107
lower in thyrotoxicosis. However, studies have shown that upon reversal of thyrotoxicosis, the lipid levels can be normalised, although the response may vary
depending on pathophysiological characteristics of individuals [22, 23].
Thyroid Hormones and Bones Metabolism
Thyroid hormones have a greater influence on the skeletal development. The thyroid
stimulating hormone receptors (TSHR) are also located on the surface of osteoblasts and osteoclasts. T3 hormones produce its effects on bones by chondrogenesis
and mineralisation of bones. It also stimulates the interleukin 1 and 8, along with
intensification of interleukin 1 and 6, augmented synthesis of osteocalcin, enhanced
proliferation and differentiation of osteoblasts, and ultimate apoptosis [24].
TH
CETP
HDL2
Liver
E xtrahepatic
Cells
TH
FC
LCAT
TH
HDL3
Chulomicrons
Remnants
VLDL
IDL
LDL
Blood Vessel
VLDL
Tg
LPL
Hepatic
Lipase
Fig. 6.4 Effect of thyroid hormones on cholesterol transport. LPL lipoprotein lipase; VLDL very
low-density lipoprotein; IDL intermediate density lipoprotein; HDL high-density lipoprotein;
LCAT lecithin cholesterol acyltransferase; CETP cholesteryl ester transfer proteins; FC free cholesterol; HDL high-density lipoproteins; HL hepatic lipase; Tg triglyceride; TH thyroid hormones.
(Permission is granted by Elsevier under the license number: 4704470977456) [22]
6 Impaired Thyroid Function in Metabolic Disorders