Flashpoint: Regulating Your Body s Temperature Presented by: Shari M. Lawson, MD MBA Date Presented: November 1, 2014 1
Disclosures None 2
Objectives Today s discussion will cover How body temperature is regulated What causes flushing How to prevent or manage menopausal hot flashes Other conditions that may cause heat or cold intolerance 3
What are hot flushes/hot flashes? Recurrent episodes of flushing and perspiration Sensation of warmth intense heat in the face and chest Frequently associated with sweating 4
Hot flashes and night sweats Hot flushes with perspiration that occur at night are night sweats Can cause sleep disturbances and contribute to mood swings and irritability http://www.natural-homeremedies.com 5
How does the body regulate temperature? Body temperature Regulated in the anterior hypothalamus via actions of norepinephrine Lowest at dawn Highest between 4-6 pm Heat Generated by muscle and liver Lost through perspiration and respiration 6
How does the body change temperature? With increased set point Vasoconstriction diminishes heat loss Shivering generates heat When body temperature is higher than the set point Vasodilation increases heat loss Sweating leads to rapid cooling 7
Vasoconstriction and vasodilation https://pmgbiology.wordpress.com 8
Mechanisms of flushing Nervous system mediated Circulating vasoactive substances mediated http://ginews.blogspot.com http://buzzle.com 9
Flushing mediated by nervous system Thermoregulatory Fever, exercise, hyperthermia, hot food Menopausal Emotional Blushing, anxiety Neurologic Parkinson s, spinal cord injury, other neurologic conditions 10
Flushing mediated by circulating substances Rosacea Inflammatory/vasoactive proteins Food/drink Capsaicin, nitrates, MSG Medications Calcium cannel blockers, nicotinic acid Cancer syndromes Hyperthyroidism 11
What are menopausal hot flashes? 50-80% of over 45 women experience menopausal hot flashes Hot flashes can last up to five minutes Associated with sweating (diaphoresis) Followed by rapid cooling and shivering http://boywoman.wordpress.com 12
What are risk factors for hot flashes? African American > Caucasian > Asian Obesity Smoking Sedentary lifestyle Surgical removal of ovaries 13
What causes hot flashes? Prior to menopause, core body temperature can increase by up to 0.75 before vasodilation occurs and perspiration increases After menopause, an even smaller increase in temperature triggers a more exaggerated response 14
Premenopausal thermoregulation Vasoconstriction Shivering Thermoneutral Zone Vasodilation Sweating 15
Postmenopausal thermoregulation Vasoconstriction Shivering Vasodilation Sweating Thermoneutral Zone 16
How can I prevent hot flashes? Dress in layers Set thermostat lower at home Exercise regularly Achieve/maintain normal body weight Avoid triggers such as hot or spicy food/drink http://longevity.about.com 17
What are my options if I am still experiencing hot flashes? http://thehealthsite.com 18
Management of hot flashes Estrogen replacement therapy Selective serotonin receptor inhibitors - SSRIs (antidepressants) Gabapentin Clonidine http://1000words1000days.com 19
Management of hot flashes Systemic estrogen replacement Oral Transdermal patch Topical lotion or gel Vaginal ring Progesterone required if uterus is intact Oral Intrauterine 20
Hormone replacement therapy Systemic estrogens Conjugated equine estrogens Plant derived estrogens (soy, yam) Systemic and local progestins Synthetic derivatives Plant derived (soy, yam) http://www.rawforestfoodsblog.com 21
Bioidentical hormone replacement Practice of developing individualized treatments based on testing, symptoms Hormones prescribed are bioidentical to ones in the body More expensive, variable results No evidence supporting greater safety or efficacy of compounded hormones over conventional ones 22
Selective serotonin reuptake inhibitors (SSRIs) Often used a first line agent in women not using estrogen Works by increasing circulating levels of serotonin Can reduce effectiveness of tamoxifen in women being treated for breast cancer 23
Gabapentin Originally developed as an anti-seizure medication; found to be effective against neuropathic pain and hot flashes Can cause drowsiness and is useful for hot flashes that wake people from sleep Mechanism of action is unknown 24
Clonidine Clonidine Can be given orally or transdermally Alpha 2 agonist decreases circulating levels of norepinephrine Side effects such as dry mouth, constipation, and sedation are often not well tolerated Not a first line agent 25
What about menopausal supplements/herbal remedies? Anecdotally, patients report relief with these supplements Safety and efficacy are not proven Commonly used supplements include Black cohosh Red clover Evening primrose oil Vitamin E 26
Phytoestrogens Categorized as isoflavones, lignans, and coumestans Are naturally occurring in plants Soybeans, chick peas, lentils, flaxseed Have estrogenic and antiestrogenic properties No demonstrated benefit in clinical trials 27
Black cohosh and phytoestrogens Black cohosh and phytoestrogens Can have potent estrogenic effects on the breast and inhibit effect of tamoxifen Avoid if personal history of breast cancer or at high risk http://michellgroup.com 28
Other causes of heat intolerance Thyroid disease Master gland controls metabolism Hyperthyroidism can have many symptoms Heat intolerance Tremor Weight loss, often with increased appetite Heart palpitations Sweating 29
Why do I feel cold all the time? Hypothyroidism Anemia Underweight Raynaud s phenomenon 30
Cold intolerance Hypothyroidism Fatigue Cold intolerance Weight gain Constipation Menstrual irregularities Goiter 31
Cold intolerance Anemia Decreased production or increased loss of red blood cells Patients may experience fatigue and cold hands and feet Underweight Insufficient muscle and fat to generate and maintain heat/body temperature 32
Cold intolerance Raynaud s phenomenon Vasoconstriction helps maintain core temperature RP is exaggerated response to cold temperature, stress Can be primary or associated with autoimmune disorders http://www.noll.psu.edu 33
When should I see the doctor? Moderate to severe menopausal symptoms Enlarged thyroid or neck mass Unexplained weight loss/weight gain Heat intolerance Cold intolerance Recurrent episodes of Raynaud s phenomenon 34
Take Home Messages Body temperature is maintained through a balance of heat generation and loss Hot flashes are an exaggerated physical response to increase in body temperature 35
Take Home Messages There are many options for preventing and managing hot flashes Patients with an intact uterus who use estrogen should also use progesterone Patients with history of breast cancer should avoid phytoestrogens and black cohosh 36
Take Home Messages Thyroid disorders can present with heat or cold intolerance Heat and cold intolerance can be a sign of other systemic disorders 37