BODY-MASS INDEX AND DISABILITY PENSION IN MIDDLE-AGED MEN - NONLINEARRELATIONS

Background. Obesity has, in a number of studies, been found to correla te to disability and mortality, primarily due to diseases of the circu latory and musculoskeletal systems. In addition, an excess mortality a mong underweight subjects has been observed in previous studies. Metho ds. Five complete birth-year cohorts (1926-1930) of male residents in Malmo (n = 7697) were invited to the survey at the Department of Preve ntive Medicine, Malmo General Hospital, and 5926 (77%) attended with c omplete data. Each subject was followed from inclusion, defined by the dale of examination, until the end of the calendar year when he turne d 58, a total study period of approximately 11 years. Data on about 30 0 questionnaire items and laboratory tests were determined at the heal th survey visit, Nationwide Swedish data registers were used for surve illance. Results. Of the participants, 4.7% were underweight, 37.7% ov erweight, 7.3% obese and 50.3% normal weight; 849 (14.3%) had been gra nted disability pension at the end of follow-up, 717 after screening. After adjustment for smoking there was a J-shaped relation between bod y mass index (BMI) and incidence of disability pension, the relative r isk (with the normal group as reference) among underweight men being 1 .9. For the overweight subjects it was 1.3 and for the obese 2.8, all differences were significant. Diseases of the musculoskeletal and circ ulatory systems and mental disorders accounted for 67.2% of all main d iagnoses resulting in disability pensions during follow-up. A total of 377 (6.4%) men died during follow-up. Diseases of the circulatory sys tem, neoplasms, injury/poisoning and diseases of the respiratory syste m accounted for 91.8% of the deaths. Conclusions. Both underweight, ov erweight and obesity were related to risk of disability pension, with a J-shaped risk relationship.