Dietary Inflammatory Index, Pre-Frailty and Frailty among Older US Adults: Evidence from the National Health and Nutrition Examination Survey, 2007-2014.

OBJECTIVE: This study aimed to investigate the association between dietary inflammation, pre-frailty and frailty among older US adults. Additionally, effect modification of gender on the association between dietary inflammation and frailty was assessed. DESIGN: Study data came from the National Health and Nutrition Examination Survey (2007-2014) - a nationally representative, cross-sectional study of adults. PARTICIPANTS: The analytic sample included adults ≥60 years (n=7,182). MEASUREMENTS: Dietary Inflammatory Index (DII®) scores were calculated from 24-hour dietary recalls; DII was categorized into quintiles from Quintile 1 (Q1) (least inflammatory) to Q5 (most inflammatory). Frailty was assessed by four criteria: exhaustion, weakness, low body mass, and low physical activity. Individuals were then categorized into robust (0 criteria), pre-frail (1-2 criteria), or frail (3-4 criteria). Multinomial logistic regression was used to examine the odds of frailty categories (pre-frail vs. robust; frail vs. robust). RESULTS: After adjusting for potential confounders, individuals in DII quintile 5 (vs Q1) were more likely to be pre-frail (OR = 1.71; 95% CI: 1.36-2.15) and frail (OR = 1.70; 95% CI: 1.02-2.85). Individuals in Q4 had greater odds of frailty only (OR = 1.82; 95% CI: 1.13, 2.93). No evidence of effect modification by gender on the association of DII and frailty was found. CONCLUSION: This study expands upon previous evidence of a relationship between dietary inflammation and frailty. When designing nutrition-based frailty interventions, inflammatory properties of diets should be considered.

Association of Obesity and Frailty in Older Adults: NHANES 1999-2004.

OBJECTIVES: Body composition changes with aging can increase rates of obesity, frailty and impact function. Measuring adiposity using body fat (%BF) or central adiposity using waist circumference (WC) have greater diagnostic accuracy than traditional measures such as body mass index (BMI). DESIGN: This is an observational study. SETTING: This study focused on older community-dwelling participants. PARTICIPANTS: We identified individuals age ≥ 60 years old using the 1999-2004 cross-sectional National Health and Nutrition Survey (NHANES). INTERVENTION: The primary analysis evaluated the association between frailty and %BF or WC. Frailty was the primary predictor (robust=referent) and %BF and WC were considered continuous outcomes. Multiple imputation analyses accounted for missing characteristics. MEASUREMENT: Dual energy x-ray absorptiometry was used to assess %BF and WC was objectively measured. Frailty was defined using an adapted version of Fried's criteria that was self-reported: (low BMI<18.5kg/m2; slow walking speed [<0.8m/s]; weakness [unable to lift 10lbs]; exhaustion [difficulty walking between rooms on same floor] and low physical activity [compared to others]). Robust, pre-frail and frail persons met zero, 1 or 2, and ≥3 criteria, respectively. RESULTS: Of the 4,984 participants, the mean age was 71.1±0.2 (SE) years and 56.5% were females. We classified 2,246 (50.4%), 2,195 (40.3%), and 541 (9.2%) individuals as robust, pre-frail and frail, respectively. Percent BF was 35.9±0.13, 38.3±0.20 and 40.0±0.46 in the robust, pre-frail and frail individuals, respectively. WC was 99.5±0.32 in the robust, 100.1±0.43 in pre-frail, 104.7±1.17 in frail individuals. Compared to robust individuals, only frail individuals had greater %BF on average (ß=0.97±0.43,p=0.03); however, pre-frail and frail individuals had 2.18 and 4.80 greater WC, respectively (ß=2.18±0.64,p=0.002, and ß=4.80±1.1,p<0.001). CONCLUSION: Our results demonstrate that in older adults, frailty and pre-frailty are associated with a greater likelihood of high WC (as dichotomized) and a greater average WC (continuous).