Few studies have addressed the role of obesity in young adulthood in knee problems later in life. We assessed the associations of overweight/obesity with knee pain and functional limitations of the knee across the life course.Methods:
Military health records from 1967 to 2000 (baseline) were searched for 18- to 50-year-old Finnish men (n = 1913) who participated in the Health 2000 Study (follow-up). Visits to health care were followed during service. Height and weight were measured at baseline and follow-up and waist circumference at follow-up. Weight was inquired at follow-up for ages of 20, 30, 40 and 50 years, if applicable. Life course body mass index (BMI) was calculated. One-month knee pain and functional limitations (walking difficulties and limping) due to knee problems were enquired with interview at follow-up. Cox regression model, logistic regression and trajectory analysis were applied.Results:
Body mass index at the age of 20 increased the risk of unilateral knee pain by 38% and functional limitations by 27% for one standard deviation increment of BMI, respectively. One-unit increment of Z-score of life course BMI increased knee pain by 32%. Development of severe obesity during the follow-up increased the risk of knee pain by 80% and functional limitations by 93%. The effect of obesity on functional limitations was partly mediated by traumatic knee problems during military service.Conclusions:
Reducing overweight already in adolescence and avoiding further weight gain during life course may prevent knee pain and associated disability.What does this study add?:
BMI at the age of 20 increases the likelihood of knee pain and functional limitations of the knee later in life.What does this study add?:
Development of severe obesity in adulthood increases the risk of knee pain by 80% and functional limitations by more than 90%.What does this study add?:
Both general and abdominal obesity are associated with knee pain, associations being stronger for general obesity.