First, the description of the methods for ascertaining cardiac events is not clear. Specifically, it is not clear what events were considered in addition to documented myocardial infarction or death from coronary disease.30, 34 Symptoms of overt thyroid dysfunction also can be vague and at times difficult to diagnose, and therefore, thyroid screening may allow the diagnosis of overt disease earlier in the clinical course, thus reducing morbidity.
Subclinical hypothyroidism may be a risk factor for atherosclerosis and myocardial infarction, but epidemiologic studies of this question have had mixed results. 38-42 Four recent meta-analyses have evaluated the association of subclinical thyroid disorder on cardiac mortality or all-cause mortality.When a person has hyperthyroidism, he may be at risk for developing Graves disease, chronic thyroiditis, trophoblastic disease and toxic multimodal goiter. Common symptoms of hyperthyroidism are as follows. Hyperactivity Insomnina Heat sensitivity Excessive Sweating Tremors.
In the Health, Aging, and Body Composition Study cohort, 338 of 2,730 individuals, ages 70 to 79 were found to have subclinical hypothyroidism. 41 After a 4 year followup, a total of 178 individuals had a CHF event.23 Unlike the earlier report from the Whickham study, 48 the new analysis included only subjects who had mildly elevated TSH levels, excluded subjects who had known thyroid disease or ischemic heart disease, stratified subjects according to whether they were treated with thyroxine during the followup period, and adjusted for several cardiovascular risk factors as.
The 2004 USPSTF review by Helfand found that evidence regarding mildly elevated TSH levels and hyperlipidemia and atherosclerosis was inconsistent. 1 In the recent reanalysis of the Whickham study data, subjects with subclinical hypothyroidism had higher baseline systolic blood pressure (146.9 26.4 mm Hg vs.139.5 24.7 mm Hg) and total cholesterol levels (6.2 1.3 mmol/L.44 The third review, which included 10 population-based prospective studies and two studies of convenience samples of cardiac patients or patients with a history of stroke or hip replacement, found no overall statistically significant association between either subclinical hypothyroidism or subclinical hyperthyroidism and total mortality or coronary morbidity or mortality.
This association deserves further study. However, it is still unknown if thyroid replacement therapy would modify this potential risk).Low Thyroxine Hormone Level When thyroxine level falls lower than the acceptable level, the person may start to manifest symptoms of hypothyroidism. Low levels of thyroid hormones are caused by the underactive thyroid gland, and the symptoms usually are: Dry, cool skin Loss of concentration.
Thyroid Hormone Level Guide Low level - Less than 4.5 mcg/deciliter of blood. Acceptable level - 4.5 to 11.2 mcg/deciliter of blood. High level - More than 11.2 mcg/deciliter of blood.Aside from that, people who have hypothyroidism may experience changes in their metabolism which may lead to weight gain and other medical conditions such as an increase in the levels of bad cholesterol or.
Radioactive iodine used for treatment of hyperthyroidism (overactive thyroid) Special x-ray dyes Surgical removal of part or all of the thyroid gland. Some women develop hypothyroidism after pregnancy (often referred to as postpartum thyroiditis.Reference from A.D.A.M. Back to Top Causes » The thyroid gland is an important organ that regulates metabolism. It is located in the front of the neck just below the voice box (larynx).
In the context of risk factor epidemiology, for a broadly defined composite endpoint, the hazard ratios are low, making it more likely that confounding or methodological factors account for the observed differences.This helps in the monitoring and diagnosing problems related to the thyroid gland itself. In addition to that, the hormone plays an important role in the regulation of the heart and digestive functions, bone maintenance, brain development, muscle control as well as the metabolic rate of the body.
Subclinical Hypothyroidism Although there is wide agreement that the long-term benefits of early treatment of subclinical thyroid dysfunction have not been proven, there is disagreement about what to do until better evidence is available.30, 34, 37 For subclinical hypothyroidism, treatment with levothyroxine is noninvasive and inexpensive. Finally, proponents argue that the potential harms of screening are small in relation to the potential benefits: Because the potential harm of early detection and treatment appear to be so minor and preventable, it seems prudent to err on the side of.
40 The other was an reanalysis of the Wickham Study, a survey of 2,779 adults sampled from a mixed urban and rural area of England conducted between July 1972 and June 1974.In other cases, the cause of hypothyroidism is unknown. Problems with the pituitary gland and hypothalamus may also cause the thyroid gland to produce too little thyroid hormone. This condition is called secondary hypothyroidism.
Risk factors for hypothyroidism include: Age (older than 50) Female gender Obesity. Thyroid surgery X-ray or radiation treatments to the neck. In-Depth Causes ».Thyax is just one type of product that helps with this. The only time that synthetic thyroxine is given is when the person does not produce enough thyroxine or can no longer produce thyroxine naturally.
46 Five studies provided longitudinal data on the risk of coronary events; in these, overall there was no difference in incident ischemic heart disease (IHD) in subclinical hypothyroid participants and euthyroid participants (OR 1.27 ).The thyroid hormone thyroxine is also called T4 and is scientifically known as 3, 5, 35,-tetraiodothyronine. It is a hormone produced by the thyroid gland and is a very important hormone in the body.
41 While those with a TSH of 4.5 to 6.9 did not have a statistically significant higher rate of CHF events compared to those without subclinical hypothyroidism, those with a TSH of 7 to 9.9 had a hazard ratio of 2.58 (95 CI, ) and those with a TSH 10 had a hazard ratio of.45 A statistically significant, but small, increased risk for heart disease was found for individuals younger than 65. 45 The last meta-analysis included 15 studies (six population-based cross-sectional studies and nine longitudinal cohort studies) with 2,531 subclinical hypothyroid participants and 26,491 euthyroid individuals.
51 After a median of 12 years of followup, those with a TSH 10 had a hazard ratio of 1.88 (95 CI of developing a CHF event, while those with a TSH of 4.5 to 9.9 were not more likely to have a CHF event.5.9 1.2 228.2 46.4 mg/dL) and were slightly less likely to smoke than euthyroid subjects (see Appendix A for lipid conversion factors). After adjustment for age, gender, weight, smoking, and relevant medications, however, systolic blood pressure was associated with subclinical hypothyroidism, but total cholesterol was not.
46. The epidemiological studies included in these reviews had serious limitations. Many included individuals who had known thyroid disease, ischemic heart disease, or TSH levels within the reference range. Many included subjects who underwent treatment with levothyroxine during the followup period.These medications supplement the lack of thyroxine in the body by providing synthetic hormones that are identical to thyroxine itself. While these medications are generally effective they may cause side effects.