摘要：Objectives. We examined trends in obesity and arthritis prevalence among the “baby boom” (born 1946–1965) and “silent” (born 1926–1945) generations. Methods. We conducted birth cohort analyses using successive waves of the National Health and Nutrition Examination Survey (1971–2002). Results. Obesity rates increased markedly, beginning earlier in life with each successive birth cohort. When the members of the silent generation were aged 35–44 years, 14%–18% were obese. At comparable ages, 28%–32% of the youngest baby boomers were obese. Differences in arthritis prevalence were not evident across birth cohorts. However, the relative risk of arthritis because of obesity increased over time; consequently, the percentage of arthritis cases attributable to obesity increased from 3% to 18% between 1971 and 2002. Conclusions. Our results showed that members of the baby boom generation were more obese, and became so at younger ages than their predecessors. Although differences in arthritis prevalence are not yet evident, findings suggest that obesity has contributed to more cases of arthritis in recent years than in previous decades. The aging of the “baby boom” generation—that is, individuals born from 1946 through 1964—in the United States has profound societal implications because of the size of this generation relative to previous and subsequent ones. 1 – 3 Understanding the effects on population disability of this progressing demographic shift is essential to anticipating health care needs and developing appropriate services for the new generation of elderly people. Although apparent declines in disability rates in the older population in recent decades have generated great optimism, 4 – 6 it remains uncertain whether aging baby boomers will continue this trend. Several factors inspire hope for continued improvement while others raise concerns, especially regarding possible increases in disability from arthritis and chronic joint symptoms caused by widespread adoption of unhealthy lifestyle practices. Trends in problems associated with sedentary behavior and obesity are worrisome, especially among baby boomers. 7 , 8 Access to better nutrition has improved, but at the same time consumption of high-fat, high-carbohydrate foods has increased. In recent years, rates of obesity have risen dramatically, although physical activity rates have remained unchanged. 8 Among children, rates of sedentary behavior are increasing. 8 Moreover, substantial differences exist in prevalence of obesity, especially among women of differing racial/ethnic groups. More than half of non-Hispanic Black women aged 40 years and older were obese in 1999–2000, as compared with approximately one third of non-Hispanic White women in the same age group; 40%–50% of Mexican American women were obese. 7 In the coming decades, such lifestyle factors are likely to contribute to large increases in rates of arthritis, as well as increases in diabetes and cardiovascular disease. Recent projections show that the aging of baby boomers will result in a doubling of the numbers of persons aged 65 years or older with arthritis or chronic joint symptoms by 2030, when the last of the baby boom generation will turn 65 years old. 2 However, these calculations assume stability in arthritis prevalence and probably underestimate an impending surge in prevalence among more obese baby boomers. At the population level, disability and increased use of health services have accompanied higher rates of arthritis. 9 We used US census data to examine changes in the racial/ethnic composition of the baby boom generation and its predecessor, commonly referred to as the “silent generation” (individuals born between 1926 and 1945). Also, to assess trends in prevalence of obesity, overweight, and arthritis among baby boomers and their predecessors, we analyzed data from successive waves of the National Health and Nutrition Examination Survey (NHANES) conducted between 1971 and 2002. In addition, we studied the relationship between obesity and arthritis among these birth cohorts.
