Dyadic Loneliness and Changes to HbA1c Among Older US Couples: The Role of Marital Support as Stress Buffer.

Both experiencing loneliness and having a lonely partner can be psychosocial stressors, with implications for health. Yet, marital support may buffer against the cardiometabolic effects of loneliness. This study examines (1) whether own and/or partner's loneliness predict changes in HbA1c over 4 years and (2) whether marital support moderates these effects. Actor-partner interdependence models analyzed data from 1,854 older couples who provided psychosocial and biomarker data at two timepoints (2008/2012 or 2010/2014) of the Health and Retirement Study. Neither partner's loneliness predicted changes in HbA1c overall. However, significant interactions indicated that both own baseline loneliness and partner's baseline loneliness predicted significant increases to HbA1c over 4 years among those who reported below-average marital support. Both the experience of loneliness and loneliness of a dyadic partner may have longitudinal consequences for cardiometabolic health. However, these effects are contingent upon perceived quality of the marriage, specifically marital support.