Limitations of insulin resistance assessment in polycystic ovary syndrome

Abstract

BackgroundThough insulin resistance (IR) is common in polycystic ovary syndrome (PCOS), there is no agreement as to what surrogate method of assessment of IR is most reliable.Subjects and methodsIn 478 women with PCOS, we compared methods based on fasting insulin and either fasting glucose (HOMA-IR and QUICKI) or triglycerides (McAuley Index) with IR indices derived from glucose and insulin during OGTT (Belfiore, Matsuda and Stumvoll indices).ResultsThere was a strong correlation between IR indices derived from fasting values HOMA-IR/QUICKI, r = −0.999, HOMA-IR/McAuley index, r = −0.849 and between all OGTT-derived IR indices (e.g. r = −0.876, for IRI/Matsuda, r = −0.808, for IRI/Stumvoll, and r = 0.947, for Matsuda/Stumvoll index, P < 0.001 for all), contrasting with a significant (P < 0.001), but highly variable correlation between IR indices derived from fasting vs OGTT-derived variables, ranging from r = −0.881 (HOMA-IR/Matsuda), through r = 0.58, or r = −0.58 (IRI/HOMA-IR, IRI/QUICKI, respectively) to r = 0.41 (QUICKI/Stumvoll), and r = 0.386 for QUICKI/Matsuda indices. Detailed comparison between HOMA-IR and IRI revealed that concordance between HOMA and IRI was poor for HOMA-IR/IRI values above 75th and 90th percentile. For instance, only 53% (70/132) women with HOMA-IR >75th percentile had IRI value also above 75th percentile. There was a significant, but weak correlation of all IR indices with testosterone concentrations.ConclusionsSignificant number of women with PCOS can be classified as being either insulin sensitive or insulin resistant depending on the method applied, as correlation between various IR indices is highly variable. Clinical application of surrogate indices for assessment of IR in PCOS must be therefore viewed with an extreme caution.

High prevalence of early (1st trimester) gestational diabetes mellitus in Polish women is accompanied by insulin resistance similar to women with polycystic ovary syndrome (PCOS)

“…In our previous study [28], we reported a significant but rather moderate correlation between fasting and OGTT-derived IR indices in women with PCOS, and now we have also demonstrated the same phenomenon for 1 st -trimester pregnant women (Table 3). Hence, in our opinion, with the multitude of mathematical models, there is no universal "gold standard" for the assessment of insulin sensitivity derived from surrogate markers of insulin resistance.…”

C-Peptide and leptin system in dichorionic, small and appropriate for gestational age twins—possible link to metabolic programming?

“…For obstetric reasons it was, however, not possible to ensure identical condition for each delivery. There are also several methods to assess insulin resistance 39 , apart from the C-peptide-glucose product that we have employed in our study, but they were not validated for infants, so the choice of "the best" method for the time of delivery is debatable and inconclusive.…”

Prevalence of Dyslipidaemia and Pre-Diabetes Among Women with Polycystic Ovary Syndrome (PCOS): Do We Overestimate Cardiovascular Risk?

“…Interestingly in our study there was also no significant increase in insulin resistance indices, despite increasing androgenaemia. Detailed information on aspects related to assessment of insulin resistance in our PCOS subjects has been already presented [28].…”