Mediterranean dietary pattern adherence: associations with prediabetes, metabolic syndrome, and related microinflammation.

Background: The adherence to the Mediterranean Diet (Med Diet) seems to reduce the incidence of metabolic syndrome. The present study aimed to explore whether the adherence to the overall Med Diet pattern and to specific Med Diet items is associated with the presence of metabolic syndrome, impaired fasting glucose (IFG), insulin resistance (IR), and microinflammation in subjects free of diabetes and cardiovascular diseases.

Measurements: Each patient underwent clinical assessment. Adherence to the Med Diet was measured by a previously validated 14-item questionnaire. Metabolic syndrome was defined by the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria; IR was defined by homeostasis model assessment of insulin resistance (HOMA-IR); inflammation was assessed through a high-sensitivity C-reactive protein (hsCRP) assay.

Results: A total of 120 subjects (64.2% women, mean age 59.8±10.2 years) were enrolled at this study. Subjects with lower Med Diet pattern adherence exhibited higher occurrence of metabolic syndrome and all its components and higher HOMA-IR and hsCRP values (P for all <0.0001). Subjects with metabolic syndrome were less likely to consume olive oil (P=0.002) and vegetables (P=0.023). By multivariable analyses, the overall Med Diet score was found to be strongly and inversely associated with the presence of metabolic syndrome [B=-0.066; 95% confidence interval (CI) -0.105 to -0.028; P=0.001], IFG (B=-0.076; 95% CI -0.114 to -0.038; p<0.0001), high HOMA-IR (B=-0.071; 95% CI -0.108 to -0.034; P<0.0001) and high hsCRP (B=-0.082; 95% CI -0.125 to -0.045; P<0.0001). None of specific Med Diet items independently predicted metabolic syndrome, IFG, and high HOMA-IR. Instead, the consumption of white meat over red meat (B=-0.324; 95% CI -0.467 to -0.178; P<0.0001) was found to be inversely associated with increased hsCRP.

Conclusions: The inverse associations between adherence to Med Diet and the prevalence of metabolic syndrome and prediabetes may be due more to the effects of the entire dietary pattern rather than to individual food components. Metabolic syndrome-related microinflammation may further be linked to specific Med Diet components.