Time of day makes a difference in thyroid testing

Time of day makes a difference in thyroid testing
Jacob Schor ND August 14, 2012
 www.DenverNaturopathic.com


The level of the hormone, TSH that is often used to evaluate thyroid function, varies with the time of day the samples are collected.  Collecting afternoon samples can lead to under diagnosis of hypothyroidism.

Doctors test thyroid stimulating hormone, also known as TSH, to screen for and diagnose hypothyroidism, a condition of inadequate thyroid hormone.  TSH is made in the brain and as its name implies, stimulates the thyroid gland to produce more thyroid hormone.  Thus if TSH levels increase, it the brain is telling the body to make more thyroid hormone. When TSH levels stay high it suggests that the body cannot make enough thyroid hormone.  Most laboratories define  ‘normal’ TSH as between 0.5 and 5.0 uM/L.  TSH levels above 5.0 are considered hypothyroidism and those below 0.5, hyperthyroidism.

A new study published in the August 2012 issue of Endocrine Research reveals that our current approach to diagnosing hypothyroidism has been too simplistic and needs change.  Production of TSH follows a circadian rhythm that is it follows a 24-hour cycle with regular fluctuations.  TSH production peaks at its highest level between 2:00 and 4:00 am each morning and then drops reaching its low point between 4 and 8 pm in the evening.  Though this phenomenon is well known the actual extent of these fluctuations was much greater than was previously thought.

In this current study, researchers from the Federal Endocrinological Research Centre in Moscow, tested 20 women with subclinical hypothyroidism.  Morning and afternoon TSH levels were measured and compared.    The median morning TSH value for women with subclinical hypothyroidism was 5.83 mU/L.  Their afternoon median TSH dropped down to 3.79 mU/L.  Following the current guidelines for diagnosis hypothyroidism would have been diagnosed in only half of these cases when tested in the afternoon. 

These new data explain why many people who appear to have symptoms of hypothyroidism have been told their test results were normal, that they are fine, when in truth they hypothyroid.  TSH levels measured in blood samples drawn in the afternoon should be viewed with caution, as they may be falsely low and appear normal.  Samples for all thyroid tests should be collected first thing in the morning. 

It gets more complicated than this.  Many practitioners consider the current normal range for TSH values to be too broad.  Rather than judging TSH levels above 5 as hypothryoidism, some consider the upper limit of normal to be as low as 3.0, while researchers looking at what is called sub-clinical hypothyroidism define the condition by a TSH greater than 2.5.  Apparently that is the level at which risk for cardiovascular disease increases significantly.

Combining these two bits of news, the circadian variability of TSH and the benefits of treating even slight increases in TSH, leads me to think that we should be relooking at a fair number of patients who have previously been told that their thyroids were fine.  They might not be…..


Reference:

Sviridonova MA, Fadeyev VV, Sych YP, Melnichenko GA. Clinical Significance of TSH Circadian Variability in Patients with Hypothyroidism. Endocr Res. 2012 Aug 2.

Duntas LH, Biondi B. New insights into subclinical hypothyroidism and cardiovascular risk. Semin Thromb Hemost. 2011 Feb;37(1):27-34. Epub 2011 Jan 19.

Emerald City Clinic supports these wonderful classes offered by friend and colleague, Crystal Steltzer.

Greetings Community,

I’m pleased to announce my up-coming community class schedule for this fall.  I will be presenting three classes, which will be hosted at Dandelion Botanical in Ballard.  Below is a brief description of the class. 
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Saturday, September, 29^th from 12-2pm

Supporting the Immune System: herbs to help strengthen the immune system for cold and flu prevention

Before we know it the cold and flu season will be upon us.  Prevention is the key, and herbal support is paramount in maintaining a healthy and strong immune system throughout the fall and winter months.  In this workshop we will discuss --in simple concepts -- how the immune system functions, and then explore which herbs are best at strengthening the different functions of the immune system, and then we will end by delving into specific herbs to help support you in relieving the symptoms of catching a cold/flu.  Handouts will be provided, including herbal recipes, and samples will be passed around for tasting yummy herbal remedies.

Cost is $30, which will include handouts.

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Saturday, Oct. 3^rd-Nov. 3^rd from 12-2pm

Simple Home Remedies:  How to Make Your Own Herbal Medicine

Wk1: Intro to Herbal Medicine Making: Syrups, Elixirs, and Cordials   

Sat, Oct. 6th, 12-2pm, $25

Wk2: Honey, Vinegar, Oxymiel, and Wine Infusions                              

Sat, Oct. 13th, 12-2pm, $25

Wk3: Herbal Infused Oils (fresh/dry), Salves, Lip Balms, and Vapor-Rubs 

Sat, Oct. 20th, 12-2pm, $25

Wk4: Creams, Lotions, Essential Oil Emulsions and Spritzers         

 Sat, Oct. 27th, 12-2pm, $25

Wk5: Glycerites, Tinctures (fresh and dry), and Spirits                   

Sat, Nov. 3rd, 12-2pm, $25

Sign up for one class, or take the series of five for only $110!

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Saturday, Nov. 3^rd from 4-6pm

Simple Home Remedies:  How to Make Your Own Herbal Spa Products

We go to the spa to feel pampered and beautiful.  Making your own spa products is easy and rewarding.  Bring the spa into your home -- come learn how to make your very own herbally inspired spa products!  During this two hour workshop you will learn how to create herbal facial scrubs, toners, masques, and steam blends; as well as body scrubs, and foot soaks.  We will discuss herbal blends for any skin type, and explore the healing and rejuvenating qualities of the various products discussed.  Handouts will include instructions on how to make a range of products, as well as a discussion on the therapeutic properties of the herbs chosen.  In this workshop, each class participant will be able to make 3 products to take home with them!!!

Cost is $50, which will include handouts and supplies for making your own spa products. 

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For All Classes:

Registration is limited.  Payment is due in full at time of registration and is non-refundable.  Classes with fewer than five attendees are subject to cancellation.

To Register: Contact Dandelion Botanical at www.dandelionbotanical.com; 206-545-8892

I hope to see you there :-)

Green Blessings,

Crystal

May your herbal medicine support you in health and well being!

Do you know any families looking for low-cost ways to improve their health?

Tell them about APPLE Core!

APPLE Core Workshop

(Applied Pediatric and Parental Lifestyle Education)

An innovative healthy lifestyle program for families with kids 8-12!

Saturday, August 11, 2012

9 a.m. – 2 p.m.

Bastyr University, 14500 Juanita Drive NE, Kenmore, WA

Cost: $15 per family

Hosted by the Bastyr’s Department of Nutrition and Exercise Science, the one-day program includes:

Whole-food nutrition education for the entire family, with acclaimed chef Maxime Bilet

Behavioral counseling for the child and family

Fun, family-oriented physical activity

A family cooking class

Each family will receive lunch, t-shirts and a QFC gift card for purchasing healthy groceries!

To be eligible, children should be between the ages of 8 and 12, and parents must complete a registration and health history questionnaire form.

Play Together · Cook Together · Laugh Together

Sign up here!

Here is a link to video from last year’s event!