Abstract Background Overweight, health knowledge, sociodemographic and psychosocial risk factors are known predictors of mortality. The proportion of overweight adults increases every year and reached 65.6% in 2022 in Poland. Purpose The present study aimed to identify and compare the determinants of all-cause mortality in adults with normal weight and overweight. Methods The data of the WOBASZ II Survey participants (1061 men (M), 1217 women (W)) were used. Respondents were divided into two subgroups according to the body mass index (BMI): 35.4% had normal weight (18.5≤BMI25kg/m2) and 64.6% were overweight (BMI≥25kg/m2). The Newest Vital Sign Test, the Beck's Depression Inventory, and Berkman and Syme Questionnaire were used to estimate functional health literacy (HL), depression and social support (SS), respectively. The median (IQR) observation period was 10.0(9.9-10.2) years. The proportional hazard regression was conducted to estimate hazard ratio (HR) with 95% confidence interval (CI) related to analysed risk factors. Results The subgroup with overweight compared to the subgroup with normal weight was significantly older (M: 52(39-62) vs 41(29-58) years; W: 57(45-65) vs 41(32-55) years), but there was no difference between groups in prevalence of depression (M: 14.3% vs 15.4%; W: 22.1% vs 20.4%). In addition, much more women with overweight had inadequate HL (50.7% vs 33.5%) and low SS (57.3% vs 49.5%). In general, age≥60 years was an independent risk factor of all-cause mortality (HR, 95%CI: M: 9.45(3.65-24.44), W: 4.13(1.18-14.47), and M: 3.04(1.91-4.84), W: 5.25(2.21-12.49) in the subgroups with normal weight and overweight, respectively). In turn, being in a relationship (married or cohabited) was associated with a lower mortality risk in people with overweight (HR, 95%CI: M: 0.56(0.36-0.90), W: 0.64(0.41-0.99)) and in men with normal weight (HR, 95%CI: 0.36(0.19-0.70)). In man with overweight inadequate HL (HR, 95%CI: 1.68(1.09-2.58), depression (HR, 95%CI: 1.65(1.05-2.59) and low SS (HR, 95%CI: 1.92(1.25-2.94)) were related to higher risk of death. In turn, in women with overweight only inadequate HL (HR, 95%CI: 1.79(1.07-3.02)) and primary education (HR, 95%CI: 1.85(1.17-2.93)) were significantly associated with higher risk of death, while living in commune less than 8.000 of people was associated with lower mortality risk (HR, 95%CI: 0.56(0.35-0.89)). Primary education of women was also associated with higher risk of death (HR, 95%CI: 5.71(2.23-14.65)) in the subgroup with normal weight. Conclusion Being overweight compared to having normal weight is associated with more risk factors of mortality. We revealed that inadequate HL and psychosocial risk factors play a key role in increasing risk of death in people with overweight. Thus, there is a need to continuous learning to improve health knowledge and pay more attention to the role of psychosocial factors in health outcomes.
Cicha-Mikolajczyk et al. (Sat,) studied this question.