Homonal changes in PCOD (i) LH is elevated (ii) Total free estrone is decreased (iii) Insulin is elevated (iv) SHBG is increased (v) Progesterone is decreased
**Core Concept**
Polycystic Ovary Syndrome (PCOS) is characterized by hormonal dysregulation, insulin resistance, and ovarian dysfunction. The underlying pathophysiology involves hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology.
**Why the Correct Answer is Right**
In PCOS, insulin resistance is a key feature, leading to elevated insulin levels. Elevated insulin levels stimulate the androgen-producing cells in the ovarian stroma, resulting in increased androgen production. This, in turn, leads to decreased SHBG (Sex Hormone-Binding Globulin) levels, as insulin resistance decreases SHBG production. Decreased SHBG levels result in increased free testosterone levels. Elevated LH levels are also seen in PCOS, due to the disruption of the normal feedback mechanism between estrogen and gonadotropin-releasing hormone (GnRH). Progesterone levels are often decreased due to anovulation.
**Why Each Wrong Option is Incorrect**
**Option A:** LH is not elevated in all cases of PCOS; however, it is a common feature.
**Option B:** Total free estrone is not typically decreased in PCOS; in fact, estrogen levels are often elevated due to increased aromatization of androgens.
**Option C:** SHBG is typically decreased, not increased, in PCOS due to insulin resistance.
**Option D:** Progesterone is often decreased due to anovulation, not increased.
**Clinical Pearl / High-Yield Fact**
In PCOS, insulin resistance is a key feature, and lifestyle modifications such as weight loss and exercise can improve insulin sensitivity, thereby improving hormonal and reproductive function.
**Correct Answer:** C. SHBG is decreased in PCOS.