Published online Jan 15, 2021. doi: 10.4239/wjd.v12.i1.69
Peer-review started: May 18, 2020
First decision: September 24, 2020
Revised: November 13, 2020
Accepted: December 22, 2020
Article in press: December 22, 2020
Published online: January 15, 2021
In spite of an increase in the incidence and prevalence of diabetes mellitus (DM) and Alzheimer’s disease (AD) in the aging population, limited attention has been paid to investigate their associations.
To investigate the association of DM and cardiometabolic syndrome with risk of AD among the United States older adults.
To examine the association of DM and cardiometabolic syndrome (CMS, a precursor to DM) with risk of incident AD among postmenopausal women.
Postmenopausal women aged 50-79 (n = 63117) who participated in the U.S. Women’s Health Initiative Observational Study (WHIOS), recruited in 1993-1998 without baseline AD and followed up through March 1, 2019 were analyzed. AD was classified by participants-reported history of doctor-diagnosis of first-listed AD. DM was defined by participant-report or serum glucose concentrations or those anti-diabetic medication use. CMS was defined as having ≥ 3 of five CMS components: large waist circumference, high blood pressure, elevated triglycerides, elevated glucose, and low high-density lipoprotein cholesterol. The associations of DM and CMS with AD were analyzed using Cox’s proportional hazards regression analysis.
Within a median follow-up of 20 years (range: 3.36 to 23.36 years), of 63117 participants, 8340 had incident AD. Women with DM had significantly higher incidence of AD [8.5, 95% confidence interval (CI): 8.0-9.0 per 1000 person-years (PY)] than those without DM (7.1, 95%CI: 6.9-7.2 per 1000 PY). Multivariate Cox’s regression analysis indicates that women with DM or CMS had significantly higher risk of AD than those without DM or CMS. The corresponding hazard ratios [HR (95%CI)] were 1.22 (1.13-1.31, P < 0.001) in subjects with DM, and 1.18 (1.09-1.27, P < 0.001) in subjects with CMS. The HRs of AD in those with DM or MS vs those without DM or CMS diminished with age and became non-significant in the oldest age group.
Diabetes and cardiometabolic syndrome were significantly associated with risk of Alzheimer's disease.
Further studies are needed to investigate the mechanisms by which DM and CMS may cause the development of AD.