Acanthosis
nigricans
Typically
thick dark velvety skin situated on the nape of the neck axillae groins and other frictional areas
may often be the first clue of insulin
resistance . The thickening occurs due to the stimulation of tyrosine kinase growth
factor – signaling pathways
in the epidermis . Insulin - like
growth factor receptor 1 is
present in many tissues including the epidermis and ovary High levels of
insulin directly or indirectly stimulate
the IGF1R resulting in the skin
changes . skin tags
in the frictional areas like the neck
axillae groins infra mammary or
even under a pendulous abdominal fold
are common especially in obese individuals.
Obesity
Obesity is
a common
finding in PCOS and aggravates
many of its reproductive and metabolic features. In fact approximately
50% of PCOS women are overweight or obese and
the history of the weight gain frequently precedes the onset of oligomenorrhea and hyperandrogenism suggesting a pathogenetic role of
obesity in the subsequent
development of the syndrome
PCOS women are characterized by a high
prevalence of several metabolic abnormalities which are
strongly influenced by the presence of obesity. Adequate confirmation
on the genuine role of obesity in determining hyperinsulinemia and insulin
resistance in women with PCOS
drives from studies comparing groups
of normal weight and obese PCOS women
. both fasting and glucose
stimulated insulin concentrations are in
fact significantly higher in obese
than in non obese PCOS
subgroups.
It is well
documented that women with PCOS
have a high prevalence of abdominal body fat distribution even if they
are normal weight . The impact of abdominal
obesity on PCOS may be greater
than expected since this phenotype is associated with a more
pronounced hyperandrogenism and insulin resistance than the peripheral one .
Multiple therapies may be needed to address the variety of PCOS
symptoms However it is
important to address the common
cause linked to these PCOS symptoms .
PCO & Its Etio pathogensis: This is the arena of
battlefield:-Insulin Resistance – A pathophysiological contributor in
50-80% of the PCOS women
According to Indian
journal of Endocrinology and
metabolism , 2011 insulin resistance is a pathophysiological contributor
in around 50-80 % of women with
PCOS especially in those with more severe PCOS diagnosed on the basis of National
institutes of health criteria and in
women who are overweight.
Insulin
resistance contributes not only to metabolic features
but also to reproductive features
through augmenting androgen production and increasing free androgens
by reducing sex hormone binding globulin . Obesity increases hyperandrogenism hirsutism infertility and pregnancy complications both independently
and by exacerbating PCOS.
Further more women with PCOS have increased risk factors for T2DM cardiovascular disease impaired glucose tolerance.
Glucose
metabolism in a normal cell includes
several processes
· Insulin first binds to its
receptor located on the cell wall forming
a complex called insulin receptor
substrate.
· This complex enters into the
cell for stimulating the most
vital messenger called
phosphatidylinositol 3 kinase.
· Once PI 3 kinase is activated it causes
translocations of glucose
transport 4 to its cell membrane.
· Glucose is then taken by GLUT 4 through glucose channel for utilizing energy .
· Once energy is utilized through glucose the IRS complex
breaks down releasing the
receptor to relocate back to its original site.
· This is how glucose utilization takes place in
the presence of normal insulin sensitive condition.
Phosphatidylinositol 3- Kinase – A key messenger in Insulin sensitivity
Phosphatidylinositol 3 kinase is a key messenger / enzyme responsible for
activation of glucose transport so as
to utilize glucose and liberating
energy. It plays very important role in preserving insulin actions and thus improving insulin sensitivity. This enzyme
plays a vital role in PCOS in
which the most prominent cause is IR. Inositol acts as
a precursor for the synthesis
of phosphatidyl inositol .
Inositol acts as a precursor for the
synthesis of phosphatidyl inositol. Inositol
plays an important role in the production of PI3 kinase. Hence inositol is an integral part
of PI3 kinase.
Theory 2:-Inositol &
PCO:_PCOS…characterized by reduced levels
of inositol
Evidences suggest that a deficiency of
inositol contribute to insulin
resistance in PCOS
individuals . It was observed that deficiency
of inositol shows defective
insulin signaling pathway
in patients with PCOS. The women
with PCOS and normal women were assessed for circulating inositol
and 24 hr urinary clearance of inositol
and insulin sensitivity . The findings
indicated a marked alteration in
inositol urinary clearance
and deficient insulin stimulated PI 3 kinase release in PCOS women.
Plasma concentrations of inositol
is significantly lower in PCOS women compared with normal control subjects
consequently urinary clearance of Inositol was significantly
higher in
CPOS women compared with normal control subjects .
CPOS women compared with normal control subjects .
Increased urinary clearance of inositol is an independent predictor of
insulin resistance in PCOS patients
Consequently AUC inositol was significantly lower in PCOS women compared with normal control
subjects
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