Thyroid deficiency

USP XXII specifies that sodium iodide contains 99—101.5% Nal, calculated on an anhydrous basis (4). It is used iaterchangeably with potassium iodide as a therapeutic agent, except where sodium ion is contraindicated (see Potassium compounds). Intravenous sodium iodide formulations have been used for a variety of diseases, from thyroid deficiency to neuralgia (see Thyroid and antithyroid preparations). However, these solutions are no longer listed ia the XFXUII (4), iadicatiag that their therapeutic value has not been satisfactorily demonstrated. 

Decreased activity of the thyroid gland results in hypothyroidism and, in severe cases, myxoedema. It is often of immunological origin and the manifestations are low metabolic rate, slow speech, lethargy, bradycardia, increased sensitivity to cold, and mental impairment. Myxoedema includes a characteristic thickening of the skin. Therapy of thyroid tumours is another cause of hypothyroidism. Thyroid deficiency... 

Thyroid deficiency (hypothroidism) has been connected to cretinism and myxedema. Cretinism occurs when hypothyroid children are born intellectually handicapped, are small, and have coarse hair and thick skin. Myxedema, seen in older hypothyroid people, is characterized by subcutaneous semifluid deposits, causing puffiness of the hands and face. The basal metabolism of these patients is depressed to 30 0% below normal, and their body temperature and pulse rate are also reduced. Women suffering from hypothyroidism may give birth to children afflicted with cretinism. 

There are relationships between the adrenal cortical hormones and the thyroid and pituitary glands. Depression or the function of the adrenals produces thyroid deficiency, w hereas administration of thyroxine stimulates the ACTH-adrenal conical mechanism. 

There is no such clear cut difTcrcnlialiun as metamorphosis in the mammal, but development is an extremely complex process and has been shown to depend upon the presence of adequate amounts of thyroid hormones. Deficient development, especially of the central nervous system, is marked in ehildren suffering from thyroid deficiency early in life, ansi this inadequacy cannot be overcome completely by medication commenced after the first few weeks. In the adult, thyroxine is important in the maintenance of energy turnover in most of the tissues of the body, such as the heart, skeletal muscle, liver, and kidney, Other physiological functions, most notably brain aclivity and reproduction, are also dependent upon thyroxine, although the metabolic rales of the tissues concerned in these functions do not seem to be altered. 

Haddow JE, Palomaki GE, Allan WC, Williams JR, Knight GJ, Gagnon J, O Heir CE, Mitchell ML, Hermos RJ, Waisbren SE, Faix JD, Klein RZ (1999) Maternal thyroid deficiency during pregnancy and subsequent neuropsychological development of the child. N Engl J Med, 341 549-555. 

Thyroid disorders may be divided into over- and underproduction of the thyroid hormones. These may be caused by thyroid gland disorders or disorders of the pituitary gland (TSH production) or hypothalamus (thyrotropin-releasing hormone release). Thyroid hormone deficiency in infancy may cause mental retardation if it is not corrected immediately after birth. For this reason, many states require thyroid function tests in all newborns. In adults, thyroid deficiency may be caused by Hashimoto s thyroiditis, an immune disorder, or dietary iodine deficiency, in which case it is called simple goiter. The term "myxedema" has been used to refer to hypothyroidism of whatever cause. Myxedemas may... 

Q2 There maybe several causes of fatigue and memory loss, for example dementia, severe anaemia and thyroid deficiency. What factors in the history suggest that this lady has a thyroid problem ... 

Q4 Weight gain without an increase in appetite is a feature of myxoedema, a severe form of thyroid deficiency. Some of the factors which appear to be involved include reduced metabolic rate, and oxygen and calorie consumption. In addition complexes of protein with polysaccharides and other substances accumulate under the patient s skin to promote water... 

