title: Duration of diabetes and its association with depression in later life: The Health In Men Study (HIMS).
abstract: OBJECTIVE
  To examine if diabetes and duration of diabetes are direct or indirect causes of depression in later life.
  
  
  METHODS
  Cross-sectional study of a community-derived sample of 5462 men aged 70-89 years. Men with 'current depression' scored 7 or more on the abbreviated Geriatric Depression Scale (GDS-15), whereas men with 'ever depression' were either currently depressed or reported history or treatment for past depression. The presence of diabetes was established by self-reported history, fasting glucose ≥7 mmol/L (126 mg/dL), or use of insulin or hypoglycemic drugs. Duration of diabetes relied on self-report. Other measured factors included age, place of birth, education, smoking history, and the FRAIL scale.
  
  
  RESULTS
  Diabetes was associated with increased odds ratio (OR) of ever (OR=1.49, 95%CI=1.25, 1.76) and current depression (OR=1.94, 95%CI=1.15, 2.48). The association between duration of diabetes and risk of current depression was 'J-shaped' with odds ratios of 1.92 (95%CI=1.44, 2.54), 1.56 (95%CI=0.89, 2.75), 2.49 (95%CI=1.16, 5.32) and 3.13 (95%CI=1.28, 7.63) for <10, 10-19.9, 20-29.9 and ≥30 years of diabetes history compared with older men without diabetes. The strength of these associations was attenuated after the analyses were adjusted for other measured factors, but the shape of the curve did not change. Structural equation modeling showed that frailty mediated some of the association between diabetes duration and depression (about 15%) and was a strong predictor of depression in the sample.
  
  
  CONCLUSIONS
  In older men, the association between time lived with the diagnosis of diabetes and the risk of depression is 'J-shaped'. Frailty mediates some of the association between diabetes and depression, although other unmeasured factors are also likely to play a role. The introduction of strategies that are effective at decreasing diabetes-related complications may also contribute to decrease the risk of depression among older men.
authors.affiliation: School of Psychiatry & Clinical Neurosciences, University of Western Australia, Perth, Australia; WA Centre for Health & Ageing of Centre for Medical Research, Harry Perkins Institute of Medical Research, Perth, Australia; Department of Psychiatry, Royal Perth Hospital, Perth, Australia. Electronic address: osvaldo.almeida@uwa.edu.au.
authors.forename: Osvaldo P
authors.initials: OP
authors.lastname: Almeida
authors.affiliation: WA Centre for Health & Ageing of Centre for Medical Research, Harry Perkins Institute of Medical Research, Perth, Australia.
authors.forename: Kieran
authors.initials: K
authors.lastname: McCaul
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; Department of Neurology, Sir Charles Gairdner Hospital, Perth, Australia.
authors.forename: Graeme J
authors.initials: GJ
authors.lastname: Hankey
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; Department of Endocrinology, Fiona Stanley Hospital, Perth, Australia.
authors.forename: Bu B
authors.initials: BB
authors.lastname: Yeap
authors.affiliation: Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Australia; Department of Vascular and Endovascular Surgery, The Townsville Hospital, Townsville, Australia.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Golledge
authors.affiliation: School of Surgery, University of Western Australia & Department of Surgery, Fiona Stanley Hospital, Australia.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Norman
authors.affiliation: WA Centre for Health & Ageing of Centre for Medical Research, Harry Perkins Institute of Medical Research, Perth, Australia; School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; Department of Geriatric Medicine, Royal Perth Hospital, Perth, Australia.
authors.forename: Leon
authors.initials: L
authors.lastname: Flicker
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003863:Depression / Q000209:etiology*; D003866:Depressive Disorder; D003920:Diabetes Mellitus / Q000523:psychology*; D016330:Frail Elderly / Q000523:psychology; D006801:Humans; D008297:Male; D016017:Odds Ratio; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D013997:Time Factors
keywords: Aged; Depression; Depressive disorder; Diabetes; Elderly; Epidemiology; Risk factors