Abstract
OBJECTIVES: To study the importance of weight change with regard to mortality in older people. DESIGN: Prospective cohort study. PARTICIPANTS: The cohort includes participants in the Hordaland Health Study, Norway, 1997-99 (N=2935, age 71-74 years) who had previously participated in a survey in 1992-93. MEASUREMENTS: Participants with weight measured at both surveys were followed for mortality through 2012. Cox proportional hazards models were used to calculate risk of death according to changes in weight. Hazard ratios (HR) with 95% confidence intervals (CIs) for people with stable weight (± <5% weight change) were compared to people who lost (≥5%) or gained (≥5%) weight. Cox regression with penalized spline was used to evaluate the association between weight change (in kg) and mortality. Analyses were adjusted for age, sex, physical activity, smoking, diabetes, hypertension, and previous myocardial infarction or stroke. Participants with cancer were excluded. RESULTS: Compared to those with stable weight, participants who lost ≥5% weight had an increased mortality risk (HR 1.59 [95% CI: 1.35-1.89]) while the group with weight gain ≥5% did not (HR 1.07 [95% CI 0.90-1.28]). Penalized spline identified those who lost more than about three kg or gained more than about 12 kg as having increased risk of death. CONCLUSION: Even a minor weight loss of ≥5% or >3 kg were significantly associated with increased risk of mortality. Thus, weight should be routinely measured in older adults.