Development and validation of empirical indices to assess the insulinaemic potential of diet and lifestyle

Abstract

The glycemic and insulin indices assess postprandial glycemic and insulin response to foods respectively, which may not reflect the long-term effects of diet on insulin response. We developed and evaluated the validity of four empirical indices to assess the insulinemic potential of usual diets and lifestyles, using dietary, lifestyle and biomarker data from the Nurses’ Health Study (NHS, n=5,812 for hyperinsulinemia, n=3,929 for insulin resistance). The four indices were: the empirical dietary index for hyperinsulinemia (EDIH) and empirical lifestyle index for hyperinsulinemia (ELIH); empirical dietary index for insulin resistance (EDIR) and empirical lifestyle index for insulin resistance (ELIR). We entered 39 food frequency questionnaire-derived food groups in stepwise linear regression models and defined indices as the patterns most predictive of fasting plasma C-peptide, for the hyperinsulinemia pathway (EDIH and ELIH); and of the triglyceride/high density lipoprotein-cholesterol (TG/HDL) ratio, for the insulin resistance pathway (EDIR and ELIR). We evaluated the validity of indices in two independent samples from NHS-II and Health Professionals Follow-up Study (HPFS) using multivariable-adjusted linear regression analyses to calculate relative concentrations of biomarkers. EDIH is comprised of 18 food groups; 13 were positively associated with C-peptide, five inversely. EDIR is comprised of 18 food groups; ten were positively associated with TG/HDL and eight inversely. Lifestyle indices had fewer dietary components, and included BMI and physical activity as components. In the validation samples, all indices significantly predicted biomarker concentrations, e.g., the relative concentrations (95%CI) of the corresponding biomarkers comparing extreme index quintiles in HPFS were: EDIH, 1.29(1.22, 1.37); ELIH, 1.78(1.68, 1.88); EDIR, 1.44(1.34, 1.55); ELIR, 2.03(1.89, 2.19); all P-trend<0.0001. The robust associations of these novel hypothesis-driven indices with insulin response biomarker concentrations suggests their usefulness in assessing the ability of whole diets and lifestyles to stimulate and/or sustain insulin secretion.

Dietary Inflammatory Index and Cardiovascular Risk and Mortality—A Meta-Analysis

“…Up until the development of the DII, all dietary indices fell into one of three categories: (1) those based on dietary recommendations such as the Healthy Eating Index-2010 (HEI-2010) [ 51 ], or the Alternative Healthy Eating Index (AHEI) [ 52 ], both based on the US Dietary Guidelines or the Dietary Approaches to Stop Hypertension (DASH) [ 53 ], which was promoted by the National Heart, Lung, and Blood Institute; (2) those related to adherence to a particular foodway or cuisine such as the Mediterranean Dietary Index (MDI) [ 54 ]; or (3) those derived from a particular study using some kind of regression technique such as principal components analysis or reduced rank regression [ 55 ]. These indices have been examined with CVD incidence and mortality as outcome in the past [ 56 ].…”

Meta‐analysis of 16 studies of the association of alcohol with colorectal cancer

“…8,13,15,30,32 Alcohol consumption can also interfere with the breakdown and absorption of other nutrients, and alcohol metabolism generates reactive oxygen species which can damage DNA, proteins, and lipids. 30 Moderate alcohol empirically lowers inflammatory markers and C-peptide, [33][34][35] and a short-term randomized clinical trial observed a benefit of alcohol on insulin parameters. 36 A 2017 study of the effects of moderate alcohol consumption in rats observed that moderate levels of alcohol intake did not elevate biological risk factors for CRC development and may provide beneficial effects through reduced inflammation and lower DNA damage.…”

Dietary Patterns and Colorectal Cancer Risk: a Review of 17 Years of Evidence (2000–2016)

“…One advantage of the empirical hypothesis-oriented dietary patterns is their focus on a specific biological pathway linking diet and disease outcomes. Dietary indices have been developed with inflammation [24]**[17, 74] and insulin response [25]** as the central theme in their development. Association of these indices with disease incidence indicates that inflammation or insulin response, respectively may be mediating the development of the disease, e.g., dietary inflammatory potential has been found to be associated with colorectal cancer risk in several studies [43]*[75].…”

“…The validity of the score relative to the underlying hypothesis is evaluated in independent study populations, and the dietary pattern score is then derived and used in different study populations (in the same manner as a priori patterns) to examine its association with disease risk [24, 25]**. For example, Tabung et al , used reduced rank regression [26] to develop an empirical dietary inflammatory pattern (EDIP) score [24]**, and stepwise linear regression analyses to develop empirical indices to assess the insulinemic potential of diet and lifestyle [25]**. These indices may then be used to examine associations with diseases whose development is hypothesized to be mediated through the inflammatory or insulin response pathways respectively.…”