Objective: This study examined whether a positive association exists between waist circumference (WC) and dementia among older persons. Methods: The study population comprised 872,082 participants aged 65 years and older who participated in a Korean national health screening examination between January 1, 2009, and December 31, 2009. Adjusted hazard ratios and 95% CIs for dementia during follow-up from 2009 to 2015 were calculated according to baseline BMI and WC categories. Results: After a multivariate adjustment that included BMI, the hazard ratios for dementia showed a stepwise increase according to the increase in WC categories by 5 cm from 85 to 90 cm in men and from 80 to 85 cm in women until ≥ 110 cm (from 1.06 [95% CI: 1.03-1.09] to 1.64 [95% CI: 1.37-1.94] in men and from 1.04 [95% CI: 1.02-1.07] to 1.58 [95% CI: 1.36-1.84] in women). The influence of the current WC category for abdominal obesity on the risk of dementia was different according to BMI; especially, the normal weight men and women with abdominal obesity had a prominent increased risk of dementia compared with those without abdominal obesity. Conclusions: Abdominal obesity, as measured by WC, was associated with significantly increased risk of dementia after adjustment for general obesity.
Bibliographical noteFunding Information:
We identified participants aged 65 years or older who had participated in the NHSE between January 1, 2009, and December 31, 2009. Among these 1,278,060 people, participants with an extreme BMI, defined as < 15 kg/m 2 or ≥ 40 kg/m 2 ( N = 1,575), participants who were diagnosed with dementia within 1 year ( N = 86,979), and people with at least one piece of missing data in the NHSE report ( S1 N = 317,424) were excluded. The remaining 872,082 individuals were observed until December 31, 2015, and monitored for a dementia diagnosis using the NHIS claims database. A flowchart of participant enrollment is shown in Supporting Information Figure . The median follow‐up duration for dementia was 6.46 (interquartile range 6.12‐6.75) years. The study population was observed from baseline until the date of development of dementia, death, or December 31, 2015, whichever came first. This study was approved by the Institutional Review Board of Korea University Medical Center (2018GR0024). An exemption from informed consent was granted by the board because all data were analyzed anonymously.
agencies: HJY was supported by the Basic Science Research Program through the National Research Foundation of Korea, which is funded by the Ministry of Education (2018R1D1A1B07047587), and GJC was also supported by the Basic Science Research Program through the National Research Foundation of Korea, which is funded by the Ministry of Education (2018R1D1A1B07048788).
© 2019 The Obesity Society
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Endocrinology, Diabetes and Metabolism
- Nutrition and Dietetics