Subgroups of participants
To assess the levels of fructose and uric acid in various metabolic
states and the impact of clinical characteristics on cases and controls,
the study population was further subdivided according to PCOS-related
metabolic alterations, including obesity, insulin resistance,
dyslipidemia, metabolic syndrome.
According to the WHO-defined diagnostic criteria for lean, overweight,
and obese individuals in Asia,13 we categorized the
participants into the following three subgroups: lean (BMI <
23 kg/m2), overweight (23 kg/m2 ≤
BMI < 25 kg/m2), and obese (BMI ≥ 25
kg/m2) (Table S1).
The degree of insulin resistance was estimated using a homeostasis model
(HOMA-IR). We calculated the HOMA-IR index as follows: FPG (mM) × FSI
(mIU/l)/22.5; insulin resistance could be defined as HOMA-IR
> 2.5; this threshold value has been widely used earlier
(Table S2).14
Participants were classified as dyslipidemia and normolipidemia
groups based on the following criteria: TC ≥ 6.2 mmol/l; TG ≥ 2.3
mmol/l; LDL-C ≥ 4.1 mmol/l; and HDL-C < 1.0 mmol/l, fulfilling
at least one of the above criteria (Table S3).15
According to the criteria proposed by the American Association of
Clinical Endocrinologists/American College of Endocrinology, the
manifestation of three or more of the following factors is sufficient
for the diagnosis of metabolic syndrome16:BMI ≥ 25
kg/m2; TG ≥ 1.70 mmol/l; HDL-C < 1.29
mmol/l; blood pressure ≥ 130/85 mmHg; plasma glucose after a 2-h load
> 7.8 mmol/l, 6.1 mmol/l ≤ FPG ≤ 7. 0 mmol/l; other risk
factors included type 2 diabetes, PCOS, sedentary lifestyle, old age,
family history of hypertension or cardiovascular disease, and ethnicity
with a high risk of type 2 diabetes or cardiovascular disease (Table
S4).