Dietary inflammatory potential and risk of mortality in metabolically healthy and unhealthy phenotypes among overweight and obese adults.

BACKGROUND & AIMS: This study was designed to investigate the association between the dietary inflammatory index (DII®) scores, metabolic phenotypes, and risk of mortality risk in overweight/obese individuals from a representative sample of the U.S.

METHODS

Data from 3733 overweight/obese adults (BMI ≥ 25 kg/m2) aged 20-90 years from the National Health and Nutrition Examination Survey III, 1988-1994 were analyzed; these participants were followed for mortality through December 31, 2011. DII scores were computed based on baseline dietary intake using 24-h dietary recalls. Metabolically unhealthy status was defined as having 2 or more of these metabolic abnormalities: high glucose, insulin resistance, elevated blood pressure, triglycerides, C-reactive protein levels, or low high-density lipoprotein-cholesterol values.

RESULTS

In metabolically unhealthy overweight/obese (MUO) individuals, DII score was associated with increased risk of all-cause mortality (HRTertile 3 vs Tertile 1 1.44; 95% CI 1.11-1.86 Ptrend = 0.008; HR1SD increase 1.08; 95% CI 0.99-1.18). Additionally, a stronger association with cardiovascular mortality was observed (HRT3 vs T1 3.29; 95% CI 2.01-5.37 Ptrend < 0.001; HR1SD increase 1.40; 95% CI 1.18-1.66), after adjusting for potential confounders. Furthermore, when analyses were restricted to obese individuals (BMI ≥ 30 kg/m2), the association was more pronounced, especially for cardiovascular mortality (HRT3 vs T1 5.55; 95% CI 2.11-14.57 Ptrend = 0.006; HR1SD increase 1.74; 95% CI 1.21-2.50). No association was observed between DII score and risk of mortality in individuals with metabolically healthy overweight/obese (MHO) phenotype, or for cancer mortality in either MHO or MUO phenotype.

CONCLUSIONS

A pro-inflammatory diet appears to increase risk of all-cause and cardiovascular mortality in the MUO phenotype, but not among the MHO phenotype.