Weight loss from adolescence to midlife curbs arthritis risk
Losing weight from young adulthood into midlife is associated with a substantially reduced risk for arthritis, according to data published in Arthritis Care & Research.
“In addition to increases in the overall prevalence of obesity, recent U.S. birth cohorts are becoming obese earlier in life and, thus, spending greater portions of their lives with excess weight,” Kaitlyn M. Berry, MPH, of the University of Minnesota School of Public Health, and colleagues wrote. “The effects of these weight shifts on the risk of arthritis are largely unknown. Using data from the Nurses’ Health Study, one recent study estimated that weight gain from early to mid-adulthood of 2.5-10 kg, 10-20 kg, or more than 20 kg was associated with a 20%, 31%, and 40% increase in the likelihood of osteoarthritis-related total hip replacement.”
“However, the study did not investigate the risk of other types of arthritis or the effects of weight loss,” they added. “If the effects of obesity on arthritis conditions are cumulative, those who lose weight may experience residual risk due to irreversible pathologic processes from carrying excess weight earlier in life. Additionally, although some studies have demonstrated how weight change modifies risk of arthritis conditions at the individual-level, the aggregate effect of population-level weight loss or obesity prevention remains uncertain.”
To analyze the link between weight change from adolescence to midlife and the risk for arthritis, Berry and colleagues studied data from the National Health and Nutrition Examination Survey (NHANES). According to the researchers, NHANES is a nationally representative survey of adults in the United States with information on demographic characteristics, weight history and health behaviors and conditions. For their study, Berry and colleagues combined cross-sectional data from NHANES III, conducted form 1988-1994, with repeat information from NHANES “continuous waves,” collected in two-year cycles between 1999 and 2016.
The researchers examined a sample of 13,669 adults aged 40 to 69 years at their midlife weight measure. Berry and colleagues grouped these participants into weight change categories based on participants’ recalled weight during adolescence and midlife. Investigators then used Cox models to estimate the association between weight change and arthritis over 10 years. Findings were extrapolated to the entire U.S. population to then analyze the proportion of incident arthritis cases that could be averted if the nation’s population maintained a normal BMI in young adulthood and midlife.
According to the researchers, 3,603 of the included participants developed arthritis. Compared with adults who maintained a normal BMI in both adolescence and midlife, those who transitioned from normal to overweight, normal to obese and overweight to obese, plus those who remained obese throughout, demonstrated a significantly higher risk for incident arthritis conditions. However, those who shifted from obese to overweight still had a lower risk for arthritis than with those who remained obese throughout, and had a comparable risk to those who remained overweight.
In their extrapolation, the researchers estimated that nearly one-quarter of arthritis cases, representing 2.7 million patients, could have been avoided had all individuals maintained normal weight from young adulthood to midlife.
“Those who lost weight had a risk comparable to those who maintained a lower weight, suggesting there may not be residual risk associated with having previously been heavier,” Berry and colleagues wrote. “Extrapolating to the population-level, we estimate that a substantial portion of incident arthritis cases could be avoided through effective weight loss strategies for individuals and population-level policies that encourage primary prevention of overweight/obesity.”
The researchers added that their “findings highlight the critical need to expand obesity treatment and prevention activities in order to achieve meaningful reductions in the burden of arthritis in the U.S. population.” – by Jason Laday
Disclosures: Berry reports an award from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Please see the study for all other authors’ relevant financial disclosures.