Table 3.

Risk reduction and residual risk: HRs for weight change^a and incident arthritis conditions^b, NHANES 1988–1994 & 1999–2016 (n=13,669)

Weight Change	HRc	95% CI	P value
Risk Reduction Hypothesis (weight loss vs higher weight maintenance)
overweight-normal vs overweight-overweightd	0.94	0.67–1.34	0.739
obese-overweight vs obese-obese	0.54	0.32–0.92	0.023
Residual Risk Hypothesis (weight loss vs lower weight maintenance)
overweight-normal vs normal-normal	1.06	0.76–1.47	0.752
obese-overweight vs overweight-overweight	1.01	0.61–1.68	0.972

^aWeight change categories based on BMI at age 25 (young adulthood) and BMI 10 years prior to the survey (midlife). Weight change categories are defined in Table S1.

^bIncident arthritis conditions reflects new arthritis conditions that occurred over the 10-years of follow-up from the recalled midlife weight measure to the time of survey.

^cHazard ratios generated via post-estimation through the lincom command of the base model comparing all weight change categories to the normal-normal reference group. All estimates sample weighted and adjusted for categorical age at the midlife measure, gender, race/ethnicity, education level at survey, smoking status at the midlife measure, and survey year.

^dThis model presents the hazards of developing an arthritis condition for individuals who were overweight in young adulthood and lost to normal weight at midlife compared with individuals who were overweight and remained overweight. The other comparisons were constructed in the same fashion.