Psychological well-being and restorative biological processes: HDL-C in older English adults

Rationale: Psychological well-being is associated with better cardiovascular health, but the underlying mechanisms are unclear. Objective: This study investigates one possible mechanism by examining psychological well-being's prospective association with lipid levels, focusing on high-density lipoprotein cholesterol (HDL-C). Methods: Participants were 4757 healthy men and women ages >= 50 from the English Longitudinal Study of Ageing with clinical data from three times, three to five years apart. Psychological well-being was assessed at baseline using the Control, Autonomy, Satisfaction, and Pleasure scale; HDL-C, triglycerides, and total cholesterol were assayed from blood samples. Descriptive statistics and linear mixed models were used to examine associations between psychological well-being and lipid levels over time; the latter controlled for confounders and health behaviours. Results: In descriptive analyses, HDL-C levels were initially higher in people with greater psychological wellbeing. Among those who met recommended levels of HDL-C at baseline, fewer individuals with higher versus lower psychological well-being dropped below HDL-C recommendations over time. Mixed models indicated that HDL-C increased over time (beta = 0.64; 95% CI = 0.58 to 0.69) and higher baseline psychological well-being was associated with higher baseline HDL-C (beta= 0.51; 95% CI = 0.03 to 0.99). A significant well-being by time interaction indicated individuals with higher versus lower well-being exhibited a more rapid rate of increase in HDL-C over follow-up. Higher psychological well-being was also significantly associated with lower triglycerides, but main effects for both HDL-C and triglycerides were attenuated after accounting for health behaviours. Conclusion: Higher psychological well-being is associated with healthier HDL-C levels; these effects may compound over time. This protective effect may be partly explained by health behaviours.