can low TSH be just a temporary fluctuation?
in [Thyroid]
|
Prev: What point am I missing?
Next: Armour + ?
From: diana_uretski on 9 Dec 2005 00:54 I just had a blood test that showed very supressed TSH, with the thyroid hormones being normal: TSH <0.06 [0.49-4.67] Free T4 1.51 [0.70-1.80] T3 138 [79-149] And I have symptoms of HYPOthyroid, in spite of these labs. Feeling cold, constipation, dry skin, etc. I don't know what's going on. My doctor is sending me to have some thyroid nuclear scan done, which I understand is not a pleasant procedure. Seeing how my throid hormones levels are normal, is it possible that the drop in TSH is just temporary and not clinically significant? It was 1.6 only a few months ago and now it's 0.06... I've been drinking this herbal tea that's supposed to regulate women's hormones, could it affect the TSH? :) Thanks!
From: dj on 9 Dec 2005 06:44 Diana, If the tea has certain herbs in it, it could affect your TSH level. After having a TSH hovering around 5.0 for years....mine dropped to <0.01 in July (and like you my thyroid hormone levels were normal) and the first thing my endo asked me was if I had been taking anything "herbal" and specifically asked about soy and kelp. I hadn't, but it struck me as soon as I read your posting. At the time I didn't feel particularly hyper. Unfortunately I do now...but that's a whole 'nother thread. ;O) And the nuclear scan is not big deal. They will take a baseline reading from a random body part (involves a camera of sorts and a computer), you will swallow some pills, and a few hours later they will take some pictures of your neck and then another reading the next day. The worst of it is that you will have lie still cause each pic can take about 5 minutes or so. Yes, the pills are radioactive...but no more than a typical xray. They will make a big deal about giving them to you from lead container and tell you take them straight from the container and not to drop them into your hand first. It makes some people think they are really "hot". But that's not it. If they touch your hand then some of the radioactivity will be transferred to your skin and interfere with the readings they will take later. But no needles. No pain. Just time consuming. I didn't even have to change into one of those humbling hospital gowns. Good Luck! Diane diana_uretski(a)sbcglobal.net wrote: > I just had a blood test that showed very supressed TSH, with the > thyroid hormones being normal: > > TSH <0.06 [0.49-4.67] > Free T4 1.51 [0.70-1.80] > T3 138 [79-149] > > > And I have symptoms of HYPOthyroid, in spite of these labs. Feeling > cold, constipation, dry skin, etc. I don't know what's going on. My > doctor is sending me to have some thyroid nuclear scan done, which I > understand is not a pleasant procedure. > > Seeing how my throid hormones levels are normal, is it possible that > the drop in TSH is just temporary and not clinically significant? > It was 1.6 only a few months ago and now it's 0.06... > I've been drinking this herbal tea that's supposed to regulate women's > hormones, could it affect the TSH? :) > > Thanks!
From: skipperbeers on 9 Dec 2005 11:57 >Seeing how my throid hormones levels are normal, is it >possible that >the drop in TSH is just temporary and not clinically >significant? Of course it can be transitory. One TSH level means very little. http://www.drlowe.com/frf/guttler/addenda.htm "In general, the endocrinology specialty shares Dr. Guttler's dogmatic belief in the infallibility of thyroid function tests. Because of this, I'm fond of collecting published studies in which researchers have documented significant, normal variations in the blood levels of TSH, T4, and T3. In my forthcoming book, Tyranny of the TSH, I include the most representative of these studies. Here, however, I'll mention only a few to illustrate, contrary to Dr. Guttler's pronouncements, what science really shows. In 1997, researchers reported that when they measured patients' TSH levels week-to-week, the levels did not significantly correlate. The correlation is reported as an "r" value. 1.00 is a perfect correlation, and 0.00 is no correlation whatever. The r value for week-to-week TSH levels was a mere 0.17-just a teensy bit (17%) above no correlation at all. The r value was not statistically significant. This means that the very weak positive correlation week-to-week could have been due merely to chance similarities in the TSH levels, and there may actually have been no correlation at all.[38] Another way of looking at this is that patients' TSH levels significantly differed week-to-week. A Japanese researcher studied variations in TSH levels in normal and depressed men and women. He reported, "A large intra-individual variation [variations in the same person] of serum TSH levels determined on different days was found equally in both men and women." He also reported, "The present study demonstrated a large variation of TSH levels in various conditions, even in the same individuals . . . .."[42] Still other researchers, Weete and colleagues, reported significant variations in the levels of the free T4 and TSH in normal men-levels Dr. Guttler assumes to be impeccably consistent. Variations in the levels of the hormones, however, are of great enough magnitude to lead to misdiagnoses of patients' thyroid status. The researchers reported that from day to night, men's TSH levels increased an average of 140%. Their free T4 levels increased by 7%. The researchers also took blood samples every five minutes in a six-to-seven hour period starting between 7 pm and 10 pm. On average, the free T4 level varied by 11%, the free T3 by 15%, and the TSH by 13%. The researchers reported that "a significant regular variation" in the levels of the hormones occurred every 30 minutes.[39] Aside from natural variations in TSH levels, the levels may vary according to other factors, such as lost sleep or absorption of thyroid hormone into the blood. When normal women were partially deprived of sleep, their TSH concentrations increased significantly. The levels remained high through the following day.[40] Sleep deprivation is so common nowadays that it's likely that many patients' TSH levels are tested the day following a night of insufficient sleep. This study suggests that their TSH levels may be higher than they would be following a night of enough sleep. This variation in TSH levels could easily lead doctors to misdiagnoses[25] if they aren't cognizant of the effect of too little sleep and inquire about it when they test a patient's TSH level. After a patient takes a dose of T4, her free T4 level remains elevated for some 9 hours. In patients taking T4-replacement, the T4 level was increased an average of 13%. The TSH level in these patients was decreased by 19%.