ABSTRACT
OBJECTIVE: Chronic stress adversely affects mental and physical well-being. However, health outcomes vary among people experiencing the same stressor. Individual differences in physical and emotional well-being may depend on mitochondrial biology, as energy production is crucial for stress regulation. This study investigated whether mitochondrial respiratory capacity corresponds to individual differences in dementia spousal caregivers' mental and physical health. METHODS: Spousal caregivers of individuals with Alzheimer's disease and related dementias (N = 102, mean age = 71, 78% female, 83% White) provided peripheral blood samples and completed self-report questionnaires on quality of life, caregiver burden, and a 7-day affect scale. Multiple and mixed linear regression were used to test the relationship between mitochondrial biology and well-being. RESULTS: Spare respiratory capacity (b = 12.76, CI[5.23, 20.28 ], p = .001), maximum respiratory capacity (b = 8.45, CI [4.54, 12.35], p < .0001), and ATP-linked respiration (b = 10.11, CI [5.05, 15.18], p = .0001) were positively associated with physical functioning. At average (b = -2.23, CI [-3.64, -.82], p = .002) and below average (b = -4.96, CI [-7.22, 2.70], p < .0001) levels of spare respiratory capacity, caregiver burden was negatively associated with daily positive affect. At above average levels of spare respiratory capacity, caregiver burden was not associated with positive affect (p = .65). CONCLUSIONS: Findings suggest that better mitochondrial health is associated with better psychological and physical health - a pattern consistent with related research. These findings provide some of the earliest evidence that cellular bioenergetics are related to well-being.
ABSTRACT
OBJECTIVE: Sleep quality is an important health-protective factor. Psychosocial factors, including attachment orientation, may be valuable for understanding who is at risk of poor sleep quality and associated adverse health outcomes. High attachment anxiety is reliably associated with adverse health outcomes, whereas high attachment avoidance is associated with adverse health outcomes when co-occurring with poor self-regulatory capacity, indexed by heart rate variability (HRV). We examined the associations between attachment anxiety, attachment avoidance, HRV, and sleep quality. METHODS: Using longitudinal data from a sample of 171 older adults measured four times over 1 year ( M = 66.18 years old; 67.83% women), we separated the between-person variance (which we call "trait") and within-person variance (which we call "state") for attachment anxiety, attachment avoidance, and HRV (via the root mean square of successive differences). Sleep quality was measured with the Pittsburgh Sleep Quality Index. RESULTS: Higher trait attachment anxiety was associated with poorer global sleep quality ( B = 0.22, p = .005). Higher state attachment avoidance was associated with poorer sleep quality ( B = -0.13, p = .01), except for those with higher trait HRV. Higher state attachment anxiety was associated with poorer sleep quality ( B = -0.15, p = .002), except for those with higher or mean trait HRV. Higher trait attachment anxiety was associated with poorer sleep quality ( B = -0.31, p = .02), except for those with higher trait HRV. CONCLUSIONS: High trait HRV mitigated the adverse effects of attachment insecurity on sleep quality. Our results suggest that people with high trait HRV had greater self-regulation capacity, which may enable them to enact emotion regulation strategies effectively.
