5 can be considered as a significant sleep disturbance.) |
| Menopause-Specific Quality of Life Questionnaire (MENQOL) scores and its association with hot flashes per night | 1 day | Scores of MENQOL and its association with hot flashes per night (There is no limit, higher scores on the MENQOL indicate a poorer quality of life.) |
Countries
Turkey (Türkiye)
Outcome results
None listed