Mei Chung Moh, PhD; Serena Low, MBBS, MSc; Tze Pin Ng, MD; Su Fen Ang, PhD; Keven Ang, PhD; Chee Fang Sum, MBBS; Tavintharan Subramaniam, MBBS; Su Chi Lim, MBBS, PhD
Background: Studies investigating the association between depression and aortic stiffness in older patients with type 2 diabetes are lacking. We postulated an association between depressive symptoms and aortic stiffness, and this relationship may be mediated by increased adiposity.
Methods: We analyzed participants with type 2 diabetes aged 55 years or older (n = 958). We measured aortic stiffness using carotid–femoral pulse wave velocity (cut-off ≥ 12 m/s) using the tonometry method. We defined depressive symptoms as a score of greater than 5 on the Geriatric Depression Scale–15 (GDS-15). Adiposity indices we assessed were body mass index, waist circumference, waistto-height ratio, visceral fat area and fat mass.
Results: Among the participants, 27.2% had aortic stiffness, of whom 6.5% had depressive symptoms. Score on the GDS-15 was correlated with pulse wave velocity, and both variables were correlated with the adiposity markers we analyzed (all p < 0.05). Depressive symptoms were associated with pulse wave velocity (B = 1.79, 95% confidence interval [CI] 0.83–2.75) or aortic stiffness (risk ratio 1.60, 95% CI 1.10–2.33) in the unadjusted model. The association persisted after controlling for demographics, duration of diabetes, glycated hemoglobin, comorbidities and medications. Further adjustment for visceral fat area and fat mass in separate models reduced the association between depressive symptoms and pulse wave velocity or aortic stiffness. Mediation models revealed that the mediation proportions of fat mass and visceral fat area on the association between depressive symptoms and pulse wave velocity were 11.8% and 9.7%, respectively. A preliminary analysis of longitudinal data (n = 184) showed similar findings.
Limitations: Causality cannot be inferred from the associations we observed.
Conclusion: Depressive symptoms are associated with elevated pulse wave velocity in older people with type 2 diabetes, and this relationship may be partially mediated by increased adiposity.
Submitted Apr. 26, 2020; Revised Jul. 9, 2020; Accepted Jul. 29, 2020
Acknowledgments: The authors thank the staff from the Singapore Clinical Research Institute (SCRI) for their contribution to the study protocol and database design. Study data were collected and managed using REDCap electronic data capture tools hosted at the SCRI.
Affiliations: From the Clinical Research Unit, Khoo Teck Puat Hospital, Singapore (Moh, Low, S. Ang, K. Ang, Subramaniam, Lim); the Diabetes Centre, Admiralty Medical Centre, Khoo Teck Puat Hospital, Singapore (Low, Sum, Subramaniam, Lim); the Gerontology Research Programme, Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore (Ng); and the Saw Swee Hock School of Public Health, National University Hospital, Singapore (Lim).
Competing interests: None declared.
Contributors: All authors designed the study. S. Low and K. Ang acquired the data, which M. Moh, S. Low and S. Lim analyzed. M. Moh wrote the article, which all authors reviewed. All authors approved the final version to be published and can certify that no other individuals not listed as authors have made substantial contributions to the paper.
Funding: The SMART2D cohort is supported by the Singapore Ministry of Health’s National Medical Research Council CS-IRG (MOH-000066). S. Lim is supported by the Singapore Ministry of Health’s National Medical Research Council Clinical Scientist Award (NMRC/CSA-INV/0020/2017).
Content licence: This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY-NC-ND 4.0) licence, which permits use, distribution and reproduction in any medium, provided that the original publication is properly cited, the use is non-commercial (i.e. research or educational use), and no modifications or adaptations are made. See: https://creativecommons.org/licenses/by-nc-nd/4.0/
Correspondence to: S.C. Lim, Diabetes Centre, Admiralty Medical Centre, Khoo Teck Puat Hospital, 676 Woodlands Drive 71 #03-01, Singapore 730676; firstname.lastname@example.org