Dietary carbohydrate composition is associated with polycystic ovary syndrome: a case-control study.

BACKGROUND

The present study aimed to investigate the association between dietary carbohydrate components and polycystic ovary syndrome (PCOS) in Iran.

METHODS

In this case-control study, the diagnosis of PCOS was made based on the Rotterdam criteria in hospital clinics. Dietary assessments were performed using a validated semi-quantitative food frequency questionnaire. In total, 281 women with incident PCOS and 472 age-matched controls were assessed. Participants were interviewed through the clinics in Tehran, Iran, from February 2012 until March 2014. Average dietary glycaemic index (GI) and glycaemic load (GL) were calculated using GI of Iranian Foods Table and international tables of GI and GL values. We also assessed total dietary carbohydrate, refined grains, whole grains and fibre intakes.

RESULTS

Participation rates were 97.5% among cases and 96.3% among controls. Mean (SD) dietary GI values among the controls and cases were 51.8 (4.7) and 59.7 (5.9) (P = 0.02) and GL values were 155.34 (35.2) and 173.6 (39.1) (P < 0.001), respectively. The multivariate adjusted odds ratio (OR) comparing the highest tertile of dietary GI and GL with the lowest tertile were 2.18 [95% confidence interval (CI) = 1.29-3.81; P-test for trend = 0.012] and 2.39 (95% CI = 1.23-3.01; P-test for trend = 0.001), respectively, with a significant trend. Fibre intake was inversely associated with PCOS (OR = 0.73; 95% CI = 0.49-0.91; P-test for trend = 0.013).

CONCLUSIONS

The findings of the present study suggest that high dietary GI and GL and low fibre intake are significantly associated with PCOS.