Psychosocial factors and obesity in 17 high-, middle- and low-income countries: the Prospective Urban Rural Epidemiologic study.

Background/objectives: Psychosocial stress has been proposed to contribute to obesity, particularly abdominal, or central obesity, through chronic activation of the neuroendocrine systems. However, these putative relationships are complex and dependent on country and cultural context. We investigated the association between psychosocial factors and general and abdominal obesity in the Prospective Urban Rural Epidemiologic study.

Subjects/methods: This observational, cross-sectional study enrolled 151 966 individuals aged 35-70 years from 628 urban and rural communities in 17 high-, middle- and low-income countries. Data were collected for 125 290 individuals regarding education, anthropometrics, hypertension/diabetes, tobacco/alcohol use, diet and psychosocial factors (self-perceived stress and depression).

Results: After standardization for age, sex, country income and urban/rural location, the proportion with obesity (body mass index ≥30 kg m(-)(2)) increased from 15.7% in 40 831 individuals with no stress to 20.5% in 7720 individuals with permanent stress, with corresponding proportions for ethnicity- and sex-specific central obesity of 48.6% and 53.5%, respectively (P<0.0001 for both). Associations between stress and hypertension/diabetes tended to be inverse. Estimating the total effect of permanent stress with age, sex, physical activity, education and region as confounders, no relationship between stress and obesity persisted (adjusted prevalence ratio (PR) for obesity 1.04 (95% confidence interval: 0.99-1.10)). There was no relationship between ethnicity- and sex-specific central obesity (adjusted PR 1.00 (0.97-1.02)). Stratification by region yielded inconsistent associations. Depression was weakly but independently linked to obesity (PR 1.08 (1.04-1.12)), and very marginally to abdominal obesity (PR 1.01 (1.00-1.03)).

Conclusions: Although individuals with permanent stress tended to be slightly more obese, there was no overall independent effect and no evidence that abdominal obesity or its consequences (hypertension, diabetes) increased with higher levels of stress or depression. This study does not support a causal link between psychosocial factors and abdominal obesity.