Greater weight change per decade from midlife through late life predicts incident MCI

Abstract

Unintentional weight loss has been associated with risk of dementia. Few large population-based studies have examined the association of weight change with risk of mild cognitive impairment (MCI). We aim to investigate the association of rate of weight change per decade with risk of MCI. Cognitively normal participants (n=2,061; mean age, 78.8 years; 50.5% male) in the population-based prospective Mayo Clinic Study of Aging were clinically evaluated every 15 months for incident MCI. Weight and height at ages 70 or older were measured at each evaluation. Maximum adult weight and height in midlife (i.e. ages 40 to 65 years; mean, 59.7) were ascertained for each participant using a medical records linkage system. We investigated the association of weight change per decade (from midlife through late life) with risk of MCI using proportional hazards models with age as the time scale. Over a mean (SD) follow-up of 4.4 (2.4) years, 578 participants developed incident MCI. The mean weight change per decade (in kilograms) was -1.8 (6.5) for persons with incident MCI cases vs. -1.2 (6.1) for persons who remained cognitively normal (p = 0.015). Declining weight per decade was associated with an increased risk of MCI (beta (SE), -0.031 [0.007]; p <0.0001) after adjustment for sex and education. There was a sex difference showing a stronger association in men (beta, -0.04 [0.012], p = 0.0002) than in women (beta, -0.022 [0.010]; p = 0.026). Risk of MCI also increased with decline in body mass index per decade (-0.059 [0.019], p = 0.002). The rate of weight change from midlife through late life predicts incident MCI and should be considered in risk stratification models for MCI. The stronger association in men may relate to the earlier onset of MCI in men observed in our previous studies.