Objective: To investigate the association between body mass index (BMI) and functional health according to age and the support available from a close confidant.
Design: A cross-sectional population-based study.
Participants: A total of 20 921 participants in the European Prospective Investigation into Cancer and Nutrition, aged 41-80 y resident in Norfolk, England.
Measurements: Standardised clinic-based assessment of BMI, self-reported functional health status assessment (according to the anglicised Short Form 36 (SF-36) Health Survey questionnaire) and the availability (and quality) of a close confiding relationship.
Results: Self-reported physical functioning declined steadily with increasing age. Obesity (BMI >/=30) was strongly associated with self-reported physical functional health, equivalent to being 11 y older for men and 16 y older for women (after adjustment that included prevalent chronic physical conditions and cigarette smoking). This adverse effect of obesity on physical functional health was found to increase with age for both men and women. Perceived inadequacy of a confiding relationship was associated with reduced physical functional capacity, equivalent to being 4 y older for men and 5 y older for women. For those with markedly inadequate confidant relationships, the impact of obesity on physical functional capacity was approximately constant by age. For those not critical of the adequacy of their confiding relationships, the impact of obesity was least for those younger but rose to equivalent levels as those with markedly inadequate confidant relationships among older participants.
Conclusions: The availability of a close confidant relationship (perceived as uncritical and characterised by the absence of shared negative interactions) may delay the impact of obesity in reducing physical functional capacity.