[41] Obviously, if a patient's blood is drawn during this 9-hour time, the decision her doctor makes about a dosage adjustment may be quite different from the one he would make if her blood is drawn after the 9-hour period. Based on this finding, the following scenario is highly likely to occur in the clinic of an endocrinologist. Like a quasi-accountant, this endocrinologist bases his decisions strictly by the numbers-by the patient's lab test levels.[25]" Also, the scan may be a waste of time, since it's unlikely you are hyperthyroid - http://www.emedicine.com/MED/topic1145.htm "Radioactive iodine uptake (RAIU) and thyroid scanning are not useful in hypothyroidism because these tests require some level of endogenous function in the hypofunctioning gland to provide information. Patients with Hashimoto thyroiditis may have relatively high early uptake (after 4 h) but do not have the usual doubling of uptake at 24 hours suggestive of an organification defect." The question is what's he looking for that can justify exposure to radiation? Granted, it may be low levels but there should be a valid reason to get it done. If not, it's not worth the risk. Maybe he's not talking about the kind of scan I have in quotes. When I was choking awake at night and had food getting stuck in my throat, I had a thyroid ultrasound. They diagnosed it as "small to normal" but when I increased thyroid meds, those problems went away. I was hoping it was swollen and enlarged and was causing the problems, but regardless of whether it was or not, increasing dosage fixed the problem. TSH is not a very good indication of overtreatment, these are - http://www.emedicine.com/MED/topic1145.htm "Patients should be monitored for symptoms and signs of overtreatment, which include tachycardia, palpitations, nervousness, tiredness, headache, increased excitability, sleeplessness, tremors, and possible angina." ******************************** This is one of the best short articles I've read by an endocrinologist, but this portion of the article is not on line any more - * Risks of excess thyroid hormone o Low serum thyrotropin (TSH) concentrations may be transient and innocent. Studies of euthyroid and subclinical hyperthyroid patients with low TSH levels demonstrate that many had normal TSH levels upon retesting 2-3 weeks later. o The risk for a patient with a low TSH and normal T4 and T3 levels is the risk of subclinical hyperthyroidism. Some subclinical hyperthyroidism disappears and some slowly progresses. o The only defined risk associated with subclinical hyperthyroidism is a higher prevalence of atrial fibrillation (or other tachyarrhythmias) and a higher prevalence of thrombotic events. o Previously, osteoporosis was thought to be a risk; however, more recent studies have not consistently confirmed this hypothesis. o The risks associated with a slightly low level of TSH in otherwise healthy patients are low, and changing their thyroid dose is often not necessary. Because TSH levels vary on a daily basis, changing doses frequently may complicate and raise the cost of therapy. Compliance with daily dosing is a major reason for TSH changes in individual patients (which a careful history reveals) and thus militates against prescribing a new dose of medication. ******************************************* That's from Author: Philip R Orlander, MD , Director of Endocrinology and Metabolism Fellowship, Director, Professor, Department of Medicine, Division of Endocrinology, University of Texas Health Science Center at Houston Coauthor(s): Walter R Woodhouse, MD, MSA , Program Director of Transitional Year Program, St Vincent Mercy Medical Center; Associate Professor, Department of Family Practice, Medical College of Ohio A current and somewhat similar article can be found at http://www.emedicine.com/MED/topic1145.htm Skipper
From: Scott Seidman on 9 Dec 2005 12:03 skipperbeers(a)sbcglobal.net wrote in news:1134147445.348335.198220 @z14g2000cwz.googlegroups.com: > In 1997, researchers reported that when they measured patients' TSH > levels week-to-week, the levels did not significantly correlate. The > correlation is reported as an "r" value. 1.00 is a perfect correlation, > and 0.00 is no correlation whatever. The r value for week-to-week TSH > levels was a mere 0.17-just a teensy bit (17%) above no correlation > at all. The r value was not statistically significant. This means that > the very weak positive correlation week-to-week could have been due > merely to chance similarities in the TSH levels, and there may actually > have been no correlation at all.[38] Another way of looking at this is > that patients' TSH levels significantly differed week-to-week. Sounds like something is left out. You can't compute correlation of something-- you correlate between two somethings. -- Scott Reverse name to reply
From: Barbara Needham on 9 Dec 2005 12:38
Scott Seidman <namdiesttocs(a)mindspring.com> wrote: > skipperbeers(a)sbcglobal.net wrote in news:1134147445.348335.198220 > @z14g2000cwz.googlegroups.com: > > > In 1997, researchers reported that when they measured patients' TSH > > levels week-to-week, the levels did not significantly correlate. The > > correlation is reported as an "r" value. 1.00 is a perfect correlation, > > and 0.00 is no correlation whatever. The r value for week-to-week TSH > > levels was a mere 0.17-just a teensy bit (17%) above no correlation > > at all. The r value was not statistically significant. This means that > > the very weak positive correlation week-to-week could have been due > > merely to chance similarities in the TSH levels, and there may actually > > have been no correlation at all.[38] Another way of looking at this is > > that patients' TSH levels significantly differed week-to-week. > > > Sounds like something is left out. You can't compute correlation of > something-- you correlate between two somethings. Between the readings of one week and the readings of the next week etc. If TSH is a steady measurement you would expect it not to vary much from one week to the next. What above is saying is that TSH is more up and down than a flat line thing. So the variable is the week number. |