The Dietary Inflammatory Index Is Directly Associated With Polycystic Ovary Syndrome

A Case-Control Study

Elnaz Zirak Sharkesh; Seyed A. Keshavarz; Leila Nazari; Behnood Abbasi


Clin Endocrinol. 2022;96(5):698-706. 

In This Article


The mean ± SD age of the study subject was 29.67 ± 5.92 years. The mean ± SD BMI was 24.51 ± 4.71 kg/m2. The mean score of DII across study population was −3.84 ± 8.56 and 0.98.

The characteristics of sociodemographic, physical activity, anthropometrics, and mean DII score of PCOS patients and control groups are indicated in Table 1. Compared with controls subjects, PCOS patients had significantly higher weight, BMI, and WC, but had lower physical activity. Also, the subjects in the case group had higher intake of vitamin D and folic acid supplements and lower intake of omega-3 supplements compared to the control group. The level of education was significantly higher in the control group compared to the case group. Furthermore, no significant differences were found for other characteristics between cases and control groups.

Table 2 illustrates the macro- and micronutrients and the intakes of food groups in PCOS patients versus controls groups. PCOS subjects had higher intakes of carbohydrate, cholesterol, and refined grains, but lower intakes of PUFA, fibre, vitamin B12, vitamin D, and dairy as compared to controls. There were no significant differences between the PCOS group and controls for all other dietary intakes.

General characteristics and dietary intake of subjects across quartiles of DII are presented in Table 3. Compared with those in the lowest quartiles of DII, subjects in the highest quartiles had lower age. No other significant difference was found in other general characteristics across quartiles of DII. Also, individuals in the highest quartiles of DII had higher intake of energy, carbohydrate, protein, total fat, SFAs, cholesterol, MUFA, PUFA, sodium, vitamin B12, refined grains, and red and processed meat as well as a lower intake of fibre, fructose, glucose, potassium, phosphor, calcium, iron, zinc, magnesium, chromium, caffeine, vitamin C, vitamin B6, B9, dairy, fruits, and vegetables compared with those in the bottom quartiles.

The ORs and 95% CIs for PCOS subjects based on the quartiles of DII score are reported in Table 4. In the crude model, the DII was directly associated with the risk of PCOS, with an OR of 1.60 for the highest quartile, as compared to the lowest quartile (p for trend = .025). However, after we adjusted for age and BMI (in the Adjusted Model 1), no significant association was found between DII index and the risk of PCOS (OR = 1.47, 95% CI: 0.85–2.53; p = .071 for trend). Although, after adjusting for confounders according to the second model (adjusted based on Model 1 and weight, WC, education status, marital status, physical activity, and use of multivitamin mineral supplements, vitamin D supplements, folic acid supplements, and omega 3 supplements), those in the highest quartile of the DII index had significantly higher risk of PCOS than those in the lowest quartile (OR = 1.75, 95% CI: 0.95—3.22; p for trend = .047).