Associations of a novel UK-based diet quality score (DQS-UK-2022) with cardiovascular disease risk markers in UK adults: a cross-sectional analysis using National Diet and Nutrition Survey data

Diet quality scores (DQSs) are widely used in research to quantify diet quality based on adherence to population-based dietary recommendations and favourable dietary patterns. Many DQSs exist (e.g. Healthy Eating Index and Mediterranean Diet Score), but there are no recognised DQSs developed for a UK population (1) . The evidence-based DQS-UK-2022 was developed to quantify diet quality in UK adults (2) . This research aims to explore its relationship with CVD risk in UK adults. Cross-sectional data from the UK’s National Diet and Nutrition Survey (NDNS) rolling programme (2008-2014) (3,4) were used (n=4738 adults). Markers of CVD risk included blood pressure, anthropometric measurements, fasting serum lipids, C-reactive protein (CRP), haemoglobin A1C, fasting glucose, and homocysteine (n=2387 for blood biomarkers). The DQS-UK-2022 was calculated for dietary intake data (nutrients and food groups) from estimated diet diaries collected as part of NDNS. The DQS includes 6 adequacy components (fruits, vegetables, wholegrains, dairy, nuts/pulses and oily fish, where greater intakes scored higher), 4 moderation components (sodium, alcohol, red/processed meats and free sugars, where lower intakes scored higher) and a mixed component (saturated fatty acids (SFA) and ratio of unsaturated to SFA) 2. Each component had absolute cut-offs broadly based on current UK dietary recommendations. Intakes above/below the maximum/minimum cut-offs scored 10 or 0 points, respectively, with intermediate intakes scored proportionately using linear interpolation. Component scores were summed and scaled to a total score out of 100, with higher DQS-UK-2022 scores indicating greater adherence to UK dietary recommendations. Participants with unfeasible energy intakes (<600 and >4500 kcal/d) were excluded (n=34). DQS scores were divided into quintiles (Q1: ≤35 points; Q5: ≥57 points). All continuous variables were log transformed to normalise data. Associations between DQS quintiles and CVD risk markers were assessed using analysis of covariance (ANCOVA) adjusted for age, sex and ethnicity. Where significant (p<0.05), a comparison between Q1 and Q5 was conducted, with Bonferroni correction for all potential pairwise comparisons. Results are presented as estimated marginal means ±SD. Those in Q5 vs Q1 had significantly lower body mass index (26.9 ±0.2 vs 28.0 ±0.2 kg/m2), waist circumference (90.7 ±0.5 vs 95.1 ±0.5 cm), waist-to-hip ratio (0.86 ±0.03 vs 0.89 ±0.03), serum triacylglycerol (1.15 ±0.04 vs 1.50 ±0.04 mmol/l), total cholesterol to high density lipoprotein cholesterol (HDL-C) ratio (3.52 ±0.06 vs 3.91 ±0.06), CRP (2.67 ±0.32 vs 4.52 ±0.34 mg/l), homocysteine (9.0 ±0.2 vs 11.5 ±0.2 μmol/l), systolic blood pressure (125 ±1 vs 128 ±1 mmHg) and diastolic blood pressure (72.5 ±0.4 vs 75.0 ±0.5 mmHg) and higher HDL-C (1.54 ±0.02 vs 1.44 ±0.02 mmol/l) (ANCOVA: p≤0.007 for all). Higher scores from the novel DQS-UK-2022 were associated with lower CVD risk factors. To strengthen these findings, prospective associations between the DQS-UK-2022 and CVD incidence/mortality will be investigated.