Myoinositol in Gynaecology – From an expert Desk

Inositol – myo-inositol, is a carbocyclic sugar that is abundant in the brain and other mammalian tissues; it mediates cell signal transduction in response to a variety of hormones, neurotransmitters, and growth factors and participates in osmo regulation. Made naturally in humans from glucose. Human kidney makes two grams per day &Other tissues synthesizes it. Highest concentration is in the brain.

Myo-Inositol is synthesized from glucose 6-phosphate (G6P) in two steps. First, G6P is isomerised by an inositol-3-phosphate synthase enzyme to myo-inositol 1-phosphate, which is then dephosphorylated by an inositol mono phosphatase enzyme to give free myo-Inositol.
Large doses of inositol have given for treatment of depression, panic disorder or obsessive-compulsive disorder.

• • ROLE IN POLYCYSTIC OVARIAN SYNDROME
  • Myoinositol is used as a dietary supplement in the management of
  • polycystic ovary syndrome (PCOS).
  • It works by increasing insulin sensitivity
  • Improves ovarian function.
  • Reduces hyperandrogenism.
  • Reduces the risk of metabolic disease in people with PCOS.
  • Helps in weight reduction with lifestyle modification.

MYO-INOSITOL AS SECOND MESSENGER:

1. 1. Effective in restoring FSH/LH ratio and menstrual cycle regularization.
   2. Help in ovarian follicle maturation and consequently to a higher oocyte quality.

In contrast, D-chiro-inositol can impair oocyte quality in a dose-dependent manner. The high level of DCI seems to be related to elevated insulin levels retrieved in about 70% of PCOS women.

The plasmatic ratio of myo-inositol and D-chiro-inositol in healthy subjects is 40:1. The use of the 40:1 ratio shows the same efficacy of myo-inositol alone but in a shorter time.

ROLE IN GESTATIONAL DIABETES MELLITUS

Inositol also helps to prevent high blood sugar levels during pregnancy when taken in combination with folic acid, but more studies are needed to confirm this effect.

GDM is onset of diabetes first time in pregnancy. Myoinositol intake during pregnancy reduces the incidence of GDM, reduces macrosomia incidence and reduces the dose of insulin injections during pregnancy. However, it needs more studies to confirm.

In my experience Myoinositol has no side effects and helpful in PCOS when taken in appropriate dose of 4gms for 6 months with lifestyle modifications – 3 meals, 3 snacks with high fibre diet and 30 minutes exercise. In GDM cases insulin dose can be minimised & macrosomia incidence reduced.

Dr. S. SAMPATHKUMARI.MD, DGO, FICOG, FIME, FC Dia., Professor & HOD – OG, Sri Muthukumaran Medical College Hospital & Research Institute, Chennai.