Obesity and its pathophysiologic sequela have become a
burgeoning medical issue not only in Africa but worldwide. Obese and overweight
patients may sometimes present with symptoms suggestive of disordered
carbohydrate metabolism and thyroidal parameters including hypothyroidism.
However, when the usual routine thyroid battery of labs comes back, they may
identify markers of insulin resistance but often fail to identify any obvious
abnormal findings in their hypothalamic-thyroidal axis. To determine the potential
for subclinical thyroidal actions as a contributing factor for hormonal
regulation of energy balance and the development of obesity and metabolic
syndrome, studies of resting and catecholamine stimulated metabolism, in vivo thyroid hormone half-life,
thyroid hormone binding characteristics and weight gain, groups of lean and
obese congenic LA/Ntul//-cp rats were offered stock or high energy diets and in
vivo and in vitro parameters of
thyroid hormone action determined. The obese phenotype demonstrated impaired
thermic responses to diet and environment and cold-induced thermoregulation, in
association with decreases in plasma T3 but not T4 concentrations.
Administration of I-131 T4 and I-131 T3 in the obese phenotype of corpulent
rats resulted in clearance rates for T3, but T4 clearance was consistently
prolonged by approximately 50% among the obese phenotype. The plasma half-life
of T4 was ~50% longer in obese than in lean littermates, while the half-life of
T3 was similar in both phenotypes. Measures of nuclear thyroid hormone receptor
density were similar in both phenotypes, but receptor affinity for T3 was
diminished in the obese phenotype, consistent with impaired thyroidal actions
as a contributing factor for subclinical hypothyroidism in the obese phenotype
of this strain. In conclusion, the current trends in the increasing prevalence
of obese and overweight conditions will in all likelihood become a pressing
global priority to identify and more fully characterize at the molecular,
tissue and organ system levels of effective resolutions to the critical issues
of overweight and obese conditions. A doable solution must be found, as urgency
is emerging that signals that a metabolic and global healthcare epidemic is
tantamount to a tsunami if left unattended.
Author (s) Details
Orien L Tulp
Department of Medicine, University of Science, Arts and Technology,
Olveston, Montserrat, UK, Department of Medicine, Einstein Medical Institute,
North Palm Beach, USA and Department of Natural Medicine, East West College of
Natural Medicine, Sarasota FL, USA.
O F Obidi
Department of Medicine, University of Lagos, Lagos, Nigeria.
T C Oyesile
Department of Medicine, University of Lagos, Lagos, Nigeria.
Frantz Sainvil
Department of Medicine, University of Science, Arts and Technology, Olveston,
Montserrat, UK, Department of Medicine, Einstein Medical Institute, North Palm
Beach, USA and Department of Medicine, Broward College, Davie FL, USA.
Rolando Branly
Department of Medicine, University of Science, Arts and Technology,
Olveston, Montserrat, UK and Department of Medicine, Broward College, Davie FL,
USA.
A Sciranka
Department of Medicine, University of Science, Arts and Technology,
Olveston, Montserrat, UK.
Syed AA Rizv
Department of Medicine, University of Science, Arts and Technology,
Olveston, Montserrat, UK and Department of Medicine, Larkin Hospital, Miami FL,
USA.
Aftab Awan
Department of Veterinary Medicine, Cambridge University, Cambridge, UK.
Michael Anderson
Department of Medicine, University of Science, Arts and Technology,
Olveston, Montserrat, UK.
George P Einstein
Department of Medicine, University of Science, Arts and Technology,
Olveston, Montserrat, UK and Department of Medicine, Einstein Medical
Institute, North Palm Beach, USA.
Syed AA Rizvi
Department of Medicine, University of Science, Arts and Technology,
Olveston, Montserrat, UK and Department of Medicine, Larkin Hospital, Miami FL,
USA.
Please see the book
here:- https://doi.org/10.9734/bpi/msti/v13/5230