Cumulative Effect of Depressive Symptoms Predicts Diurnal Cortisol Pattern in the Oldest-Old Helena Chui 1, Christiane Hoppmann 2, Denis Gerstorf 3, Ruth Walker 1, Mary Luszcz 1 1 Flinders University, 2 University of British Columbia, 3 Humboldt University
Overview 1. Depressive symptoms and Hypothalamic- Pituitary-Adrenal (HPA) axis function 2. Research questions 3. Method 1. Australian Longitudinal Study of Ageing (ALSA) 2. ALSA Daily Life Time-Sampling Study (ADuLTS) 4. Results 5. Conclusion 2
1. Depressive symptoms and HPA axis function Increased HPA axis activity has been associated with higher risk of depression in children, adolescents, and young adults (for a review, Stetler & Miller, 2011). HPA axis functioning: 1. Age (Almeida et al., 2009) 2. Depressive symptoms (Clinical vs. community samples) (Miller et al., 2007) 3
1. Depressive symptoms and HPA axis function Community sample (Heaney et al., 2010) Young adults: 18-22 years; Older adults: 65-88 years 4
1. Depressive symptoms and HPA axis function If the HPA is different between depressed and non-depressed older adults: 1. An effect of current depressive symptoms on cortisol? 2. A cumulative effect of depressive symptoms on cortisol? 5
2. Research Questions 1. Do current depressive symptoms predict cortisol in the oldest-old? 2. Does the cumulative effect of depressive symptoms predict cortisol in the oldest-old? 6
3. Method Nesselroade & Featherman (1991) ALSA and ADuLTS 7
3. Method 1. Australian Longitudinal Study of Ageing (ALSA) Started in 1992, 11 waves Baseline: n = 2,087, M age = 78.2 years (SD = 6.7) 2. ALSA Daily Life Time-Sampling Study (ADuLTS) 2010, 7 consecutive days, 7 times a day (at waking, 30 mins, every 3 hours thereafter) n = 50, M age = 89.04 years (SD = 2.50) 8
3. Method: ALSA Measures 1. Depressive symptoms 20-item Center for Epidemiological Studies Depression Scale (CES-D; Radloff, 1977). 4-point scale (0 = Rarely or none of the time; 3 = Most or all of the time). Mean substitution was performed when less than 20 percent of responses were missing. Cronbach s alpha ranged from.78 in Wave 1 to.84 in Wave 3, suggesting satisfactory internal consistency across waves. 9
3. Method: ALSA Whole ALSA sample Wave 1 (1992) N=2051 Wave 3 (1994) N=1156 Wave 6 (2000) N=649 ADuLTS subset (positively selected) Wave 7 (2003) N=404 Wave 9 (2008) N=190 M (SD) M (SD) M (SD) M (SD) M (SD) CESD 8.32 (7.46) 8.35 (7.31) 9.07 (6.67) 8.53 (7.42) 9.88 (7.15) Wave 1 (1992) N=50 Wave 3 (1994) N=49 Wave 6 (2000) N=49 Wave 7 (2003) N=48 Wave 9 (2008) N=45 M (SD) M (SD) M (SD) M (SD) M (SD) CESD 4.67 (4.32) 5.11 (5.56) 7.44 (5.86) 6.67 (6.68) 8.26 (6.74) 10
3. Method: ALSA Cumulative effect of depressive symptoms Sum of CESD in ALSA Waves 1, 3, 6, 7 and 9 M = 31.61, SD = 23.04 25 20 CES-D 15 10 5 0 0 5 10 15 Year 11
3. Method: ADuLTS 1. Current depressive symptoms 10-item CESD short form (Radloff, 1977; Andresen 1994). 4-point scale (0 = Rarely or none of the time; 3 = Most or all of the time). Mean substitution was performed when less than 20 percent of responses were missing. Cronbach s alpha =.65 (removed sleep item). M = 4.69, SD = 3.46. 12
