College Papers

INTRODUCTION One of the important gland of endocrine

INTRODUCTION

One
of the important gland of endocrine system is thyroid gland. In 17th
and 20th century researchers understand the anatomy, function and
its diseases .It is the first gland which develops first in embryo. This gland
secrete hormones which perform different functions in the body. Pituitary
regulate the thyroid gland secretion. It is located down in the front of neck
and weigh 25 grams. The gland consist of two pear shaped lobes where the right
lobe is large than left. This gland has capsule which is covered by envelope of
pretracheal fascia thick posteriorly and attached to upper tracheal ring and
cricoid cartilage. This attachment is responsible for moving during swallowing
of gland up and down with larynx (Khatawkar & Awati, 2015). The relation of thyroid and other
body function was studied by experimental thyroidectomy and internal secretory
function was formulated by king after 9 years (Majid & Siddique, 2009).

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Thyroid
hormones play important role in all normal body functions including liver.
These hormones also play role in the regulating of the basal metabolic rate of
hepatocyte. For normal function of the body normal serum level of thyroid
hormones are necessary. The normal serum vales of T3and T4 are 80-180 ng/dl,
4.6-12 ug/dl respectively (Yousef et al.,
2017). It is well established that thyroid hormone status correlates with body
weight and energy expenditure (Mullur, Liu, & Brent, 2014).

Thyroid
function test is perform for the estimation of thyroid hormones T3 (Serum Triiodothyronine) and T4 (Serum
thyroxine) which are secreted by thyroid gland. Thyroid hormones
are needed for normal growth of the body as well as for metabolisms and
development. The thyroid gland transports diet actively from blood which
consist of iodine through iodide pump in cell membrane which is called
sodium-iodide symporter. Iodine and tyrosines combine in thyroglobulin which
are mediated by thyroperoxidase to form T3 or T4. This process are controlled
by thyroid stimulating hormones (TSH) which is secreted by pituitary gland.
Thyroglobulin as co-secreted with thyroid hormones and in the blood bound to
the thyroid hormones binding protein. And some little amount of free fraction
is available for the uptake by cell. The secreted thyroid hormones consist of
90% T4 and 10% T3 (Mortimer, 2011).

The
pathophysiology of thyroid diseases is related to the three hormones TSH, T3
and T4. The most important chemical marker of thyroid function is TSH.
Hyperthyroidism is the result when the low level of TSH profile, whereas high
value leads to hypothyroidism (Attaullah, Haq, & Muska, 2016). The most common disorders of
thyroid gland are Hyperthyroidism and Hypothyroidism. It can be treated by
hormones therapy (Hannemann et al., 2010).

Most
common cause of hypothyroidism is a decrease intake of iodine in the diet due
to this body cannot synthesized thyroxine. Another cause of hypothyroidisms is
the autoimmune condition called Hashimoto’s thyroiditis. Hypothyroidism can create
number of symptoms like tiredness, sensitivity to cold, weight gain and dry
skin (KUMAR, RASOOL, AHMED, & MAKHIJA,
2016).

Hyperthyroidism
is mostly caused by Graves’ disease, followed by toxic multinodular goiter,
other cause of hyperthyroidism included an autonomously functioning thyroid
adenoma, or thyroiditis (Peter, 2009). Subclinical thyroid dysfunction is
a risk factor for developing symptomatic thyroid disease (Helfand, 2004).

Thyroid
abnormalities affect a considerable portion of the population. However, the
prevalence and the pattern of thyroid disorders depend on ethnic and
geographical factors and especially on iodine intake (Bjoro et al., 2000).

In
2003 study shows that Global total goiter prevalence (TGP) in the general
population was 16 %. A total of 37 % (285 million) school-age children were
estimated to have an insufficient iodine intake, ranging from 10 % in the WHO
Region of the Americas to 60 % in the European Region (Andersson, Takkouche, Egli, Allen,
& Benoist, 2005).

Thyroid
disorders are a widespread endocrinological problem, but data on its prevalence
in India is scanty (Deokar, Nagdeote, Lanje, &
Basutkar, 2016). South Asian
population has a particularly high prevalence of thyroid disorders mainly due
to iodine deficiency and goitrogen use. April 2007 the prevalence of hypothyroidism (5 %), Graves’ disease (0.6
%), gestational transient thyrotoxicosis (6 %), and thyroid autoimmunity (TAI
-12 %). This study collected from Mumbai (India) (Nambiar et
al., 2011).

Thyroid
diseases are increasing globally but are growing more rapidly in Asia (Attaullah et al., 2016). Form Jan – Dec 2007, the prevalence
of thyroid disorder 14 % of hyperthyroidism and 17 % of hyperthyroidism in
eastern Nepal and thyroid disorder is 17 % in western Nepal (Risal, Maharjan, Koju, Makaju, &
Gautem, 2010).

In
2001 the data collected from various studies showed that 42 millions of Indian
people have thyroid disorders. Hypothyroidism, hyperthyroidism, goiter and
iodine deficiency disorders, Hashimoto’s thyroiditis, and thyroid cancer. (Unnikrishnan & Menon, 2011).

There
is no data available for prevalence of thyroid disorders in the general
population living in no mountainous regions of Pakistan. February 2011, some
data collected from different areas of Pakistan shows that Median age of the
participant was 34 years, (50 %) were males.(29 %) subjects presented with
goiter(Jawa et al., 2015).

January
2013 to December2014, study of Thyroid Dysfunction in Punjab was detected in 15
% of patients: 9 % hypothyroidism and 6 % hyperthyroidism. In increasing order
subclinical hypothyroidism, overt hypothyroidism, overt hyperthyroidism, and
subclinical hyperthyroidism were found in (5 %), (4 %), (4 %), and (3 %)
patients, respectively (Batool, Elahi, Saleem, & Ashraf,
2017).

From
2003 to 2009, the thyroid cancer found in Baluchistan that leading thyroid
cancer is papillary carcinoma which accounts for 71 (82 %) cases. Follicular
carcinoma has been reported in 6 (7 %) cases while 10 (12 %) cases presented
with mixed papillary and follicular carcinoma (Iftikhar et al., 2011).

From
January 2009 to December 2015, Data collected from Lyari general hospital and
Abbasi Shaheed hospital in Sindh. A total of 367 patients had thyroid
disorders. The prevalence of sub-clinical thyroid disorders was (9 %). 265 (7
%) had sub-clinical hypothyroidism and 102 (3 %) had overt or subclinical
hyperthyroidism (A. S. Rahman et al., 2017).

Study
from Khyber Pakhtunkhwa was conducted from 07-2010 to 07-2011 at cardiology
department of Hayatabad medical complex, Peshawar. According to this study out
of 753 patients, there were 431 (57 %) male and 322 (43 %) female patients.
Subclinical thyroid disease was found in 46 (6 %) patients including 26 (4 %)
males and 20 (3 %) females. Subclinical hypothyroidism was found in 30 (4 %)
patients of CHF including 19 (3 %) males and 11 (2 %) females. Subclinical
hyperthyroidism was found in 16 (2 %) patients with Congestive heart failure (CHF) including 7 (1 %) males and 9
(1 %) females. Majority of subclinical hypothyroid (67 %) and subclinical
hyperthyroid (81 %) patients were