Poor social relations and adverse health behaviour: stronger associations in low socioeconomic groups?

Poor social relations are supposed to contribute to adverse health behaviour. We examined this association and the role of low socio-economic position. We regressed health behaviour on composite variables of the two exposures of social relations and socio-economic position (SEP). Social relations included networks and support; health behaviour was analysed in terms of smoking, poor nutrition and physical inactivity; socio-economic position comprised of income and education. Cross sectional data from a population based epidemiological study in German (4,814 men and women aged 45-75) was analysed. Among the indicators for social relations, social isolation was consistently associated with adverse health behaviour; social support showed modest effect. A combination of poor social relations and low SEP displayed stronger (additive) associations with adverse health behaviour than each factor alone. However, superadditivity was excluded. Given the important role of health adverse behaviour in chronic disease development, results underline the relevance of social environment and socio-economic structure in Public Health interventions.