(P27-036-25) Performance of Metrics From the Diet Quality Questionnaire (DQQ) for Predicting Human Milk Micronutrient Concentrations Among Lactating Women From Northern Ghana

Objectives: Diet quality metrics are increasingly used for population assessments, but their utility for assessing micronutrient deficiency risk among breastfeeding dyads is uncertain. We aimed to assess and compare the convergent validity of the Global Dietary Recommendations (GDR) and Dietary Diversity (DDS) scores from the Diet Quality Questionnaire (DQQ) for predicting human milk concentrations of vitamins A (VA) and B12.

Methods: We analyzed data from lactating participants (15-49 y, 4-18 mo postpartum at enrollment) in the CoMIT trial. GDR (range 0-18) and DDS (range 0-10) were calculated from DQQs administered at four visits (wk 0, n=599; wk 4, n=545; wk 8, n=540; wk 12 n=299). Milk samples collected at wks 11-12 were analyzed for fat (Creamatocrit), VA (HPLC) and B12 (immunoassay). Spearman rank correlations (rho) determined associations between monthly scores and milk micronutrients. Steiger tests compared the predictive performance of the GDR and DDS. Receiver operating characteristic (ROC) curves assessed the performance of each metric against inadequate infant B12 and VA intakes (low milk concentrations: B12 [≤310 pmol/L], VA [≤28 nmol/g fat]). Optimal performance was defined as area under the ROC curve (AUC) ≥ 0.7.

Results: Longitudinal dietary patterns were consistent; monthly mean scores ranged from 12.1-12.2 (GDR) and 4.0-4.5 (DDS). Prevalence of low milk VA and B12 was 26% and 79%, respectively. Statistically significant (p < 0.05) correlations were observed between GDR and milk VA (wk 8, rho=0.17) and B12 (wk 0, rho=0.11) and between DDS and milk VA (wk 8, rho=0.22) and B12 (wk 8, rho=0.09), but not at other timepoints. DDS significantly outperformed GDR at predicting both nutrients, except for B12 at wk 0. Monthly AUCs were low, ranging from 0.50–0.60 (DDS) and 0.50–0.58 (GDR) for low milk VA, and for low milk B12, 0.51–0.61 (GDR) and 0.51–0.57 (DDS).

Conclusions: Despite the low dietary diversity observed in this population (DDS < 5), which is consistent with prevalent low milk VA and B12, high population GDR scores (≥10) suggested overall good diet quality. While DDS outperformed GDR, both metrics showed weak, inconsistent relationships with milk VA and B12, indicating limited utility for assessment of micronutrient deficiency risk among breastfeeding dyads in this context.

Funding Sources: Helen Keller International via Bill & Melinda Gates Foundation