The insulin-androgen connection
Insulin receptors are present not only in the liver, muscle, and fat — the tissues most discussed in the context of insulin resistance — but also in the ovaries and the adrenal glands. When circulating insulin is chronically elevated (as it is in insulin resistance), ovarian theca cells respond by producing more androgens, particularly testosterone. The pituitary also amplifies LH (luteinising hormone) secretion in a hyperinsulinaemic environment, which further stimulates ovarian androgen production.
The result: elevated androgens, which then interfere with follicular maturation, suppress ovulation, and create the hormonal environment that defines the classic PCOS phenotype. This is why PCOS, at its core, is a metabolic condition that expresses itself through reproductive and hormonal consequences.
The ICMR-PCOS national study published in 2024 found that dyslipidaemia was present in 91.9% of PCOS patients and metabolic syndrome in 24.9% — a metabolic burden that would not be predicted from a condition described primarily as a menstrual or hormonal disorder.
How insulin resistance presents in PCOS
Insulin resistance in PCOS often has visible clinical correlates:
Central weight accumulation. The abdomen is the site of preferential fat deposition in insulin resistance. Many PCOS patients describe gaining weight "around the middle" even when overall weight has not changed significantly.
Acanthosis nigricans. Darkened, thickened skin at the back of the neck, armpits, or groin creases is a clinical sign of chronic hyperinsulinaemia. It is present in a significant minority of PCOS patients, particularly in those with more severe insulin resistance.
Post-meal fatigue and carbohydrate cravings. The exaggerated insulin response to carbohydrate intake creates a reactive hypoglycaemic tendency — a blood glucose dip that triggers hunger and fatigue one to two hours after eating. Many patients describe this as "needing something sweet after lunch" or "crashing in the afternoon."
Difficulty with weight management. The same mechanisms that drive fat storage and suppress fat breakdown in insulin resistance make weight loss physiologically more difficult — not a character failing, but a metabolic constraint.
The test that is often missing
A fasting glucose that is within the normal range does not rule out insulin resistance. As described in the insulin resistance article, fasting insulin and HOMA-IR provide the metabolic picture that glucose alone cannot. In a PCOS assessment:
- Fasting insulin should be measured alongside fasting glucose
- HOMA-IR above 2.5–3.0 indicates significant insulin resistance
- 2-hour glucose tolerance test (75 g OGTT) identifies impaired glucose tolerance and early type 2 diabetes, which occurs earlier and at lower BMIs in PCOS patients than in age-matched controls
The progression to type 2 diabetes is substantially accelerated in PCOS. Estimates from prospective studies suggest that PCOS patients have a three- to seven-fold higher risk of developing type 2 diabetes over their lifetime compared with women without PCOS. Early metabolic evaluation creates an intervention window that can substantially modify this trajectory.
What insulin sensitisation looks like in PCOS management
Addressing insulin resistance is not peripheral to PCOS management — it is often central to it. The clinical approaches include:
Lifestyle modification. Reducing refined carbohydrate intake, increasing physical activity (both aerobic and resistance training), and achieving even modest weight reduction (5–10% of body weight in women with PCOS and overweight) can substantially improve insulin sensitivity, ovulation frequency, and androgen levels.
Metformin. The most studied insulin-sensitising medication in PCOS. It reduces hepatic glucose output, improves peripheral insulin sensitivity, and has been shown to improve ovulation rates, menstrual regularity, and androgen levels in PCOS patients. It is not a weight loss drug, but weight loss often accompanies its use as insulin sensitivity improves. Its use in PCOS is off-label but extensively supported by evidence and commonly recommended in Indian clinical practice.
Inositol. Myo-inositol and D-chiro-inositol are naturally occurring compounds that act as secondary messengers in insulin signalling pathways. Several randomised trials have demonstrated improvements in insulin sensitivity, ovulation rate, and androgen levels in PCOS patients treated with myo-inositol. The evidence base is smaller than for metformin, but the side effect profile is more favourable.
Why treating symptoms without addressing the metabolic root gives incomplete results
Many PCOS patients are offered oral contraceptive pills (OCPs) as the first and often only treatment. OCPs effectively regulate cycles and suppress androgens — but they do not address insulin resistance. A patient who takes OCPs for years without metabolic intervention may find their hormonal symptoms return whenever OCPs are discontinued, and they may be accumulating metabolic risk (increased insulin resistance, worsening dyslipidaemia) silently.
An effective PCOS plan evaluates the metabolic component alongside the hormonal component, and addresses both. For many patients, improving insulin sensitivity is the intervention that resolves the most symptoms and modifies the most long-term risk.