Life-course social and economic inequalities in non-communicable disease prevalence: the Tromsø Study (2015–2016)

AIM: To systematically examine associations between six inequality indicators from different life-course domains and the adult prevalence of six non-communicable diseases (NCDs) within a Nordic population-based study. METHODS: We conducted a cross-sectional analysis using data from the seventh Tromsø Study survey (2015-2016) in Norway. All residents aged ⩾40 years were invited (65% participation). Age-adjusted, sex-stratified logistic regression models were used to assess associations between inequality indicators (parental and own educational level, childhood economic status, adverse childhood experiences (ACEs), income, and subjective occupational status) on continuous 0-1 cumulative proportion scales, and NCDs (major adverse cardiovascular events (MACE), cancer, chronic obstructive pulmonary disease (COPD), diabetes, musculoskeletal symptoms, and mental distress). Odds ratios (ORs), with 95% confidence intervals (CIs), were estimated, where OR >1 indicates higher odds of an NCD with greater disadvantage. RESULTS: Among 21,069 participants, greater social and economic disadvantage was associated with higher odds of MACE, COPD, diabetes, musculoskeletal symptoms, and mental distress. For musculoskeletal symptoms, significant associations were observed across all inequality indicators in both sexes. The steepest gradients were observed in mental distress for ACEs in women (OR 7.81, 95% CI 6.20-9.86) and men (10.09, 7.34-13.88). In contrast, greater disadvantage was associated with lower odds of cancer for some indicators; sensitivity analyses indicated these findings reflected cancer types with known positive socioeconomic gradients. CONCLUSIONS: Life-course social and economic disadvantage was consistently associated with higher prevalence of MACE, COPD, diabetes, musculoskeletal symptoms, and mental distress, with the pattern and magnitude varying across inequality indicators and NCDs.