PCOS as a Cardiometabolic Condition: What the 2023 International Guideline Recommends Testing

The 2023 International Evidence-based PCOS Guideline treats polycystic ovary syndrome as a cardiometabolic condition carrying raised diabetes and cardiovascular risk, and yet it advises against routine fasting-insulin levels and insulin-resistance indices in ordinary care. It asks instead for an oral glucose tolerance test, HbA1c, and a lipid profile. Holding those two positions at once is not a contradiction. It is the single most instructive lesson the guideline teaches.

Key points#

• PCOS is now framed as a cardiometabolic syndrome, not only a reproductive one, so glucose and cardiovascular risk assessment is recommended for everyone with the diagnosis.
• Insulin resistance is central to the biology, but the guideline says fasting insulin and indices such as HOMA-IR are of limited clinical value and should not be ordered routinely.
• The recommended glucose test is the 75-gram oral glucose tolerance test (OGTT), regardless of body weight, with HbA1c or fasting glucose as less accurate alternatives.
• A fasting lipid profile and regular blood pressure checks cover the cardiovascular side.
• The theme underneath is an evidence-appraisal one: a real mechanism does not automatically earn a useful test.

Why the syndrome earns the "cardiometabolic" label#

Start with the evidence for the risk itself, because that is what justifies testing anyone at all. To inform the 2023 update, the guideline group commissioned a systematic review and meta-analysis of clinical cardiovascular events, later published in the Journal of the American Heart Association. Pooling the available studies, it found significant associations between PCOS and composite cardiovascular disease, composite ischemic heart disease, myocardial infarction, and stroke.

Two qualifiers travel with those numbers and should not be dropped. The pooled analysis did not show a significant association with cardiovascular death, so the signal is stronger for events than for mortality. And these are observational estimates assembled from studies that defined PCOS differently and adjusted for weight and other confounders to varying degrees. That combination supports a population-level statement (people with PCOS carry elevated risk, so assess it in all of them) without licensing precise prediction for any one patient. Stating those limits out loud is what turns a screening policy into a defensible one rather than an overreach.

So the label is earned. The next question is which instrument should carry the assessment, and here the guideline makes a move that surprises many clinicians.

The test you would reach for, and why the guideline sets it aside#

Insulin resistance sits close to the middle of how PCOS is explained. It ties the ovarian, metabolic, and reproductive threads into one story, and it is genuinely present in a large fraction of patients. The natural instinct, then, is to measure it: draw a fasting insulin, or compute an index like HOMA-IR, and read risk off the result.

The guideline declines. Its practice point is direct: insulin resistance is a real pathophysiological factor in PCOS, but the insulin assays available in clinical laboratories are of limited clinical relevance and should not be used in routine care. The problem is not the biology. The problem is the measurement.

Unlike glucose or cholesterol assays, insulin assays are not standardized across laboratories, so one blood sample can return different values depending on where it is analyzed. Fasting insulin also swings considerably within the same person from one day to the next, and any index built on it inherits that noise. A test that is imprecise, poorly standardized, and missing validated action thresholds cannot sharpen a decision. It supplies a number that looks quantitative while rarely changing what a clinician does next. A mechanism can be central and true and still fail to yield a test worth ordering; those are separate judgments, decided on separate evidence.

What the guideline asks for instead#

Having set the appealing test aside, the guideline does not go soft on the risk. It swaps an unreliable instrument for reliable ones.

For glucose status, the strong recommendation is the 75-gram OGTT as the most accurate assessment, and it is to be offered regardless of body mass index. That last phrase does real work: it refuses the familiar shortcut of screening only heavier patients, because dysglycemia in PCOS is not limited to them. HbA1c or fasting plasma glucose may be used as alternatives, but the guideline is candid that both are less accurate than the OGTT in this population. That is a ranking, not a menu of equals.

For cardiovascular risk, it calls for a fasting lipid profile at diagnosis (total cholesterol, LDL, HDL, and triglycerides) together with regular blood pressure measurement. None of these are exotic. They are the same well-standardized measures used throughout general cardiovascular prevention, chosen precisely because their performance and interpretation are settled.

The rule underneath is consistent. Where an assay is reliable and connected to a decision, recommend it. Where the biology is compelling but the assay is not, hold back. The direction of risk stays in full view; only the shaky instrument is removed.

The appraisal habit worth carrying elsewhere#

This is a clean, teachable instance of a distinction that matters far beyond PCOS, and it is one that anyone trained in evidence appraisal and cardiometabolic epidemiology will recognize. A screening recommendation is a claim about what a test reliably tells you and what you can act on. It is not a claim about what the biology suggests ought to be measurable. Those two claims answer to different evidence, and conflating them is how a plausible-sounding number ends up on a lab order for no benefit.

The 2023 guideline models the discipline in a single condition: take the cardiometabolic risk seriously, recommend standardized glucose and lipid testing, and decline the intuitive insulin assay because the measurement cannot bear the weight of the decision. Carry that habit into the next mechanism you find compelling, and the guideline has done more than manage PCOS.