Some interesting results on soman toxicity, thyroid deficiency, and plasma CarbE were reported by Swisher et al. (1986). They observed reduced effect of soman intoxication in hypothyroid rats with respect to both seizure aetivity and lethality. The resistanee to soman was ascribed to inereased binding of soman to plasma proteins, since both ChE and CarbE (tributyrinase) of plasma displayed nearly two-fold higher activity in hypothyroid than euthyroid rats. The latter result inspired us to investigate hypothyroid rats with respeet to possible parallel eoregulation of CarbE and ChE in plasma and liver. Plasma ChE is undoubtedly synthesized in liver (Augustinsson, 1948 Koelle, 1963) and the ChE aetivity in rat plasma as well as liver is known to differ between males and females (Leeuwin, 1966 Edwards... 

Saw palmetto (Serenoa repens) Saw palmetto relieves symptoms of benign prostatic hypertrophy (enlarged prostate) and other urinary conditions. Saw palmetto is an expectorant and treats for colds, asthma, bronchitis, and thyroid deficiency. 

It has been long known that hypothyroidism leads to retardation and other serious developmental disorders. 52 It has been shown that the neuropsychological development of a fetus is adversely affected when thyroid deficiency occurs in a pregnant woman and her fetus. 53 Even very small reductions in thyroid levels in mothers during pregnancy have been shown... 

Cretins or other individuals with iodine or thyroid deficiencies may be more sensitive to adverse health effects from selenium exposure (Contempre et al. 1991b, 1992). Iodine supplementation of these individuals without selenium supplementation may further exacerbate the effects. The elderly may be less susceptible to the negative effects of selenium and more prone to selenium deficiencies. A number of researchers have reported lower absorption of selenium and lower selenium tissue concentrations in the elderly compared to younger adults (Martin et al. 1991 Morisi et al. 1989). 

In regard to other endocrine effects, one Web site (www.hometownrx.com/Doc/Herhs/Sawpalm html I claims there is preliminary evidence that saw palmetto can aid those with "thyroid deficiency."... 

Marc C, Clavel M-C, Rabie A (1986) Non-phosphorylated and phosphorylated neurofilaments in the cerebellum of the rat an immunocytochemical study using monoclonal antibodies. Development in normal and thyroid-deficient animals. Dev. Brain Res., 26, 249 260. 

Thyroid hormone Levothyroxine (Synthroid) Thyroid deficiency... 

Pentahydrate, triclinic crystals or cream-colored powder. Odorless and tasteless. Somewhat hygroscopic, dj 2.381. MB -4. 4 (c = 3 In 70% ethanol). Soly at 25" in water about 15 mg/100 ml. (Higher solys have been reported). Sol in mineral acids and In solns of alkali hydroxides and carbonates. More sol in alcohol. Very slightly sol in chloroform, ether. pH of a satd water sotn 8.35 to 9.35. therap cat Treatment of hypothyroidism. therap cat (vet) In thyroid deficiency (dogs). Has been used in obeaity. renal insufficiency, chronic skin conditions. Has also been used in lowered fertility in bulls and to slim -ulate lactation. 

It is important to remember, however, that on a worldwide basis, the most important cause of maternal thyroid deficiency remains iodine deficiency, known to affect over 1.2 billion individuals. 

There is definitely an overlap in responses obtained in normd subjects and those obtained in patients with partial thyroid deficiency, even if the number of injections of TSH is reduced. However, failure of the thyroid uptake and total T4 to increase after TSH is strong evidence of primary thyroid disease. In the patients receiving thyroid hormone therapy, a significant response to TSH fairly conclusively excludes underlying thyroid failure unless the patient has been taking this therapy in full doses for many years. The test is probably most useful in distinguishing idiopathic thyroid failure from secondary or pituitary hypothyroidism. 

Thyroid hormones act on tissues all over the body and have far-reaching effects on energy metabolism, turnover of proteins, lipids and carbohydrates and consequently growth. Thyroid deficiency in early childhood, if untreated, leads to stunted growth and poor development of the nervous system. Such individuals are termed cretins. This is a word that has unfortunately passed into common usage as a term of abuse but refers to a specific clinical condition brought about by endocrine insufficiency. 

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