3. Method: ADuLTS 2. HPA axis functioning Salivary cortisol 7 times a day for 7 consecutive days (waking, 30 minutes after waking, every 3 hours thereafter) Compliance rate: 94% (M = 47, SD = 2.62) No backfiling: 91% Area Under Curve (mean across seven days) M = 99.65, SD = 36.97 13
3. Method: ADuLTS Diurnal cortisol pattern Wake up Cortisol awakening response (CAR) Slope 14
3. Method: ALSA & ADuLTS Correlations CESD cumulative CESD current Cortisol AUC CESD cumulative --.57*** -.16 CESD current -- -.03 Cortisol AUC (Mean across days) -- 15
3. Method: ALSA & ADuLTS Adam et al. (2006); CAR: Dummy-coded (1 = 15-45 mins after waking; 0 = other times) 16
3. Method: ADuLTS Level 3 covariates: current CESD and cumulative CESD 17
3. Method: ADuLTS Control variables: Between-person level: gender, body mass index, medication use: (a) depression, (b) anxiety, (c) thyroid conditions Day level: wake up time, sleep duration Within-person level: nicotine, medicine, cold shower, caffeine, food, brushed teeth, alcohol, exercise 18
4. Results: Diurnal cortisol pattern Model 1 Fixed effect Estimate(SE) Intercept 14.15(.45)*** Time since waking -1.49(.09)*** Time since waking 2.05(.01)*** Cortisol (Fitted Values) 0 5 10 15 20 CAR 5.53(.82)*** 0 5 10 15 Time Since Waking (Hours) Fixed effects of control variables and random effects are not presented for simplicity. 19
4. Results: CESD (current / cumulative) on cortisol Model 2 Model 3 Fixed effect Estimate(SE) Estimate(SE) Intercept 14.18(.45)*** 14.15(.45)*** Time since waking -1.51(.09)*** -1.49(.09)*** Time since waking 2.06(.01)***.05(.01)*** CAR 5.56(.82)*** 5.49(.77)*** CESD current -.06(.12) -- CESD current x time.02(.01) -- since waking CESD current x CAR -.20(.23) -- CESD cumulative -- -.02(.02) CESD cumulative x time --.002(.002) since waking CESD cumulative x CAR -- -.09(.03)** CESD current and CESD cumulative are grand mean centered. 20
4. Results: CESD (current & cumulative) on cortisol Fixed effect Model 4 Estimate(SE) Intercept 14.13(.45)*** Time since waking -1.50(.09)*** Time since waking 2.06(.01)*** CAR 5.51(.77)*** CESD current.04(.15) CESD current x time.02(.01) since waking CESD current x CAR.18(.27) CESD cumulative -.02(.02) CESD cumulative x time since waking CESD cumulative x CAR.00002(.002) -.10(.04)* CESD current and CESD cumulative are grand mean centered. Cortisol (Fitted Values) 0 5 10 15 20 25 CESD cumulative +1SD CESD cumulative -1SD 0 5 10 15 Time Since Waking (Hours) 21
5. Conclusion Lower CAR in oldest-old adults with higher cumulative depressive symptoms. Current depressive symptoms were not associated with cortisol in oldest-old. CAR: Sleep inertia (Clow et al., 2010), fatigue (Adam, et al. 2006), depressive symptoms (Heaney, et al. 2010). Past research: Chronic stress -> lower HPA axis activity, e.g. lower socio-economic status, PTSD, bereavement (Agbedia et al, 2011; Miller et al, 2007; Ong et al, 2011) 22
5. Conclusion Future research: Age-related changes in HPA axis (Ferrari et al. 2001). Integrating long-term changes and short-term variability: Cumulative disadvantage on health. 23
Acknowledgement Australian Research Council (ARC Linkage Project) (LP100200413) ARC Discovery Project (0879152) Canadian Institutes for Health Research ECH Inc Helping Hand Aged Care Inc Minister for the Ageing (DFC) Minister for Health (DoH) Anglicare SA COTA Seniors Voice 24
Questions and comments? Thank you very much. 25